db_view/service/internal/common/databases/drivers/mysql/v8/meta.go

package v8

import (
	"context"
	"database/sql"
	"dbview/service/internal/common/databases/meta"
	"encoding/json"
	"fmt"
	"reflect"
	"sort"
	"strconv"
	"strings"
	"time"
)

// GetObjectDetails 获取对象详情（含子对象，如表的字段、索引）
// path: 从根到目标对象的完整路径（见 meta.ObjectPath），最后一项为目标对象
// 注意：不再兼容旧的 dotted objectID 格式，调用方应传入结构化路径
func (q *MySQLDriver) getObjectDetails(ctx context.Context, path meta.ObjectPath, fetch bool) (meta.GenericObject, error) {
	if len(path) == 0 {
		return meta.GenericObject{}, fmt.Errorf("empty path")
	}
	last := path[len(path)-1]
	t := strings.ToLower(last.Type)
	switch t {
	case "table", "view":
		tableName := last.Name
		var dbName string
		if len(path) >= 2 {
			dbName = path[len(path)-2].Name
		} else {
			dbName = ""
		}
		// 构造表对象的 ID 与 parentID
		parentID := dbName
		objectID := fmt.Sprintf("%s.table-%s", parentID, tableName)

		// 获取表基本信息
		tableObj, err := q.getTableBaseInfo(ctx, dbName, tableName, parentID)
		if err != nil {
			return meta.GenericObject{}, fmt.Errorf("获取表 %s.%s 的基础信息失败：%w", dbName, tableName, err)
		}

		// 如果不需要拉取子对象细节（如列/索引），返回可用子类型清单（供前端按类型按需加载）
		if !fetch {
			var types []meta.GenericObject
			// columns
			types = append(types, meta.GenericObject{
				ID:          fmt.Sprintf("%s.type-column", objectID),
				Name:        "column",
				Description: "列（column）类型占位；调用同一对象详情接口并设置 fetch=true 可获取列列表",
				Type:        "column",
				ParentID:    objectID,
				DBType:      "mysql",
				Attrs:       map[string]string{},
			})
			// indexes
			types = append(types, meta.GenericObject{
				ID:          fmt.Sprintf("%s.type-index", objectID),
				Name:        "index",
				Description: "索引（index）类型占位；调用对象详情接口并设置 fetch=true 可获取索引信息",
				Type:        "index",
				ParentID:    objectID,
				DBType:      "mysql",
				Attrs:       map[string]string{},
			})
			// 将 types 作为 Children 返回（空的 Children 表示未展开，带 types 表示可按类型加载）
			tableObj.Children = types
			return tableObj, nil
		}

		// 查询字段（子对象）
		columns, err := q.getTableColumns(ctx, dbName, tableName, objectID)
		if err != nil {
			return meta.GenericObject{}, fmt.Errorf("获取表 %s.%s 列信息失败：%w", dbName, tableName, err)
		}
		tableObj.Children = append(tableObj.Children, columns...)

		// 查询索引（子对象）
		indexes, err := q.getTableIndexes(ctx, dbName, tableName, objectID)
		if err != nil {
			return meta.GenericObject{}, fmt.Errorf("获取表 %s.%s 索引信息失败：%w", dbName, tableName, err)
		}
		tableObj.Children = append(tableObj.Children, indexes...)
		return tableObj, nil
	default:
		return meta.GenericObject{}, fmt.Errorf("不支持的对象类型: %s", last.Type)
	}
}

// getTableBaseInfo 返回表的基础信息，用于构造 table 对象
func (q *MySQLDriver) getTableBaseInfo(ctx context.Context, dbName, tableName, parentName string) (meta.GenericObject, error) {
	db := q.db
	var engine sql.NullString
	var tableType sql.NullString
	var createTime sql.NullString
	if err := db.QueryRowContext(ctx, `
		SELECT ENGINE, TABLE_TYPE, CREATE_TIME FROM INFORMATION_SCHEMA.TABLES
		WHERE TABLE_SCHEMA = ? AND TABLE_NAME = ?
	`, dbName, tableName).Scan(&engine, &tableType, &createTime); err != nil {
		return meta.GenericObject{}, fmt.Errorf("查询表 %s.%s 的基础信息失败：%w", dbName, tableName, err)
	}
	objType := "table"
	if strings.EqualFold(tableType.String, "VIEW") {
		objType = "view"
	}
	parentID := parentName
	objectID := fmt.Sprintf("%s.table-%s", parentName, tableName)
	return meta.GenericObject{
		ID:       objectID,
		Name:     tableName,
		Type:     objType,
		ParentID: parentID,
		DBType:   "mysql",
		Attrs: map[string]string{
			"engine":     engine.String,
			"createTime": createTime.String,
		},
		Children: []meta.GenericObject{},
	}, nil
}

// getTableColumns 返回表的列信息（作为子对象）
func (q *MySQLDriver) getTableColumns(ctx context.Context, dbName, tableName, objectID string) ([]meta.GenericObject, error) {
	db := q.db
	rows, err := db.QueryContext(ctx, `
		SELECT COLUMN_NAME, COLUMN_TYPE, DATA_TYPE, IS_NULLABLE, COLUMN_DEFAULT, CHARACTER_MAXIMUM_LENGTH, ORDINAL_POSITION
		FROM INFORMATION_SCHEMA.COLUMNS
		WHERE TABLE_SCHEMA = ? AND TABLE_NAME = ?
		ORDER BY ORDINAL_POSITION
	`, dbName, tableName)
	if err != nil {
		return nil, fmt.Errorf("查询表 %s.%s 的列信息失败：%w", dbName, tableName, err)
	}
	defer rows.Close()

	var cols []meta.GenericObject
	for rows.Next() {
		var colName sql.NullString
		var columnType sql.NullString
		var dataType sql.NullString
		var isNullable sql.NullString
		var colDefault sql.NullString
		var charMax sql.NullInt64
		var ord sql.NullInt64
		if err := rows.Scan(&colName, &columnType, &dataType, &isNullable, &colDefault, &charMax, &ord); err != nil {
			continue
		}
		id := fmt.Sprintf("%s.column-%s", objectID, colName.String)
		cols = append(cols, meta.GenericObject{
			ID:       id,
			Name:     colName.String,
			Type:     "column",
			ParentID: objectID,
			DBType:   "mysql",
			Attrs: map[string]string{
				"columnType": columnType.String,
				"dataType":   dataType.String,
				"nullable":   isNullable.String,
				"default":    colDefault.String,
				"charMax":    fmt.Sprintf("%d", charMax.Int64),
				"position":   fmt.Sprintf("%d", ord.Int64),
			},
		})
	}
	if err := rows.Err(); err != nil {
		return nil, fmt.Errorf("遍历列结果集出错（%s.%s）：%w", dbName, tableName, err)
	}
	return cols, nil
}

// getTableIndexes 返回表的索引信息（作为子对象）
func (q *MySQLDriver) getTableIndexes(ctx context.Context, dbName, tableName, objectID string) ([]meta.GenericObject, error) {
	db := q.db
	rows, err := db.QueryContext(ctx, `
		SELECT INDEX_NAME, NON_UNIQUE, GROUP_CONCAT(COLUMN_NAME ORDER BY SEQ_IN_INDEX) AS columns
		FROM INFORMATION_SCHEMA.STATISTICS
		WHERE TABLE_SCHEMA = ? AND TABLE_NAME = ?
		GROUP BY INDEX_NAME, NON_UNIQUE
	`, dbName, tableName)
	if err != nil {
		return nil, fmt.Errorf("查询表 %s.%s 的索引信息失败：%w", dbName, tableName, err)
	}
	defer rows.Close()

	var idxs []meta.GenericObject
	for rows.Next() {
		var idxName sql.NullString
		var nonUnique sql.NullInt64
		var cols sql.NullString
		if err := rows.Scan(&idxName, &nonUnique, &cols); err != nil {
			continue
		}
		id := fmt.Sprintf("%s.index-%s", objectID, idxName.String)
		idxs = append(idxs, meta.GenericObject{
			ID:       id,
			Name:     idxName.String,
			Type:     "index",
			ParentID: objectID,
			DBType:   "mysql",
			Attrs: map[string]string{
				"columns":   cols.String,
				"nonUnique": fmt.Sprintf("%d", nonUnique.Int64),
			},
		})
	}
	if err := rows.Err(); err != nil {
		return nil, fmt.Errorf("遍历索引结果集出错（%s.%s）：%w", dbName, tableName, err)
	}
	return idxs, nil
}

// DeleteRootObjects：根据前端传入的 rootName（支持通配符 * 或 SQL %）、typeName（如 database/table/view）
// 返回匹配到的对象列表与总数（注：默认不直接执行 DROP，仅列出匹配项）
func (q *MySQLDriver) deleteRootObjects(ctx context.Context, req meta.ObjectOperationRequest) (meta.ObjectOperationResponse, error) {
	var resp meta.ObjectOperationResponse
	db := q.db
	rootName := req.Object.Name
	typeName := req.Object.Type
	t := strings.ToLower(typeName)
	// 处理通配符
	pattern := rootName
	if strings.Contains(pattern, "*") {
		pattern = strings.ReplaceAll(pattern, "*", "%")
	}
	useLike := strings.Contains(pattern, "%") || strings.Contains(pattern, "_")

	switch t {
	case "database", "schema":
		var rows *sql.Rows
		var err error
		if pattern == "" {
			rows, err = db.QueryContext(ctx, `SELECT SCHEMA_NAME, DEFAULT_CHARACTER_SET_NAME FROM INFORMATION_SCHEMA.SCHEMATA`)
		} else if useLike {
			rows, err = db.QueryContext(ctx, `SELECT SCHEMA_NAME, DEFAULT_CHARACTER_SET_NAME FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME LIKE ?`, pattern)
		} else {
			rows, err = db.QueryContext(ctx, `SELECT SCHEMA_NAME, DEFAULT_CHARACTER_SET_NAME FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = ?`, pattern)
		}
		if err != nil {
			return resp, fmt.Errorf("查询 schema 列表以供删除匹配失败：%w", err)
		}
		defer rows.Close()
		var objs []meta.GenericObject
		var total int64
		for rows.Next() {
			var name sql.NullString
			var charset sql.NullString
			if err := rows.Scan(&name, &charset); err != nil {
				continue
			}
			total++
			objs = append(objs, meta.GenericObject{
				ID:       fmt.Sprintf("db-%s", name.String),
				Name:     name.String,
				Type:     "database",
				ParentID: "",
				DBType:   "mysql",
				Attrs: map[string]string{
					"charset": charset.String,
				},
			})
		}
		if err := rows.Err(); err != nil {
			return resp, fmt.Errorf("遍历 schema 结果出错：%w", err)
		}
		resp.Affected = total
		resp.ObjectID = ""
		// 将匹配对象放入 Options 供前端显示（不能放在 Object 因为可能是多个）
		respMap := map[string]interface{}{"matches": objs}
		if respMapBytes, err := json.Marshal(respMap); err == nil {
			// 当仅生成 SQL（不执行）时，把匹配对象的 JSON 放到 Sql 字段供前端查看；
			// 若 Execute==true，则我们会尝试执行对应的 DROP 语句并在 Sql 中也返回执行的语句列表。
			resp.Sql = string(respMapBytes)
		}

		// 如果请求不要求执行，直接返回列出匹配项
		if !req.Execute {
			return resp, nil
		}

		// Execute==true: 执行删除操作（注意：对 DDL 的事务语义依赖于具体数据库；MySQL 的 DROP 在多数情况下不可回滚）
		tx, err := db.BeginTx(ctx, nil)
		if err != nil {
			return resp, fmt.Errorf("开始事务失败：%w", err)
		}
		var execCount int64
		var execSQLs []string
		for _, o := range objs {
			// 对不同类型生成对应的 DROP 语句
			switch o.Type {
			case "database":
				sqlStr := fmt.Sprintf("DROP DATABASE `%s`", o.Name)
				if _, err := tx.ExecContext(ctx, sqlStr); err != nil {
					_ = tx.Rollback()
					return resp, fmt.Errorf("执行 SQL 失败：%s, err: %w", sqlStr, err)
				}
				execSQLs = append(execSQLs, sqlStr)
				execCount++
			default:
				// 其他 root 类型目前不支持直接删除，记录并继续
			}
		}
		if err := tx.Commit(); err != nil {
			_ = tx.Rollback()
			return resp, fmt.Errorf("提交事务失败：%w", err)
		}
		resp.Affected = execCount
		if b, err := json.Marshal(execSQLs); err == nil {
			resp.Sql = string(b)
		}
		return resp, nil

	case "table", "view":
		tableType := "BASE TABLE"
		if t == "view" {
			tableType = "VIEW"
		}
		var rows *sql.Rows
		var err error
		if pattern == "" {
			rows, err = db.QueryContext(ctx, `SELECT TABLE_SCHEMA, TABLE_NAME, NULL AS ENGINE, CREATE_TIME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = ?`, tableType)
		} else if useLike {
			rows, err = db.QueryContext(ctx, `SELECT TABLE_SCHEMA, TABLE_NAME, NULL AS ENGINE, CREATE_TIME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = ? AND TABLE_NAME LIKE ?`, tableType, pattern)
		} else {
			rows, err = db.QueryContext(ctx, `SELECT TABLE_SCHEMA, TABLE_NAME, NULL AS ENGINE, CREATE_TIME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = ? AND TABLE_NAME = ?`, tableType, pattern)
		}
		if err != nil {
			return resp, fmt.Errorf("查询表/视图以供删除匹配失败：%w", err)
		}
		defer rows.Close()
		var objs []meta.GenericObject
		var total int64
		for rows.Next() {
			var schema sql.NullString
			var tname sql.NullString
			var engine sql.NullString
			var ctime sql.NullString
			if err := rows.Scan(&schema, &tname, &engine, &ctime); err != nil {
				continue
			}
			total++
			pid := fmt.Sprintf("db-%s", schema.String)
			id := fmt.Sprintf("%s.table-%s", pid, tname.String)
			objs = append(objs, meta.GenericObject{
				ID:       id,
				Name:     tname.String,
				Type:     t,
				ParentID: pid,
				DBType:   "mysql",
				Attrs: map[string]string{
					"engine":     engine.String,
					"createTime": ctime.String,
				},
			})
		}
		if err := rows.Err(); err != nil {
			return resp, fmt.Errorf("遍历表/视图结果出错：%w", err)
		}
		resp.Affected = total
		matchMap := map[string]interface{}{"matches": objs}
		if b, err := json.Marshal(matchMap); err == nil {
			resp.Sql = string(b)
		}
		return resp, nil

	default:
		return resp, fmt.Errorf("不支持的 root 类型: %s", typeName)
	}
}

// DeleteChildObjects：根据 parentID（如 db-xxx 或 conn.db-xxx）和 filter（type/name）返回匹配的子对象列表与总数
func (q *MySQLDriver) deleteChildObjects(ctx context.Context, req meta.ObjectOperationRequest) (meta.ObjectOperationResponse, error) {
	var resp meta.ObjectOperationResponse
	parentID := req.Object.ParentID
	filter := map[string]string{}
	if req.Object.Name != "" {
		filter["name"] = req.Object.Name
	}
	if req.Object.Type != "" {
		filter["type"] = req.Object.Type
	}
	// reuse previous logic but adapt to return ObjectOperationResponse
	parts := strings.Split(parentID, ".")
	var dbPart string
	if len(parts) >= 2 {
		dbPart = parts[1]
	} else {
		dbPart = parentID
	}
	dbName := strings.TrimPrefix(dbPart, "db-")
	objectType := strings.ToLower(filter["type"])
	namePattern := filter["name"]
	if strings.Contains(namePattern, "*") {
		namePattern = strings.ReplaceAll(namePattern, "*", "%")
	}
	useLike := strings.Contains(namePattern, "%") || strings.Contains(namePattern, "_")

	db := q.db
	switch objectType {
	case "index":
		// 表级或库级索引
		var rows *sql.Rows
		var err error
		if namePattern == "" {
			rows, err = db.QueryContext(ctx, `SELECT INDEX_NAME, TABLE_NAME, NON_UNIQUE FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_SCHEMA = ? GROUP BY INDEX_NAME, TABLE_NAME, NON_UNIQUE`, dbName)
		} else if useLike {
			rows, err = db.QueryContext(ctx, `SELECT INDEX_NAME, TABLE_NAME, NON_UNIQUE FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_SCHEMA = ? AND INDEX_NAME LIKE ? GROUP BY INDEX_NAME, TABLE_NAME, NON_UNIQUE`, dbName, namePattern)
		} else {
			rows, err = db.QueryContext(ctx, `SELECT INDEX_NAME, TABLE_NAME, NON_UNIQUE FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_SCHEMA = ? AND INDEX_NAME = ? GROUP BY INDEX_NAME, TABLE_NAME, NON_UNIQUE`, dbName, namePattern)
		}
		if err != nil {
			return resp, fmt.Errorf("查询索引以供删除匹配失败：%w", err)
		}
		defer rows.Close()
		var res []meta.GenericObject
		var total int64
		for rows.Next() {
			var idx sql.NullString
			var tname sql.NullString
			var nonUnique sql.NullInt64
			if err := rows.Scan(&idx, &tname, &nonUnique); err != nil {
				continue
			}
			total++
			id := fmt.Sprintf("%s.table-%s.index-%s", parentID, tname.String, idx.String)
			res = append(res, meta.GenericObject{
				ID:       id,
				Name:     idx.String,
				Type:     "index",
				ParentID: fmt.Sprintf("%s.table-%s", parentID, tname.String),
				DBType:   "mysql",
				Attrs: map[string]string{
					"table":     tname.String,
					"nonUnique": fmt.Sprintf("%d", nonUnique.Int64),
				},
			})
		}
		if err := rows.Err(); err != nil {
			return resp, fmt.Errorf("遍历索引结果出错：%w", err)
		}
		resp.Affected = total
		m := map[string]interface{}{"matches": res}
		if b, err := json.Marshal(m); err == nil {
			resp.Sql = string(b)
		}
		return resp, nil

	case "procedure", "proc":
		var rows *sql.Rows
		var err error
		if namePattern == "" {
			rows, err = db.QueryContext(ctx, `SELECT ROUTINE_NAME, ROUTINE_DEFINITION, CREATED FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_SCHEMA = ? AND ROUTINE_TYPE = 'PROCEDURE'`, dbName)
		} else if useLike {
			rows, err = db.QueryContext(ctx, `SELECT ROUTINE_NAME, ROUTINE_DEFINITION, CREATED FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_SCHEMA = ? AND ROUTINE_TYPE = 'PROCEDURE' AND ROUTINE_NAME LIKE ?`, dbName, namePattern)
		} else {
			rows, err = db.QueryContext(ctx, `SELECT ROUTINE_NAME, ROUTINE_DEFINITION, CREATED FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_SCHEMA = ? AND ROUTINE_TYPE = 'PROCEDURE' AND ROUTINE_NAME = ?`, dbName, namePattern)
		}
		if err != nil {
			return resp, fmt.Errorf("查询存储过程以供删除匹配失败：%w", err)
		}
		defer rows.Close()
		var res []meta.GenericObject
		var total int64
		for rows.Next() {
			var rName sql.NullString
			var def sql.NullString
			var created sql.NullString
			if err := rows.Scan(&rName, &def, &created); err != nil {
				continue
			}
			total++
			id := fmt.Sprintf("%s.proc-%s", parentID, rName.String)
			res = append(res, meta.GenericObject{
				ID:       id,
				Name:     rName.String,
				Type:     "procedure",
				ParentID: parentID,
				DBType:   "mysql",
				Attrs: map[string]string{
					"definition": def.String,
					"created":    created.String,
				},
			})
		}
		if err := rows.Err(); err != nil {
			return resp, fmt.Errorf("遍历存储过程结果出错：%w", err)
		}
		resp.Affected = total
		m := map[string]interface{}{"matches": res}
		if b, err := json.Marshal(m); err == nil {
			resp.Sql = string(b)
		}
		return resp, nil

	case "trigger":
		var rows *sql.Rows
		var err error
		if namePattern == "" {
			rows, err = db.QueryContext(ctx, `SELECT TRIGGER_NAME, EVENT_MANIPULATION, EVENT_OBJECT_TABLE, ACTION_TIMING, ACTION_STATEMENT FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_SCHEMA = ?`, dbName)
		} else if useLike {
			rows, err = db.QueryContext(ctx, `SELECT TRIGGER_NAME, EVENT_MANIPULATION, EVENT_OBJECT_TABLE, ACTION_TIMING, ACTION_STATEMENT FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_SCHEMA = ? AND TRIGGER_NAME LIKE ?`, dbName, namePattern)
		} else {
			rows, err = db.QueryContext(ctx, `SELECT TRIGGER_NAME, EVENT_MANIPULATION, EVENT_OBJECT_TABLE, ACTION_TIMING, ACTION_STATEMENT FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_SCHEMA = ? AND TRIGGER_NAME = ?`, dbName, namePattern)
		}
		if err != nil {
			return resp, fmt.Errorf("查询触发器以供删除匹配失败：%w", err)
		}
		defer rows.Close()
		var res []meta.GenericObject
		var total int64
		for rows.Next() {
			var tName sql.NullString
			var event sql.NullString
			var objTable sql.NullString
			var timing sql.NullString
			var stmt sql.NullString
			if err := rows.Scan(&tName, &event, &objTable, &timing, &stmt); err != nil {
				continue
			}
			total++
			id := fmt.Sprintf("%s.trigger-%s", parentID, tName.String)
			res = append(res, meta.GenericObject{
				ID:       id,
				Name:     tName.String,
				Type:     "trigger",
				ParentID: parentID,
				DBType:   "mysql",
				Attrs: map[string]string{
					"event":     event.String,
					"table":     objTable.String,
					"timing":    timing.String,
					"statement": stmt.String,
				},
			})
		}
		if err := rows.Err(); err != nil {
			return resp, fmt.Errorf("遍历触发器结果出错：%w", err)
		}
		resp.Affected = total
		m := map[string]interface{}{"matches": res}
		if b, err := json.Marshal(m); err == nil {
			resp.Sql = string(b)
		}
		return resp, nil

	default:
		return resp, fmt.Errorf("不支持的 child 类型: %s", objectType)
	}
}

// DescribeCreateTemplate 返回创建指定类型对象的表单模板（供前端渲染）
// getDatabaseTemplateFields 返回数据库相关的模板字段
func getDatabaseTemplateFields(isUpdate bool, currentValues map[string]string) []meta.TemplateField {
	fields := []meta.TemplateField{
		{Name: "databaseName", Label: "Database Name", Type: meta.FieldTypeString, Required: true},
		{Name: "charset", Label: "Character Set", Type: meta.FieldTypeEnum, Required: false, Default: "utf8mb4", EnumOptions: []string{"utf8mb4", "utf8", "latin1", "ascii", "ucs2", "utf16", "utf32", "big5", "gbk"}},
		{Name: "collation", Label: "Collation", Type: meta.FieldTypeString, Required: false},
	}

	if !isUpdate {
		// 创建模式：添加ifNotExists字段
		fields = append(fields, meta.TemplateField{Name: "ifNotExists", Label: "If Not Exists", Type: meta.FieldTypeBool, Required: false, Default: "false"})
		fields[0].Help = "要创建的数据库名称，不含前缀"
	} else {
		// 修改模式：设置当前值和可编辑性（currentValues 采用 map[string]string）
		if currentValues != nil {
			if dbName, ok := currentValues["databaseName"]; ok {
				fields[0].Current = dbName
				fields[0].Editable = &[]bool{false}[0] // 数据库名通常不可修改
			}
			if charset, ok := currentValues["charset"]; ok {
				fields[1].Current = charset
			}
			if collation, ok := currentValues["collation"]; ok {
				fields[2].Current = collation
			}
		}
	}

	return fields
}

// getTableTemplateFields 返回表相关的模板字段
func getTableTemplateFields(isUpdate bool, currentValues map[string]string) []meta.TemplateField {
	fields := []meta.TemplateField{
		{Name: "tableName", Label: "Table Name", Type: meta.FieldTypeString, Required: true},
		{Name: "engine", Label: "Engine", Type: meta.FieldTypeEnum, Required: false, EnumOptions: []string{"InnoDB", "MyISAM"}, Default: "InnoDB"},
		{Name: "charset", Label: "Charset", Type: meta.FieldTypeEnum, Required: false, Default: "utf8mb4", EnumOptions: []string{"utf8mb4", "utf8", "latin1", "ascii", "ucs2", "utf16", "utf32", "big5", "gbk"}},
		{Name: "collation", Label: "Collation", Type: meta.FieldTypeString, Required: false},
	}

	if !isUpdate {
		// 创建模式：添加ifNotExists和columns字段
		fields = append(fields, meta.TemplateField{Name: "ifNotExists", Label: "If Not Exists", Type: meta.FieldTypeBool, Required: false, Default: "false"})
		fields = append(fields, meta.TemplateField{
			Name: "columns", Label: "Columns", Type: meta.FieldTypeList, Required: true, NestedFields: []meta.TemplateField{
				{Name: "name", Label: "Column Name", Type: meta.FieldTypeString, Required: true},
				{Name: "type", Label: "Data Type", Type: meta.FieldTypeString, Required: true},
				{Name: "nullable", Label: "Nullable", Type: meta.FieldTypeBool, Required: false, Default: "false"},
				{Name: "default", Label: "Default", Type: meta.FieldTypeString, Required: false},
				{Name: "autoIncrement", Label: "Auto Increment", Type: meta.FieldTypeBool, Required: false, Default: "false"},
			}})
	} else {
		// 修改模式：设置当前值和可编辑性（currentValues 采用 map[string]string）
		if currentValues != nil {
			if tableName, ok := currentValues["tableName"]; ok {
				fields[0].Current = tableName
				fields[0].Editable = &[]bool{false}[0] // 表名修改需要重命名
			}
			if engine, ok := currentValues["engine"]; ok {
				fields[1].Current = engine
			}
			if charset, ok := currentValues["charset"]; ok {
				fields[2].Current = charset
			}
			if collation, ok := currentValues["collation"]; ok {
				fields[3].Current = collation
			}
		}
	}

	return fields
}

// getIndexTemplateFields 返回索引相关的模板字段
func getIndexTemplateFields(isUpdate bool, currentValues map[string]string) []meta.TemplateField {
	fields := []meta.TemplateField{
		{Name: "indexName", Label: "Index Name", Type: meta.FieldTypeString, Required: true},
		{Name: "columns", Label: "Columns (comma separated)", Type: meta.FieldTypeString, Required: true},
		{Name: "unique", Label: "Unique", Type: meta.FieldTypeBool, Required: false, Default: "false"},
	}

	if isUpdate && currentValues != nil {
		// 修改模式：设置当前值（currentValues 为 map[string]string）
		if indexName, ok := currentValues["indexName"]; ok {
			fields[0].Current = indexName
		}
		if columns, ok := currentValues["columns"]; ok {
			fields[1].Current = columns
		}
		if uniqueStr, ok := currentValues["unique"]; ok {
			fields[2].Current = uniqueStr
		}
	}

	return fields
}

// getCurrentDatabaseInfo 获取数据库的当前信息
func (q *MySQLDriver) getCurrentDatabaseInfo(ctx context.Context, dbName string) (map[string]string, error) {
	var charset, collation sql.NullString
	query := "SELECT DEFAULT_CHARACTER_SET_NAME, DEFAULT_COLLATION_NAME FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = ?"
	err := q.db.QueryRowContext(ctx, query, dbName).Scan(&charset, &collation)
	if err != nil {
		return nil, fmt.Errorf("获取数据库信息失败: %w", err)
	}

	return map[string]string{
		"databaseName": dbName,
		"charset":      charset.String,
		"collation":    collation.String,
	}, nil
}

// getCurrentTableInfo 获取表的当前信息
func (q *MySQLDriver) getCurrentTableInfo(ctx context.Context, dbName, tableName string) (map[string]string, error) {
	var engine, charset, collation sql.NullString
	query := "SELECT ENGINE, TABLE_COLLATION, SUBSTRING_INDEX(TABLE_COLLATION, '_', 1) AS TABLE_CHARSET FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = ? AND TABLE_NAME = ?"
	err := q.db.QueryRowContext(ctx, query, dbName, tableName).Scan(&engine, &collation, &charset)
	if err != nil {
		return nil, fmt.Errorf("获取表信息失败: %w", err)
	}

	return map[string]string{
		"tableName": tableName,
		"engine":    engine.String,
		"charset":   charset.String,
		"collation": collation.String,
	}, nil
}

func (q *MySQLDriver) describeCreateTemplate(ctx context.Context, path meta.ObjectPath) (meta.ObjectTemplate, error) {
	// 从路径中提取对象类型和父名称
	var objectType, parentName string
	if len(path) > 0 {
		lastEntry := path[len(path)-1]
		objectType = strings.ToLower(lastEntry.Type)
		// 对于创建操作，最后一个元素是待创建的对象类型
		// 前面的元素构成父上下文
		if len(path) > 1 {
			parentEntry := path[len(path)-2] // 父对象是倒数第二个元素
			parentName = parentEntry.Name
		}
	} else {
		return meta.ObjectTemplate{}, fmt.Errorf("创建模板需要指定对象类型路径")
	}

	switch objectType {
	case "database":
		// 示例值均以字符串形式表示
		ex := map[string]string{"databaseName": "mydb", "charset": "utf8mb4", "ifNotExists": "true"}
		tpl := meta.ObjectTemplate{
			Operation:  "create",
			ObjectType: "database",
			ParentHint: "",
			Fields:     getDatabaseTemplateFields(false, nil),
			Example:    ex,
		}
		return tpl, nil
	case "table":
		parentHint := "parentName should be the database name"
		if parentName != "" {
			parentHint = "database: " + parentName
		}
		// 将复杂的 columns 示例编码为 JSON 字符串以便前端展示/解析
		colsExample := []map[string]interface{}{{"name": "id", "type": "INT", "nullable": false}}
		colsB, _ := json.Marshal(colsExample)
		ex := map[string]string{"tableName": "users", "columns": string(colsB), "engine": "InnoDB"}
		tpl := meta.ObjectTemplate{
			Operation:  "create",
			ObjectType: "table",
			ParentHint: parentHint,
			Fields:     getTableTemplateFields(false, nil),
			Example:    ex,
		}
		return tpl, nil
	case "index":
		parentHint := "parentName can be table name"
		if parentName != "" {
			parentHint = "table: " + parentName
		}
		ex := map[string]string{"indexName": "idx_users_email", "columns": "email", "unique": "true"}
		tpl := meta.ObjectTemplate{
			Operation:  "create",
			ObjectType: "index",
			ParentHint: parentHint,
			Fields:     getIndexTemplateFields(false, nil),
			Example:    ex,
		}
		return tpl, nil
	default:
		return meta.ObjectTemplate{}, fmt.Errorf("不支持的 create 类型: %s", objectType)
	}
}

// GetMetadataInfo 返回数据库的元信息（关键字、字段类型、能力等）
func (q *MySQLDriver) GetMetadataInfo(ctx context.Context) (meta.MetadataCapabilities, error) {
	var caps meta.MetadataCapabilities

	// 1) 尝试从 INFORMATION_SCHEMA.COLUMNS 获取字段类型
	rows, err := q.db.QueryContext(ctx, "SELECT DISTINCT DATA_TYPE FROM INFORMATION_SCHEMA.COLUMNS")
	if err == nil {
		defer rows.Close()
		for rows.Next() {
			var dt sql.NullString
			if err := rows.Scan(&dt); err != nil {
				continue
			}
			if dt.Valid && dt.String != "" {
				caps.FieldTypes = append(caps.FieldTypes, strings.ToUpper(dt.String))
			}
		}
	} else {
		// 回退到一组常见类型
		caps.FieldTypes = []string{"INT", "BIGINT", "VARCHAR", "TEXT", "DATETIME", "TIMESTAMP", "DATE", "CHAR", "FLOAT", "DOUBLE", "DECIMAL", "BOOLEAN"}
	}

	// 2) 尝试从 mysql.help_keyword 获取关键字（部分 MySQL 安装提供）
	rows2, err2 := q.db.QueryContext(ctx, "SELECT DISTINCT word FROM mysql.help_keyword")
	if err2 == nil {
		defer rows2.Close()
		for rows2.Next() {
			var kw sql.NullString
			if err := rows2.Scan(&kw); err != nil {
				continue
			}
			if kw.Valid && kw.String != "" {
				caps.Keywords = append(caps.Keywords, kw.String)
			}
		}
	} else {
		// 3) 尝试 INFORMATION_SCHEMA.KEYWORDS（部分版本可用）
		rows3, err3 := q.db.QueryContext(ctx, "SELECT DISTINCT keyword FROM INFORMATION_SCHEMA.KEYWORDS")
		if err3 == nil {
			defer rows3.Close()
			for rows3.Next() {
				var kw sql.NullString
				if err := rows3.Scan(&kw); err != nil {
					continue
				}
				if kw.Valid && kw.String != "" {
					caps.Keywords = append(caps.Keywords, kw.String)
				}
			}
		}
	}

	// 4) 去重与排序
	if len(caps.FieldTypes) > 0 {
		m := map[string]struct{}{}
		for _, v := range caps.FieldTypes {
			m[v] = struct{}{}
		}
		caps.FieldTypes = caps.FieldTypes[:0]
		for k := range m {
			caps.FieldTypes = append(caps.FieldTypes, k)
		}
		sort.Strings(caps.FieldTypes)
	}
	if len(caps.Keywords) > 0 {
		m := map[string]struct{}{}
		for _, v := range caps.Keywords {
			m[v] = struct{}{}
		}
		caps.Keywords = caps.Keywords[:0]
		for k := range m {
			caps.Keywords = append(caps.Keywords, k)
		}
		sort.Strings(caps.Keywords)
	}

	// 5) 常见能力标记
	caps.Capabilities = map[string]bool{
		"supportsTransactions":   true,
		"supportsDDLTransaction": false,
	}

	return caps, nil
}

// CreateObject 仅实现 preview（execute==false）路径：校验输入并生成 SQL，execute=true 尚未实现
func (q *MySQLDriver) createObject(ctx context.Context, req meta.CreateObjectRequest) (meta.CreateObjectResponse, error) {
	var resp meta.CreateObjectResponse
	t := strings.ToLower(req.ObjectType)
	// Basic validation
	if req.ObjectType == "" {
		return meta.CreateObjectResponse{}, fmt.Errorf("缺少必填字段: objectType")
	}
	switch t {
	case "database":
		props := req.Properties
		nameI, ok := props["databaseName"]
		if !ok {
			return meta.CreateObjectResponse{}, fmt.Errorf("缺少必填字段: databaseName")
		}
		name, _ := nameI.(string)
		if name == "" {
			return meta.CreateObjectResponse{}, fmt.Errorf("databaseName 不能为空")
		}
		if req.Execute {
			return meta.CreateObjectResponse{}, fmt.Errorf("execute 路径未实现（当前仅支持预览 execute=false）")
		}
		charset := "utf8mb4"
		if cs, ok := props["charset"].(string); ok && cs != "" {
			charset = cs
		}
		ifNot := false
		if v, ok := props["ifNotExists"].(bool); ok {
			ifNot = v
		}
		sql := "CREATE DATABASE"
		if ifNot {
			sql += " IF NOT EXISTS"
		}
		sql = fmt.Sprintf("%s `%s` DEFAULT CHARACTER SET = %s;", sql, name, charset)
		resp.GeneratedSQL = []string{sql}
		return resp, nil

	case "table":
		props := req.Properties
		tnameI, ok := props["tableName"]
		if !ok {
			return meta.CreateObjectResponse{}, fmt.Errorf("缺少必填字段: tableName")
		}
		tname, _ := tnameI.(string)
		if tname == "" {
			return meta.CreateObjectResponse{}, fmt.Errorf("tableName 不能为空")
		}
		colsI, ok := props["columns"]
		if !ok {
			return meta.CreateObjectResponse{}, fmt.Errorf("缺少必填字段: columns")
		}
		colsSlice, ok := colsI.([]interface{})
		if !ok {
			return meta.CreateObjectResponse{}, fmt.Errorf("columns 格式无效，期望为数组类型的列定义，例如 [{\"name\":\"id\",\"type\":\"INT\"}]")
		}
		if req.Execute {
			return meta.CreateObjectResponse{}, fmt.Errorf("execute 路径未实现（当前仅支持预览 execute=false）")
		}
		engine := "InnoDB"
		if e, ok := props["engine"].(string); ok && e != "" {
			engine = e
		}
		charset := "utf8mb4"
		if cs, ok := props["charset"].(string); ok && cs != "" {
			charset = cs
		}
		ifNot := false
		if v, ok := props["ifNotExists"].(bool); ok {
			ifNot = v
		}

		// build column definitions
		var colDefs []string
		for _, ci := range colsSlice {
			m, ok := ci.(map[string]interface{})
			if !ok {
				continue
			}
			cname, _ := m["name"].(string)
			ctype, _ := m["type"].(string)
			if cname == "" || ctype == "" {
				// skip invalid
				continue
			}
			nullable := true
			if n, ok := m["nullable"].(bool); ok {
				nullable = n
			}
			autoInc := false
			if a, ok := m["autoIncrement"].(bool); ok {
				autoInc = a
			}
			defStr := ""
			if d, ok := m["default"]; ok && d != nil {
				// simple formatting: quote strings, otherwise use fmt.Sprint
				switch v := d.(type) {
				case string:
					defStr = fmt.Sprintf(" DEFAULT '%s'", strings.ReplaceAll(v, "'", "\\'"))
				default:
					defStr = fmt.Sprintf(" DEFAULT %v", v)
				}
			}
			col := fmt.Sprintf("`%s` %s", cname, ctype)
			if !nullable {
				col += " NOT NULL"
			}
			if autoInc {
				col += " AUTO_INCREMENT"
			}
			col += defStr
			colDefs = append(colDefs, col)
		}
		if len(colDefs) == 0 {
			return meta.CreateObjectResponse{}, fmt.Errorf("未找到有效的列定义，请检查 properties.columns 字段，示例格式: [{\"name\":\"id\",\"type\":\"INT\"}]")
		}
		// build create statement (include parent/db if provided)
		createStmt := "CREATE TABLE"
		if ifNot {
			createStmt += " IF NOT EXISTS"
		}
		// If parent provided, include database qualifier
		if req.ParentName != "" {
			createStmt = fmt.Sprintf("%s `%s`.`%s` ( %s ) ENGINE=%s DEFAULT CHARSET=%s;", createStmt, req.ParentName, tname, strings.Join(colDefs, ", "), engine, charset)
		} else {
			createStmt = fmt.Sprintf("%s `%s` ( %s ) ENGINE=%s DEFAULT CHARSET=%s;", createStmt, tname, strings.Join(colDefs, ", "), engine, charset)
		}
		resp.GeneratedSQL = []string{createStmt}
		return resp, nil

	case "index":
		props := req.Properties
		iname, _ := props["indexName"].(string)
		cols, _ := props["columns"].(string)
		unique := false
		if u, ok := props["unique"].(bool); ok {
			unique = u
		}
		if iname == "" || cols == "" {
			return meta.CreateObjectResponse{}, fmt.Errorf("indexName 与 columns 为必填字段")
		}
		if req.Execute {
			return meta.CreateObjectResponse{}, fmt.Errorf("execute 路径未实现（当前仅支持预览 execute=false）")
		}
		uq := ""
		if unique {
			uq = "UNIQUE "
		}
		// parentName ideally should be table name
		tableRef := iname
		if req.ParentName != "" {
			tableRef = req.ParentName
		}
		stmt := fmt.Sprintf("CREATE %sINDEX `%s` ON `%s` (%s);", uq, iname, tableRef, cols)
		resp.GeneratedSQL = []string{stmt}
		return resp, nil

	default:
		return meta.CreateObjectResponse{}, fmt.Errorf("不支持的 create 类型: %s", req.ObjectType)
	}
}

// QueryData 执行数据查询（实现 DataReader 接口）
func (q *MySQLDriver) QueryData(ctx context.Context, path meta.ObjectPath, req meta.DataQueryRequest, includeLarge bool) (meta.QueryResult, error) {
	startTime := time.Now()
	db := q.db

	// 解析路径：path 应为 [{"type":"database","name":"db"},{"type":"table","name":"table"}]
	if len(path) < 2 {
		return meta.QueryResult{}, fmt.Errorf("invalid path: need at least database and table")
	}
	dbName := path[0].Name
	tableName := path[1].Name

	// 切换到指定数据库（如果需要）
	if _, err := db.ExecContext(ctx, fmt.Sprintf("USE `%s`", dbName)); err != nil {
		return meta.QueryResult{}, fmt.Errorf("failed to switch to database %s: %w", dbName, err)
	}

	// 构建列信息
	var columns []meta.DataMeta
	var columnNames []string
	if len(req.Columns) == 0 {
		// 查询所有列
		query := fmt.Sprintf("SELECT COLUMN_NAME, DATA_TYPE, IS_NULLABLE FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = '%s' AND TABLE_NAME = '%s' ORDER BY ORDINAL_POSITION", dbName, tableName)
		rows, err := db.QueryContext(ctx, query)
		if err != nil {
			return meta.QueryResult{}, fmt.Errorf("failed to query columns: %w", err)
		}
		defer rows.Close()
		for rows.Next() {
			var colName, dataType, nullable sql.NullString
			if err := rows.Scan(&colName, &dataType, &nullable); err != nil {
				continue
			}
			columns = append(columns, meta.DataMeta{
				Name:     colName.String,
				Type:     "column",
				DBType:   dataType.String,
				Nullable: nullable.String == "YES",
			})
			columnNames = append(columnNames, colName.String)
		}
	} else {
		// 指定列
		columnNames = req.Columns
		for _, col := range req.Columns {
			columns = append(columns, meta.DataMeta{
				Name: col,
				Type: "column",
			})
		}
	}

	// 构建 SELECT 语句
	selectClause := "*"
	if len(columnNames) > 0 {
		selectClause = "`" + strings.Join(columnNames, "`, `") + "`"
	}
	sql := fmt.Sprintf("SELECT %s FROM `%s`", selectClause, tableName)

	// 添加 WHERE 子句
	if len(req.Filters) > 0 {
		var conditions []string
		for col, val := range req.Filters {
			conditions = append(conditions, fmt.Sprintf("`%s` = '%s'", col, val)) // 简单等值，注意 SQL 注入风险（生产环境需参数化）
		}
		sql += " WHERE " + strings.Join(conditions, " AND ")
	}

	// 添加 ORDER BY
	if len(req.Order) > 0 {
		var orders []string
		for _, o := range req.Order {
			dir := "ASC"
			if o.Desc {
				dir = "DESC"
			}
			orders = append(orders, fmt.Sprintf("`%s` %s", o.Column, dir))
		}
		sql += " ORDER BY " + strings.Join(orders, ", ")
	}

	// 添加 LIMIT
	if req.Limit > 0 {
		sql += fmt.Sprintf(" LIMIT %d", req.Limit)
		if req.Offset > 0 {
			sql += fmt.Sprintf(" OFFSET %d", req.Offset)
		}
	}

	// 如果 Fetch=false，仅返回 SQL，不执行查询，但计算总数
	if !req.Fetch {
		var total int64
		countSQL := fmt.Sprintf("SELECT COUNT(*) FROM `%s`", tableName)
		if len(req.Filters) > 0 {
			var conditions []string
			for col, val := range req.Filters {
				conditions = append(conditions, fmt.Sprintf("`%s` = '%s'", col, val))
			}
			countSQL += " WHERE " + strings.Join(conditions, " AND ")
		}
		if err := db.QueryRowContext(ctx, countSQL).Scan(&total); err != nil {
			return meta.QueryResult{}, fmt.Errorf("failed to count total: %w", err)
		}
		return meta.QueryResult{
			Columns:       columns,
			Rows:          []meta.DataMeta{},
			Total:         &total,
			Returned:      int(total),
			Truncated:     false,
			Stats:         map[string]string{"sql": sql},
			ExecutionTime: time.Since(startTime).Milliseconds(),
		}, nil
	}

	// 执行查询
	rows, err := db.QueryContext(ctx, sql)
	if err != nil {
		return meta.QueryResult{}, fmt.Errorf("failed to execute query: %w", err)
	}
	defer rows.Close()

	// 获取列信息（如果未指定列）
	if len(req.Columns) == 0 {
		colTypes, err := rows.ColumnTypes()
		if err != nil {
			return meta.QueryResult{}, fmt.Errorf("failed to get column types: %w", err)
		}
		for i, ct := range colTypes {
			nullable, _ := ct.Nullable()
			columns[i].DBType = ct.DatabaseTypeName()
			columns[i].Nullable = nullable
		}
	}

	// 读取数据
	var resultRows []meta.DataMeta
	for rows.Next() {
		values := make([]interface{}, len(columns))
		valuePtrs := make([]interface{}, len(columns))
		for i := range values {
			valuePtrs[i] = &values[i]
		}
		if err := rows.Scan(valuePtrs...); err != nil {
			return meta.QueryResult{}, fmt.Errorf("failed to scan row: %w", err)
		}

		var children []meta.DataMeta
		for i, val := range values {
			// 安全检查：确保val是有效的interface{}
			if i >= len(columns) {
				continue // 跳过超出列数的字段
			}

			// 处理 []byte 与 time.Time 类型；根据 includeLarge 决定是否返回或省略大型字段
			omitted := false
			var sizeStr string
			if val != nil {
				switch v := val.(type) {
				case []byte:
					// 仅对数据库类型为 BLOB/TEXT/CLOB 等大字段在 includeLarge==false 时省略。
					dbType := strings.ToUpper(columns[i].DBType)
					isLargeType := strings.Contains(dbType, "BLOB") || strings.Contains(dbType, "TEXT") || strings.Contains(dbType, "CLOB") || strings.Contains(dbType, "LONG")
					if includeLarge || !isLargeType {
						val = string(v)
					} else {
						omitted = true
						sizeStr = strconv.Itoa(len(v))
						val = nil
					}
				case time.Time:
					val = v.Format(time.RFC3339)
				}
			}

			// 根据值类型设置 ValueType
			var valueType meta.FieldType
			if val == nil {
				valueType = meta.FieldTypeString // nil值当作字符串处理
			} else {
				// 根据值类型设置 ValueType
				switch reflect.TypeOf(val).Kind() {
				case reflect.String:
					valueType = meta.FieldTypeString
				case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
					valueType = meta.FieldTypeInt
				case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
					valueType = meta.FieldTypeInt
				case reflect.Float32, reflect.Float64:
					valueType = meta.FieldTypeNumber
				case reflect.Bool:
					valueType = meta.FieldTypeBool
				default:
					valueType = meta.FieldTypeString // 默认当作字符串
				}
			}

			child := meta.DataMeta{
				Name:      columns[i].Name,
				Type:      "value",
				Value:     val,
				ValueType: valueType,
			}
			if omitted {
				if child.Meta == nil {
					child.Meta = map[string]string{}
				}
				child.Omitted = true
				child.Meta["size"] = sizeStr
			}
			children = append(children, child)
		}
		resultRows = append(resultRows, meta.DataMeta{
			Name:     getRowName(children), // 设置行 name 为第一个列的值（通常为主键或 ID）
			Type:     "row",
			RowID:    "",
			Children: children,
		})
	}

	// 计算总数（如果请求）
	var total *int64
	if req.IncludeTotal {
		countSQL := fmt.Sprintf("SELECT COUNT(*) FROM `%s`", tableName)
		if len(req.Filters) > 0 {
			var conditions []string
			for col, val := range req.Filters {
				conditions = append(conditions, fmt.Sprintf("`%s` = '%s'", col, val))
			}
			countSQL += " WHERE " + strings.Join(conditions, " AND ")
		}
		var t int64
		if err := db.QueryRowContext(ctx, countSQL).Scan(&t); err != nil {
			return meta.QueryResult{}, fmt.Errorf("failed to count total: %w", err)
		}
		total = &t
	}

	return meta.QueryResult{
		Columns:   columns,
		Rows:      resultRows,
		Total:     total,
		Returned:  len(resultRows),
		Truncated: req.Limit > 0 && len(resultRows) == req.Limit,
		Stats:     map[string]string{"query": sql},
	}, nil
}

// ExecuteSQL 执行SQL语句并返回执行结果
// includeLarge: 当为 true 时，驱动应尽量返回大型字段（BLOB/CLOB）的完整内容；
// 当为 false 时，驱动可按策略省略大型字段并在返回的 DataMeta 中设置 `omitted:true`，以便前端按需加载。
func (q *MySQLDriver) ExecuteSQL(ctx context.Context, path meta.ObjectPath, sql string, params []interface{}, includeLarge bool) (meta.ExecuteResult, error) {
	startTime := time.Now()
	result := meta.ExecuteResult{
		Success:       false,
		ExecutionTime: 0,
	}

	// 清理和标准化SQL
	sql = strings.TrimSpace(sql)
	if sql == "" {
		result.ErrorMessage = "SQL语句不能为空：请提供有效的SQL查询或执行语句"
		return result, nil
	}

	// 分析SQL类型
	sqlType := q.analyzeSQLType(sql)

	db := q.db

	// 若调用方传入了结构化路径且首段为 database，则在当前会话中切换到该数据库
	// 这样用户可以在指定数据库上下文中运行任意 SQL（例如省略库名前缀的表名）
	if len(path) >= 1 && path[0].Name != "" {
		if _, err := db.ExecContext(ctx, fmt.Sprintf("USE `%s`", path[0].Name)); err != nil {
			result.ErrorMessage = fmt.Sprintf("切换数据库 `%s` 失败：%v", path[0].Name, err)
			result.ExecutionTime = time.Since(startTime).Milliseconds()
			return result, nil
		}
	}

	// 对于SELECT语句，使用 Query 执行
	if strings.HasPrefix(strings.ToUpper(sqlType), "SELECT") {
		rows, err := db.QueryContext(ctx, sql, params...)
		if err != nil {
			result.ErrorMessage = fmt.Sprintf("SELECT查询执行失败：SQL语法错误或数据库连接问题。原始错误：%v", err)
			result.ExecutionTime = time.Since(startTime).Milliseconds()
			return result, nil
		}
		defer rows.Close()

		// 获取列信息
		columns, err := rows.Columns()
		if err != nil {
			result.ErrorMessage = fmt.Sprintf("获取查询结果列信息失败：无法解析结果集结构。原始错误：%v", err)
			result.ExecutionTime = time.Since(startTime).Milliseconds()
			return result, nil
		}

		// 构建列元信息
		var columnMetas []meta.DataMeta
		columnTypes, err := rows.ColumnTypes()
		if err == nil {
			for i, col := range columns {
				dbType := ""
				if i < len(columnTypes) {
					dbType = columnTypes[i].DatabaseTypeName()
				}
				columnMetas = append(columnMetas, meta.DataMeta{
					Name:      col,
					Type:      "column",
					DBType:    dbType,
					ValueType: "string", // 简化处理
				})
			}
		}

		// 读取数据
		var resultRows []meta.DataMeta
		rowCount := 0
		for rows.Next() && rowCount < 1000 { // 限制最大行数
			values := make([]interface{}, len(columns))
			valuePtrs := make([]interface{}, len(columns))
			for i := range values {
				valuePtrs[i] = &values[i]
			}

			if err := rows.Scan(valuePtrs...); err != nil {
				result.ErrorMessage = fmt.Sprintf("扫描查询结果行数据失败：数据类型不匹配或结果集损坏。原始错误：%v", err)
				result.ExecutionTime = time.Since(startTime).Milliseconds()
				return result, nil
			}

			// 构建行数据
			var rowValues []meta.DataMeta
			for i, val := range values {
				colName := ""
				if i < len(columns) {
					colName = columns[i]
				}

				// 获取列的数据库类型（如果可用）以便判断是否为大对象类型
				dbType := ""
				if i < len(columnTypes) {
					dbType = columnTypes[i].DatabaseTypeName()
				}

				// 判断是否为大对象类型（简单规则：包含 BLOB/TEXT/CLOB/BINARY/VARBINARY 等）
				upperDBType := strings.ToUpper(dbType)
				isLargeDB := strings.Contains(upperDBType, "BLOB") || strings.Contains(upperDBType, "TEXT") || strings.Contains(upperDBType, "CLOB") || strings.Contains(upperDBType, "BINARY") || strings.Contains(upperDBType, "VARBINARY")

				// 根据值的实际类型决定最终的 Value 字段与是否在响应中省略
				var value interface{}
				var omitted bool
				var metaMap map[string]string

				if val == nil {
					value = nil
				} else {
					switch v := val.(type) {
					case []byte:
						// 对于 []byte，根据 includeLarge 决定是否返回完整内容。
						// - includeLarge == true: 返回字符串形式的内容
						// - includeLarge == false: 若列类型为大对象或长度超过阈值（1KB），则省略并标记 omitted
						if includeLarge {
							value = string(v)
						} else if isLargeDB || len(v) > 1024 {
							omitted = true
							value = nil
							metaMap = map[string]string{"size": fmt.Sprintf("%d", len(v))}
						} else {
							value = string(v)
						}
					case time.Time:
						value = v.Format(time.RFC3339Nano)
					default:
						value = fmt.Sprintf("%v", v)
					}
				}

				dm := meta.DataMeta{
					Name:    colName,
					Type:    "value",
					Value:   value,
					DBType:  dbType,
					Omitted: omitted,
				}
				if len(metaMap) > 0 {
					dm.Meta = metaMap
				}

				rowValues = append(rowValues, dm)
			}

			resultRows = append(resultRows, meta.DataMeta{
				Type:     "row",
				RowID:    "",
				Children: rowValues,
			})
			rowCount++
		}

		// 构建查询结果
		queryResult := &meta.QueryResult{
			Columns:       columnMetas,
			Rows:          resultRows,
			Returned:      len(resultRows),
			Truncated:     rowCount >= 1000,
			ExecutionTime: time.Since(startTime).Milliseconds(),
		}

		result.Success = true
		result.SQLType = sqlType
		result.Data = queryResult
		result.ExecutionTime = time.Since(startTime).Milliseconds()
		result.RowsReturned = len(resultRows)

		// 对于非SELECT语句，使用Exec执行
		execResult, err := db.ExecContext(ctx, sql, params...)
		if err != nil {
			result.ErrorMessage = fmt.Sprintf("%s语句执行失败：SQL语法错误、权限不足或数据库约束冲突。原始错误：%v", sqlType, err)
			result.ExecutionTime = time.Since(startTime).Milliseconds()
			return result, nil
		}

		// 获取影响行数
		affectedRows, _ := execResult.RowsAffected()
		result.AffectedRows = affectedRows

		// 获取最后插入ID（如果适用）
		if strings.HasPrefix(strings.ToUpper(sqlType), "INSERT") {
			lastInsertID, _ := execResult.LastInsertId()
			result.LastInsertID = lastInsertID
		}

		result.Success = true
		result.SQLType = sqlType
		result.ExecutionTime = time.Since(startTime).Milliseconds()
	}

	return result, nil
}

// analyzeSQLType 分析SQL语句类型
func (q *MySQLDriver) analyzeSQLType(sql string) string {
	upperSQL := strings.ToUpper(strings.TrimSpace(sql))

	switch {
	case strings.HasPrefix(upperSQL, "SELECT"):
		return "SELECT"
	case strings.HasPrefix(upperSQL, "INSERT"):
		return "INSERT"
	case strings.HasPrefix(upperSQL, "UPDATE"):
		return "UPDATE"
	case strings.HasPrefix(upperSQL, "DELETE"):
		return "DELETE"
	case strings.HasPrefix(upperSQL, "CREATE"):
		if strings.Contains(upperSQL, "TABLE") {
			return "CREATE TABLE"
		} else if strings.Contains(upperSQL, "DATABASE") {
			return "CREATE DATABASE"
		} else if strings.Contains(upperSQL, "INDEX") {
			return "CREATE INDEX"
		}
		return "CREATE"
	case strings.HasPrefix(upperSQL, "DROP"):
		if strings.Contains(upperSQL, "TABLE") {
			return "DROP TABLE"
		} else if strings.Contains(upperSQL, "DATABASE") {
			return "DROP DATABASE"
		} else if strings.Contains(upperSQL, "INDEX") {
			return "DROP INDEX"
		}
		return "DROP"
	case strings.HasPrefix(upperSQL, "ALTER"):
		return "ALTER"
	case strings.HasPrefix(upperSQL, "TRUNCATE"):
		return "TRUNCATE"
	default:
		return "UNKNOWN"
	}
}

// getRowName 安全地获取行名，避免空指针引用
func getRowName(children []meta.DataMeta) string {
	if len(children) == 0 {
		return ""
	}
	if children[0].Value == nil {
		return "<NULL>"
	}
	return fmt.Sprintf("%v", children[0].Value)
}

// DescribeUpdateTemplate 返回指定对象的修改模板，用于前端动态生成表单
func (q *MySQLDriver) describeUpdateTemplate(ctx context.Context, path meta.ObjectPath) (meta.ObjectTemplate, error) {
	if len(path) == 0 {
		return meta.ObjectTemplate{}, fmt.Errorf("路径不能为空")
	}

	lastEntry := path[len(path)-1]
	objectType := strings.ToLower(lastEntry.Type)
	objectName := lastEntry.Name

	switch objectType {
	case "database":
		// 获取数据库的当前信息
		currentValues, err := q.getCurrentDatabaseInfo(ctx, objectName)
		if err != nil {
			return meta.ObjectTemplate{}, err
		}

		tpl := meta.ObjectTemplate{
			Operation:  "update",
			ObjectType: "database",
			ParentHint: "",
			Fields:     getDatabaseTemplateFields(true, currentValues),
			Current:    currentValues,
			Example:    map[string]string{"charset": "utf8mb4"},
		}
		return tpl, nil

	case "table":
		if len(path) < 2 {
			return meta.ObjectTemplate{}, fmt.Errorf("表路径需要包含数据库信息")
		}
		dbName := path[0].Name
		tableName := objectName

		// 获取表的当前信息
		currentValues, err := q.getCurrentTableInfo(ctx, dbName, tableName)
		if err != nil {
			return meta.ObjectTemplate{}, err
		}

		tpl := meta.ObjectTemplate{
			Operation:  "update",
			ObjectType: "table",
			ParentHint: "database: " + dbName,
			Fields:     getTableTemplateFields(true, currentValues),
			Current:    currentValues,
			Example:    map[string]string{"engine": "InnoDB", "charset": "utf8mb4"},
		}
		return tpl, nil

	default:
		return meta.ObjectTemplate{}, fmt.Errorf("不支持的 update 类型: %s", objectType)
	}
}

// UpdateObject 执行对象的修改操作
func (q *MySQLDriver) updateObject(ctx context.Context, req meta.UpdateObjectRequest) (meta.UpdateObjectResponse, error) {
	if len(req.Path) == 0 {
		return meta.UpdateObjectResponse{}, fmt.Errorf("路径不能为空")
	}

	lastEntry := req.Path[len(req.Path)-1]
	objectType := strings.ToLower(lastEntry.Type)
	objectName := lastEntry.Name

	var sqls []string

	switch objectType {
	case "database":
		dbName := objectName
		charset, charsetOk := req.Properties["charset"].(string)
		collation, collationOk := req.Properties["collation"].(string)

		if charsetOk && charset != "" {
			sql := fmt.Sprintf("ALTER DATABASE `%s` CHARACTER SET %s", dbName, charset)
			sqls = append(sqls, sql)
		}

		if collationOk && collation != "" {
			sql := fmt.Sprintf("ALTER DATABASE `%s` COLLATE %s", dbName, collation)
			sqls = append(sqls, sql)
		}

	case "table":
		if len(req.Path) < 2 {
			return meta.UpdateObjectResponse{}, fmt.Errorf("表路径需要包含数据库信息")
		}
		dbName := req.Path[0].Name
		tableName := objectName

		engine, engineOk := req.Properties["engine"].(string)
		charset, charsetOk := req.Properties["charset"].(string)
		collation, collationOk := req.Properties["collation"].(string)

		if engineOk && engine != "" {
			sql := fmt.Sprintf("ALTER TABLE `%s`.`%s` ENGINE = %s", dbName, tableName, engine)
			sqls = append(sqls, sql)
		}

		if charsetOk && charset != "" {
			sql := fmt.Sprintf("ALTER TABLE `%s`.`%s` CONVERT TO CHARACTER SET %s", dbName, tableName, charset)
			sqls = append(sqls, sql)
		}

		if collationOk && collation != "" {
			sql := fmt.Sprintf("ALTER TABLE `%s`.`%s` COLLATE %s", dbName, tableName, collation)
			sqls = append(sqls, sql)
		}

	default:
		return meta.UpdateObjectResponse{}, fmt.Errorf("不支持的 update 类型: %s", objectType)
	}

	if !req.Execute {
		// 预览模式，只返回生成的SQL
		return meta.UpdateObjectResponse{
			GeneratedSQL: sqls,
		}, nil
	}

	// 执行模式
	for _, sql := range sqls {
		if _, err := q.db.ExecContext(ctx, sql); err != nil {
			return meta.UpdateObjectResponse{}, fmt.Errorf("执行SQL失败: %s, 错误: %v", sql, err)
		}
	}

	return meta.UpdateObjectResponse{
		GeneratedSQL: sqls,
	}, nil
}

// DescribeDeleteTemplate 返回指定对象的删除模板，用于前端显示删除确认和影响预览
func (q *MySQLDriver) describeDeleteTemplate(ctx context.Context, path meta.ObjectPath) (meta.ObjectTemplate, error) {
	if len(path) == 0 {
		return meta.ObjectTemplate{}, fmt.Errorf("路径不能为空")
	}

	lastEntry := path[len(path)-1]
	objectType := strings.ToLower(lastEntry.Type)
	objectName := lastEntry.Name

	switch objectType {
	case "database":
		dbName := objectName

		// 查询数据库中的表数量
		var tableCount int64
		err := q.db.QueryRowContext(ctx, "SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = ?", dbName).Scan(&tableCount)
		if err != nil {
			return meta.ObjectTemplate{}, fmt.Errorf("获取数据库表数量失败: %w", err)
		}

		tpl := meta.ObjectTemplate{
			Operation:  "delete",
			ObjectType: "database",
			ParentHint: "",
			Current: map[string]string{
				"databaseName": dbName,
				"tableCount":   fmt.Sprintf("%d", tableCount),
			},
			Fields: []meta.TemplateField{
				{Name: "databaseName", Label: "Database Name", Type: meta.FieldTypeString, Required: true, Current: dbName, Editable: &[]bool{false}[0]},
				{Name: "tableCount", Label: "Tables Count", Type: meta.FieldTypeString, Required: false, Current: fmt.Sprintf("%d", tableCount), Editable: &[]bool{false}[0]},
				{Name: "confirmDelete", Label: "Confirm Delete", Type: meta.FieldTypeBool, Required: true, Help: "删除数据库将同时删除所有表和数据，此操作不可恢复"},
			},
			Notes: "警告：删除数据库将永久删除所有表、数据和相关对象。此操作不可恢复。",
		}
		return tpl, nil

	case "table":
		if len(path) < 2 {
			return meta.ObjectTemplate{}, fmt.Errorf("表路径需要包含数据库信息")
		}
		dbName := path[0].Name
		tableName := objectName

		// 查询表中的行数
		var rowCount int64
		query := fmt.Sprintf("SELECT COUNT(*) FROM `%s`.`%s`", dbName, tableName)
		err := q.db.QueryRowContext(ctx, query).Scan(&rowCount)
		if err != nil {
			// 如果查询失败，可能表不存在或权限问题
			rowCount = -1
		}

		tpl := meta.ObjectTemplate{
			Operation:  "delete",
			ObjectType: "table",
			ParentHint: "database: " + dbName,
			Current: map[string]string{
				"tableName": tableName,
				"rowCount":  fmt.Sprintf("%d", rowCount),
			},
			Fields: []meta.TemplateField{
				{Name: "tableName", Label: "Table Name", Type: meta.FieldTypeString, Required: true, Current: tableName, Editable: &[]bool{false}[0]},
				{Name: "rowCount", Label: "Row Count", Type: meta.FieldTypeString, Required: false, Current: fmt.Sprintf("%d", rowCount), Editable: &[]bool{false}[0]},
				{Name: "confirmDelete", Label: "Confirm Delete", Type: meta.FieldTypeBool, Required: true, Help: "删除表将永久删除所有数据，此操作不可恢复"},
			},
			Notes: "警告：删除表将永久删除所有数据。此操作不可恢复。",
		}
		return tpl, nil

	default:
		return meta.ObjectTemplate{}, fmt.Errorf("不支持的 delete 类型: %s", objectType)
	}
}

// --- 适配器方法：实现新的 MetadataReader / ObjectManager 接口 ---

// GetStructureDefinition 返回 MySQL 的节点类型定义
// 这些定义用于上层构建树状导航（例如数据库->表->列），包含类型标识、显示标签、图标与允许的子类型
func (q *MySQLDriver) GetStructureDefinition(ctx context.Context) ([]meta.NodeTypeDefinition, error) {
	defs := []meta.NodeTypeDefinition{
		{Type: "database", Label: "Database", Icon: "database", ChildTypes: []string{"table", "view", "procedure", "trigger", "index"}, IsLeaf: false},
		{Type: "table", Label: "Table", Icon: "table", ChildTypes: []string{"column", "index"}, IsLeaf: false},
		{Type: "view", Label: "View", Icon: "eye", ChildTypes: []string{"column"}, IsLeaf: false},
		{Type: "column", Label: "Column", Icon: "column", ChildTypes: nil, IsLeaf: true},
	}
	return defs, nil
}

// 辅助函数：将内部通用对象 meta.GenericObject 转换为通用节点 meta.Node
// - basePath: 如果提供，将在当前对象之前作为路径前缀
// - 该函数不会访问数据库，仅基于传入的 GenericObject 构造 Node，用于适配层返回统一模型
func genericToNode(g meta.GenericObject, basePath meta.ObjectPath) meta.Node {
	// 构建路径：复制 basePath 并在末尾追加当前对象的路径段
	var p meta.ObjectPath
	if basePath != nil {
		p = append(meta.ObjectPath{}, basePath...)
	}
	// 将当前对象作为最后一个路径段追加
	p = append(p, meta.ObjectPathEntry{Type: g.Type, Name: g.Name})

	// 将 GenericObject 的 Attrs 复制到 Properties（保持简单的 key->value 映射）
	props := make(map[string]interface{})
	for k, v := range g.Attrs {
		props[k] = v
	}

	return meta.Node{
		Name:        g.Name,
		Type:        g.Type,
		Path:        p,
		HasChildren: len(g.Children) > 0,
		Properties:  props,
	}
}

// ListNodes 实现了 MetadataReader.ListNodes，内部委托到已有的 getRootObjects/getChildObjects
// - path: 结构化路径，空路径表示根节点（返回数据库列表）
// - req: 支持分页和按类型过滤（TypeFilter）
func (q *MySQLDriver) ListNodes(ctx context.Context, path meta.ObjectPath, req meta.ListNodesRequest) ([]meta.Node, int64, error) {
	page := 1
	pageSize := 100
	if req.Page > 0 {
		page = req.Page
	}
	if req.PageSize > 0 {
		pageSize = req.PageSize
	}

	if len(path) == 0 {
		// root: databases
		db := q.db

		// 2. 查询总数（分页用）
		var total int64
		if err := db.QueryRowContext(ctx, "SELECT COUNT(*) FROM INFORMATION_SCHEMA.SCHEMATA").Scan(&total); err != nil {
			return nil, 0, fmt.Errorf("查询数据库实例下的 schema 总数失败（INFORMATION_SCHEMA.SCHEMATA）：%w", err)
		}

		// 3. 分页查询库列表
		offset := (page - 1) * pageSize
		query := fmt.Sprintf(
			"SELECT SCHEMA_NAME, DEFAULT_CHARACTER_SET_NAME  FROM INFORMATION_SCHEMA.SCHEMATA LIMIT %d OFFSET %d",
			pageSize, offset)

		// 只返回类型占位
		if !true { // fetch is always true in ListNodes usage
			types := []meta.GenericObject{{
				ID:          fmt.Sprintf("%s.type-database", q.Name),
				Name:        "database",
				Description: "数据库（root）类型，占位用于导航；前端可据此请求数据库下的子类型/条目",
				Type:        "database",
				ParentID:    q.Name,
				DBType:      "mysql",
				Attrs:       map[string]string{},
			}}
			var nodes []meta.Node
			for _, g := range types {
				nodes = append(nodes, genericToNode(g, path))
			}
			return nodes, total, nil
		}

		rows, err := db.QueryContext(ctx, query)
		if err != nil {
			return nil, 0, fmt.Errorf("分页查询 schema 列表失败（conn=%s,page=%d,pageSize=%d, sql=%s）：%w", q.Name, page, pageSize, query, err)
		}
		defer rows.Close()

		var gos []meta.GenericObject
		for rows.Next() {
			var dbName sql.NullString
			var charset sql.NullString
			if err := rows.Scan(&dbName, &charset); err != nil {
				continue
			}
			gos = append(gos, meta.GenericObject{
				ID:       fmt.Sprintf("%s.db-%s", q.Name, dbName.String),
				Name:     dbName.String,
				Type:     "database",
				ParentID: q.Name,
				DBType:   "mysql",
				Attrs: map[string]string{
					"charset":    charset.String,
					"createTime": "",
				},
				Children: []meta.GenericObject{},
			})
		}
		if err := rows.Err(); err != nil {
			return nil, 0, fmt.Errorf("遍历 schema 结果集出错：%w", err)
		}
		var nodes []meta.Node
		for _, g := range gos {
			nodes = append(nodes, genericToNode(g, path))
		}
		return nodes, total, nil
	}

	// 在 path 的最后一项下列出子对象
	childType := ""
	if len(req.TypeFilter) > 0 {
		childType = req.TypeFilter[0]
	}

	// inline getChildObjects logic
	db := q.db
	if len(path) == 0 {
		return nil, 0, fmt.Errorf("empty path")
	}
	parentEntry := path[len(path)-1]
	dbName := parentEntry.Name
	objectType := strings.ToLower(childType)
	if objectType == "" {
		objectType = "table"
	}

	switch objectType {
	case "table":
		tableType := "BASE TABLE"
		// count
		var total int64
		if err := db.QueryRowContext(ctx, `
			SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES
			WHERE TABLE_SCHEMA = ? AND TABLE_TYPE = ?
		`, dbName, tableType).Scan(&total); err != nil {
			return nil, 0, fmt.Errorf("查询库 %s 中 %s 数量失败：%w", dbName, tableType, err)
		}
		offset := (page - 1) * pageSize
		rows, err := db.QueryContext(ctx, `
			SELECT TABLE_NAME, ENGINE, CREATE_TIME
			FROM INFORMATION_SCHEMA.TABLES
			WHERE TABLE_SCHEMA = ? AND TABLE_TYPE = ?
			LIMIT ? OFFSET ?
		`, dbName, tableType, pageSize, offset)
		if err != nil {
			return nil, 0, fmt.Errorf("分页查询库 %s 的 %s 列表失败（page=%d,pageSize=%d）：%w", dbName, tableType, page, pageSize, err)
		}
		defer rows.Close()
		var gos []meta.GenericObject
		for rows.Next() {
			var tName sql.NullString
			var engine sql.NullString
			var createTime sql.NullString
			if err := rows.Scan(&tName, &engine, &createTime); err != nil {
				continue
			}
			gos = append(gos, meta.GenericObject{
				ID:       fmt.Sprintf("%s.table-%s", dbName, tName.String),
				Name:     tName.String,
				Type:     "table",
				ParentID: dbName,
				DBType:   "mysql",
				Attrs: map[string]string{
					"engine":     engine.String,
					"createTime": createTime.String,
				},
			})
		}
		if err := rows.Err(); err != nil {
			return nil, 0, fmt.Errorf("遍历表结果集出错（%s.%s）：%w", dbName, tableType, err)
		}
		var nodes []meta.Node
		for _, g := range gos {
			nodes = append(nodes, genericToNode(g, path))
		}
		return nodes, total, nil
	case "view":
		tableType := "VIEW"
		var total int64
		if err := db.QueryRowContext(ctx, `
			SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES
			WHERE TABLE_SCHEMA = ? AND TABLE_TYPE = ?
		`, dbName, tableType).Scan(&total); err != nil {
			return nil, 0, fmt.Errorf("查询库 %s 中 %s 数量失败：%w", dbName, tableType, err)
		}
		offset := (page - 1) * pageSize
		rows, err := db.QueryContext(ctx, `
			SELECT TABLE_NAME, NULL AS ENGINE, CREATE_TIME
			FROM INFORMATION_SCHEMA.TABLES
			WHERE TABLE_SCHEMA = ? AND TABLE_TYPE = ?
			LIMIT ? OFFSET ?
		`, dbName, tableType, pageSize, offset)
		if err != nil {
			return nil, 0, fmt.Errorf("分页查询库 %s 的 %s 列表失败（page=%d,pageSize=%d）：%w", dbName, tableType, page, pageSize, err)
		}
		defer rows.Close()
		var gos []meta.GenericObject
		for rows.Next() {
			var tName sql.NullString
			var engine sql.NullString
			var createTime sql.NullString
			if err := rows.Scan(&tName, &engine, &createTime); err != nil {
				continue
			}
			gos = append(gos, meta.GenericObject{
				ID:       fmt.Sprintf("%s.table-%s", dbName, tName.String),
				Name:     tName.String,
				Type:     "view",
				ParentID: dbName,
				DBType:   "mysql",
				Attrs: map[string]string{
					"engine":     engine.String,
					"createTime": createTime.String,
				},
			})
		}
		if err := rows.Err(); err != nil {
			return nil, 0, fmt.Errorf("遍历视图结果集出错（%s.%s）：%w", dbName, tableType, err)
		}
		var nodes []meta.Node
		for _, g := range gos {
			nodes = append(nodes, genericToNode(g, path))
		}
		return nodes, total, nil
	case "index":
		var total int64
		if err := db.QueryRowContext(ctx, `
			SELECT COUNT(DISTINCT CONCAT(TABLE_NAME,'::',INDEX_NAME))
			FROM INFORMATION_SCHEMA.STATISTICS
			WHERE TABLE_SCHEMA = ?
		`, dbName).Scan(&total); err != nil {
			return nil, 0, err
		}
		offset := (page - 1) * pageSize
		rows, err := db.QueryContext(ctx, `
			SELECT DISTINCT INDEX_NAME, TABLE_NAME, NON_UNIQUE
			FROM INFORMATION_SCHEMA.STATISTICS
			WHERE TABLE_SCHEMA = ?
			LIMIT ? OFFSET ?
		`, dbName, pageSize, offset)
		if err != nil {
			return nil, 0, err
		}
		defer rows.Close()
		var gos []meta.GenericObject
		for rows.Next() {
			var idxName sql.NullString
			var tName sql.NullString
			var nonUnique sql.NullInt64
			if err := rows.Scan(&idxName, &tName, &nonUnique); err != nil {
				continue
			}
			id := fmt.Sprintf("%s.index-%s-%s", dbName, tName.String, idxName.String)
			gos = append(gos, meta.GenericObject{
				ID:       id,
				Name:     idxName.String,
				Type:     "index",
				ParentID: dbName,
				DBType:   "mysql",
				Attrs: map[string]string{
					"table":     tName.String,
					"nonUnique": fmt.Sprintf("%d", nonUnique.Int64),
				},
			})
		}
		if err := rows.Err(); err != nil {
			return nil, 0, fmt.Errorf("遍历索引结果集出错（库级，%s）：%w", dbName, err)
		}
		var nodes []meta.Node
		for _, g := range gos {
			nodes = append(nodes, genericToNode(g, path))
		}
		return nodes, total, nil
	case "procedure", "proc":
		var total int64
		if err := db.QueryRowContext(ctx, `
			SELECT COUNT(*) FROM INFORMATION_SCHEMA.ROUTINES
			WHERE ROUTINE_SCHEMA = ? AND ROUTINE_TYPE = 'PROCEDURE'
		`, dbName).Scan(&total); err != nil {
			return nil, 0, fmt.Errorf("查询库 %s 存储过程数量失败：%w", dbName, err)
		}
		offset := (page - 1) * pageSize
		rows, err := db.QueryContext(ctx, `
			SELECT ROUTINE_NAME, ROUTINE_DEFINITION, CREATED
			FROM INFORMATION_SCHEMA.ROUTINES
			WHERE ROUTINE_SCHEMA = ? AND ROUTINE_TYPE = 'PROCEDURE'
			LIMIT ? OFFSET ?
		`, dbName, pageSize, offset)
		if err != nil {
			return nil, 0, fmt.Errorf("分页查询库 %s 存储过程列表失败（page=%d,pageSize=%d）：%w", dbName, page, pageSize, err)
		}
		defer rows.Close()
		var gos []meta.GenericObject
		for rows.Next() {
			var rName sql.NullString
			var def sql.NullString
			var created sql.NullString
			if err := rows.Scan(&rName, &def, &created); err != nil {
				continue
			}
			id := fmt.Sprintf("%s.proc-%s", dbName, rName.String)
			gos = append(gos, meta.GenericObject{
				ID:       id,
				Name:     rName.String,
				Type:     "procedure",
				ParentID: dbName,
				DBType:   "mysql",
				Attrs: map[string]string{
					"definition": def.String,
					"created":    created.String,
				},
			})
		}
		if err := rows.Err(); err != nil {
			return nil, 0, fmt.Errorf("遍历存储过程结果出错（%s）：%w", dbName, err)
		}
		var nodes []meta.Node
		for _, g := range gos {
			nodes = append(nodes, genericToNode(g, path))
		}
		return nodes, total, nil
	case "trigger":
		var total int64
		if err := db.QueryRowContext(ctx, `
			SELECT COUNT(*) FROM INFORMATION_SCHEMA.TRIGGERS
			WHERE TRIGGER_SCHEMA = ?
		`, dbName).Scan(&total); err != nil {
			return nil, 0, fmt.Errorf("查询库 %s 触发器数量失败：%w", dbName, err)
		}
		offset := (page - 1) * pageSize
		rows, err := db.QueryContext(ctx, `
			SELECT TRIGGER_NAME, EVENT_MANIPULATION, EVENT_OBJECT_TABLE, ACTION_TIMING, ACTION_STATEMENT
			FROM INFORMATION_SCHEMA.TRIGGERS
			WHERE TRIGGER_SCHEMA = ?
			LIMIT ? OFFSET ?
		`, dbName, pageSize, offset)
		if err != nil {
			return nil, 0, fmt.Errorf("分页查询库 %s 触发器列表失败（page=%d,pageSize=%d）：%w", dbName, page, pageSize, err)
		}
		defer rows.Close()
		var gos []meta.GenericObject
		for rows.Next() {
			var tName sql.NullString
			var event sql.NullString
			var objTable sql.NullString
			var timing sql.NullString
			var stmt sql.NullString
			if err := rows.Scan(&tName, &event, &objTable, &timing, &stmt); err != nil {
				continue
			}
			id := fmt.Sprintf("%s.trigger-%s", dbName, tName.String)
			gos = append(gos, meta.GenericObject{
				ID:       id,
				Name:     tName.String,
				Type:     "trigger",
				ParentID: dbName,
				DBType:   "mysql",
				Attrs: map[string]string{
					"event":     event.String,
					"table":     objTable.String,
					"timing":    timing.String,
					"statement": stmt.String,
				},
			})
		}
		if err := rows.Err(); err != nil {
			return nil, 0, fmt.Errorf("遍历触发器结果出错（%s）：%w", dbName, err)
		}
		var nodes []meta.Node
		for _, g := range gos {
			nodes = append(nodes, genericToNode(g, path))
		}
		return nodes, total, nil
	default:
		return nil, 0, fmt.Errorf("不支持的类型: %s", objectType)
	}
}

// GetNodeDetails 将内部的 GetObjectDetails 结果映射为 NodeDetails 供上层使用
// - path: 目标对象的结构化路径
func (q *MySQLDriver) GetNodeDetails(ctx context.Context, path meta.ObjectPath) (meta.NodeDetails, error) {
	// 复用已有的 getObjectDetails 来获取完整的 GenericObject（含子对象）
	g, err := q.getObjectDetails(ctx, path, true)
	if err != nil {
		return meta.NodeDetails{}, err
	}
	node := genericToNode(g, path[:len(path)-1])
	// 将一些原始属性填入 RawMetadata，便于上层展示或调试
	raw := map[string]interface{}{
		"attrs":       g.Attrs,
		"child_count": len(g.Children),
	}
	return meta.NodeDetails{Node: node, RawMetadata: raw}, nil
}

// SearchNodes 提供基本的节点搜索实现：根据传入的作用域（scope）在数据库名或表名中搜索
// - 如果 scope 为空：在数据库名中搜索（返回数据库节点）
// - 如果 scope 指向某个数据库：在该数据库下搜索表名
func (q *MySQLDriver) SearchNodes(ctx context.Context, keyword string, scope meta.ObjectPath) ([]meta.Node, error) {
	db := q.db
	kw := "%" + strings.ReplaceAll(keyword, "%", "\\%") + "%"
	// 如果 scope 为空，则在数据库名称中搜索
	if len(scope) == 0 {
		rows, err := db.QueryContext(ctx, `SELECT SCHEMA_NAME, DEFAULT_CHARACTER_SET_NAME FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME LIKE ? LIMIT 100`, kw)
		if err != nil {
			return nil, err
		}
		defer rows.Close()
		var res []meta.Node
		for rows.Next() {
			var name sql.NullString
			var cs sql.NullString
			if err := rows.Scan(&name, &cs); err != nil {
				continue
			}
			g := meta.GenericObject{Name: name.String, Type: "database", Attrs: map[string]string{"charset": cs.String}}
			res = append(res, genericToNode(g, nil))
		}
		return res, nil
	}
	// 如果 scope 指向一个数据库，则在该数据库的表名中搜索
	if len(scope) >= 1 && strings.ToLower(scope[len(scope)-1].Type) == "database" {
		dbName := scope[len(scope)-1].Name
		rows, err := db.QueryContext(ctx, `SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = ? AND TABLE_NAME LIKE ? LIMIT 200`, dbName, kw)
		if err != nil {
			return nil, err
		}
		defer rows.Close()
		var res []meta.Node
		for rows.Next() {
			var t sql.NullString
			if err := rows.Scan(&t); err != nil {
				continue
			}
			g := meta.GenericObject{Name: t.String, Type: "table", ParentID: dbName}
			res = append(res, genericToNode(g, scope))
		}
		return res, nil
	}
	return nil, nil
}

// ObjectManager: GetObjectProperties 将 DescribeCreateTemplate/DescribeUpdateTemplate 映射为 PropertyDefinitions
// - 返回对前端友好的属性定义列表（PropertyDefinitions）以及当前值（PropertyValues），供表单渲染与预览使用
func (q *MySQLDriver) GetObjectProperties(ctx context.Context, path meta.ObjectPath) (meta.PropertyDefinitions, meta.PropertyValues, error) {
	// 根据 path 的最后一项是否包含 Name 字段决定是创建模板还是更新模板
	if len(path) == 0 {
		return nil, nil, fmt.Errorf("path required")
	}
	last := path[len(path)-1]
	var tpl meta.ObjectTemplate
	var err error
	if last.Name == "" {
		tpl, err = q.describeCreateTemplate(ctx, path)
	} else {
		tpl, err = q.describeUpdateTemplate(ctx, path)
	}
	if err != nil {
		return nil, nil, err
	}
	// 将 ObjectTemplate 中的 TemplateField 转换为通用的 PropertyDefinition，并收集 Current 值到 PropertyValues
	var defs meta.PropertyDefinitions
	curr := make(meta.PropertyValues)
	for _, f := range tpl.Fields {
		pd := meta.PropertyDefinition{
			Key:         f.Name,
			Label:       f.Label,
			Type:        string(f.Type),
			Required:    f.Required,
			Description: f.Help,
			ReadOnly:    false,
		}
		if f.Default != "" {
			pd.DefaultValue = f.Default
		}
		if len(f.EnumOptions) > 0 {
			pd.Options = f.EnumOptions
		}
		defs = append(defs, pd)
		if f.Current != nil {
			curr[f.Name] = f.Current
		}
	}
	// also copy tmpl.Current (map[string]string) into curr
	for k, v := range tpl.Current {
		curr[k] = v
	}
	return defs, curr, nil
}

// ApplyChanges 实现对象的创建/更新/删除操作，内部委托到已有的 createObject/updateObject/delete* helper
// - action: create/update/delete
// - options.DryRun=true 时仅预览（不执行），否则执行对应操作
func (q *MySQLDriver) ApplyChanges(ctx context.Context, action meta.ObjectAction, path meta.ObjectPath, changes meta.PropertyValues, options meta.ApplyOptions) (meta.ApplyResult, error) {
	// 注意：DryRun=true 对应 Execute=false（旧接口中 Execute 控制是否执行 SQL）
	execute := !options.DryRun
	switch action {
	case meta.ObjectAction("create"):
		// 使用已有的 createObject API 生成/执行创建语句
		req := meta.CreateObjectRequest{
			ObjectType: path[len(path)-1].Type,
			ParentName: "",
			Properties: changes,
			Execute:    execute,
		}
		if len(path) >= 2 {
			req.ParentName = path[len(path)-2].Name
		}
		resp, err := q.createObject(ctx, req)
		if err != nil {
			return meta.ApplyResult{}, err
		}
		var script string
		if len(resp.GeneratedSQL) > 0 {
			script = strings.Join(resp.GeneratedSQL, "\n")
		}
		return meta.ApplyResult{Script: script, Message: "ok"}, nil
	case meta.ObjectAction("update"):
		ureq := meta.UpdateObjectRequest{
			Path:       path,
			Properties: changes,
			Execute:    execute,
		}
		uresp, err := q.updateObject(ctx, ureq)
		if err != nil {
			return meta.ApplyResult{}, err
		}
		var script string
		if len(uresp.GeneratedSQL) > 0 {
			script = strings.Join(uresp.GeneratedSQL, "\n")
		}
		return meta.ApplyResult{Script: script, Message: "ok"}, nil
	case meta.ObjectAction("delete"):
		// Build ObjectOperationRequest
		if len(path) == 0 {
			return meta.ApplyResult{}, fmt.Errorf("path required for delete")
		}
		last := path[len(path)-1]
		obj := meta.GenericObject{Type: last.Type, Name: last.Name}
		doreq := meta.ObjectOperationRequest{Object: obj, Execute: execute}
		// If deleting root (database)
		if len(path) == 1 {
			resp, err := q.deleteRootObjects(ctx, doreq)
			if err != nil {
				return meta.ApplyResult{}, err
			}
			return meta.ApplyResult{Script: resp.Sql, AffectedRows: resp.Affected}, nil
		}
		// else child
		resp, err := q.deleteChildObjects(ctx, doreq)
		if err != nil {
			return meta.ApplyResult{}, err
		}
		return meta.ApplyResult{Script: resp.Sql, AffectedRows: resp.Affected}, nil
	default:
		return meta.ApplyResult{}, fmt.Errorf("unsupported action: %s", action)
	}
}