package handler

import (
	"context"
	"errors"
	"net/http"
	"strings"

	"dbview/service/internal/common/response"
	"dbview/service/internal/modules/connection_pool/api"
	"dbview/service/internal/modules/connection_pool/service"

	"github.com/gin-gonic/gin"
)

// RegisterConnection 注册新的数据库连接
func RegisterConnection(c *gin.Context) {
	var req api.RegisterConnectionRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, response.ParamErrorWithDetail("请求参数错误", err))
		return
	}

	connID := buildConnectionID(req.ConnID, c.ClientIP())
	req.ConnID = connID

	stat, err := service.RegisterConnection(&req)
	if err != nil {
		c.JSON(http.StatusInternalServerError, response.ErrorWithDetail("注册连接失败", err))
		return
	}

	c.JSON(http.StatusOK, response.SuccessWithMsg("注册连接成功", stat))
}

func buildConnectionID(baseID, clientIP string) string {
	if clientIP == "" {
		return baseID
	}
	replacer := strings.NewReplacer("::", "-", ":", "-", ".", "-", "%", "-", "[", "", "]", "")
	sanitized := replacer.Replace(clientIP)
	if baseID == "" {
		return sanitized
	}
	return baseID + "@" + sanitized
}

// GetConnectionStats 返回连接池状态
func GetConnectionStats(c *gin.Context) {
	stats, err := service.GetConnectionStats()
	if err != nil {
		c.JSON(http.StatusInternalServerError, response.ErrorWithDetail("获取连接池状态失败", err))
		return
	}

	c.JSON(http.StatusOK, response.Success(api.ConnectionStatsResponse{Connections: stats}))
}

// CloseConnection 关闭指定连接
func CloseConnection(c *gin.Context) {
	var req api.CloseConnectionRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, response.ParamErrorWithDetail("请求参数错误", err))
		return
	}

	connID := buildConnectionID(req.ConnID, c.ClientIP())

	if err := service.CloseConnection(connID); err != nil {
		if errors.Is(err, response.ErrConnNotExist) {
			c.JSON(http.StatusNotFound, response.NotFoundWithDetail("连接不存在", err))
			return
		}
		c.JSON(http.StatusInternalServerError, response.ErrorWithDetail("关闭连接失败", err))
		return
	}

	c.JSON(http.StatusOK, response.SuccessWithMsg("连接已关闭", nil))
}

// CloseAllConnections 关闭所有连接
func CloseAllConnections(c *gin.Context) {
	if err := service.CloseAllConnections(); err != nil {
		c.JSON(http.StatusInternalServerError, response.ErrorWithDetail("关闭所有连接失败", err))
		return
	}

	c.JSON(http.StatusOK, response.SuccessWithMsg("所有连接已关闭", nil))
}

// PingConnection 检查连接是否可用
func PingConnection(c *gin.Context) {
	var req api.PingConnectionRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, response.ParamErrorWithDetail("请求参数错误", err))
		return
	}

	ctx := c.Request.Context()
	if ctx == nil {
		ctx = context.Background()
	}

	connID := buildConnectionID(req.ConnID, c.ClientIP())

	if err := service.PingConnection(ctx, connID); err != nil {
		if errors.Is(err, response.ErrConnNotExist) {
			c.JSON(http.StatusNotFound, response.NotFoundWithDetail("连接不存在", err))
			return
		}
		c.JSON(http.StatusInternalServerError, response.ErrorWithDetail("连接检测失败", err))
		return
	}

	c.JSON(http.StatusOK, response.SuccessWithMsg("连接可用", nil))
}