package xugu

import (
	"errors"
	"fmt"
	"strings"
)

// cgo_xgc_sql_type -> fun_sql_type
// 判断sql类型
func xgSqlType(sql string) int {
	// 去掉首尾的空格、换行符和回车符
	sql = strings.TrimSpace(sql)
	if len(sql) < 6 {
		return SQL_OTHER
	}

	// 取前6个字符并转为大写
	kstr := strings.ToUpper(sql[:6])

	// 根据SQL语句前缀判断类型
	switch {
	case strings.HasPrefix(kstr, "SELECT"):
		if strings.Contains(sql, ";") && len(sql[strings.Index(sql, ";"):]) > 5 {
			return SQL_OTHER // 多结果集
		}
		return SQL_SELECT
	case strings.HasPrefix(kstr, "INSERT"):
		return SQL_INSERT
	case strings.HasPrefix(kstr, "UPDATE"):
		return SQL_UPDATE
	case strings.HasPrefix(kstr, "DELETE"):
		return SQL_DELETE
	case strings.HasPrefix(kstr, "CREATE"):
		return SQL_CREATE
	case strings.HasPrefix(kstr, "ALTER "):
		return SQL_ALTER
	case strings.HasPrefix(kstr, "EXEC "):
		return SQL_PROCEDURE
	case strings.HasPrefix(kstr, "EXECUT"):
		return SQL_PROCEDURE
	case strings.HasPrefix(kstr, "STC"):
		return SQL_SELECT
	default:
		return SQL_OTHER
	}
}

func xgSockPrepare(conn *xugusqlConn, sql string) (int, error) {
	ret := 0

	//p_params := &conn.params
	if conn.havePrepare != 0 {
		ret = xgCmdUnprepare(conn, conn.prepareName)
		if ret < 0 {
			return ret, nil
		}
		conn.prepareName = ""
	}

	conn.prepareName = fmt.Sprintf(conn.prepareName+"STC%d", conn.prepareNo)
	ret, err := xgCmdPrepare(conn, sql, &conn.prepareName)
	if err != nil {
		return ret, err
	}
	return ret, err
}

// SQL语句prepare准备执行
func xgSockPrepare2(conn *xugusqlConn, cmd_sql string, prepareName *string) (int, error) {

	if "" == *prepareName {
		return xgSockPrepare(conn, cmd_sql)
	}

	ret := 0
	pconn := conn
	//	XGCSParam* p_params= pconn->params;
	old_p := pconn.havePrepare
	//	char* sql=strdup(cmd_sql);

	*prepareName = fmt.Sprintf("STC%d", pconn.prepareNo)
	pconn.prepareNo++ // 递增 prepare_no 的值

	ret, err := xgCmdPrepare(conn, cmd_sql, &conn.prepareName)
	if err != nil {
		return 0, err
	}
	pconn.havePrepare = old_p // this keeped by prepare_name

	return ret, nil
}

func xgCmdUnprepare(pconn *xugusqlConn, prepareName string) int {
	var ch byte
	var err error
	ret := XG_OK

	sql := fmt.Sprintf("DEALLOCATE %s ", prepareName)
	pconn.mu.Lock()
	sockSendCommand0(pconn, sql)
	boolRet, err := rhRecvChar(pconn, &ch)
	if boolRet || err != nil {
		ret = XG_NET_ERROR
	} else if ch == 'K' {
		pconn.havePrepare = 0
	} else {
		pconn.havePrepare = 0
		var errStre []byte
		ret, err = rhRecvStr(pconn, &errStre)
		if err != nil || ret < 0 {
			pconn.mu.Unlock()
			return ret
		}

		rhRecvChar(pconn, &ch)
		ret = XG_ERROR
	}
	pconn.mu.Unlock()
	return 0
}

func xgCmdPrepare(pconn *xugusqlConn, cmd_sql string, prepareName *string) (int, error) {

	sqlRet := fmt.Sprintf("PREPARE %s AS %s", prepareName, cmd_sql)
	//上锁
	//lockConnect(pconn)
	pconn.mu.Lock()
	sockSendCommand0(pconn, sqlRet)
	var ch byte
	var ret int
	for {
		recvRet, err := rhRecvChar(pconn, &ch)
		if err != nil {
			return 0, err
		}
		if !recvRet {
			pconn.mu.Unlock()
			return -4, errors.New("XG_NET_ERROR")
		}
		//A: SelectResult A在协议里为select返回
		if ch == 'A' {
			pres := Result{}
			pres.Type = HT_RS
			ret, err = recvFiledsInfo(pconn, &pres)
			if err != nil {
				return ret, err
			}
			pconn.presPrepareCata = &pres
			ret = RETURN_PREPARE_SELECT
			continue
		} else if ch == '$' {
			var params XGCSParam
			params.Type = HT_PARAMS
			params.ImpExpType = 2
			recvParamsInfo2(pconn, &params)
			pconn.params = &params
			continue
		} else if ch == 'K' {
			pconn.havePrepare = 1
		} else {
			var errStr []byte
			ret, err = rhRecvStr(pconn, &errStr)
			if ret < 0 || err != nil {
				pconn.mu.Unlock()
				return ret, err
			}
			pconn.errStr = errStr
			ret = XG_ERROR
			rhRecvChar(pconn, &ch)
			if ch != 'K' {
				pconn.bkChar = ch
				continue
			}
		}
		break
	}
	pconn.mu.Unlock()
	return ret, nil
}