package mysql

import (
	"database/sql"
	"fmt"
	"mayfly-go/internal/db/dbm/dbi"
	"strings"
	"time"
)

type MysqlDialect struct {
	dbi.DefaultDialect

	dc *dbi.DbConn
}

// GetDbProgram 获取数据库程序模块，用于数据库备份与恢复
func (md *MysqlDialect) GetDbProgram() (dbi.DbProgram, error) {
	return NewDbProgramMysql(md.dc), nil
}

func (md *MysqlDialect) BatchInsert(tx *sql.Tx, tableName string, columns []string, values [][]any, duplicateStrategy int) (int64, error) {
	// 生成占位符字符串：如：(?,?)
	// 重复字符串并用逗号连接
	repeated := strings.Repeat("?,", len(columns))
	// 去除最后一个逗号，占位符由括号包裹
	placeholder := fmt.Sprintf("(%s)", strings.TrimSuffix(repeated, ","))

	// 执行批量insert sql，mysql支持批量insert语法
	// insert into table_name (column1, column2, ...) values (value1, value2, ...), (value1, value2, ...), ...

	// 重复占位符字符串n遍
	repeated = strings.Repeat(placeholder+",", len(values))
	// 去除最后一个逗号
	placeholder = strings.TrimSuffix(repeated, ",")

	prefix := "insert into"
	if duplicateStrategy == 1 {
		prefix = "insert ignore into"
	} else if duplicateStrategy == 2 {
		prefix = "replace into"
	}

	sqlStr := fmt.Sprintf("%s %s (%s) values %s", prefix, md.dc.GetMetaData().QuoteIdentifier(tableName), strings.Join(columns, ","), placeholder)
	// 执行批量insert sql
	// 把二维数组转为一维数组
	var args []any
	for _, v := range values {
		args = append(args, v...)
	}
	return md.dc.TxExec(tx, sqlStr, args...)
}

func (md *MysqlDialect) CopyTable(copy *dbi.DbCopyTable) error {
	tableName := copy.TableName

	// 生成新表名,为老表明+_copy_时间戳
	newTableName := tableName + "_copy_" + time.Now().Format("20060102150405")

	// 复制表结构创建表
	_, err := md.dc.Exec(fmt.Sprintf("create table %s like %s", newTableName, tableName))
	if err != nil {
		return err
	}

	// 复制数据
	if copy.CopyData {
		go func() {
			_, _ = md.dc.Exec(fmt.Sprintf("insert into %s select * from %s", newTableName, tableName))
		}()
	}
	return err
}

func (md *MysqlDialect) CreateTable(columns []dbi.Column, tableInfo dbi.Table, dropOldTable bool) (int, error) {
	sqlArr := md.dc.GetMetaData().GenerateTableDDL(columns, tableInfo, dropOldTable)
	for _, sqlStr := range sqlArr {
		_, err := md.dc.Exec(sqlStr)
		if err != nil {
			return 0, err
		}
	}
	return len(sqlArr), nil
}

func (md *MysqlDialect) CreateIndex(tableInfo dbi.Table, indexs []dbi.Index) error {
	meta := md.dc.GetMetaData()
	sqlArr := meta.GenerateIndexDDL(indexs, tableInfo)
	for _, sqlStr := range sqlArr {
		_, err := md.dc.Exec(sqlStr)
		if err != nil {
			return err
		}
	}
	return nil
}