/**
 * DB transaction
 */
package dbquery

import (
	"database/sql"
	"errors"
	"log"
	"strings"
	"time"
)

/**
 * 创建数据
 */
func TxInsert(tx *sql.Tx, dbname, table string, data map[string]string) (int64, error) {

	var insertId int64
	var err error
	if dbname == "" && table == "" {
		return 0, errors.New("参数错误，没有数据表")
	}
	dbName := ""
	if strings.Contains(table, "select ") {
		dbName = table
	} else {
		dbName = getTableName(dbname, table)
	}
	if len(data) < 1 {
		return 0, errors.New("参数错误，没有要写入的数据")
	}

	keyList := make([]string, len(data))
	keyStr := make([]string, len(data))
	valueList := make([]interface{}, len(data))

	var i int = 0

	for key, value := range data {
		keyList[i] = key
		keyStr[i] = "?"
		valueList[i] = value
		i++
	}

	result, err := tx.Exec("insert into "+dbName+" ("+strings.Join(keyList, ",")+") value("+strings.Join(keyStr, ",")+")", valueList...)

	if err != nil {
		log.Println("ERROR", "insert into ", dbName, "error:", err)
		return insertId, err
	} else {
		insertId, _ = result.LastInsertId()
		time.Sleep(time.Second * 2)
		return insertId, nil
	}

}

/**
 * 准备写入
 * return Stmt error
 */
func TxPreInsert(tx *sql.Tx, dbname, table string, data map[string]interface{}) (int64, error) {

	if dbname == "" && table == "" {
		return 0, errors.New("params error,no db or table")
	}

	dbName := ""
	if strings.Contains(table, "select ") {
		dbName = table
	} else {
		dbName = getTableName(dbname, table)
	}

	if len(data) < 1 {
		return 0, errors.New("params error,no data to insert")
	}

	var err error

	var stmt *sql.Stmt

	var field []string = make([]string, len(data))
	var valuelist []interface{} = make([]interface{}, len(data))

	var i int = 0
	for key, item := range data {
		field[i] = key + "=?"
		valuelist[i] = item
		i++
	}

	sql := "insert into " + dbName + " set " + strings.Join(field, " , ")
	stmt, err = tx.Prepare(sql)

	if err != nil {
		log.Println("insert prepare error:", sql, err)
		return 0, errors.New("insert prepare error：" + err.Error())
	}
	result, err := stmt.Exec(valuelist...)
	if err != nil {
		log.Println("insert exec error：", sql, valuelist, err)
		return 0, errors.New("insert exec error：" + err.Error())
	}
	insertId, _ := result.LastInsertId()
	return insertId, nil

}

/**
 * 修改数据
 */
func TxUpdate(tx *sql.Tx, dbname, table string, data map[string]string, where map[string]string) (int64, error) {
	var rowsAffected int64
	var err error
	if dbname == "" && table == "" {
		return rowsAffected, errors.New("参数错误，没有数据表")
	}
	dbName := ""
	if strings.Contains(table, "select ") {
		dbName = table
	} else {
		dbName = getTableName(dbname, table)
	}
	if len(data) < 1 {
		return rowsAffected, errors.New("参数错误，没有要写入的数据")
	}
	if len(where) < 1 {
		return rowsAffected, errors.New("参数错误，没有修改条件")
	}

	keyList := make([]string, len(data))
	valueList := make([]interface{}, len(data), len(data)+len(where))

	whereStr := make([]string, len(where))

	var i int = 0

	empty := false

	for key, value := range data {
		keyList[i] = key + "=?"
		valueList[i] = value
		i++
	}
	i = 0
	for key, value := range where {
		if value == "" {
			empty = true
			break
		}
		whereStr[i] = key + "=?"
		valueList = append(valueList, value)
		i++
	}

	if empty {
		log.Println("ERROR", "update", dbName, "error, params empty")
		return rowsAffected, errors.New("params empty")
	}
	result, err := tx.Exec("update "+dbName+" set "+strings.Join(keyList, " , ")+" where "+strings.Join(whereStr, " and "), valueList...)

	if err != nil {
		log.Println("ERROR", "update", dbName, "error:", err)
		return rowsAffected, err
	} else {
		rowsAffected, _ = result.RowsAffected()
		return rowsAffected, nil
	}

}

/**
 * 准备更新
 * return Stmt error
 */
func TxPreUpdate(tx *sql.Tx, dbname, table string, data []string, where []string, valuelist []interface{}) (int64, error) {

	if dbname == "" && table == "" {
		return 0, errors.New("params error,no db or table")
	}

	dbName := ""
	if strings.Contains(table, "select ") {
		dbName = table
	} else {
		dbName = getTableName(dbname, table)
	}

	if len(where) < 1 {
		return 0, errors.New("params error, no data for update")
	}

	var err error

	var stmt *sql.Stmt

	sql := "update " + dbName + " set " + strings.Join(data, " , ") + " where " + strings.Join(where, " and ")

	stmt, err = tx.Prepare(sql)

	if err != nil {
		log.Println("update prepare error:", sql, err)
		return 0, errors.New("update prepare error：" + err.Error())
	}
	res, err := stmt.Exec(valuelist...)
	if err != nil {
		log.Println("update exec error：", sql, valuelist, err)
		return 0, errors.New("update exec error:" + err.Error())
	}

	return res.RowsAffected()
}

/**
 * 删除数据
 * @param count 删除数量
 */
func TxDelete(tx *sql.Tx, dbname, table string, where map[string]string, del_count ...string) (int64, error) {
	var count int64
	var err error
	if dbname == "" && table == "" {
		return count, errors.New("参数错误，没有数据表")
	}
	dbName := ""
	if strings.Contains(table, "select ") {
		dbName = table
	} else {
		dbName = getTableName(dbname, table)
	}
	if len(where) < 1 {
		return count, errors.New("参数错误，没有删除条件")
	}
	keyList := make([]string, len(where))
	valueList := make([]interface{}, len(where))

	var i int = 0

	empty := false
	for key, value := range where {
		if value == "" {
			empty = true
			break
		}
		keyList[i] = key + "=?"
		valueList[i] = value
		i++
	}

	if empty {
		log.Println("ERROR", "delete from", dbName, "error, where：", where)
		return count, errors.New("params empty")
	}

	var limitStr string = ""

	if len(del_count) > 0 {
		limitStr = " limit " + del_count[0]

	}
	result, err := tx.Exec("delete from "+dbName+" where "+strings.Join(keyList, " and ")+limitStr, valueList...)

	if err != nil {
		log.Println("ERROR", "delete from", dbName, "error:", err)
		return count, err
	} else {
		count, _ = result.RowsAffected()
		return count, nil
	}

}

/**
 * 准备查询
 * return Stmt error
 */
func TxForRead(tx *sql.Tx, dbName, table string, title string, where []string) (*sql.Stmt, error) {

	if dbName == "" && table == "" {
		return nil, errors.New("参数错误，没有数据表")
	}
	if strings.Contains(table, "select ") {
		dbName = table
	} else {
		dbName = getTableName(dbName, table)
	}

	if len(title) < 1 {
		return nil, errors.New("没有要查询内容")
	}

	var stmt *sql.Stmt
	var err error

	if len(where) > 0 {
		// log.Println("SELECT " + title + " FROM " + dbName + " where " + strings.Join(where, " and ") + " FOR UPDATE")
		stmt, err = tx.Prepare("SELECT " + title + " FROM " + dbName + " where " + strings.Join(where, " and ") + " FOR UPDATE")
	} else {
		// log.Println("SELECT " + title + " FROM " + dbName + " FOR UPDATE")
		stmt, err = tx.Prepare("SELECT " + title + " FROM " + dbName + " FOR UPDATE")
	}

	return stmt, err
}

/**
 * 使用db prepare方式查询单条数据
 * @param dbName
 * @param title 查询的字段名
 * @param where 查询条件
 * @param valuelist 查询的条件值
 * @param limit 查询排序
 * GZ
 * 2020/05/19
 */
func TxGetData(tx *sql.Tx, dbName string, table string, title string, where []string, valuelist []interface{}) (map[string]string, error) {

	stmt, err := TxForRead(tx, dbName, table, title, where)

	if err != nil {
		return nil, err
	}
	defer stmt.Close()

	return StmtForQueryRow(stmt, valuelist)
}