package db

import (
	"fmt"
	"strings"

	"base-go-v2/internal/utils/mapx"
)

// ---------------- 内部辅助函数 ----------------

// buildInsertSQL 构建插入 SQL 和参数
func buildInsertSQL(table string, data mapx.M, returning string) (string, []interface{}) {
	columns := make([]string, 0, len(data))
	placeholders := make([]string, 0, len(data))
	values := make([]interface{}, 0, len(data))

	i := 1
	for k, v := range data {
		columns = append(columns, k)
		placeholders = append(placeholders, fmt.Sprintf("$%d", i))
		values = append(values, v)
		i++
	}

	sql := fmt.Sprintf("INSERT INTO %s (%s) VALUES (%s)", table,
		strings.Join(columns, ","), strings.Join(placeholders, ","))

	if returning != "" {
		sql += " RETURNING " + returning
	}

	return sql, values
}

// ---------------- 公共方法 ----------------

// InsertOne 插入单条记录，返回受影响行数
func InsertOne(table string, data mapx.M) (int64, error) {
	tx, err := DB.Beginx()
	if err != nil {
		return 0, err
	}

	sql, values := buildInsertSQL(table, data, "")
	res, err := tx.Exec(sql, values...)
	if err != nil {
		tx.Rollback()
		return 0, err
	}

	if err := tx.Commit(); err != nil {
		return 0, err
	}

	return res.RowsAffected()
}

// InsertBatch 批量插入，返回总受影响行数
func InsertBatch(table string, dataList []mapx.M) (int64, error) {
	if len(dataList) == 0 {
		return 0, nil
	}

	tx, err := DB.Beginx()
	if err != nil {
		return 0, err
	}

	total := int64(0)

	for _, data := range dataList {
		sql, values := buildInsertSQL(table, data, "")
		res, err := tx.Exec(sql, values...)
		if err != nil {
			tx.Rollback()
			return 0, err
		}
		rows, err := res.RowsAffected()
		if err != nil {
			tx.Rollback()
			return 0, err
		}
		total += rows
	}

	if err := tx.Commit(); err != nil {
		return 0, err
	}

	return total, nil
}

// InsertOneReturnPK 插入单条记录，返回主键值
func InsertOneReturnPK(table string, pkColumn string, data mapx.M) (int64, error) {
	tx, err := DB.Beginx()
	if err != nil {
		return 0, err
	}

	sql, values := buildInsertSQL(table, data, pkColumn)

	var pk int64
	err = tx.Get(&pk, sql, values...)
	if err != nil {
		tx.Rollback()
		return 0, err
	}

	if err := tx.Commit(); err != nil {
		return 0, err
	}

	return pk, nil
}

// InsertBatchReturnPK 批量插入多条记录，返回主键数组
func InsertBatchReturnPK(table string, pkColumn string, dataList []mapx.M) ([]int64, error) {
	if len(dataList) == 0 {
		return nil, nil
	}

	tx, err := DB.Beginx()
	if err != nil {
		return nil, err
	}

	var pkList []int64

	for _, data := range dataList {
		sql, values := buildInsertSQL(table, data, pkColumn)

		var pk int64
		err := tx.Get(&pk, sql, values...)
		if err != nil {
			tx.Rollback()
			return nil, err
		}

		pkList = append(pkList, pk)
	}

	if err := tx.Commit(); err != nil {
		return nil, err
	}

	return pkList, nil
}