package db

import (
	"allapp-go/internal/middleware"
	"context"
	"fmt"
	"sort"
	"strings"
	"time"
)

// 构建 INSERT SQL（单条）
func buildInsertSQL(table string, data map[string]any) (string, []any) {
	var (
		columns      []string
		placeholders []string
		args         []any
	)

	i := 1
	for col, val := range data {
		columns = append(columns, col)
		placeholders = append(placeholders, fmt.Sprintf("$%d", i))
		args = append(args, val)
		i++
	}

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

	return sql, args
}

func (c *Client) Insert(
	ctx context.Context,
	table string,
	keyField string,
	data map[string]any,
) error {
	if _, err := validateData(table, keyField, data); err != nil {
		return err
	}

	if !auditExcludeTables[table] {
		now := time.Now()

		delete(data, "create_time")
		delete(data, "update_time")
		delete(data, "create_by")
		delete(data, "update_by")

		data["create_time"] = now
		data["update_time"] = now

		userID, flag := middleware.GetUserID(ctx)

		if flag {
			data["create_by"] = userID
			data["update_by"] = userID
		}
	}

	sql, args := buildInsertSQL(table, data)

	_, err := c.exec().Exec(ctx, sql, args...)
	return err
}

func (c *Client) BatchInsert(
	ctx context.Context,
	table string,
	keyField string,
	dataList []map[string]any,
) error {
	if len(dataList) == 0 {
		return fmt.Errorf("数据不能为空")
	}

	// 用第一条确定列顺序
	first := dataList[0]
	if _, err := validateData(table, keyField, first); err != nil {
		return err
	}

	var columns []string
	for col := range first {
		columns = append(columns, col)
	}

	sort.Strings(columns)

	var (
		valueStrings []string
		args         []any
		argIndex     = 1
	)

	for _, data := range dataList {
		// 统一校验
		if _, err := validateData(table, keyField, data); err != nil {
			return err
		}

		// 字段数量检查
		if len(data) != len(columns) {
			return fmt.Errorf("批量插入失败：数据字段不一致")
		}

		var placeholders []string

		for _, col := range columns {
			val, ok := data[col]
			if !ok {
				return fmt.Errorf("缺少字段: %s", col)
			}

			placeholders = append(placeholders, fmt.Sprintf("$%d", argIndex))
			args = append(args, val)
			argIndex++
		}

		valueStrings = append(
			valueStrings,
			fmt.Sprintf("(%s)", strings.Join(placeholders, ", ")),
		)
	}

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

	_, err := c.exec().Exec(ctx, sql, args...)
	return err
}