package db

import (
	"fmt"
	"strings"
)

// ---------------- 通用查询方法 ----------------

// GetOne 根据主键查询单条记录，返回 map[string]interface{}
func GetOne(table string, pkColumn string, pkValue interface{}) (map[string]interface{}, error) {
	query := fmt.Sprintf("SELECT * FROM %s WHERE %s=$1", table, pkColumn)

	row := make(map[string]interface{})
	err := DB.Get(&row, query, pkValue)
	if err != nil {
		return nil, err
	}
	return row, nil
}

// GetBatch 根据主键批量查询，返回 []map[string]interface{}
func GetBatch(table string, pkColumn string, pkValues []interface{}) ([]map[string]interface{}, error) {
	if len(pkValues) == 0 {
		return nil, nil
	}

	var rows []map[string]interface{}

	// 构建 IN 占位符
	placeholders := make([]string, len(pkValues))
	for i := range pkValues {
		placeholders[i] = fmt.Sprintf("$%d", i+1)
	}

	query := fmt.Sprintf("SELECT * FROM %s WHERE %s IN (%s)", table, pkColumn, strings.Join(placeholders, ","))
	err := DB.Select(&rows, query, pkValues...)
	if err != nil {
		return nil, err
	}

	return rows, nil
}

// Find 根据条件查询多条记录，可选排序
// conditions: map[column]value, 将以 AND 拼接
// orderBy: 可选排序字段，如 "created_at ASC"，为空默认 "b_id DESC"
func Find(table string, conditions map[string]interface{}, orderBy ...string) ([]map[string]interface{}, error) {
	if len(conditions) == 0 {
		return nil, fmt.Errorf("查询条件不能为空")
	}

	var whereParts []string
	var values []interface{}
	i := 1
	for k, v := range conditions {
		whereParts = append(whereParts, fmt.Sprintf("%s=$%d", k, i))
		values = append(values, v)
		i++
	}

	query := fmt.Sprintf("SELECT * FROM %s WHERE %s", table, strings.Join(whereParts, " AND "))

	order := "b_id DESC"
	if len(orderBy) > 0 && orderBy[0] != "" {
		order = orderBy[0]
	}
	query += " ORDER BY " + order

	var rows []map[string]interface{}
	err := DB.Select(&rows, query, values...)
	if err != nil {
		return nil, err
	}

	return rows, nil
}

// FindAll 查询整个表，可选排序
func FindAll(table string, orderBy ...string) ([]map[string]interface{}, error) {
	query := fmt.Sprintf("SELECT * FROM %s", table)

	order := "b_id DESC"
	if len(orderBy) > 0 && orderBy[0] != "" {
		order = orderBy[0]
	}
	query += " ORDER BY " + order

	var rows []map[string]interface{}
	err := DB.Select(&rows, query)
	if err != nil {
		return nil, err
	}

	return rows, nil
}