package dao

import (
	"database/sql"
	"fmt"

	"dd_fiber_api/internal/camp"
	"dd_fiber_api/pkg/database"

	"github.com/didi/gendry/builder"
)

// CategoryDAO 分类数据访问对象
type CategoryDAO struct {
	client *database.MySQLClient
}

// NewCategoryDAO 创建分类DAO实例
func NewCategoryDAO(client *database.MySQLClient) *CategoryDAO {
	return &CategoryDAO{
		client: client,
	}
}

// Create 创建分类
func (d *CategoryDAO) Create(category *camp.Category) error {
	table := "camp_categories"
	data := []map[string]any{
		{
			"id":         category.ID,
			"name":       category.Name,
			"sort_order": category.SortOrder,
		},
	}

	cond, vals, err := builder.BuildInsert(table, data)
	if err != nil {
		return fmt.Errorf("构建插入语句失败: %v", err)
	}

	_, err = d.client.DB.Exec(cond, vals...)
	if err != nil {
		return fmt.Errorf("创建分类失败: %v", err)
	}
	return nil
}

// GetByID 根据ID获取分类
func (d *CategoryDAO) GetByID(id string) (*camp.Category, error) {
	table := "camp_categories"
	where := map[string]any{
		"id": id,
	}
	selectFields := []string{"id", "name", "sort_order"}

	cond, vals, err := builder.BuildSelect(table, where, selectFields)
	if err != nil {
		return nil, fmt.Errorf("构建查询失败: %v", err)
	}

	var category camp.Category
	err = d.client.DB.QueryRow(cond, vals...).Scan(
		&category.ID,
		&category.Name,
		&category.SortOrder,
	)

	if err == sql.ErrNoRows {
		return nil, fmt.Errorf("分类不存在: %s", id)
	}
	if err != nil {
		return nil, fmt.Errorf("查询分类失败: %v", err)
	}

	return &category, nil
}

// Update 更新分类
func (d *CategoryDAO) Update(category *camp.Category) error {
	table := "camp_categories"
	where := map[string]any{
		"id": category.ID,
	}
	data := map[string]any{
		"name":       category.Name,
		"sort_order": category.SortOrder,
	}

	cond, vals, err := builder.BuildUpdate(table, where, data)
	if err != nil {
		return fmt.Errorf("构建更新语句失败: %v", err)
	}

	result, err := d.client.DB.Exec(cond, vals...)
	if err != nil {
		return fmt.Errorf("更新分类失败: %v", err)
	}

	rows, err := result.RowsAffected()
	if err != nil {
		return fmt.Errorf("获取影响行数失败: %v", err)
	}
	if rows == 0 {
		return fmt.Errorf("分类不存在: %s", category.ID)
	}

	return nil
}

// Delete 删除分类
func (d *CategoryDAO) Delete(id string) error {
	table := "camp_categories"
	where := map[string]any{
		"id": id,
	}

	cond, vals, err := builder.BuildDelete(table, where)
	if err != nil {
		return fmt.Errorf("构建删除语句失败: %v", err)
	}

	result, err := d.client.DB.Exec(cond, vals...)
	if err != nil {
		return fmt.Errorf("删除分类失败: %v", err)
	}

	rows, err := result.RowsAffected()
	if err != nil {
		return fmt.Errorf("获取影响行数失败: %v", err)
	}
	if rows == 0 {
		return fmt.Errorf("分类不存在: %s", id)
	}

	return nil
}

// List 列出分类（支持关键词搜索和分页）
func (d *CategoryDAO) List(keyword string, page, pageSize int) ([]*camp.Category, int, error) {
	table := "camp_categories"

	// 构建查询条件
	where := map[string]any{}

	if keyword != "" {
		// gendry 支持 LIKE 查询
		where["_or"] = []map[string]any{
			{"name like": "%" + keyword + "%"},
			{"id like": "%" + keyword + "%"},
		}
	}

	// 查询总数
	countFields := []string{"COUNT(*) as total"}
	countCond, countVals, err := builder.BuildSelect(table, where, countFields)
	if err != nil {
		return nil, 0, fmt.Errorf("构建统计查询失败: %v", err)
	}

	var total int
	err = d.client.DB.QueryRow(countCond, countVals...).Scan(&total)
	if err != nil {
		return nil, 0, fmt.Errorf("查询分类总数失败: %v", err)
	}

	// 查询数据
	selectFields := []string{"id", "name", "sort_order"}
	cond, vals, err := builder.BuildSelect(table, where, selectFields)
	if err != nil {
		return nil, 0, fmt.Errorf("构建查询失败: %v", err)
	}

	// 添加排序和分页
	offset := (page - 1) * pageSize
	cond += " ORDER BY sort_order DESC LIMIT ? OFFSET ?"
	vals = append(vals, pageSize, offset)

	rows, err := d.client.DB.Query(cond, vals...)
	if err != nil {
		return nil, 0, fmt.Errorf("查询分类列表失败: %v", err)
	}
	defer rows.Close()

	categories := make([]*camp.Category, 0)
	for rows.Next() {
		var category camp.Category

		err := rows.Scan(
			&category.ID,
			&category.Name,
			&category.SortOrder,
		)
		if err != nil {
			continue
		}

		categories = append(categories, &category)
	}

	if err = rows.Err(); err != nil {
		return nil, 0, fmt.Errorf("遍历分类数据失败: %v", err)
	}

	return categories, total, nil
}