package database

import (
	"context"
	"fmt"
	"time"

	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"

	"billai-server/config"
)

var (
	// Client MongoDB 客户端实例
	Client *mongo.Client
	// DB 数据库实例
	DB *mongo.Database
	// RawBillCollection 原始账单数据集合
	RawBillCollection *mongo.Collection
	// CleanedBillCollection 清洗后账单数据集合
	CleanedBillCollection *mongo.Collection
)

// Connect 连接 MongoDB
func Connect() error {
	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()

	// 创建客户端选项
	clientOptions := options.Client().ApplyURI(config.Global.MongoURI)

	// 连接 MongoDB
	client, err := mongo.Connect(ctx, clientOptions)
	if err != nil {
		return fmt.Errorf("连接 MongoDB 失败: %w", err)
	}

	// 测试连接
	if err := client.Ping(ctx, nil); err != nil {
		return fmt.Errorf("MongoDB Ping 失败: %w", err)
	}

	// 设置全局变量
	Client = client
	DB = client.Database(config.Global.MongoDatabase)
	RawBillCollection = DB.Collection(config.Global.MongoRawCollection)
	CleanedBillCollection = DB.Collection(config.Global.MongoCleanedCollection)

	fmt.Printf("🍃 MongoDB 连接成功: %s\n", config.Global.MongoDatabase)
	fmt.Printf("   📄 原始数据集合: %s\n", config.Global.MongoRawCollection)
	fmt.Printf("   📄 清洗数据集合: %s\n", config.Global.MongoCleanedCollection)
	return nil
}

// Disconnect 断开 MongoDB 连接
func Disconnect() error {
	if Client == nil {
		return nil
	}

	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()

	if err := Client.Disconnect(ctx); err != nil {
		return fmt.Errorf("断开 MongoDB 连接失败: %w", err)
	}

	fmt.Println("🍃 MongoDB 连接已断开")
	return nil
}