package config

import (
	"context"
	"fmt"
	"os"
	"time"

	"github.com/redis/go-redis/v9"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"
)

// Config 应用配置
type Config struct {
	DB    *gorm.DB
	Redis *redis.Client
}

// New 创建配置实例
func New() *Config {
	return &Config{}
}

// InitDB 初始化数据库连接
func (c *Config) InitDB() error {
	dsn := fmt.Sprintf("host=%s user=%s password=%s dbname=%s port=%s sslmode=%s",
		getEnv("DB_HOST", "localhost"),
		getEnv("DB_USER", "postgres"),
		getEnv("DB_PASSWORD", "postgres"),
		getEnv("DB_NAME", "appdb"),
		getEnv("DB_PORT", "5432"),
		getEnv("DB_SSL_MODE", "disable"),
	)

	// 配置 GORM
	config := &gorm.Config{
		Logger: logger.Default.LogMode(logger.Info),
	}

	if os.Getenv("APP_ENV") == "production" {
		config.Logger = logger.Default.LogMode(logger.Silent)
	}

	db, err := gorm.Open(postgres.Open(dsn), config)
	if err != nil {
		return fmt.Errorf("failed to connect to database: %w", err)
	}

	// 获取底层的 sqlDB
	sqlDB, err := db.DB()
	if err != nil {
		return fmt.Errorf("failed to get sqlDB: %w", err)
	}

	// 设置连接池
	sqlDB.SetMaxIdleConns(10)
	sqlDB.SetMaxOpenConns(100)
	sqlDB.SetConnMaxLifetime(time.Hour)

	c.DB = db
	return nil
}

// CloseDB 关闭数据库连接
func (c *Config) CloseDB() error {
	if c.DB != nil {
		sqlDB, err := c.DB.DB()
		if err != nil {
			return err
		}
		return sqlDB.Close()
	}
	return nil
}

// InitRedis 初始化 Redis 连接
func (c *Config) InitRedis() error {
	opt := &redis.Options{
		Addr: fmt.Sprintf("%s:%s",
			getEnv("REDIS_HOST", "localhost"),
			getEnv("REDIS_PORT", "6379"),
		),
		Password: getEnv("REDIS_PASSWORD", ""),
		DB:       0,
	}

	client := redis.NewClient(opt)

	// 测试连接
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	if err := client.Ping(ctx).Err(); err != nil {
		return fmt.Errorf("failed to connect to redis: %w", err)
	}

	c.Redis = client
	return nil
}

// CloseRedis 关闭 Redis 连接
func (c *Config) CloseRedis() error {
	if c.Redis != nil {
		return c.Redis.Close()
	}
	return nil
}

// getEnv 获取环境变量，如果不存在则返回默认值
func getEnv(key, defaultValue string) string {
	if value := os.Getenv(key); value != "" {
		return value
	}
	return defaultValue
}