package config

import (
	"fmt"
	"log"
	"os"

	"github.com/spf13/viper"
)

// Config 应用配置结构
type Config struct {
	Server    ServerConfig    `mapstructure:"server"`
	Database  DatabaseConfig  `mapstructure:"database"`
	Redis     RedisConfig     `mapstructure:"redis"`
	JWT       JWTConfig       `mapstructure:"jwt"`
	RateLimit RateLimitConfig `mapstructure:"rateLimit"`
	CORS      CORSConfig      `mapstructure:"cors"`
	Log       LogConfig       `mapstructure:"log"`
}

// ServerConfig 服务器配置
type ServerConfig struct {
	Port string `mapstructure:"port"`
	Mode string `mapstructure:"mode"`
}

// DatabaseConfig 数据库配置
type DatabaseConfig struct {
	Host         string `mapstructure:"host"`
	Port         int    `mapstructure:"port"`
	Username     string `mapstructure:"username"`
	Password     string `mapstructure:"password"`
	DBName       string `mapstructure:"dbname"`
	Charset      string `mapstructure:"charset"`
	ParseTime    bool   `mapstructure:"parseTime"`
	Loc          string `mapstructure:"loc"`
	MaxIdleConns int    `mapstructure:"maxIdleConns"`
	MaxOpenConns int    `mapstructure:"maxOpenConns"`
}

// RedisConfig Redis配置
type RedisConfig struct {
	Host     string `mapstructure:"host"`
	Port     int    `mapstructure:"port"`
	Password string `mapstructure:"password"`
	DB       int    `mapstructure:"db"`
	PoolSize int    `mapstructure:"poolSize"`
}

// JWTConfig JWT配置
type JWTConfig struct {
	Secret      string `mapstructure:"secret"`
	ExpireHours int    `mapstructure:"expireHours"`
}

// RateLimitConfig 频率限制配置
type RateLimitConfig struct {
	Enabled  bool `mapstructure:"enabled"`
	Requests int  `mapstructure:"requests"`
	Window   int  `mapstructure:"window"`
}

// CORSConfig CORS配置
type CORSConfig struct {
	AllowOrigins []string `mapstructure:"allowOrigins"`
	AllowMethods []string `mapstructure:"allowMethods"`
	AllowHeaders []string `mapstructure:"allowHeaders"`
}

// LogConfig 日志配置
type LogConfig struct {
	Level  string `mapstructure:"level"`
	Format string `mapstructure:"format"`
	Output string `mapstructure:"output"`
}

var AppConfig *Config

// LoadConfig 加载配置文件
func LoadConfig(env string) (*Config, error) {
	if env == "" {
		env = "dev"
	}

	viper.SetConfigName(env)
	viper.SetConfigType("yaml")
	viper.AddConfigPath("./config")
	viper.AddConfigPath("../config")
	viper.AddConfigPath("../../config")

	// 设置环境变量前缀
	viper.SetEnvPrefix("YINLI")
	viper.AutomaticEnv()

	if err := viper.ReadInConfig(); err != nil {
		return nil, fmt.Errorf("读取配置文件失败: %w", err)
	}

	var config Config
	if err := viper.Unmarshal(&config); err != nil {
		return nil, fmt.Errorf("解析配置文件失败: %w", err)
	}

	AppConfig = &config
	log.Printf("已加载配置文件: %s", viper.ConfigFileUsed())
	return &config, 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
}

// GetDSN 获取数据库连接字符串
func (c *Config) GetDSN() string {
	return fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?charset=%s&parseTime=%t&loc=%s",
		c.Database.Username,
		c.Database.Password,
		c.Database.Host,
		c.Database.Port,
		c.Database.DBName,
		c.Database.Charset,
		c.Database.ParseTime,
		c.Database.Loc,
	)
}

// GetRedisAddr 获取Redis连接地址
func (c *Config) GetRedisAddr() string {
	return fmt.Sprintf("%s:%d", c.Redis.Host, c.Redis.Port)
}