package config

import (
	"fmt"
	"time"
	"github.com/spf13/viper"
)

// Config 应用配置
type Config struct {
	App       AppConfig       `mapstructure:"app"`
	Database  DatabaseConfig  `mapstructure:"database"`
	Redis     RedisConfig     `mapstructure:"redis"`
	JWT       JWTConfig       `mapstructure:"jwt"`
	Storage   StorageConfig   `mapstructure:"storage"`
	Upload    UploadConfig    `mapstructure:"upload"`
	Logger    LoggerConfig    `mapstructure:"logger"`
	CORS      CORSConfig      `mapstructure:"cors"`
	RateLimit RateLimitConfig `mapstructure:"rate_limit"`
}

// AppConfig 应用配置
type AppConfig struct {
	Name        string `mapstructure:"name"`
	Version     string `mapstructure:"version"`
	Environment string `mapstructure:"environment"`
	Port        int    `mapstructure:"port"`
	Debug       bool   `mapstructure:"debug"`
}

// 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"`
	Database        string `mapstructure:"database"`
	SSLMode         string `mapstructure:"ssl_mode"`
	MaxOpenConns    int    `mapstructure:"max_open_conns"`
	MaxIdleConns    int    `mapstructure:"max_idle_conns"`
	ConnMaxLifetime int    `mapstructure:"conn_max_lifetime"`
}

// RedisConfig Redis配置
type RedisConfig struct {
	Host         string `mapstructure:"host"`
	Port         int    `mapstructure:"port"`
	Password     string `mapstructure:"password"`
	Database     int    `mapstructure:"database"`
	PoolSize     int    `mapstructure:"pool_size"`
	MinIdleConns int    `mapstructure:"min_idle_conns"`
}

// JWTConfig JWT配置
type JWTConfig struct {
	Secret           string `mapstructure:"secret"`
	ExpiresIn        string `mapstructure:"expires_in"`
	RefreshExpiresIn string `mapstructure:"refresh_expires_in"`
}

// StorageConfig 存储配置
type StorageConfig struct {
	Type  string      `mapstructure:"type"`
	Local LocalConfig `mapstructure:"local"`
	S3    S3Config    `mapstructure:"s3"`
}

// LocalConfig 本地存储配置
type LocalConfig struct {
	BasePath string `mapstructure:"base_path"`
	BaseURL  string `mapstructure:"base_url"`
}

// S3Config S3存储配置
type S3Config struct {
	Region    string `mapstructure:"region"`
	Bucket    string `mapstructure:"bucket"`
	AccessKey string `mapstructure:"access_key"`
	SecretKey string `mapstructure:"secret_key"`
	Endpoint  string `mapstructure:"endpoint"`
}

// UploadConfig 上传配置
type UploadConfig struct {
	MaxFileSize    int64           `mapstructure:"max_file_size"`
	AllowedTypes   []string        `mapstructure:"allowed_types"`
	ThumbnailSizes []ThumbnailSize `mapstructure:"thumbnail_sizes"`
}

// ThumbnailSize 缩略图尺寸
type ThumbnailSize struct {
	Name   string `mapstructure:"name"`
	Width  int    `mapstructure:"width"`
	Height int    `mapstructure:"height"`
}

// LoggerConfig 日志配置
type LoggerConfig struct {
	Level    string `mapstructure:"level"`
	Format   string `mapstructure:"format"`
	Output   string `mapstructure:"output"`
	Filename string `mapstructure:"filename"`
	MaxSize  int    `mapstructure:"max_size"`
	MaxAge   int    `mapstructure:"max_age"`
	Compress bool   `mapstructure:"compress"`
}

// CORSConfig CORS配置
type CORSConfig struct {
	AllowedOrigins   []string `mapstructure:"allowed_origins"`
	AllowedMethods   []string `mapstructure:"allowed_methods"`
	AllowedHeaders   []string `mapstructure:"allowed_headers"`
	AllowCredentials bool     `mapstructure:"allow_credentials"`
}

// RateLimitConfig 限流配置
type RateLimitConfig struct {
	Enabled           bool `mapstructure:"enabled"`
	RequestsPerMinute int  `mapstructure:"requests_per_minute"`
	Burst             int  `mapstructure:"burst"`
}

var AppConfig *Config

// LoadConfig 加载配置
func LoadConfig(configPath string) (*Config, error) {
	viper.SetConfigFile(configPath)
	viper.SetConfigType("yaml")
	
	// 设置环境变量前缀
	viper.SetEnvPrefix("PHOTOGRAPHY")
	viper.AutomaticEnv()
	
	// 环境变量替换配置
	viper.BindEnv("database.host", "DB_HOST")
	viper.BindEnv("database.port", "DB_PORT")
	viper.BindEnv("database.username", "DB_USER")
	viper.BindEnv("database.password", "DB_PASSWORD")
	viper.BindEnv("database.database", "DB_NAME")
	viper.BindEnv("redis.host", "REDIS_HOST")
	viper.BindEnv("redis.port", "REDIS_PORT")
	viper.BindEnv("redis.password", "REDIS_PASSWORD")
	viper.BindEnv("jwt.secret", "JWT_SECRET")
	viper.BindEnv("storage.s3.access_key", "AWS_ACCESS_KEY_ID")
	viper.BindEnv("storage.s3.secret_key", "AWS_SECRET_ACCESS_KEY")
	viper.BindEnv("app.port", "PORT")
	
	if err := viper.ReadInConfig(); err != nil {
		return nil, fmt.Errorf("failed to read config file: %w", err)
	}
	
	var config Config
	if err := viper.Unmarshal(&config); err != nil {
		return nil, fmt.Errorf("failed to unmarshal config: %w", err)
	}
	
	// 验证配置
	if err := validateConfig(&config); err != nil {
		return nil, fmt.Errorf("config validation failed: %w", err)
	}
	
	AppConfig = &config
	return &config, nil
}

// validateConfig 验证配置
func validateConfig(config *Config) error {
	if config.App.Name == "" {
		return fmt.Errorf("app name is required")
	}
	
	if config.Database.Host == "" {
		return fmt.Errorf("database host is required")
	}
	
	if config.JWT.Secret == "" {
		return fmt.Errorf("jwt secret is required")
	}
	
	return nil
}

// GetJWTExpiration 获取JWT过期时间
func (c *Config) GetJWTExpiration() time.Duration {
	duration, err := time.ParseDuration(c.JWT.ExpiresIn)
	if err != nil {
		return 24 * time.Hour // 默认24小时
	}
	return duration
}

// GetJWTRefreshExpiration 获取JWT刷新过期时间
func (c *Config) GetJWTRefreshExpiration() time.Duration {
	duration, err := time.ParseDuration(c.JWT.RefreshExpiresIn)
	if err != nil {
		return 7 * 24 * time.Hour // 默认7天
	}
	return duration
}

// GetDatabaseDSN 获取数据库DSN
func (c *Config) GetDatabaseDSN() string {
	return fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=%s",
		c.Database.Host,
		c.Database.Port,
		c.Database.Username,
		c.Database.Password,
		c.Database.Database,
		c.Database.SSLMode,
	)
}

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

// GetServerAddr 获取服务器地址
func (c *Config) GetServerAddr() string {
	return fmt.Sprintf(":%d", c.App.Port)
}

// IsDevelopment 是否为开发环境
func (c *Config) IsDevelopment() bool {
	return c.App.Environment == "development"
}

// IsProduction 是否为生产环境
func (c *Config) IsProduction() bool {
	return c.App.Environment == "production"
}