package config

import (
	"fmt"
	"os"
	"strconv"
	"strings"
	"time"

	"github.com/joho/godotenv"
	"github.com/spf13/viper"
)

// Config 应用配置结构体
type Config struct {
	Environment string         `mapstructure:"environment"`
	Site        SiteConfig     `mapstructure:"site"`
	Server      ServerConfig   `mapstructure:"server"`
	Database    DatabaseConfig `mapstructure:"database"`
	Redis       RedisConfig    `mapstructure:"redis"`
	RustFS      RustFSConfig   `mapstructure:"rustfs"`
	JWT         JWTConfig      `mapstructure:"jwt"`
	Casbin      CasbinConfig   `mapstructure:"casbin"`
	Log         LogConfig      `mapstructure:"log"`
	Email       EmailConfig    `mapstructure:"email"`
	Security    SecurityConfig `mapstructure:"security"`
}

// SiteConfig 站点配置
type SiteConfig struct {
	Name                  string `mapstructure:"name"`
	Description           string `mapstructure:"description"`
	RegistrationEnabled   bool   `mapstructure:"registration_enabled"`
	DefaultAvatar         string `mapstructure:"default_avatar"`
	MaxTexturesPerUser    int    `mapstructure:"max_textures_per_user"`
	MaxProfilesPerUser    int    `mapstructure:"max_profiles_per_user"`
	CheckinReward         int    `mapstructure:"checkin_reward"`
	TextureDownloadReward int    `mapstructure:"texture_download_reward"`
}

// ServerConfig 服务器配置
type ServerConfig struct {
	Port         string        `mapstructure:"port"`
	Mode         string        `mapstructure:"mode"`
	ReadTimeout  time.Duration `mapstructure:"read_timeout"`
	WriteTimeout time.Duration `mapstructure:"write_timeout"`
}

// DatabaseConfig 数据库配置
type DatabaseConfig struct {
	Driver          string        `mapstructure:"driver"`
	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"`
	Timezone        string        `mapstructure:"timezone"`
	MaxIdleConns    int           `mapstructure:"max_idle_conns"`
	MaxOpenConns    int           `mapstructure:"max_open_conns"`
	ConnMaxLifetime time.Duration `mapstructure:"conn_max_lifetime"`
	ConnMaxIdleTime time.Duration `mapstructure:"conn_max_idle_time"` // 连接最大空闲时间
}

// 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"`          // 连接池大小
	MinIdleConns    int           `mapstructure:"min_idle_conns"`     // 最小空闲连接数
	MaxRetries      int           `mapstructure:"max_retries"`        // 最大重试次数
	DialTimeout     time.Duration `mapstructure:"dial_timeout"`       // 连接超时
	ReadTimeout     time.Duration `mapstructure:"read_timeout"`       // 读取超时
	WriteTimeout    time.Duration `mapstructure:"write_timeout"`      // 写入超时
	PoolTimeout     time.Duration `mapstructure:"pool_timeout"`       // 连接池超时
	ConnMaxIdleTime time.Duration `mapstructure:"conn_max_idle_time"` // 连接最大空闲时间
}

// RustFSConfig RustFS对象存储配置 (S3兼容)
type RustFSConfig struct {
	Endpoint  string            `mapstructure:"endpoint"`
	PublicURL string            `mapstructure:"public_url"` // 公开访问URL (用于生成文件访问链接)
	AccessKey string            `mapstructure:"access_key"`
	SecretKey string            `mapstructure:"secret_key"`
	UseSSL    bool              `mapstructure:"use_ssl"`
	Buckets   map[string]string `mapstructure:"buckets"`
}

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

// CasbinConfig Casbin权限配置
type CasbinConfig struct {
	ModelPath     string `mapstructure:"model_path"`
	PolicyAdapter string `mapstructure:"policy_adapter"`
}

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

// EmailConfig 邮件配置
type EmailConfig struct {
	Enabled  bool   `mapstructure:"enabled"`
	SMTPHost string `mapstructure:"smtp_host"`
	SMTPPort int    `mapstructure:"smtp_port"`
	Username string `mapstructure:"username"`
	Password string `mapstructure:"password"`
	FromName string `mapstructure:"from_name"`
}

// SecurityConfig 安全配置
type SecurityConfig struct {
	AllowedOrigins []string `mapstructure:"allowed_origins"` // 允许的CORS来源
	AllowedDomains []string `mapstructure:"allowed_domains"` // 允许的头像/材质URL域名
}

// Load 加载配置 - 完全从环境变量加载，不依赖YAML文件
func Load() (*Config, error) {
	// 加载.env文件（如果存在）
	_ = godotenv.Load(".env")

	// 设置默认值
	setDefaults()

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

	// 手动设置环境变量映射
	setupEnvMappings()

	// 直接从环境变量解析配置
	var config Config
	if err := viper.Unmarshal(&config); err != nil {
		return nil, fmt.Errorf("解析配置失败: %w", err)
	}

	// 从环境变量中覆盖配置
	overrideFromEnv(&config)

	return &config, nil
}

// setDefaults 设置默认配置值
func setDefaults() {
	// 服务器默认配置
	viper.SetDefault("server.port", ":8080")
	viper.SetDefault("server.mode", "debug")
	viper.SetDefault("server.read_timeout", "30s")
	viper.SetDefault("server.write_timeout", "30s")

	// 数据库默认配置
	viper.SetDefault("database.driver", "postgres")
	viper.SetDefault("database.host", "localhost")
	viper.SetDefault("database.port", 5432)
	viper.SetDefault("database.ssl_mode", "disable")
	viper.SetDefault("database.timezone", "Asia/Shanghai")
	viper.SetDefault("database.max_idle_conns", 10)
	viper.SetDefault("database.max_open_conns", 100)
	viper.SetDefault("database.conn_max_lifetime", "1h")
	viper.SetDefault("database.conn_max_idle_time", "10m")

	// Redis默认配置
	viper.SetDefault("redis.host", "localhost")
	viper.SetDefault("redis.port", 6379)
	viper.SetDefault("redis.database", 0)
	viper.SetDefault("redis.pool_size", 10)
	viper.SetDefault("redis.min_idle_conns", 5)
	viper.SetDefault("redis.max_retries", 3)
	viper.SetDefault("redis.dial_timeout", "5s")
	viper.SetDefault("redis.read_timeout", "3s")
	viper.SetDefault("redis.write_timeout", "3s")
	viper.SetDefault("redis.pool_timeout", "4s")
	viper.SetDefault("redis.conn_max_idle_time", "30m")

	// RustFS默认配置
	viper.SetDefault("rustfs.endpoint", "127.0.0.1:9000")
	viper.SetDefault("rustfs.public_url", "") // 为空时使用 endpoint 构建 URL
	viper.SetDefault("rustfs.use_ssl", false)

	// JWT默认配置
	viper.SetDefault("jwt.expire_hours", 168)

	// Casbin默认配置
	viper.SetDefault("casbin.model_path", "configs/casbin/rbac_model.conf")
	viper.SetDefault("casbin.policy_adapter", "gorm")

	// 日志默认配置
	viper.SetDefault("log.level", "info")
	viper.SetDefault("log.format", "json")
	viper.SetDefault("log.output", "logs/app.log")
	viper.SetDefault("log.max_size", 100)
	viper.SetDefault("log.max_backups", 3)
	viper.SetDefault("log.max_age", 28)
	viper.SetDefault("log.compress", true)

	// 邮件默认配置
	viper.SetDefault("email.enabled", false)
	viper.SetDefault("email.smtp_port", 587)

	// 安全默认配置
	viper.SetDefault("security.allowed_origins", []string{"*"})
	viper.SetDefault("security.allowed_domains", []string{"localhost", "127.0.0.1"})

	// 站点默认配置
	viper.SetDefault("site.name", "CarrotSkin")
	viper.SetDefault("site.description", "一个优秀的Minecraft皮肤站")
	viper.SetDefault("site.registration_enabled", true)
	viper.SetDefault("site.default_avatar", "")
	viper.SetDefault("site.max_textures_per_user", 50)
	viper.SetDefault("site.max_profiles_per_user", 5)
	viper.SetDefault("site.checkin_reward", 10)
	viper.SetDefault("site.texture_download_reward", 1)
}

// setupEnvMappings 设置环境变量映射
func setupEnvMappings() {
	// 服务器配置
	viper.BindEnv("server.port", "SERVER_PORT")
	viper.BindEnv("server.mode", "SERVER_MODE")
	viper.BindEnv("server.read_timeout", "SERVER_READ_TIMEOUT")
	viper.BindEnv("server.write_timeout", "SERVER_WRITE_TIMEOUT")

	// 数据库配置
	viper.BindEnv("database.driver", "DATABASE_DRIVER")
	viper.BindEnv("database.host", "DATABASE_HOST")
	viper.BindEnv("database.port", "DATABASE_PORT")
	viper.BindEnv("database.username", "DATABASE_USERNAME")
	viper.BindEnv("database.password", "DATABASE_PASSWORD")
	viper.BindEnv("database.database", "DATABASE_NAME")
	viper.BindEnv("database.ssl_mode", "DATABASE_SSL_MODE")
	viper.BindEnv("database.timezone", "DATABASE_TIMEZONE")
	viper.BindEnv("database.max_idle_conns", "DATABASE_MAX_IDLE_CONNS")
	viper.BindEnv("database.max_open_conns", "DATABASE_MAX_OPEN_CONNS")
	viper.BindEnv("database.conn_max_lifetime", "DATABASE_CONN_MAX_LIFETIME")
	viper.BindEnv("database.conn_max_idle_time", "DATABASE_CONN_MAX_IDLE_TIME")

	// Redis配置
	viper.BindEnv("redis.host", "REDIS_HOST")
	viper.BindEnv("redis.port", "REDIS_PORT")
	viper.BindEnv("redis.password", "REDIS_PASSWORD")
	viper.BindEnv("redis.database", "REDIS_DATABASE")
	viper.BindEnv("redis.pool_size", "REDIS_POOL_SIZE")
	viper.BindEnv("redis.min_idle_conns", "REDIS_MIN_IDLE_CONNS")
	viper.BindEnv("redis.max_retries", "REDIS_MAX_RETRIES")
	viper.BindEnv("redis.dial_timeout", "REDIS_DIAL_TIMEOUT")
	viper.BindEnv("redis.read_timeout", "REDIS_READ_TIMEOUT")
	viper.BindEnv("redis.write_timeout", "REDIS_WRITE_TIMEOUT")
	viper.BindEnv("redis.pool_timeout", "REDIS_POOL_TIMEOUT")
	viper.BindEnv("redis.conn_max_idle_time", "REDIS_CONN_MAX_IDLE_TIME")

	// RustFS配置
	viper.BindEnv("rustfs.endpoint", "RUSTFS_ENDPOINT")
	viper.BindEnv("rustfs.public_url", "RUSTFS_PUBLIC_URL")
	viper.BindEnv("rustfs.access_key", "RUSTFS_ACCESS_KEY")
	viper.BindEnv("rustfs.secret_key", "RUSTFS_SECRET_KEY")
	viper.BindEnv("rustfs.use_ssl", "RUSTFS_USE_SSL")

	// JWT配置
	viper.BindEnv("jwt.secret", "JWT_SECRET")
	viper.BindEnv("jwt.expire_hours", "JWT_EXPIRE_HOURS")

	// 日志配置
	viper.BindEnv("log.level", "LOG_LEVEL")
	viper.BindEnv("log.format", "LOG_FORMAT")
	viper.BindEnv("log.output", "LOG_OUTPUT")

	// 邮件配置
	viper.BindEnv("email.enabled", "EMAIL_ENABLED")
	viper.BindEnv("email.smtp_host", "EMAIL_SMTP_HOST")
	viper.BindEnv("email.smtp_port", "EMAIL_SMTP_PORT")
	viper.BindEnv("email.username", "EMAIL_USERNAME")
	viper.BindEnv("email.password", "EMAIL_PASSWORD")
	viper.BindEnv("email.from_name", "EMAIL_FROM_NAME")

	// 站点配置
	viper.BindEnv("site.name", "SITE_NAME")
	viper.BindEnv("site.description", "SITE_DESCRIPTION")
	viper.BindEnv("site.registration_enabled", "REGISTRATION_ENABLED")
	viper.BindEnv("site.default_avatar", "DEFAULT_AVATAR")
	viper.BindEnv("site.max_textures_per_user", "MAX_TEXTURES_PER_USER")
	viper.BindEnv("site.max_profiles_per_user", "MAX_PROFILES_PER_USER")
	viper.BindEnv("site.checkin_reward", "CHECKIN_REWARD")
	viper.BindEnv("site.texture_download_reward", "TEXTURE_DOWNLOAD_REWARD")
}

// overrideFromEnv 从环境变量中覆盖配置
func overrideFromEnv(config *Config) {
	// 处理RustFS存储桶配置
	if texturesBucket := os.Getenv("RUSTFS_BUCKET_TEXTURES"); texturesBucket != "" {
		if config.RustFS.Buckets == nil {
			config.RustFS.Buckets = make(map[string]string)
		}
		config.RustFS.Buckets["textures"] = texturesBucket
	}

	if avatarsBucket := os.Getenv("RUSTFS_BUCKET_AVATARS"); avatarsBucket != "" {
		if config.RustFS.Buckets == nil {
			config.RustFS.Buckets = make(map[string]string)
		}
		config.RustFS.Buckets["avatars"] = avatarsBucket
	}

	// 处理数据库连接池配置
	if maxIdleConns := os.Getenv("DATABASE_MAX_IDLE_CONNS"); maxIdleConns != "" {
		if val, err := strconv.Atoi(maxIdleConns); err == nil {
			config.Database.MaxIdleConns = val
		}
	}

	if maxOpenConns := os.Getenv("DATABASE_MAX_OPEN_CONNS"); maxOpenConns != "" {
		if val, err := strconv.Atoi(maxOpenConns); err == nil {
			config.Database.MaxOpenConns = val
		}
	}

	if connMaxLifetime := os.Getenv("DATABASE_CONN_MAX_LIFETIME"); connMaxLifetime != "" {
		if val, err := time.ParseDuration(connMaxLifetime); err == nil {
			config.Database.ConnMaxLifetime = val
		}
	}

	if connMaxIdleTime := os.Getenv("DATABASE_CONN_MAX_IDLE_TIME"); connMaxIdleTime != "" {
		if val, err := time.ParseDuration(connMaxIdleTime); err == nil {
			config.Database.ConnMaxIdleTime = val
		}
	}

	// 处理Redis连接池配置
	if poolSize := os.Getenv("REDIS_POOL_SIZE"); poolSize != "" {
		if val, err := strconv.Atoi(poolSize); err == nil {
			config.Redis.PoolSize = val
		}
	}

	if minIdleConns := os.Getenv("REDIS_MIN_IDLE_CONNS"); minIdleConns != "" {
		if val, err := strconv.Atoi(minIdleConns); err == nil {
			config.Redis.MinIdleConns = val
		}
	}

	if maxRetries := os.Getenv("REDIS_MAX_RETRIES"); maxRetries != "" {
		if val, err := strconv.Atoi(maxRetries); err == nil {
			config.Redis.MaxRetries = val
		}
	}

	if dialTimeout := os.Getenv("REDIS_DIAL_TIMEOUT"); dialTimeout != "" {
		if val, err := time.ParseDuration(dialTimeout); err == nil {
			config.Redis.DialTimeout = val
		}
	}

	if readTimeout := os.Getenv("REDIS_READ_TIMEOUT"); readTimeout != "" {
		if val, err := time.ParseDuration(readTimeout); err == nil {
			config.Redis.ReadTimeout = val
		}
	}

	if writeTimeout := os.Getenv("REDIS_WRITE_TIMEOUT"); writeTimeout != "" {
		if val, err := time.ParseDuration(writeTimeout); err == nil {
			config.Redis.WriteTimeout = val
		}
	}

	if poolTimeout := os.Getenv("REDIS_POOL_TIMEOUT"); poolTimeout != "" {
		if val, err := time.ParseDuration(poolTimeout); err == nil {
			config.Redis.PoolTimeout = val
		}
	}

	if connMaxIdleTime := os.Getenv("REDIS_CONN_MAX_IDLE_TIME"); connMaxIdleTime != "" {
		if val, err := time.ParseDuration(connMaxIdleTime); err == nil {
			config.Redis.ConnMaxIdleTime = val
		}
	}

	// 处理邮件配置
	if emailEnabled := os.Getenv("EMAIL_ENABLED"); emailEnabled != "" {
		config.Email.Enabled = emailEnabled == "true" || emailEnabled == "True" || emailEnabled == "TRUE" || emailEnabled == "1"
	}

	// 处理环境配置
	if env := os.Getenv("ENVIRONMENT"); env != "" {
		config.Environment = env
	}

	// 处理安全配置
	if allowedOrigins := os.Getenv("SECURITY_ALLOWED_ORIGINS"); allowedOrigins != "" {
		config.Security.AllowedOrigins = strings.Split(allowedOrigins, ",")
	}

	if allowedDomains := os.Getenv("SECURITY_ALLOWED_DOMAINS"); allowedDomains != "" {
		config.Security.AllowedDomains = strings.Split(allowedDomains, ",")
	}
}

// IsTestEnvironment 判断是否为测试环境
func (c *Config) IsTestEnvironment() bool {
	return c.Environment == "test"
}