package config

import (
	"log/slog"
	"time"

	"github.com/darkit/goproxy/pkg/reverse"
)

// ProxyMode 代理模式
type ProxyMode string

const (
	// ModeForward 正向代理模式
	ModeForward ProxyMode = "forward"
	// ModeReverse 反向代理模式
	ModeReverse ProxyMode = "reverse"
	// ModeTransparent 透明代理模式
	ModeTransparent ProxyMode = "transparent"
)

// UnifiedConfig 统一代理配置
type UnifiedConfig struct {
	// 基本配置
	ListenAddr         string    `json:"listen_addr" yaml:"listen_addr" toml:"listen_addr"`                            // 监听地址
	ProxyMode          ProxyMode `json:"proxy_mode" yaml:"proxy_mode" toml:"proxy_mode"`                               // 代理模式：forward, reverse, transparent
	TargetAddr         string    `json:"target_addr" yaml:"target_addr" toml:"target_addr"`                            // 目标地址(反向代理使用)
	EnableHTTPS        bool      `json:"enable_https" yaml:"enable_https" toml:"enable_https"`                         // 是否启用HTTPS
	DecryptHTTPS       bool      `json:"decrypt_https" yaml:"decrypt_https" toml:"decrypt_https"`                      // 是否解密HTTPS(正向代理使用)
	TLSCert            string    `json:"tls_cert" yaml:"tls_cert" toml:"tls_cert"`                                     // TLS证书文件路径
	TLSKey             string    `json:"tls_key" yaml:"tls_key" toml:"tls_key"`                                        // TLS密钥文件路径
	CACert             string    `json:"ca_cert" yaml:"ca_cert" toml:"ca_cert"`                                        // CA证书文件路径(用于生成动态证书)
	CAKey              string    `json:"ca_key" yaml:"ca_key" toml:"ca_key"`                                           // CA密钥文件路径(用于生成动态证书)
	UseECDSA           bool      `json:"use_ecdsa" yaml:"use_ecdsa" toml:"use_ecdsa"`                                  // 是否使用ECDSA生成证书（默认使用RSA）
	InsecureSkipVerify bool      `json:"insecure_skip_verify" yaml:"insecure_skip_verify" toml:"insecure_skip_verify"` // 是否跳过TLS证书验证

	// 连接配置
	DisableKeepAlive        bool          `json:"disable_keep_alive" yaml:"disable_keep_alive" toml:"disable_keep_alive"`                      // 是否禁用连接复用
	RequestTimeout          time.Duration `json:"request_timeout" yaml:"request_timeout" toml:"request_timeout"`                               // 请求超时时间
	IdleTimeout             time.Duration `json:"idle_timeout" yaml:"idle_timeout" toml:"idle_timeout"`                                        // 连接空闲超时时间
	MaxIdleConns            int           `json:"max_idle_conns" yaml:"max_idle_conns" toml:"max_idle_conns"`                                  // 最大空闲连接数
	EnableConnectionPool    bool          `json:"enable_connection_pool" yaml:"enable_connection_pool" toml:"enable_connection_pool"`          // 是否启用连接池
	ConnectionPoolSize      int           `json:"connection_pool_size" yaml:"connection_pool_size" toml:"connection_pool_size"`                // 连接池大小
	MaxConnections          int           `json:"max_connections" yaml:"max_connections" toml:"max_connections"`                               // 最大连接数
	EnableWebSocket         bool          `json:"enable_websocket" yaml:"enable_websocket" toml:"enable_websocket"`                            // 是否启用WebSocket
	WebSocketIntercept      bool          `json:"websocket_intercept" yaml:"websocket_intercept" toml:"websocket_intercept"`                   // 是否拦截WebSocket
	SupportWebSocketUpgrade bool          `json:"support_websocket_upgrade" yaml:"support_websocket_upgrade" toml:"support_websocket_upgrade"` // 是否支持Websocket升级

	// 缓存配置
	EnableCache bool          `json:"enable_cache" yaml:"enable_cache" toml:"enable_cache"`    // 是否启用响应缓存
	CacheTTL    time.Duration `json:"cache_ttl" yaml:"cache_ttl" toml:"cache_ttl"`             // 缓存过期时间
	DNSCacheTTL time.Duration `json:"dns_cache_ttl" yaml:"dns_cache_ttl" toml:"dns_cache_ttl"` // DNS缓存过期时间

	// 重试配置
	EnableRetry     bool          `json:"enable_retry" yaml:"enable_retry" toml:"enable_retry"`                // 是否启用重试机制
	MaxRetries      int           `json:"max_retries" yaml:"max_retries" toml:"max_retries"`                   // 最大重试次数
	RetryBackoff    time.Duration `json:"retry_backoff" yaml:"retry_backoff" toml:"retry_backoff"`             // 重试间隔基数
	MaxRetryBackoff time.Duration `json:"max_retry_backoff" yaml:"max_retry_backoff" toml:"max_retry_backoff"` // 最大重试间隔

	// HTTP头部操作
	EnableCompression bool `json:"enable_compression" yaml:"enable_compression" toml:"enable_compression"`    // 是否启用压缩
	EnableCORS        bool `json:"enable_cors" yaml:"enable_cors" toml:"enable_cors"`                         // 是否启用CORS
	PreserveClientIP  bool `json:"preserve_client_ip" yaml:"preserve_client_ip" toml:"preserve_client_ip"`    // 是否保留客户端IP
	RewriteHostHeader bool `json:"rewrite_host_header" yaml:"rewrite_host_header" toml:"rewrite_host_header"` // 重写Host头
	AddXForwardedFor  bool `json:"add_x_forwarded_for" yaml:"add_x_forwarded_for" toml:"add_x_forwarded_for"` // 是否添加X-Forwarded-For头
	AddXRealIP        bool `json:"add_x_real_ip" yaml:"add_x_real_ip" toml:"add_x_real_ip"`                   // 是否添加X-Real-IP头

	// 负载均衡配置
	EnableLoadBalancing bool          `json:"enable_load_balancing" yaml:"enable_load_balancing" toml:"enable_load_balancing"` // 是否启用负载均衡
	Backends            []string      `json:"backends" yaml:"backends" toml:"backends"`                                        // 负载均衡后端列表
	EnableHealthCheck   bool          `json:"enable_health_check" yaml:"enable_health_check" toml:"enable_health_check"`       // 是否启用健康检查
	HealthCheckInterval time.Duration `json:"health_check_interval" yaml:"health_check_interval" toml:"health_check_interval"` // 健康检查间隔时间
	HealthCheckTimeout  time.Duration `json:"health_check_timeout" yaml:"health_check_timeout" toml:"health_check_timeout"`    // 健康检查超时时间

	// 限流配置
	EnableRateLimit bool    `json:"enable_rate_limit" yaml:"enable_rate_limit" toml:"enable_rate_limit"` // 是否启用限流
	RateLimit       float64 `json:"rate_limit" yaml:"rate_limit" toml:"rate_limit"`                      // 每秒请求速率限制
	MaxBurst        int     `json:"max_burst" yaml:"max_burst" toml:"max_burst"`                         // 并发请求峰值限制

	// 监控和跟踪
	EnableMetrics bool `json:"enable_metrics" yaml:"enable_metrics" toml:"enable_metrics"` // 是否启用监控指标
	EnableTracing bool `json:"enable_tracing" yaml:"enable_tracing" toml:"enable_tracing"` // 是否启用请求追踪

	// 反向代理特有配置
	RulesFile string `json:"rules_file" yaml:"rules_file" toml:"rules_file"` // 规则文件路径

	// 日志
	Logger *slog.Logger `json:"-" yaml:"-" toml:"-"` // 日志记录器
}

// DefaultUnifiedConfig 返回默认统一配置
func DefaultUnifiedConfig() *UnifiedConfig {
	return &UnifiedConfig{
		ListenAddr:         ":8080",
		ProxyMode:          ModeForward, // 默认为正向代理
		DecryptHTTPS:       false,
		EnableHTTPS:        false,
		UseECDSA:           false,
		InsecureSkipVerify: false,

		RequestTimeout:          30 * time.Second,
		IdleTimeout:             90 * time.Second,
		MaxIdleConns:            100,
		EnableConnectionPool:    true,
		ConnectionPoolSize:      100,
		MaxConnections:          1000,
		EnableWebSocket:         true,
		WebSocketIntercept:      false,
		SupportWebSocketUpgrade: true,

		EnableCache: false,
		CacheTTL:    5 * time.Minute,
		DNSCacheTTL: 5 * time.Minute,

		EnableRetry:     true,
		MaxRetries:      3,
		RetryBackoff:    time.Second,
		MaxRetryBackoff: 10 * time.Second,

		EnableCompression: true,
		EnableCORS:        true,
		PreserveClientIP:  true,
		RewriteHostHeader: false,
		AddXForwardedFor:  true,
		AddXRealIP:        true,

		EnableLoadBalancing: false,
		Backends:            []string{},
		EnableHealthCheck:   false,
		HealthCheckInterval: 30 * time.Second,
		HealthCheckTimeout:  5 * time.Second,

		EnableRateLimit: false,
		RateLimit:       0, // 0 表示不限流
		MaxBurst:        50,

		EnableMetrics: false,
		EnableTracing: false,

		Logger: slog.Default(),
	}
}

// CreateLegacyConfig 将统一配置转换为旧的配置格式（兼容性用）
func (uc *UnifiedConfig) CreateLegacyConfig() *Config {
	cfg := DefaultConfig()

	// 基本配置
	cfg.ListenAddr = uc.ListenAddr
	cfg.TargetAddr = uc.TargetAddr
	cfg.DecryptHTTPS = uc.DecryptHTTPS
	cfg.CACert = uc.CACert
	cfg.CAKey = uc.CAKey
	cfg.UseECDSA = uc.UseECDSA
	cfg.TLSCert = uc.TLSCert
	cfg.TLSKey = uc.TLSKey
	cfg.InsecureSkipVerify = uc.InsecureSkipVerify

	// 连接配置
	cfg.DisableKeepAlive = uc.DisableKeepAlive
	cfg.RequestTimeout = uc.RequestTimeout
	cfg.EnableCache = uc.EnableCache
	cfg.IdleTimeout = uc.IdleTimeout
	cfg.MaxIdleConns = uc.MaxIdleConns

	// 缓存配置
	cfg.DNSCacheTTL = uc.DNSCacheTTL
	cfg.CacheTTL = uc.CacheTTL

	// 重试配置
	cfg.EnableRetry = uc.EnableRetry
	cfg.MaxRetries = uc.MaxRetries
	cfg.BaseBackoff = uc.RetryBackoff
	cfg.MaxBackoff = uc.MaxRetryBackoff

	// 限流配置
	cfg.RateLimit = uc.RateLimit

	// 其他配置
	cfg.EnableCORS = uc.EnableCORS

	// 负载均衡配置
	cfg.EnableLoadBalancing = uc.EnableLoadBalancing
	cfg.Backends = uc.Backends
	cfg.EnableRateLimit = uc.EnableRateLimit
	cfg.MaxBurst = uc.MaxBurst
	cfg.MaxConnections = uc.MaxConnections
	cfg.EnableConnectionPool = uc.EnableConnectionPool
	cfg.ConnectionPoolSize = uc.ConnectionPoolSize
	cfg.EnableHealthCheck = uc.EnableHealthCheck
	cfg.HealthCheckInterval = uc.HealthCheckInterval
	cfg.HealthCheckTimeout = uc.HealthCheckTimeout
	cfg.EnableMetrics = uc.EnableMetrics
	cfg.EnableTracing = uc.EnableTracing
	cfg.WebSocketIntercept = uc.WebSocketIntercept
	cfg.ReverseProxy = uc.ProxyMode == ModeReverse
	cfg.ReverseProxyRulesFile = uc.RulesFile
	cfg.PreserveClientIP = uc.PreserveClientIP
	cfg.EnableCompression = uc.EnableCompression
	cfg.RewriteHostHeader = uc.RewriteHostHeader
	cfg.AddXForwardedFor = uc.AddXForwardedFor
	cfg.AddXRealIP = uc.AddXRealIP
	cfg.SupportWebSocketUpgrade = uc.SupportWebSocketUpgrade
	cfg.Logger = uc.Logger

	return cfg
}

// CreateReverseConfig 将统一配置转换为反向代理配置
func (uc *UnifiedConfig) CreateReverseConfig() *reverse.Config {
	cfg := reverse.DefaultConfig()

	// 基础配置
	cfg.BaseConfig.ListenAddr = uc.ListenAddr
	cfg.BaseConfig.TargetAddr = uc.TargetAddr
	cfg.BaseConfig.EnableHTTPS = uc.EnableHTTPS
	if uc.TLSCert != "" && uc.TLSKey != "" {
		cfg.BaseConfig.TLSConfig = &reverse.TLSConfig{
			CertFile:           uc.TLSCert,
			KeyFile:            uc.TLSKey,
			InsecureSkipVerify: uc.InsecureSkipVerify,
			UseECDSA:           uc.UseECDSA,
		}
	}
	cfg.BaseConfig.EnableWebSocket = uc.EnableWebSocket
	cfg.BaseConfig.EnableCompression = uc.EnableCompression
	cfg.BaseConfig.EnableCORS = uc.EnableCORS
	cfg.BaseConfig.PreserveClientIP = uc.PreserveClientIP
	cfg.BaseConfig.AddXForwardedFor = uc.AddXForwardedFor
	cfg.BaseConfig.AddXRealIP = uc.AddXRealIP

	// 其他配置
	cfg.RulesFile = uc.RulesFile
	cfg.InsecureSkipVerify = uc.InsecureSkipVerify
	cfg.EnableHealthCheck = uc.EnableHealthCheck
	cfg.HealthCheckInterval = uc.HealthCheckInterval
	cfg.HealthCheckTimeout = uc.HealthCheckTimeout
	cfg.EnableRetry = uc.EnableRetry
	cfg.MaxRetries = uc.MaxRetries
	cfg.RetryBackoff = uc.RetryBackoff
	cfg.MaxRetryBackoff = uc.MaxRetryBackoff
	cfg.EnableMetrics = uc.EnableMetrics
	cfg.EnableTracing = uc.EnableTracing
	cfg.WebSocketIntercept = uc.WebSocketIntercept
	cfg.DNSCacheTTL = uc.DNSCacheTTL
	cfg.EnableCache = uc.EnableCache
	cfg.CacheTTL = uc.CacheTTL
	cfg.EnableConnectionPool = uc.EnableConnectionPool
	cfg.ConnectionPoolSize = uc.ConnectionPoolSize
	cfg.IdleTimeout = uc.IdleTimeout
	cfg.RequestTimeout = uc.RequestTimeout

	return cfg
}