package proxy

import (
	"net/http"
	"net/http/httptrace"
	"time"

	"github.com/darkit/goproxy/internal/cache"
	"github.com/darkit/goproxy/internal/config"
	"github.com/darkit/goproxy/internal/healthcheck"
	"github.com/darkit/goproxy/internal/loadbalance"
	"github.com/darkit/goproxy/internal/metrics"
)

// Option 用于配置代理选项的函数类型
type Option func(*Options)

// WithConfig 设置代理配置
func WithConfig(cfg *config.Config) Option {
	return func(opt *Options) {
		opt.Config = cfg
	}
}

// WithDisableKeepAlive 设置连接是否重用
func WithDisableKeepAlive(disableKeepAlive bool) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		// 在transport中设置DisableKeepAlives
	}
}

// WithClientTrace 设置HTTP客户端跟踪
func WithClientTrace(t *httptrace.ClientTrace) Option {
	return func(opt *Options) {
		opt.ClientTrace = t
	}
}

// WithDelegate 设置委托类
func WithDelegate(delegate Delegate) Option {
	return func(opt *Options) {
		opt.Delegate = delegate
	}
}

// WithTransport 使用自定义HTTP传输
func WithTransport(t *http.Transport) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		// 在New方法中处理transport
	}
}

// WithDecryptHTTPS 启用中间人代理解密HTTPS
func WithDecryptHTTPS(c CertificateCache) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.DecryptHTTPS = true
		opt.CertCache = c
	}
}

// WithEnableWebsocketIntercept 启用WebSocket拦截
func WithEnableWebsocketIntercept() Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		// WebSocket拦截在代理处理逻辑中实现
	}
}

// WithHTTPCache 设置HTTP缓存
func WithHTTPCache(c cache.Cache) Option {
	return func(opt *Options) {
		opt.HTTPCache = c
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.EnableCache = true
	}
}

// WithLoadBalancer 设置负载均衡器
func WithLoadBalancer(lb loadbalance.LoadBalancer) Option {
	return func(opt *Options) {
		opt.LoadBalancer = lb
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.EnableLoadBalancing = true
	}
}

// WithHealthChecker 设置健康检查器
func WithHealthChecker(hc *healthcheck.HealthChecker) Option {
	return func(opt *Options) {
		opt.HealthChecker = hc
	}
}

// WithMetrics 设置监控指标
func WithMetrics(m metrics.Metrics) Option {
	return func(opt *Options) {
		opt.Metrics = m
	}
}

// WithTLSCertAndKey 设置TLS证书和密钥
func WithTLSCertAndKey(certPath, keyPath string) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.TLSCert = certPath
		opt.Config.TLSKey = keyPath
	}
}

// WithCACertAndKey 设置CA证书和密钥（用于生成动态证书）
func WithCACertAndKey(caCertPath, caKeyPath string) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.CACert = caCertPath
		opt.Config.CAKey = caKeyPath
	}
}

// WithConnectionPoolSize 设置连接池大小
func WithConnectionPoolSize(size int) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.ConnectionPoolSize = size
	}
}

// WithIdleTimeout 设置空闲超时时间
func WithIdleTimeout(timeout time.Duration) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.IdleTimeout = timeout
	}
}

// WithRequestTimeout 设置请求超时时间
func WithRequestTimeout(timeout time.Duration) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.RequestTimeout = timeout
	}
}

// WithReverseProxy 启用反向代理模式
func WithReverseProxy(enable bool) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.ReverseProxy = enable
	}
}

// WithEnableRetry 启用请求重试
func WithEnableRetry(maxRetries int, baseBackoff, maxBackoff time.Duration) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.EnableRetry = true
		opt.Config.MaxRetries = maxRetries
		opt.Config.RetryBackoff = baseBackoff
		opt.Config.MaxRetryBackoff = maxBackoff
	}
}

// WithRateLimit 设置请求限流
func WithRateLimit(rps float64) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.EnableRateLimit = true
		opt.Config.RateLimit = rps
	}
}

// WithDNSCacheTTL 设置DNS缓存TTL
func WithDNSCacheTTL(ttl time.Duration) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.DNSCacheTTL = ttl
	}
}

// WithURLRewrite 启用URL重写
func WithURLRewrite(enable bool) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.EnableURLRewrite = enable
	}
}

// WithEnableCORS 启用CORS支持
func WithEnableCORS(enable bool) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.EnableCORS = enable
	}
}

// WithCertManager 设置证书管理器
// 这是一个内部函数，主要用于在New方法中设置CertManager
func WithCertManager(certManager *CertManager) Option {
	return func(opt *Options) {
		opt.CertManager = certManager
	}
}

// WithEnableECDSA 启用ECDSA证书生成（默认使用RSA）
func WithEnableECDSA(enable bool) Option {
	return func(opt *Options) {
		if opt.Config == nil {
			opt.Config = config.DefaultConfig()
		}
		opt.Config.UseECDSA = enable
	}
}

// NewWithOptions 使用选项函数创建代理
func NewWithOptions(options ...Option) *Proxy {
	opts := &Options{
		Config: config.DefaultConfig(),
	}

	// 应用所有选项
	for _, option := range options {
		option(opts)
	}

	return New(opts)
}