package net

import (
	"context"
	"fmt"
	"sync"
	"time"

	"cellbot/internal/engine"
	"cellbot/internal/protocol"

	"github.com/bytedance/sonic"
	"github.com/valyala/fasthttp"
	"go.uber.org/zap"
)

// HTTPClient HTTP客户端（用于正向HTTP连接）
type HTTPClient struct {
	client     *fasthttp.Client
	logger     *zap.Logger
	eventBus   *engine.EventBus
	botID      string
	baseURL    string
	timeout    time.Duration
	retryCount int
}

// GenericRequestConfig 通用请求配置
type GenericRequestConfig struct {
	URL         string
	Method      string // GET, POST, etc.
	Headers     map[string]string
	Body        []byte
	AccessToken string
}

// GenericResponse 通用响应
type GenericResponse struct {
	StatusCode int
	Headers    map[string]string
	Body       []byte
}

// HTTPClientConfig HTTP客户端配置
type HTTPClientConfig struct {
	BotID      string
	BaseURL    string
	Timeout    time.Duration
	RetryCount int
}

// NewHTTPClient 创建HTTP客户端
func NewHTTPClient(config HTTPClientConfig, logger *zap.Logger, eventBus *engine.EventBus) *HTTPClient {
	if config.Timeout == 0 {
		config.Timeout = 30 * time.Second
	}
	if config.RetryCount == 0 {
		config.RetryCount = 3
	}

	return &HTTPClient{
		client: &fasthttp.Client{
			ReadTimeout:     config.Timeout,
			WriteTimeout:    config.Timeout,
			MaxConnsPerHost: 100,
		},
		logger:     logger.Named("http-client"),
		eventBus:   eventBus,
		botID:      config.BotID,
		baseURL:    config.BaseURL,
		timeout:    config.Timeout,
		retryCount: config.RetryCount,
	}
}

// SendAction 发送动作请求（正向HTTP）
func (hc *HTTPClient) SendAction(ctx context.Context, action protocol.Action) (map[string]interface{}, error) {
	// 序列化动作为JSON
	data, err := sonic.Marshal(action)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal action: %w", err)
	}

	req := fasthttp.AcquireRequest()
	resp := fasthttp.AcquireResponse()
	defer fasthttp.ReleaseRequest(req)
	defer fasthttp.ReleaseResponse(resp)

	url := hc.baseURL + "/action"
	req.SetRequestURI(url)
	req.Header.SetMethod("POST")
	req.Header.SetContentType("application/json")
	req.SetBody(data)

	hc.logger.Debug("Sending action",
		zap.String("url", url),
		zap.String("action", string(action.GetType())))

	// 重试机制
	var lastErr error
	for i := 0; i <= hc.retryCount; i++ {
		if i > 0 {
			hc.logger.Info("Retrying action request",
				zap.Int("attempt", i),
				zap.Int("max", hc.retryCount))
			time.Sleep(time.Duration(i) * time.Second)
		}

		err := hc.client.DoTimeout(req, resp, hc.timeout)
		if err != nil {
			lastErr = fmt.Errorf("request failed: %w", err)
			continue
		}

		if resp.StatusCode() != fasthttp.StatusOK {
			lastErr = fmt.Errorf("unexpected status code: %d", resp.StatusCode())
			continue
		}

		// 解析响应
		var result map[string]interface{}
		if err := sonic.Unmarshal(resp.Body(), &result); err != nil {
			lastErr = fmt.Errorf("failed to parse response: %w", err)
			continue
		}

		hc.logger.Info("Action sent successfully",
			zap.String("action", string(action.GetType())))

		return result, nil
	}

	return nil, fmt.Errorf("action failed after %d retries: %w", hc.retryCount, lastErr)
}

// DoGenericRequest 执行通用HTTP请求
// 用于支持适配器的特定API调用需求
func (hc *HTTPClient) DoGenericRequest(ctx context.Context, config GenericRequestConfig) (*GenericResponse, error) {
	// 如果未提供 Method，默认为 POST
	if config.Method == "" {
		config.Method = "POST"
	}

	// 重试机制
	var lastErr error
	for i := 0; i <= hc.retryCount; i++ {
		if i > 0 {
			hc.logger.Info("Retrying generic request",
				zap.String("url", config.URL),
				zap.Int("attempt", i),
				zap.Int("max", hc.retryCount))
			time.Sleep(time.Duration(i) * time.Second)
		}

		resp, err := hc.doGenericRequest(ctx, config)
		if err != nil {
			lastErr = err
			continue
		}

		return resp, nil
	}

	return nil, fmt.Errorf("generic request failed after %d retries: %w", hc.retryCount, lastErr)
}

// doGenericRequest 执行单次通用请求
func (hc *HTTPClient) doGenericRequest(ctx context.Context, config GenericRequestConfig) (*GenericResponse, error) {
	req := fasthttp.AcquireRequest()
	resp := fasthttp.AcquireResponse()
	defer fasthttp.ReleaseRequest(req)
	defer fasthttp.ReleaseResponse(resp)

	// 设置请求URL和方法
	req.SetRequestURI(config.URL)
	req.Header.SetMethod(config.Method)

	// 设置默认 Content-Type
	if config.Method == "POST" || config.Method == "PUT" || config.Method == "PATCH" {
		if req.Header.ContentType() == nil || len(req.Header.ContentType()) == 0 {
			req.Header.SetContentType("application/json")
		}
	}

	// 设置请求体
	if config.Body != nil {
		req.SetBody(config.Body)
	}

	// 设置自定义 Headers
	for key, value := range config.Headers {
		req.Header.Set(key, value)
	}

	// 设置 Authorization 头
	if config.AccessToken != "" {
		req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", config.AccessToken))
	}

	hc.logger.Debug("Sending generic HTTP request",
		zap.String("method", config.Method),
		zap.String("url", config.URL))

	// 发送请求
	err := hc.client.DoTimeout(req, resp, hc.timeout)
	if err != nil {
		return nil, fmt.Errorf("request failed: %w", err)
	}

	// 构建响应
	genericResp := &GenericResponse{
		StatusCode: resp.StatusCode(),
		Body:       make([]byte, len(resp.Body())),
		Headers:    make(map[string]string),
	}

	// 复制响应体
	copy(genericResp.Body, resp.Body())

	// 复制响应头
	resp.Header.VisitAll(func(key, value []byte) {
		genericResp.Headers[string(key)] = string(value)
	})

	hc.logger.Debug("Generic HTTP request completed",
		zap.String("method", config.Method),
		zap.String("url", config.URL),
		zap.Int("status_code", resp.StatusCode()))

	return genericResp, nil
}

// PollEvents 轮询事件（正向HTTP）
func (hc *HTTPClient) PollEvents(ctx context.Context, interval time.Duration) error {
	ticker := time.NewTicker(interval)
	defer ticker.Stop()

	hc.logger.Info("Starting event polling",
		zap.Duration("interval", interval))

	for {
		select {
		case <-ticker.C:
			if err := hc.fetchEvents(ctx); err != nil {
				hc.logger.Error("Failed to fetch events", zap.Error(err))
			}

		case <-ctx.Done():
			hc.logger.Info("Event polling stopped")
			return ctx.Err()
		}
	}
}

// fetchEvents 获取事件
func (hc *HTTPClient) fetchEvents(ctx context.Context) error {
	req := fasthttp.AcquireRequest()
	resp := fasthttp.AcquireResponse()
	defer fasthttp.ReleaseRequest(req)
	defer fasthttp.ReleaseResponse(resp)

	url := hc.baseURL + "/events"
	req.SetRequestURI(url)
	req.Header.SetMethod("GET")

	err := hc.client.DoTimeout(req, resp, hc.timeout)
	if err != nil {
		return fmt.Errorf("request failed: %w", err)
	}

	if resp.StatusCode() != fasthttp.StatusOK {
		return fmt.Errorf("unexpected status code: %d", resp.StatusCode())
	}

	// 解析事件列表
	var events []protocol.BaseEvent
	if err := sonic.Unmarshal(resp.Body(), &events); err != nil {
		return fmt.Errorf("failed to parse events: %w", err)
	}

	// 发布事件到事件总线
	for i := range events {
		hc.logger.Debug("Event received",
			zap.String("type", string(events[i].Type)),
			zap.String("detail_type", events[i].DetailType))

		hc.eventBus.Publish(&events[i])
	}

	return nil
}

// HTTPWebhookServer HTTP Webhook服务器（用于反向HTTP连接）
type HTTPWebhookServer struct {
	server   *fasthttp.Server
	logger   *zap.Logger
	eventBus *engine.EventBus
	handlers map[string]*WebhookHandler
	mu       sync.RWMutex
}

// SimpleWebhookConfig 简化版 Webhook 配置
type SimpleWebhookConfig struct {
	Addr         string
	AccessToken  string // 可选的访问令牌验证
	EventChannel chan []byte // 用于传递原始事件数据
}

// SimpleWebhookHandler 简化版 Webhook 处理函数
type SimpleWebhookHandler func(ctx *fasthttp.RequestCtx)

// SimpleWebhookServer 简化版 Webhook 服务器
// 用于接收协议端推送的事件，提供原始字节流通道
type SimpleWebhookServer struct {
	server      *fasthttp.Server
	logger      *zap.Logger
	addr        string
	accessToken string
	eventChan   chan []byte
	handler     SimpleWebhookHandler
}

// WebhookHandler Webhook处理器
type WebhookHandler struct {
	BotID     string
	Secret    string
	Validator func([]byte, string) bool
}

// NewHTTPWebhookServer 创建HTTP Webhook服务器
func NewHTTPWebhookServer(logger *zap.Logger, eventBus *engine.EventBus) *HTTPWebhookServer {
	return &HTTPWebhookServer{
		logger:   logger.Named("webhook-server"),
		eventBus: eventBus,
		handlers: make(map[string]*WebhookHandler),
	}
}

// RegisterWebhook 注册Webhook处理器
func (hws *HTTPWebhookServer) RegisterWebhook(path string, handler *WebhookHandler) {
	hws.mu.Lock()
	defer hws.mu.Unlock()

	hws.handlers[path] = handler
	hws.logger.Info("Webhook registered",
		zap.String("path", path),
		zap.String("bot_id", handler.BotID))
}

// UnregisterWebhook 注销Webhook处理器
func (hws *HTTPWebhookServer) UnregisterWebhook(path string) {
	hws.mu.Lock()
	defer hws.mu.Unlock()

	delete(hws.handlers, path)
	hws.logger.Info("Webhook unregistered", zap.String("path", path))
}

// Start 启动Webhook服务器
func (hws *HTTPWebhookServer) Start(addr string) error {
	hws.server = &fasthttp.Server{
		Handler: hws.handleWebhook,
	}

	hws.logger.Info("Starting webhook server", zap.String("address", addr))

	go func() {
		if err := hws.server.ListenAndServe(addr); err != nil {
			hws.logger.Error("Webhook server error", zap.Error(err))
		}
	}()

	return nil
}

// Stop 停止Webhook服务器
func (hws *HTTPWebhookServer) Stop() error {
	if hws.server != nil {
		hws.logger.Info("Stopping webhook server")
		return hws.server.Shutdown()
	}
	return nil
}

// NewSimpleWebhookServer 创建简化版 Webhook 服务器
func NewSimpleWebhookServer(config SimpleWebhookConfig, logger *zap.Logger) *SimpleWebhookServer {
	return &SimpleWebhookServer{
		addr:        config.Addr,
		accessToken: config.AccessToken,
		eventChan:   config.EventChannel,
		logger:      logger.Named("simple-webhook-server"),
	}
}

// Start 启动简化版 Webhook 服务器
func (s *SimpleWebhookServer) Start() error {
	s.server = &fasthttp.Server{
		Handler:            s.handleRequest,
		MaxConnsPerIP:      1000,
		MaxRequestsPerConn: 1000,
	}

	s.logger.Info("Starting simple webhook server", zap.String("addr", s.addr))

	go func() {
		if err := s.server.ListenAndServe(s.addr); err != nil {
			s.logger.Error("Simple webhook server error", zap.Error(err))
		}
	}()

	return nil
}

// handleRequest 处理 Webhook 请求
func (s *SimpleWebhookServer) handleRequest(ctx *fasthttp.RequestCtx) {
	// 只接受 POST 请求
	if !ctx.IsPost() {
		s.logger.Warn("Received non-POST request",
			zap.String("method", string(ctx.Method())))
		ctx.Error("Method Not Allowed", fasthttp.StatusMethodNotAllowed)
		return
	}

	// 检查 Content-Type
	contentType := string(ctx.Request.Header.ContentType())
	if contentType != "application/json" {
		s.logger.Warn("Invalid content type",
			zap.String("content_type", contentType))
		ctx.Error("Unsupported Media Type", fasthttp.StatusUnsupportedMediaType)
		return
	}

	// 验证访问令牌（如果配置了）
	if s.accessToken != "" {
		authHeader := string(ctx.Request.Header.Peek("Authorization"))
		if authHeader == "" {
			s.logger.Warn("Missing authorization header")
			ctx.Error("Unauthorized", fasthttp.StatusUnauthorized)
			return
		}

		// 验证 Bearer token
		expectedAuth := "Bearer " + s.accessToken
		if authHeader != expectedAuth {
			s.logger.Warn("Invalid authorization token")
			ctx.Error("Unauthorized", fasthttp.StatusUnauthorized)
			return
		}
	}

	// 获取请求体
	body := ctx.PostBody()
	if len(body) == 0 {
		s.logger.Warn("Empty request body")
		ctx.Error("Bad Request", fasthttp.StatusBadRequest)
		return
	}

	s.logger.Debug("Received webhook event",
		zap.Int("body_length", len(body)))

	// 发送到事件通道
	select {
	case s.eventChan <- body:
	default:
		s.logger.Warn("Event channel full, dropping event")
	}

	// 返回成功响应
	ctx.SetContentType("application/json")
	ctx.SetStatusCode(fasthttp.StatusOK)
	ctx.SetBodyString(`{"status":"ok"}`)
}

// Events 获取事件通道
func (s *SimpleWebhookServer) Events() <-chan []byte {
	return s.eventChan
}

// Stop 停止简化版 Webhook 服务器
func (s *SimpleWebhookServer) Stop() error {
	if s.server != nil {
		s.logger.Info("Stopping simple webhook server")
		if err := s.server.Shutdown(); err != nil {
			return fmt.Errorf("failed to shutdown: %w", err)
		}
	}
	return nil
}

// handleWebhook 处理Webhook请求
func (hws *HTTPWebhookServer) handleWebhook(ctx *fasthttp.RequestCtx) {
	path := string(ctx.Path())

	hws.mu.RLock()
	handler, exists := hws.handlers[path]
	hws.mu.RUnlock()

	if !exists {
		ctx.Error("Webhook not found", fasthttp.StatusNotFound)
		return
	}

	// 验证签名（如果配置了）
	if handler.Secret != "" && handler.Validator != nil {
		signature := string(ctx.Request.Header.Peek("X-Signature"))
		if !handler.Validator(ctx.PostBody(), signature) {
			hws.logger.Warn("Invalid webhook signature",
				zap.String("path", path),
				zap.String("bot_id", handler.BotID))
			ctx.Error("Invalid signature", fasthttp.StatusUnauthorized)
			return
		}
	}

	// 解析事件
	var event protocol.BaseEvent
	if err := sonic.Unmarshal(ctx.PostBody(), &event); err != nil {
		hws.logger.Error("Failed to parse webhook event",
			zap.Error(err),
			zap.String("path", path))
		ctx.Error("Invalid event format", fasthttp.StatusBadRequest)
		return
	}

	// 设置BotID
	if event.SelfID == "" {
		event.SelfID = handler.BotID
	}

	// 设置时间戳
	if event.Timestamp == 0 {
		event.Timestamp = time.Now().Unix()
	}

	// 确保Data字段不为nil
	if event.Data == nil {
		event.Data = make(map[string]interface{})
	}

	hws.logger.Info("Webhook event received",
		zap.String("path", path),
		zap.String("bot_id", handler.BotID),
		zap.String("type", string(event.Type)),
		zap.String("detail_type", event.DetailType))

	// 发布到事件总线
	hws.eventBus.Publish(&event)

	// 返回成功响应
	ctx.SetContentType("application/json")
	ctx.SetBodyString(`{"success":true}`)
}