package http

import (
	"context"
	"fmt"
	"net/http"
	"sort"
	"time"

	"github.com/gin-gonic/gin"
	"go.uber.org/zap"

	"tyapi-server/internal/config"
	"tyapi-server/internal/shared/interfaces"
)

// GinRouter Gin路由器实现
type GinRouter struct {
	engine      *gin.Engine
	config      *config.Config
	logger      *zap.Logger
	middlewares []interfaces.Middleware
	server      *http.Server
}

// NewGinRouter 创建Gin路由器
func NewGinRouter(cfg *config.Config, logger *zap.Logger) *GinRouter {
	// 设置Gin模式
	if cfg.App.IsProduction() {
		gin.SetMode(gin.ReleaseMode)
	} else {
		gin.SetMode(gin.DebugMode)
	}

	// 创建Gin引擎
	engine := gin.New()

	return &GinRouter{
		engine:      engine,
		config:      cfg,
		logger:      logger,
		middlewares: make([]interfaces.Middleware, 0),
	}
}

// RegisterHandler 注册处理器
func (r *GinRouter) RegisterHandler(handler interfaces.HTTPHandler) error {
	// 应用处理器中间件
	middlewares := handler.GetMiddlewares()

	// 注册路由
	r.engine.Handle(handler.GetMethod(), handler.GetPath(), append(middlewares, handler.Handle)...)

	r.logger.Info("Registered HTTP handler",
		zap.String("method", handler.GetMethod()),
		zap.String("path", handler.GetPath()))

	return nil
}

// RegisterMiddleware 注册中间件
func (r *GinRouter) RegisterMiddleware(middleware interfaces.Middleware) error {
	r.middlewares = append(r.middlewares, middleware)

	r.logger.Info("Registered middleware",
		zap.String("name", middleware.GetName()),
		zap.Int("priority", middleware.GetPriority()))

	return nil
}

// RegisterGroup 注册路由组
func (r *GinRouter) RegisterGroup(prefix string, middlewares ...gin.HandlerFunc) gin.IRoutes {
	return r.engine.Group(prefix, middlewares...)
}

// GetRoutes 获取路由信息
func (r *GinRouter) GetRoutes() gin.RoutesInfo {
	return r.engine.Routes()
}

// Start 启动路由器
func (r *GinRouter) Start(addr string) error {
	// 应用中间件（按优先级排序）
	r.applyMiddlewares()

	// 创建HTTP服务器
	r.server = &http.Server{
		Addr:         addr,
		Handler:      r.engine,
		ReadTimeout:  r.config.Server.ReadTimeout,
		WriteTimeout: r.config.Server.WriteTimeout,
		IdleTimeout:  r.config.Server.IdleTimeout,
	}

	r.logger.Info("Starting HTTP server", zap.String("addr", addr))

	// 启动服务器
	if err := r.server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
		return fmt.Errorf("failed to start server: %w", err)
	}

	return nil
}

// Stop 停止路由器
func (r *GinRouter) Stop(ctx context.Context) error {
	if r.server == nil {
		return nil
	}

	r.logger.Info("Stopping HTTP server...")

	// 优雅关闭服务器
	if err := r.server.Shutdown(ctx); err != nil {
		r.logger.Error("Failed to shutdown server gracefully", zap.Error(err))
		return err
	}

	r.logger.Info("HTTP server stopped")
	return nil
}

// GetEngine 获取Gin引擎
func (r *GinRouter) GetEngine() *gin.Engine {
	return r.engine
}

// applyMiddlewares 应用中间件
func (r *GinRouter) applyMiddlewares() {
	// 按优先级排序中间件
	sort.Slice(r.middlewares, func(i, j int) bool {
		return r.middlewares[i].GetPriority() > r.middlewares[j].GetPriority()
	})

	// 应用全局中间件
	for _, middleware := range r.middlewares {
		if middleware.IsGlobal() {
			r.engine.Use(middleware.Handle())
			r.logger.Debug("Applied global middleware",
				zap.String("name", middleware.GetName()),
				zap.Int("priority", middleware.GetPriority()))
		}
	}
}

// SetupDefaultRoutes 设置默认路由
func (r *GinRouter) SetupDefaultRoutes() {
	// 健康检查
	r.engine.GET("/health", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{
			"status":    "healthy",
			"timestamp": time.Now().Unix(),
			"service":   r.config.App.Name,
			"version":   r.config.App.Version,
		})
	})

	// API信息
	r.engine.GET("/info", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{
			"name":        r.config.App.Name,
			"version":     r.config.App.Version,
			"environment": r.config.App.Env,
			"timestamp":   time.Now().Unix(),
		})
	})

	// 404处理
	r.engine.NoRoute(func(c *gin.Context) {
		c.JSON(http.StatusNotFound, gin.H{
			"success":   false,
			"message":   "Route not found",
			"path":      c.Request.URL.Path,
			"method":    c.Request.Method,
			"timestamp": time.Now().Unix(),
		})
	})

	// 405处理
	r.engine.NoMethod(func(c *gin.Context) {
		c.JSON(http.StatusMethodNotAllowed, gin.H{
			"success":   false,
			"message":   "Method not allowed",
			"path":      c.Request.URL.Path,
			"method":    c.Request.Method,
			"timestamp": time.Now().Unix(),
		})
	})
}

// PrintRoutes 打印路由信息
func (r *GinRouter) PrintRoutes() {
	routes := r.GetRoutes()

	r.logger.Info("Registered routes:")
	for _, route := range routes {
		r.logger.Info("Route",
			zap.String("method", route.Method),
			zap.String("path", route.Path),
			zap.String("handler", route.Handler))
	}
}

// GetStats 获取路由器统计信息
func (r *GinRouter) GetStats() map[string]interface{} {
	routes := r.GetRoutes()

	stats := map[string]interface{}{
		"total_routes":      len(routes),
		"total_middlewares": len(r.middlewares),
		"server_config": map[string]interface{}{
			"read_timeout":  r.config.Server.ReadTimeout,
			"write_timeout": r.config.Server.WriteTimeout,
			"idle_timeout":  r.config.Server.IdleTimeout,
		},
	}

	// 按方法统计路由数量
	methodStats := make(map[string]int)
	for _, route := range routes {
		methodStats[route.Method]++
	}
	stats["routes_by_method"] = methodStats

	// 中间件统计
	middlewareStats := make([]map[string]interface{}, 0, len(r.middlewares))
	for _, middleware := range r.middlewares {
		middlewareStats = append(middlewareStats, map[string]interface{}{
			"name":     middleware.GetName(),
			"priority": middleware.GetPriority(),
			"global":   middleware.IsGlobal(),
		})
	}
	stats["middlewares"] = middlewareStats

	return stats
}

// EnableMetrics 启用指标收集
func (r *GinRouter) EnableMetrics(collector interfaces.MetricsCollector) {
	r.engine.Use(func(c *gin.Context) {
		start := time.Now()

		c.Next()

		duration := time.Since(start).Seconds()
		collector.RecordHTTPRequest(c.Request.Method, c.FullPath(), c.Writer.Status(), duration)
	})
}

// EnableProfiling 启用性能分析
func (r *GinRouter) EnableProfiling() {
	if r.config.Development.EnableProfiler {
		// 这里可以集成pprof
		r.logger.Info("Profiling enabled")
	}
}