// Package middleware provides HTTP middleware functions
package middleware

import (
	"net/http"
	"time"

	"spiderman/internal/logger"

	"github.com/gorilla/mux"
	"github.com/sirupsen/logrus"
)

// ResponseWriter wrapper to capture status code
type responseWriter struct {
	http.ResponseWriter
	statusCode int
	size       int
}

func (rw *responseWriter) WriteHeader(code int) {
	rw.statusCode = code
	rw.ResponseWriter.WriteHeader(code)
}

func (rw *responseWriter) Write(b []byte) (int, error) {
	size, err := rw.ResponseWriter.Write(b)
	rw.size += size
	return size, err
}

// Logging logs HTTP requests and responses
func Logging(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		start := time.Now()

		// Wrap the response writer
		wrapped := &responseWriter{
			ResponseWriter: w,
			statusCode:     http.StatusOK,
		}

		// Get route information if available
		route := mux.CurrentRoute(r)
		routeName := ""
		if route != nil {
			if name := route.GetName(); name != "" {
				routeName = name
			} else if pathTemplate, err := route.GetPathTemplate(); err == nil {
				routeName = pathTemplate
			}
		}

		// Create request logger
		requestLogger := logger.GetRequestLogger(r.Method, r.URL.Path, r.RemoteAddr).WithFields(logrus.Fields{
			"user_agent": r.UserAgent(),
			"route":      routeName,
		})

		// Log incoming request
		requestLogger.Info("Request started")

		// Process request
		next.ServeHTTP(wrapped, r)

		// Calculate duration
		duration := time.Since(start)

		// Log completed request
		requestLogger.WithFields(logrus.Fields{
			"status_code": wrapped.statusCode,
			"duration_ms": duration.Milliseconds(),
			"size_bytes":  wrapped.size,
		}).Info("Request completed")

		// Log errors for 4xx and 5xx status codes
		if wrapped.statusCode >= 400 {
			requestLogger.WithFields(logrus.Fields{
				"status_code": wrapped.statusCode,
				"duration_ms": duration.Milliseconds(),
			}).Warn("Request completed with error status")
		}
	})
}

// CORS adds CORS headers
func CORS(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		requestLogger := logger.GetRequestLogger(r.Method, r.URL.Path, r.RemoteAddr)

		// Enhanced CORS headers for Swagger UI support
		w.Header().Set("Access-Control-Allow-Origin", "*")
		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS, HEAD")
		w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization, Accept, X-Requested-With, Origin")
		w.Header().Set("Access-Control-Expose-Headers", "Content-Length, Content-Type")
		w.Header().Set("Access-Control-Allow-Credentials", "false")
		w.Header().Set("Access-Control-Max-Age", "86400")

		if r.Method == "OPTIONS" {
			requestLogger.Debug("Handling CORS preflight request")
			w.WriteHeader(http.StatusOK)
			return
		}

		next.ServeHTTP(w, r)
	})
}

// Recovery recovers from panics and logs them
func Recovery(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		defer func() {
			if err := recover(); err != nil {
				requestLogger := logger.GetRequestLogger(r.Method, r.URL.Path, r.RemoteAddr)
				requestLogger.WithFields(logrus.Fields{
					"panic": err,
				}).Error("Panic recovered")

				http.Error(w, "Internal Server Error", http.StatusInternalServerError)
			}
		}()

		next.ServeHTTP(w, r)
	})
}