package middleware

import (
	"fmt"
	"net/http"
	"strings"
)

// SecurityHeaders adds security headers to responses
func SecurityHeaders(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// HSTS - HTTP Strict Transport Security
		w.Header().Set("Strict-Transport-Security", "max-age=31536000; includeSubDomains")

		// CSRF Protection - same-site cookies
		w.Header().Set("X-Content-Type-Options", "nosniff")

		// XSS Protection
		w.Header().Set("X-XSS-Protection", "1; mode=block")

		// Clickjacking protection
		w.Header().Set("X-Frame-Options", "DENY")

		// CSP - Content Security Policy
		w.Header().Set("Content-Security-Policy",
			"default-src 'self'; "+
				"script-src 'self' 'unsafe-inline'; "+
				"style-src 'self' 'unsafe-inline'; "+
				"img-src 'self' data: https:; "+
				"font-src 'self'; "+
				"connect-src 'self'; "+
				"frame-ancestors 'none'")

		// Referrer Policy
		w.Header().Set("Referrer-Policy", "strict-origin-when-cross-origin")

		next.ServeHTTP(w, r)
	})
}

// RateLimitMiddleware implements basic rate limiting
type RateLimitMiddleware struct {
	// In production, use a proper rate limiter like github.com/go-chi/chi/middleware
	// This is a placeholder for demonstration
}

// NewRateLimitMiddleware creates a new rate limit middleware
func NewRateLimitMiddleware() *RateLimitMiddleware {
	return &RateLimitMiddleware{}
}

// Middleware returns the rate limit middleware handler
func (m *RateLimitMiddleware) Middleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// TODO: Implement proper rate limiting using distributed cache
		// For now, this is a placeholder
		next.ServeHTTP(w, r)
	})
}

// LoggingMiddleware logs HTTP requests
func LoggingMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		fmt.Printf("[%s] %s %s\n", r.Method, r.RequestURI, r.RemoteAddr)
		next.ServeHTTP(w, r)
	})
}

// CORSMiddleware enables CORS
func CORSMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		origin := r.Header.Get("Origin")
		switch {
		case origin == "http://localhost", origin == "http://localhost:5173", strings.HasPrefix(origin, "http://127.0.0.1:"):
			w.Header().Set("Access-Control-Allow-Origin", origin)
			w.Header().Set("Vary", "Origin")
		default:
			w.Header().Set("Access-Control-Allow-Origin", "http://localhost")
		}
		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS, PATCH")
		w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization, X-Requested-With")
		w.Header().Set("Access-Control-Max-Age", "600")

		if r.Method == http.MethodOptions {
			w.WriteHeader(http.StatusNoContent)
			return
		}

		next.ServeHTTP(w, r)
	})
}