package http

import (
	"context"
	"encoding/json"
	"net"
	"net/http"
	"time"

	"git.sharkk.net/Sky/Moonshark/core/logger"
	"git.sharkk.net/Sky/Moonshark/core/routers"
	"git.sharkk.net/Sky/Moonshark/core/runner"
)

// Server handles HTTP requests using Lua and static file routers
type Server struct {
	luaRouter      *routers.LuaRouter
	staticRouter   *routers.StaticRouter
	luaRunner      *runner.LuaRunner
	logger         *logger.Logger
	httpServer     *http.Server
	loggingEnabled bool
}

// New creates a new HTTP server with optimized connection settings
func New(luaRouter *routers.LuaRouter, staticRouter *routers.StaticRouter, runner *runner.LuaRunner, log *logger.Logger, loggingEnabled bool) *Server {
	server := &Server{
		luaRouter:      luaRouter,
		staticRouter:   staticRouter,
		luaRunner:      runner,
		logger:         log,
		httpServer:     &http.Server{},
		loggingEnabled: loggingEnabled,
	}
	server.httpServer.Handler = server

	// Set TCP keep-alive for connections
	server.httpServer.ConnState = func(conn net.Conn, state http.ConnState) {
		if state == http.StateNew {
			if tcpConn, ok := conn.(*net.TCPConn); ok {
				tcpConn.SetKeepAlive(true)
			}
		}
	}

	return server
}

// ListenAndServe starts the server on the given address
func (s *Server) ListenAndServe(addr string) error {
	s.httpServer.Addr = addr
	s.logger.Info("Server listening at http://localhost%s", addr)
	return s.httpServer.ListenAndServe()
}

// Shutdown gracefully shuts down the server
func (s *Server) Shutdown(ctx context.Context) error {
	s.logger.Info("Server shutting down...")
	return s.httpServer.Shutdown(ctx)
}

// ServeHTTP handles HTTP requests
func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	start := time.Now()

	// Wrap the ResponseWriter to capture status code
	wrappedWriter := newStatusCaptureWriter(w)

	// Process the request
	s.handleRequest(wrappedWriter, r)

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

	// Get the status code
	statusCode := wrappedWriter.StatusCode()

	// Log the request with our custom format
	if s.loggingEnabled {
		LogRequest(s.logger, statusCode, r, duration)
	}
}

// handleRequest processes the actual request
func (s *Server) handleRequest(w http.ResponseWriter, r *http.Request) {
	s.logger.Debug("Processing request %s %s", r.Method, r.URL.Path)

	// Try Lua routes first
	params := &routers.Params{}
	if bytecode, scriptPath, found := s.luaRouter.GetBytecode(r.Method, r.URL.Path, params); found {
		s.logger.Debug("Found Lua route match for %s %s with %d params", r.Method, r.URL.Path, params.Count)
		s.handleLuaRoute(w, r, bytecode, scriptPath, params)
		return
	}

	// Then try static files
	if filePath, found := s.staticRouter.Match(r.URL.Path); found {
		http.ServeFile(w, r, filePath)
		return
	}

	// No route found
	http.NotFound(w, r)
}

// handleLuaRoute executes a Lua route
func (s *Server) handleLuaRoute(w http.ResponseWriter, r *http.Request, bytecode []byte, scriptPath string, params *routers.Params) {
	ctx := runner.NewContext()

	// Log bytecode size
	s.logger.Debug("Executing Lua route with %d bytes of bytecode", len(bytecode))

	// Add request info directly to context
	ctx.Set("method", r.Method)
	ctx.Set("path", r.URL.Path)
	ctx.Set("host", r.Host)

	// Inline the header conversion (previously makeHeaderMap)
	headerMap := make(map[string]any, len(r.Header))
	for name, values := range r.Header {
		if len(values) == 1 {
			headerMap[name] = values[0]
		} else {
			headerMap[name] = values
		}
	}
	ctx.Set("headers", headerMap)

	// Add URL parameters
	if params.Count > 0 {
		paramMap := make(map[string]any, params.Count)
		for i := 0; i < params.Count; i++ {
			paramMap[params.Keys[i]] = params.Values[i]
		}
		ctx.Set("params", paramMap)
	}

	// Query parameters will be parsed lazily via metatable in Lua
	// Instead of parsing for every request, we'll pass the raw URL
	ctx.Set("rawQuery", r.URL.RawQuery)

	// Add form data for POST/PUT/PATCH only when needed
	if r.Method == http.MethodPost || r.Method == http.MethodPut || r.Method == http.MethodPatch {
		if formData, err := ParseForm(r); err == nil && len(formData) > 0 {
			ctx.Set("form", formData)
		}
	}

	// Execute Lua script
	result, err := s.luaRunner.Run(bytecode, ctx, scriptPath)
	if err != nil {
		s.logger.Error("Error executing Lua route: %v", err)
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
		return
	}

	writeResponse(w, result, s.logger)
}

// Content types for responses
const (
	contentTypeJSON  = "application/json"
	contentTypePlain = "text/plain"
)

// writeResponse writes the Lua result to the HTTP response
func writeResponse(w http.ResponseWriter, result any, log *logger.Logger) {
	if result == nil {
		w.WriteHeader(http.StatusNoContent)
		return
	}

	// Check for HTTPResponse type
	if httpResp, ok := result.(*runner.HTTPResponse); ok {
		// Set response headers
		for name, value := range httpResp.Headers {
			w.Header().Set(name, value)
		}

		// Set status code
		w.WriteHeader(httpResp.Status)

		// Process the body based on its type
		if httpResp.Body == nil {
			return
		}

		result = httpResp.Body // Set result to body for processing below
	}

	switch res := result.(type) {
	case string:
		// String result - plain text
		setContentTypeIfMissing(w, contentTypePlain)
		w.Write([]byte(res))
	default:
		// All other types - convert to JSON
		setContentTypeIfMissing(w, contentTypeJSON)
		data, err := json.Marshal(res)
		if err != nil {
			log.Error("Failed to marshal response: %v", err)
			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
			return
		}
		w.Write(data)
	}
}

func setContentTypeIfMissing(w http.ResponseWriter, contentType string) {
	if w.Header().Get("Content-Type") == "" {
		w.Header().Set("Content-Type", contentType)
	}
}