package http

import (
	"context"
	"sync"
	"time"

	"Moonshark/routers"
	"Moonshark/runner"
	"Moonshark/sessions"
	"Moonshark/utils"
	"Moonshark/utils/config"
	"Moonshark/utils/logger"
	"Moonshark/utils/metadata"

	"github.com/valyala/fasthttp"
)

// Server handles HTTP requests using Lua and static file routers
type Server struct {
	luaRouter      *routers.LuaRouter
	staticRouter   *routers.StaticRouter
	luaRunner      *runner.Runner
	fasthttpServer *fasthttp.Server
	loggingEnabled bool
	debugMode      bool
	config         *config.Config
	sessionManager *sessions.SessionManager
	errorConfig    utils.ErrorPageConfig
	ctxPool        sync.Pool
}

// New creates a new HTTP server
func New(luaRouter *routers.LuaRouter, staticRouter *routers.StaticRouter,
	runner *runner.Runner, loggingEnabled bool, debugMode bool,
	overrideDir string, config *config.Config) *Server {

	server := &Server{
		luaRouter:      luaRouter,
		staticRouter:   staticRouter,
		luaRunner:      runner,
		loggingEnabled: loggingEnabled,
		debugMode:      debugMode,
		config:         config,
		sessionManager: sessions.GlobalSessionManager,
		errorConfig: utils.ErrorPageConfig{
			OverrideDir: overrideDir,
			DebugMode:   debugMode,
		},
		ctxPool: sync.Pool{
			New: func() any {
				return make(map[string]any, 8)
			},
		},
	}

	server.fasthttpServer = &fasthttp.Server{
		Handler:                      server.handleRequest,
		Name:                         "Moonshark/" + metadata.Version,
		ReadTimeout:                  30 * time.Second,
		WriteTimeout:                 30 * time.Second,
		MaxRequestBodySize:           16 << 20, // 16MB
		DisableKeepalive:             false,
		TCPKeepalive:                 true,
		TCPKeepalivePeriod:           60 * time.Second,
		ReduceMemoryUsage:            true,
		GetOnly:                      false,
		DisablePreParseMultipartForm: true,
	}

	return server
}

// ListenAndServe starts the server on the given address
func (s *Server) ListenAndServe(addr string) error {
	logger.Server("Catch the swell at http://localhost%s", addr)
	return s.fasthttpServer.ListenAndServe(addr)
}

// Shutdown gracefully shuts down the server
func (s *Server) Shutdown(ctx context.Context) error {
	return s.fasthttpServer.ShutdownWithContext(ctx)
}

// handleRequest processes the HTTP request
func (s *Server) handleRequest(ctx *fasthttp.RequestCtx) {
	start := time.Now()
	methodBytes := ctx.Method()
	pathBytes := ctx.Path()

	// Only convert to string once
	method := string(methodBytes)
	path := string(pathBytes)

	if s.debugMode && path == "/debug/stats" {
		s.handleDebugStats(ctx)
		if s.loggingEnabled {
			LogRequest(ctx.Response.StatusCode(), method, path, time.Since(start))
		}
		return
	}

	s.processRequest(ctx, method, path)

	if s.loggingEnabled {
		LogRequest(ctx.Response.StatusCode(), method, path, time.Since(start))
	}
}

// In server.go, modify the processRequest method
func (s *Server) processRequest(ctx *fasthttp.RequestCtx, method, path string) {
	logger.Debug("Processing request %s %s", method, path)

	params := &routers.Params{}
	bytecode, scriptPath, routeErr, found := s.luaRouter.GetRouteInfo(method, path, params)

	if found && (len(bytecode) == 0 || routeErr != nil) {
		errorMsg := "Route exists but failed to compile. Check server logs for details."
		if routeErr != nil {
			errorMsg = routeErr.Error()
		}

		logger.Error("%s %s - %s", method, path, errorMsg)
		ctx.SetContentType("text/html; charset=utf-8")
		ctx.SetStatusCode(fasthttp.StatusInternalServerError)
		ctx.SetBody([]byte(utils.InternalErrorPage(s.errorConfig, path, errorMsg)))
		return
	}

	if found {
		logger.Debug("Found Lua route match for %s %s with %d params", method, path, params.Count)
		s.handleLuaRoute(ctx, bytecode, scriptPath, params, method, path)
		return
	}

	if s.staticRouter != nil {
		if _, found := s.staticRouter.Match(path); found {
			s.staticRouter.ServeHTTP(ctx)
			return
		}
	}

	ctx.SetContentType("text/html; charset=utf-8")
	ctx.SetStatusCode(fasthttp.StatusNotFound)
	ctx.SetBody([]byte(utils.NotFoundPage(s.errorConfig, path)))
}

// handleLuaRoute executes a Lua route
func (s *Server) handleLuaRoute(ctx *fasthttp.RequestCtx, bytecode []byte, scriptPath string, params *routers.Params, method, path string) {
	luaCtx := runner.NewHTTPContext(ctx)
	defer luaCtx.Release()

	// Get pooled map for session data
	sessionMap := s.ctxPool.Get().(map[string]any)
	defer func() {
		// Clear and return to pool
		for k := range sessionMap {
			delete(sessionMap, k)
		}
		s.ctxPool.Put(sessionMap)
	}()

	session := s.sessionManager.GetSessionFromRequest(ctx)
	sessionMap["id"] = session.ID
	sessionMap["data"] = session.Data

	luaCtx.Set("method", method)
	luaCtx.Set("path", path)
	luaCtx.Set("host", string(ctx.Host())) // Only convert when needed
	luaCtx.Set("session", sessionMap)

	// Optimize params handling
	if params.Count > 0 {
		paramMap := make(map[string]any, params.Count) // Pre-size
		for i, key := range params.Keys {
			paramMap[key] = params.Values[i]
		}
		luaCtx.Set("params", paramMap)
	} else {
		luaCtx.Set("params", emptyMap) // Reuse empty map
	}

	// Optimize form handling for POST methods
	if method == "POST" || method == "PUT" || method == "PATCH" {
		if formData, err := ParseForm(ctx); err == nil {
			luaCtx.Set("form", formData)
		} else {
			logger.Warning("Error parsing form: %v", err)
			luaCtx.Set("form", emptyMap)
		}
	} else {
		luaCtx.Set("form", emptyMap)
	}

	response, err := s.luaRunner.Run(bytecode, luaCtx, scriptPath)
	if err != nil {
		logger.Error("Error executing Lua route: %v", err)
		ctx.SetContentType("text/html; charset=utf-8")
		ctx.SetStatusCode(fasthttp.StatusInternalServerError)
		ctx.SetBody([]byte(utils.InternalErrorPage(s.errorConfig, path, err.Error())))
		return
	}

	// Session handling optimization
	if _, clearAll := response.SessionData["__clear_all"]; clearAll {
		session.Clear()
		delete(response.SessionData, "__clear_all")
	}

	for k, v := range response.SessionData {
		if v == "__SESSION_DELETE_MARKER__" {
			session.Delete(k)
		} else {
			session.Set(k, v)
		}
	}

	s.sessionManager.ApplySessionCookie(ctx, session)
	runner.ApplyResponse(response, ctx)
	runner.ReleaseResponse(response)
}

// handleDebugStats displays debug statistics
func (s *Server) handleDebugStats(ctx *fasthttp.RequestCtx) {
	stats := utils.CollectSystemStats(s.config)

	routeCount, bytecodeBytes := s.luaRouter.GetRouteStats()

	stats.Components = utils.ComponentStats{
		RouteCount:    routeCount,
		BytecodeBytes: bytecodeBytes,
		SessionStats:  sessions.GlobalSessionManager.GetCacheStats(),
	}

	ctx.SetContentType("text/html; charset=utf-8")
	ctx.SetStatusCode(fasthttp.StatusOK)
	ctx.SetBody([]byte(utils.DebugStatsPage(stats)))
}