package server

import (
	"context"
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"net/http"

	"git.pyer.club/kingecg/gologger"
	"git.pyer.club/kingecg/gotunnelserver/util"
	"github.com/gorilla/websocket"
)

var upgrader = websocket.Upgrader{
	ReadBufferSize:  1024,
	WriteBufferSize: 1024,
}

type ServerConfig struct {
	Port   string                  `json:"port"`
	Host   string                  `json:"host"`
	Cert   string                  `json:"cert"`
	Key    string                  `json:"key"`
	Salt   string                  `json:"salt"`
	Logger *gologger.LoggersConfig `json:"log"`
}

type Server struct {
	*http.Server
	mux    *http.ServeMux
	Config *ServerConfig
	logger *gologger.Logger
}

func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	s.logger.Info("request:", r.URL.Path)
	nr, ok := s.auth(r)
	if !ok {
		s.HandleUnAutherized(w, nr)
	} else {
		s.mux.ServeHTTP(w, nr)
	}
}

func (s *Server) auth(r *http.Request) (*http.Request, bool) {
	s.logger.Debug("auth:", r.RemoteAddr)
	lpath := r.URL.Path
	if lpath == "/" || lpath == "/hello" {
		return r, true
	}
	token := r.Header.Get("Authorization")
	if token == "" {
		return r, false
	}
	authEntity, err := util.ParseAuthEntity(token)
	if err != nil {
		return r, false
	}
	if strings.HasPrefix(lpath, "/ws/pipe") && authEntity.Token == "nil" {
		return r, false
	}
	if !util.VerifyAuth(authEntity, s.Config.Key) {
		return r, false
	}
	//set auth entity to request context
	ctx := r.Context()
	nctx := context.WithValue(ctx, "authEntity", authEntity)
	return r.WithContext(nctx), true
}
func (s *Server) Shutdown() {
	s.logger.Info("shutdown server")
	s.Close()
}

func (s *Server) HandleHello(w http.ResponseWriter, r *http.Request) {
	w.Write([]byte("hello"))
}

func (s *Server) HandleUnAutherized(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusUnauthorized)
}
func (s *Server) HandleWs(w http.ResponseWriter, r *http.Request) {
	lpath := r.URL.Path
	lpath = strings.TrimPrefix(lpath, "/ws/")
	c, err := upgrader.Upgrade(w, r, nil)
	if err != nil {
		s.logger.Error("upgrade failed:", err)
		return
	}
	if strings.HasPrefix(lpath, "client") {
		s.HandleClient(c, r)
	} else if strings.HasPrefix(lpath, "agent") {
		s.HandleAgent(c, r)
	} else if strings.HasPrefix(lpath, "pipe") {
		s.HandlePipe(c, r)
	} else {
		s.logger.Error("unknown path:", lpath)
		c.Close()
	}
}
func (s *Server) registHandler() {
	if s.mux == nil {
		s.mux = http.NewServeMux()
	}
	s.mux.HandleFunc("/hello", s.HandleHello)
	s.mux.HandleFunc("/ws", s.HandleWs)
}
func (s *Server) Start() {
	addr := s.Config.Host + ":" + s.Config.Port
	s.Server.Addr = addr

	s.Server.Handler = s
	s.registHandler()
	if s.Config.Cert != "" && s.Config.Key != "" {
		s.logger.Info("start https server")
		s.ListenAndServeTLS(s.Config.Cert, s.Config.Key)
	} else {
		s.logger.Info("start http server")
		s.ListenAndServe()
	}
}

func New(configFile string) *Server {
	// load config from configFile
	config, err := LoadConfig(configFile)
	if err != nil {
		return nil
	}
	gologger.Configure(*config.Logger)
	logger := gologger.GetLogger("server")
	logger.Info("create server")
	server := &Server{
		Server: &http.Server{},
		Config: config,
		logger: logger,
	}
	return server
}

func LoadConfig(configFile string) (conf *ServerConfig, err error) {
	aconfPath := configFile
	if aconfPath == "" {
		aconfPath = "conf.json"
	}
	if !filepath.IsAbs(aconfPath) {
		aconfPath, _ = filepath.Abs(aconfPath)
	}
	fileConten, err := os.ReadFile(aconfPath)
	if err != nil {
		fmt.Printf("read config file failed: %s", err)
		return nil, err
	}
	conf = new(ServerConfig)
	err = json.Unmarshal(fileConten, conf)
	if err != nil {
		fmt.Printf("parse config file failed: %s", err)
		return nil, err
	}
	if conf.Cert != "" && conf.Key != "" {
		conf.Cert = Abs(filepath.Dir(aconfPath), conf.Cert)
		conf.Key = Abs(filepath.Dir(aconfPath), conf.Key)
	} else {
		conf.Cert = ""
		conf.Key = ""
	}
	return conf, nil
}

func Abs(basePath string, path string) string {
	if filepath.IsAbs(path) {
		return path
	}
	return filepath.Join(basePath, path)
}