package main

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"recipe-manager/config"
	"recipe-manager/data"
	"recipe-manager/models"
	"recipe-manager/routers"
	"recipe-manager/services/logger"
	"recipe-manager/services/oauth"
	"recipe-manager/services/recipe"
	"recipe-manager/services/sheet"
	"strings"
	"sync"
	"time"

	"github.com/go-chi/chi/v5"
	"github.com/go-chi/cors"
	"github.com/gorilla/websocket"
	"github.com/spf13/viper"
	"go.uber.org/zap"
	"golang.org/x/oauth2"
)

var (
	Log             = logger.GetInstance()
	python_api_lock sync.Mutex

	upgrader = websocket.Upgrader{
		ReadBufferSize:  1024,
		WriteBufferSize: 1024,
		CheckOrigin:     func(r *http.Request) bool { return true },
	}
)

func loadConfig(path string) (*config.ServerConfig, error) {
	viper.AddConfigPath(path)
	viper.SetConfigName("app")
	viper.SetConfigType("env")

	viper.AutomaticEnv()

	var config config.ServerConfig
	err := viper.ReadInConfig()
	if err != nil {
		return nil, err
	}

	err = viper.Unmarshal(&config)
	if err != nil {
		return nil, err
	}

	return &config, nil
}

type Server struct {
	server *http.Server
	data   *data.Data
	cfg    *config.ServerConfig
	oauth  oauth.OAuthService
}

func NewServer() *Server {

	serverCfg, err := loadConfig(".")

	if err != nil {
		log.Fatal(err)
	}

	return &Server{
		server: &http.Server{Addr: fmt.Sprintf(":%d", serverCfg.ServerPort)},
		data:   data.NewData(),
		cfg:    serverCfg,
		oauth:  oauth.NewOAuthService(serverCfg),
	}
}

func (s *Server) Run() error {

	// logger
	// defer log_inst.Sync()

	if s.cfg.Debug {
		// logger.SetLevel("DEBUG")
		Log.Debug("Debug mode", zap.Bool("enable", s.cfg.Debug))
		logger.EnableDebug(s.cfg.Debug)
	}

	//go cli.CommandLineListener()

	s.createHandler()
	// log.Printf("Server running on %s", s.server.Addr)
	Log.Info("Server running", zap.String("addr", s.server.Addr))
	return s.server.ListenAndServe()
}

func (s *Server) createHandler() {
	r := chi.NewRouter()

	r.Use(cors.Handler(cors.Options{
		AllowedOrigins:   strings.Split(s.cfg.AllowedOrigins, ","),
		AllowedHeaders:   []string{"Accept", "Authorization", "Content-Type", "X-CSRF-Token"},
		AllowCredentials: true,
		ExposedHeaders:   []string{"Content-Type"},
		AllowedMethods:   []string{"GET", "POST", "PUT", "DELETE"},
	}))

	database := data.NewData()

	// Auth Router
	r.Group(func(r chi.Router) {
		ar := routers.NewAuthRouter(s.cfg, s.oauth)
		ar.Route(r)
	})

	// Protect Group
	r.Group(func(r chi.Router) {

		r.Use(func(next http.Handler) http.Handler {
			return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				token := &oauth2.Token{}

				if cookie, err := r.Cookie("access_token"); err == nil {
					token.AccessToken = cookie.Value
				}

				user, err := s.oauth.GetUserInfo(r.Context(), token)

				if err != nil {
					// if have refresh token, set refresh token to token
					if cookie, err := r.Cookie("refresh_token"); err == nil {
						token.RefreshToken = cookie.Value
					}

					newToken, err := s.oauth.RefreshToken(r.Context(), token)

					if err != nil {
						http.Error(w, "Unauthorized", http.StatusUnauthorized)
						return
					}

					// set new token to cookie
					w.Header().Add("set-cookie", fmt.Sprintf("access_token=%s; Path=/; HttpOnly; SameSite=None; Secure; Max-Age=3600", newToken.AccessToken))
				}

				ctx := context.WithValue(r.Context(), "user", user)

				next.ServeHTTP(w, r.WithContext(ctx))
			})
		})

		r.Post("/merge", func(w http.ResponseWriter, r *http.Request) {

			// locking
			if !pyAPIhandler(w, r) {
				Log.Warn("Merge - user tried to access while another user is requesting merge",
					zap.String("user", r.Context().Value("user").(*models.User).Name))
				return
			} else {
				Log.Debug("Merge - user has access", zap.String("user", r.Context().Value("user").(*models.User).Name))
			}

			var targetMap map[string]interface{}
			err := json.NewDecoder(r.Body).Decode(&targetMap)
			if err != nil {
				w.WriteHeader(http.StatusBadRequest)
				Log.Fatal("Merge request failed", zap.Error(err))
				return
			}
			repo_path := "cofffeemachineConfig/coffeethai02_"

			master_version := targetMap["master"].(string)
			dev_version := targetMap["dev"].(string)
			output_path := targetMap["output"].(string)
			changelog_path := targetMap["changelog"].(string)

			// find target file in the cofffeemachineConfig
			if _, err := os.Stat(repo_path + master_version + ".json"); err != nil {
				w.WriteHeader(http.StatusBadRequest)
				Log.Fatal("Merge request failed. Master file not found: ", zap.Error(err))
				return
			}
			if _, err := os.Stat(repo_path + dev_version + ".json"); err != nil {
				w.WriteHeader(http.StatusBadRequest)
				Log.Fatal("Merge request failed. Dev file not found: ", zap.Error(err))
				return
			}

			master_path := repo_path + master_version + ".json"
			dev_path := repo_path + dev_version + ".json"

			// Get who's requesting
			user := r.Context().Value("user").(*models.User)
			Log.Info("Request merge by", zap.String("user", user.Name))

			// lookup for python exec
			py_exec, err := exec.LookPath("python")
			if err != nil {
				Log.Fatal("Python error: ", zap.Error(err))
			} else {
				py_exec, err = filepath.Abs(py_exec)
			}

			Log.Info("Found python exec: ", zap.String("PythonPath", py_exec))
			// target api file
			merge_api, api_err := os.Open("./python_api/merge_recipe.py")
			if api_err != nil {
				Log.Fatal("Merge request failed. Python api error: ", zap.String("ApiErr", api_err.Error()))
			}
			defer merge_api.Close()
			// log.Println("Locate python api", merge_api.Name())
			Log.Info("Locate python api", zap.String("ApiName", merge_api.Name()))
			cmd := exec.Command(py_exec, merge_api.Name(), "merge", master_path, dev_path, output_path, changelog_path, "", user.Name)

			// log.Println("Run merge command", cmd)
			Log.Info("Merge", zap.String("master", master_path), zap.String("dev", dev_path), zap.String("output", output_path))
			Log.Debug("Run merge command", zap.String("Command", cmd.String()))
			out, err := cmd.CombinedOutput()
			// log.Println(string(out))
			Log.Debug("Merge output", zap.String("Output", string(out)))
			if err != nil {
				// log.Fatalln("Merge request failed. Python merge failed: ", err)
				Log.Fatal("Merge request failed. Python merge failed", zap.Error(err))
			}

			w.Header().Add("Content-Type", "application/json")
			w.WriteHeader(http.StatusOK)
			json.NewEncoder(w).Encode(map[string]string{"message": "Merge success"})
			Log.Info("Merge success", zap.String("output", "merge success"))
		})

		r.Post("/dllog", func(w http.ResponseWriter, r *http.Request) {
			Log.Debug("Request uri = ", zap.String("uri", r.RequestURI))

			Log.Debug("Query param = ", zap.String("query", r.URL.Query().Get("query")))
			// param
			param := r.URL.Query().Get("query")
			Log.Debug("Param = ", zap.String("param", param))

			var postRequest map[string]interface{}
			err := json.NewDecoder(r.Body).Decode(&postRequest)
			Log.Debug("Log request: ", zap.String("postRequest", fmt.Sprintf("%+v", postRequest)))

			if err != nil {
				w.WriteHeader(http.StatusBadRequest)
				Log.Fatal("Decode in request failed: ", zap.Error(err))
				return
			}

			file_ext := ".html"
			if rb, ok := postRequest["htmlfile"].(bool); ok {
				if rj, ok := postRequest["requestJson"].(bool); ok {
					if rj {
						file_ext = ".json"
					} else if !rb && !rj {
						file_ext = ".log"
					}
				}
			}

			log_name := postRequest["filename"].(string)
			Log.Warn("Log file name: ", zap.String("filename", log_name))

			if log_name == "" {
				Log.Fatal("Empty log file name")
			}

			// log.Println("Log file ext: ", file_ext)
			default_changelog_path := "cofffeemachineConfig/" + param + "/"
			Log.Debug("Default changelog path: ", zap.String("default_changelog_path", default_changelog_path))

			changelog_path := default_changelog_path + log_name + file_ext
			Log.Debug("Changelog path: ", zap.String("changelog_path", changelog_path))
			if strings.Contains(log_name, "cofffeemachineConfig") && strings.Contains(log_name, ".json") {
				changelog_path = log_name
			}

			logFile, err := os.Open(changelog_path)
			if err != nil {
				Log.Fatal("Log request failed: ", zap.Error(err))
				http.Error(w, err.Error(), http.StatusInternalServerError)
			}

			defer logFile.Close()

			if file_ext == ".json" {

				var logFileJson map[string]interface{}
				err = json.NewDecoder(logFile).Decode(&logFileJson)
				if err != nil {
					Log.Fatal("Error when decode log file: ", zap.Error(err))
				}

				w.Header().Set("Content-Type", "application/json")
				w.WriteHeader(http.StatusOK)
				json.NewEncoder(w).Encode(logFileJson)
				Log.Info("Log file: ", zap.String("filename", log_name))
			} else {
				w.Header().Set("Content-Disposition", "attachment; filename=logfile"+file_ext)
				w.Header().Set("Content-Type", "application/octet-stream")

				_, err = io.Copy(w, logFile)
				if err != nil {
					Log.Fatal("Could not send blob", zap.Error(err))
					http.Error(w, err.Error(), http.StatusInternalServerError)
					return
				}
			}

		})

		r.Get("/listFileInDir/*", func(w http.ResponseWriter, r *http.Request) {

			//spl
			spl_path := strings.Split(r.RequestURI, "/")
			if len(spl_path) > 3 {
				Log.Warn("Unexpected depth: ",
					zap.String("path", r.RequestURI),
					zap.String("depth", fmt.Sprintf("%d", len(spl_path))))
			}

			if spl_path[2] == "" {
				Log.Error("Empty target dir", zap.String("path", r.RequestURI))
			}

			Log.Debug("Split path = ", zap.Any("paths", spl_path))

			// Log.Info("Target dir: ", zap.String("dir", "cofffeemachineConfig"))

			main_folder := "cofffeemachineConfig"
			target_path := main_folder + "/" + spl_path[2]

			dir, err := os.ReadDir(target_path)
			if err != nil {
				Log.Error("Error while trying to read dir: ", zap.String("dir", target_path), zap.Error(err))
				http.Error(w, err.Error(), http.StatusInternalServerError)
			}

			// File ext
			file_ext := ".json"
			switch spl_path[2] {
			case "changelog":
				file_ext = ".html"
				break
			case "merge":
				file_ext = ".json"
				break
			}
			Log.Debug("Set file ext = ", zap.String("file_ext", file_ext))

			displayable := make([]string, 0)
			for _, file := range dir {
				if strings.Contains(file.Name(), file_ext) {
					Log.Debug("Found file: ", zap.String("file", file.Name()))
					displayable = append(displayable, file.Name()[:len(file.Name())-len(filepath.Ext(file.Name()))])
				}
			}

			// send back
			w.Header().Set("Content-Type", "application/json")
			w.WriteHeader(http.StatusOK)
			json.NewEncoder(w).Encode(map[string][]string{"dirs": displayable})
			Log.Debug("Scan dir completed < ", zap.String("path", r.RequestURI))
		})

		r.Get("/get_log_relation", func(w http.ResponseWriter, r *http.Request) {

			// Python looker
			py_exec, err := exec.LookPath("python")
			if err != nil {
				Log.Error("Error while trying to find python: ", zap.Error(err))
				http.Error(w, err.Error(), http.StatusInternalServerError)
			}

			merge_timeline, api_err := os.Open("./python_api/merge_timeline.py")
			if api_err != nil {
				Log.Error("Error while trying to open merge_timeline.json: ", zap.Error(api_err))
				http.Error(w, api_err.Error(), http.StatusInternalServerError)
			}
			defer merge_timeline.Close()

			cmd := exec.Command(py_exec, merge_timeline.Name(), "get_relate")

			Log.Debug("Command: ", zap.String("command", cmd.String()))

			out, err := cmd.CombinedOutput()

			Log.Debug("Output: ", zap.String("output", string(out)))

			if err != nil {
				Log.Error("Error while trying to run python: ", zap.Error(err))
				http.Error(w, err.Error(), http.StatusInternalServerError)
			}

			// clean up output
			clean1 := strings.ReplaceAll(string(out), "\n", "")
			clean2 := strings.ReplaceAll(clean1, "\r", "")

			w.Header().Set("Content-Type", "application/json")
			w.WriteHeader(http.StatusOK)
			json.NewEncoder(w).Encode(map[string]interface{}{
				"message": clean2,
			})
		})

		r.Post("/diffpy/*", func(w http.ResponseWriter, r *http.Request) {
			Log.Debug("Diffpy: ", zap.String("path", r.RequestURI))
			// TODO: add command exec `python_Exec` `merge_recipe.py` `diff` `master_version` `version-version-version` `debug?` `flatten={true|false}` `out={true|false}`
		})

		sheetService, err := sheet.NewSheetService(context.Background(), s.cfg)

		if err != nil {
			Log.Fatal("Error while trying to create sheet service: ", zap.Error(err))
			return
		}

		// Recipe Service
		rs := recipe.NewRecipeService(database)

		// Recipe Router
		rr := routers.NewRecipeRouter(database, rs, sheetService)
		rr.Route(r)

		// Material Router
		mr := routers.NewMaterialRouter(database)
		mr.Route(r)

	})

	r.NotFound(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Add("Content-Type", "application/json")
		w.WriteHeader(http.StatusNotFound)
		json.NewEncoder(w).Encode(map[string]string{"message": fmt.Sprintf("path %s are not exits", r.RequestURI)})
	})

	s.server.Handler = r
}

func (s *Server) Shutdown(ctx context.Context) error {
	return s.server.Shutdown(ctx)
}

func pyAPIhandler(w http.ResponseWriter, r *http.Request) bool {
	timeout := 10 * time.Second

	if !lockThenTimeout(&python_api_lock, timeout) {
		http.Error(w, "API is busy", http.StatusServiceUnavailable)
		return false
	}
	defer python_api_lock.Unlock()
	return true
}

func lockThenTimeout(mutex *sync.Mutex, timeout time.Duration) bool {
	ch := make(chan struct{})
	go func() {
		mutex.Lock()
		close(ch)
	}()
	select {
	case <-ch:
		return true
	case <-time.After(timeout):
		return false
	}
}