package v1

import (
	"crypto/md5"
	"database/sql"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"strconv"
	"strings"

	"github.com/dgrijalva/jwt-go"
	"github.com/getsentry/sentry-go"
	"github.com/gorilla/mux"
)

var lpServer *LongPollServer

func RegisterRouters(r *mux.Router) {
	sub := r.PathPrefix("/v1").Subrouter()

	lpServer = InitLongPollServer()

	sub.Use(apiMiddleware)
	sub.Use(LimitMiddleware)
	go CleanupVisitors()
	sub.Use(JWTMiddleware)

	sub.HandleFunc("/version", func(w http.ResponseWriter, _ *http.Request) {
		Response(w, nil, map[string]string{
			"version": config.Version,
			"build":   strconv.Itoa(int(config.Build)),
		})
	})

	RegisterAuthRoutes(sub)
	RegisterUsersRoutes(sub)
	RegisterNovelsRoutes(sub)
	RegisterCharactersRoutes(sub)
	RegisterGenresRoutes(sub)
	RegisterGamesRoutes(sub)
	RegisterClubRoutes(sub)
	RegisterGroupsRoutes(sub)
	RegisterNewsRoutes(sub)
	RegisterTokensRouter(sub)
	RegisterLongPollRoutes(sub)

	if config.Debug {
		err := sub.Walk(func(route *mux.Route, _ *mux.Router, _ []*mux.Route) error {
			path, err := route.GetPathTemplate()
			if err != nil {
				return err
			}
			log.Printf("loading path %s\n", path)
			return nil
		})

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

func Response(w http.ResponseWriter, err error, data interface{}) {
	const baseResponse = `{"error":false,"data":%v}`

	if err != nil {
		if err == sql.ErrNoRows {
			NotFound.Ferror(w)
		} else {
			w.WriteHeader(http.StatusInternalServerError)
			Error(w, err)
		}
	} else {
		j, err := json.Marshal(&data)
		if err != nil {
			fmt.Println(err)
			sentry.CaptureException(err)
			return
		}

		_, err = fmt.Fprintf(w, baseResponse, string(j))
		if err != nil {
			fmt.Println(err)
			sentry.CaptureException(err)
		}
	}
}

func ResponsePagination(w http.ResponseWriter, err error, data interface{}, pagination interface{}) {
	const baseResponse = `{"error":false,"pagination":%v,"data":%v}`

	if err != nil {
		if err == sql.ErrNoRows {
			NotFound.Ferror(w)
		} else {
			w.WriteHeader(http.StatusInternalServerError)
			Error(w, err)
		}
	} else {
		jsonData, err := json.Marshal(&data)
		if err != nil {
			fmt.Println(err)
			sentry.CaptureException(err)
			return
		}

		jsonPagination, err := json.Marshal(&pagination)
		if err != nil {
			fmt.Println(err)
			sentry.CaptureException(err)
			return
		}

		_, err = fmt.Fprintf(w, baseResponse, string(jsonPagination), string(jsonData))
		if err != nil {
			fmt.Println(err)
			sentry.CaptureException(err)
		}
	}
}

func RawError(w http.ResponseWriter, e string) {
	const baseError = `{"error":true,"error_data":{"code":-1,"text":"%v"}}`

	_, err := fmt.Fprintf(w, baseError, strings.ReplaceAll(e, `"`, `\"`))
	if err != nil {
		fmt.Println(err)
		sentry.CaptureException(err)
	}
}

func Error(w http.ResponseWriter, e error) {
	const baseError = `{"error":true,"error_data":{"code":-1,"text":"%v"}}`

	_, err := fmt.Fprintf(w, baseError, strings.ReplaceAll(e.Error(), `"`, `\"`))
	if err != nil {
		fmt.Println(err)
		sentry.CaptureException(err)
	}
}

func JSON(w http.ResponseWriter, data string) {
	_, err := fmt.Fprint(w, data)
	if err != nil {
		fmt.Println(err)
		sentry.CaptureException(err)
	}
}

func ReadBody(r *http.Request) ([]byte, error) {
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		return nil, err
	}

	err = r.Body.Close()
	return body, err
}

func MD5(s string) string {
	hash := md5.New()
	hash.Write([]byte(s))
	return hex.EncodeToString(hash.Sum(nil))
}

func GetCurrentUserID(r *http.Request) (uint64, error) {
	tokenCookie, err := r.Cookie("token")
	if err != nil {
		return 0, err
	}
	token, err := jwt.Parse(tokenCookie.Value, func(token *jwt.Token) (interface{}, error) {
		if token.Method != jwt.SigningMethodHS256 {
			return nil, fmt.Errorf("invalid singning method: %s", token.Method)
		}
		return []byte(privateConfig.AuthTokenSecret), nil
	})
	if err != nil {
		return 0, err
	}
	claims := token.Claims.(jwt.MapClaims)
	id := int(claims["id"].(float64))
	return uint64(id), nil
}

func apiMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Header.Get("Dev") == "1" {
			w.Header().Add("Access-Control-Allow-Origin", config.DevFrontendUrl)
		} else {
			w.Header().Add("Access-Control-Allow-Origin", config.FrontendUrl)
		}
		w.Header().Add("Access-Control-Allow-Credentials", "true")
		w.Header().Add("Content-Type", "application/json; charset=utf-8")
		//w.Header().Add("Cache-Control", "max-age=60")

		if r.Method == http.MethodOptions {
			w.Header().Add("Access-Control-Allow-Headers", "Content-Type, Date, Content-Length, Location, dev, cache")
			w.Header().Add("Access-Control-Allow-Methods", "GET, POST, DELETE, PUT, OPTIONS")
			return
		}

		if database == nil {
			log.Println("db not initialized")
			return
		}
		err := database.Ping()
		if err != nil && strings.Contains(err.Error(), "broken pipe") {
			ConnectToDB()
			log.Println("connection to db reopened")
		}

		next.ServeHTTP(w, r)
	})
}