package utils

import (
	"fmt"
	"log"
	"net/http"
	"strings"

	"github.com/dustinpianalto/errors"
	"github.com/dustinpianalto/quartermaster"
	"github.com/dustinpianalto/quartermaster/internal/jwt"
	"github.com/dustinpianalto/quartermaster/pkg/services"
	"github.com/gorilla/mux"
)

func Mount(r *mux.Router, path string, handler http.Handler) {
	r.PathPrefix(path).Handler(
		http.StripPrefix(
			strings.TrimSuffix(path, "/"),
			handler,
		),
	)
}

type RootHandler func(*http.ResponseWriter, *http.Request) error

func (rh RootHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	err := rh(&w, r)
	if err == nil {
		return
	}

	log.Println(err)

	e, ok := err.(*errors.Error)
	if !ok {
		w.WriteHeader(http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json; charset=utf-8")

	if errors.Is(errors.Permission, e) {
		body := getErrorBody("Permission Denied")
		w.WriteHeader(http.StatusForbidden)
		w.Write(body)
	}

	if errors.Is(errors.Incorrect, e) && strings.Contains(string(e.Method), "login") {
		body := getErrorBody("Invalid Login Credentials")
		w.WriteHeader(http.StatusUnauthorized)
		w.Write(body)
	}

	if errors.Is(errors.Incorrect, e) && strings.Contains(string(e.Method), "refresh") {
		body := getErrorBody("Missing or Invalid Cookie")
		w.WriteHeader(http.StatusUnauthorized)
		w.Write(body)
	}

	if errors.Is(errors.Malformed, e) {
		body := getErrorBody("Bad Request")
		w.WriteHeader(http.StatusBadRequest)
		w.Write(body)
	}

	if errors.Is(errors.Internal, e) {
		body := getErrorBody("Internal Server Error")
		w.WriteHeader(http.StatusInternalServerError)
		w.Write(body)
	}

	if errors.Is(errors.Conflict, e) && strings.Contains(string(e.Method), "register") {
		body := getErrorBody("User already exists")
		w.WriteHeader(http.StatusConflict)
		w.Write(body)
	}
}

func getErrorBody(s string) []byte {
	return []byte(fmt.Sprintf("{\"error\": \"%s\"}", s))
}

type authenticatedHandler func(*http.ResponseWriter, *http.Request, *quartermaster.User) error

func AuthenticationMiddleware(next authenticatedHandler) RootHandler {
	const method = "utils/AuthenticationMiddleware"
	return RootHandler(func(w *http.ResponseWriter, r *http.Request) error {
		claims, err := jwt.AuthenticateJWTToken(r)
		if err != nil {
			return errors.E(method, errors.Permission, "invalid token", err)
		}

		u, err := services.UserService.User(claims.Username)
		if err != nil {
			return errors.E(method, errors.Permission, "user not found", err)
		}

		err = next(w, r, u)
		if err != nil {
			return errors.E(method, "error in handler", err)
		}
		return nil
	})
}