package ext

import (
	"context"
	"encoding/base64"
	"errors"
	"net/http"
	"time"

	"github.com/sirupsen/logrus"

	"git.sr.ht/~gabrielgio/img/pkg/database/repository"
	"git.sr.ht/~gabrielgio/img/pkg/service"
)

func HTML(next http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "text/html")
		next(w, r)
	}
}

type LogMiddleware struct {
	entry *logrus.Entry
}

func NewLogMiddleare(log *logrus.Entry) *LogMiddleware {
	return &LogMiddleware{
		entry: log,
	}
}

func (l *LogMiddleware) HTTP(next http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		start := time.Now()
		next(w, r)
		elapsed := time.Since(start)
		l.entry.
			WithField("time", elapsed).
			WithField("path", r.URL.Path).
			Info(r.Method)
	}
}

type AuthMiddleware struct {
	key   []byte
	entry *logrus.Entry
}

func NewAuthMiddleware(key []byte, log *logrus.Entry) *AuthMiddleware {
	return &AuthMiddleware{
		key:   key,
		entry: log.WithField("context", "auth"),
	}
}

func (a *AuthMiddleware) LoggedIn(next http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		path := string(r.URL.Path)
		if path == "/login" || path == "/initial" {
			next(w, r)
			return
		}

		redirectLogin := "/login?redirect=" + path
		authBase64, err := r.Cookie("auth")
		if errors.Is(err, http.ErrNoCookie) {
			a.entry.Info("No auth provided")
			http.Redirect(w, r, redirectLogin, http.StatusTemporaryRedirect)
			return
		}

		auth, err := base64.StdEncoding.DecodeString(authBase64.Value)
		if err != nil {
			a.entry.Error(err)
			return
		}

		token, err := service.ReadToken(auth, a.key)
		if err != nil {
			a.entry.Error(err)
			http.Redirect(w, r, redirectLogin, http.StatusTemporaryRedirect)
			return
		}
		r = r.WithContext(context.WithValue(r.Context(), "token", token))
		a.entry.
			WithField("userID", token.UserID).
			WithField("username", token.Username).
			Info("user recognized")
		next(w, r)
	}
}

func GetTokenFromCtx(w http.ResponseWriter, r *http.Request) *service.Token {
	tokenValue := r.Context().Value("token")
	if token, ok := tokenValue.(*service.Token); ok {
		return token
	}
	return nil
}

type InitialSetupMiddleware struct {
	userRepository repository.UserRepository
}

func NewInitialSetupMiddleware(userRepository repository.UserRepository) *InitialSetupMiddleware {
	return &InitialSetupMiddleware{
		userRepository: userRepository,
	}
}

func (i *InitialSetupMiddleware) Check(next http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		// if user has been set to context it is logged in already
		token := GetTokenFromCtx(w, r)
		if token == nil {
			next(w, r)
			return
		}

		path := r.URL.Path
		if path == "/initial" {
			next(w, r)
			return
		}

		exists, err := i.userRepository.Any(r.Context())
		if err != nil {
			InternalServerError(w, err)
			return
		}

		if exists {
			next(w, r)
			return
		}
		http.Redirect(w, r, "/initial", http.StatusTemporaryRedirect)
	}
}