// Copyright 2023 wanderer <a_mirre at utb dot cz>
// SPDX-License-Identifier: AGPL-3.0-only

package handlers

import (
	"context"
	"net/http"
	"strings"

	moduser "git.dotya.ml/mirre-mt/pcmt/modules/user"
	"github.com/CAFxX/httpcompression"
	"github.com/CAFxX/httpcompression/contrib/andybalholm/brotli"
	"github.com/CAFxX/httpcompression/contrib/compress/gzip"
	"github.com/labstack/echo-contrib/session"
	"github.com/labstack/echo/v4"
)

func MiddlewareSession(next echo.HandlerFunc) echo.HandlerFunc {
	return func(c echo.Context) error {
		if c.Request().URL.Path == "/logout" && c.Request().Method == "POST" {
			log.Debug("skipping auth middleware on /logout POST", "module", "handlers/middleware")
			return next(c)
		}

		sess, _ := session.Get(setting.SessionCookieName(), c)

		if sess == nil {
			return renderErrorPage(
				c,
				http.StatusUnauthorized,
				http.StatusText(http.StatusUnauthorized)+" you need to log in again",
				"you need to log in again",
			)
		}

		if username, ok := sess.Values["username"].(string); ok {
			log.Info("Refreshing session cookie",
				"username", username,
				"module", "middleware",
				"maxAge", setting.SessionMaxAge(),
				"secure", setting.HTTPSecure(),
				"domain", setting.HTTPDomain(),
			)

			refreshSession(
				sess,
				"/",
				setting.SessionMaxAge(),
				true,
				setting.HTTPSecure(),
				http.SameSiteStrictMode,
			)

			sess.Values["username"] = username

			c.Set("sess", sess)

			var u moduser.User

			ctx := context.WithValue(context.Background(), moduser.CtxKey{}, slogger)
			if usr, err := moduser.QueryUser(ctx, dbclient, username); err == nil && usr != nil {
				u.ID = usr.ID
				u.Username = usr.Username
				u.IsAdmin = usr.IsAdmin
				u.CreatedAt = usr.CreatedAt
				u.IsActive = usr.IsActive
				u.IsLoggedIn = true
			} else {
				c.Logger().Error(http.StatusText(http.StatusInternalServerError) + " - " + err.Error())

				return renderErrorPage(
					c,
					http.StatusInternalServerError,
					http.StatusText(http.StatusInternalServerError),
					err.Error(),
				)
			}

			c.Set("sloggerCtx", ctx)
			c.Set("sessUsr", u)

			if err := sess.Save(c.Request(), c.Response()); err != nil {
				log.Error("Failed to save session", "module", "middleware")

				return renderErrorPage(
					c,
					http.StatusInternalServerError,
					http.StatusText(http.StatusInternalServerError)+" (make sure you've got cookies enabled)",
					err.Error(),
				)
			}

			return next(c)
		}

		log.Warn("Could not get username from the cookie", "module", "handlers/middleware")

		if !sess.IsNew {
			log.Warn("Expired session cookie (without a username) found, redirecting to sign in", "module", "handlers/middleware")

			sess.Values["info"] = "Log in again, please."

			if err := sess.Save(c.Request(), c.Response()); err != nil {
				log.Error("Failed to save session", "module", "middleware")

				return renderErrorPage(
					c,
					http.StatusInternalServerError,
					http.StatusText(http.StatusInternalServerError)+" could not save the session cookie",
					err.Error(),
				)
			}

			return c.Redirect(http.StatusTemporaryRedirect, "/signin")
		}

		return renderErrorPage(
			c,
			http.StatusUnauthorized,
			http.StatusText(http.StatusUnauthorized),
			ErrNoSession.Error(),
		)
	}
}

var cacheExtensions = [2]string{".png", ".svg"}

func MiddlewareCache(next echo.HandlerFunc) echo.HandlerFunc {
	return func(c echo.Context) error {
		cache := false

		for _, v := range cacheExtensions {
			if strings.HasSuffix(c.Request().URL.Path, v) {
				cache = true
				break
			}
		}

		if cache {
			c.Response().Header().Set(echo.HeaderCacheControl, "300")
		}

		return next(c)
	}
}

func WrapMiddlewareCompress() (echo.MiddlewareFunc, error) {
	brEnc, err := brotli.New(brotli.Options{})
	if err != nil {
		return nil, err
	}

	gzEnc, err := gzip.New(gzip.Options{})
	if err != nil {
		return nil, err
	}

	blocklist := true
	a, _ := httpcompression.Adapter(
		httpcompression.Compressor(brotli.Encoding, 1, brEnc),
		httpcompression.Compressor(gzip.Encoding, 0, gzEnc),
		httpcompression.Prefer(httpcompression.PreferServer),
		httpcompression.MinSize(100),
		httpcompression.ContentTypes([]string{
			"image/jpeg",
			"image/gif",
			"image/png",
		}, blocklist),
	)

	return echo.WrapMiddleware(a), nil
}