// Vikunja is a to-do list application to facilitate your life.
// Copyright 2018-2021 Vikunja and contributors. All rights reserved.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public Licensee as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public Licensee for more details.
//
// You should have received a copy of the GNU Affero General Public Licensee
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

package v1

import (
	"net/http"

	"code.vikunja.io/api/pkg/modules/keyvalue"

	"code.vikunja.io/api/pkg/db"
	"code.vikunja.io/api/pkg/models"
	"code.vikunja.io/api/pkg/modules/auth"
	user2 "code.vikunja.io/api/pkg/user"
	"code.vikunja.io/web/handler"

	"github.com/golang-jwt/jwt"
	"github.com/labstack/echo/v4"
)

// Login is the login handler
// @Summary Login
// @Description Logs a user in. Returns a JWT-Token to authenticate further requests.
// @tags user
// @Accept json
// @Produce json
// @Param credentials body user.Login true "The login credentials"
// @Success 200 {object} auth.Token
// @Failure 400 {object} models.Message "Invalid user password model."
// @Failure 412 {object} models.Message "Invalid totp passcode."
// @Failure 403 {object} models.Message "Invalid username or password."
// @Router /login [post]
func Login(c echo.Context) error {
	u := user2.Login{}
	if err := c.Bind(&u); err != nil {
		return c.JSON(http.StatusBadRequest, models.Message{Message: "Please provide a username and password."})
	}

	s := db.NewSession()
	defer s.Close()

	// Check user
	user, err := user2.CheckUserCredentials(s, &u)
	if err != nil {
		_ = s.Rollback()
		return handler.HandleHTTPError(err, c)
	}

	if user.Status == user2.StatusDisabled {
		_ = s.Rollback()
		return handler.HandleHTTPError(&user2.ErrAccountDisabled{UserID: user.ID}, c)
	}

	totpEnabled, err := user2.TOTPEnabledForUser(s, user)
	if err != nil {
		_ = s.Rollback()
		return handler.HandleHTTPError(err, c)
	}

	if totpEnabled {
		if u.TOTPPasscode == "" {
			_ = s.Rollback()
			return handler.HandleHTTPError(user2.ErrInvalidTOTPPasscode{}, c)
		}

		_, err = user2.ValidateTOTPPasscode(s, &user2.TOTPPasscode{
			User:     user,
			Passcode: u.TOTPPasscode,
		})
		if err != nil {
			if user2.IsErrInvalidTOTPPasscode(err) {
				user2.HandleFailedTOTPAuth(s, user)
			}
			_ = s.Rollback()
			return handler.HandleHTTPError(err, c)
		}
	}

	if err := keyvalue.Del(user.GetFailedTOTPAttemptsKey()); err != nil {
		return err
	}
	if err := keyvalue.Del(user.GetFailedPasswordAttemptsKey()); err != nil {
		return err
	}

	if err := s.Commit(); err != nil {
		_ = s.Rollback()
		return handler.HandleHTTPError(err, c)
	}

	// Create token
	return auth.NewUserAuthTokenResponse(user, c)
}

// RenewToken gives a new token to every user with a valid token
// If the token is valid is checked in the middleware.
// @Summary Renew user token
// @Description Returns a new valid jwt user token with an extended length.
// @tags user
// @Accept json
// @Produce json
// @Success 200 {object} auth.Token
// @Failure 400 {object} models.Message "Only user token are available for renew."
// @Router /user/token [post]
func RenewToken(c echo.Context) (err error) {

	s := db.NewSession()
	defer s.Close()

	jwtinf := c.Get("user").(*jwt.Token)
	claims := jwtinf.Claims.(jwt.MapClaims)
	typ := int(claims["type"].(float64))
	if typ == auth.AuthTypeLinkShare {
		share := &models.LinkSharing{}
		share.ID = int64(claims["id"].(float64))
		err := share.ReadOne(s, share)
		if err != nil {
			_ = s.Rollback()
			return handler.HandleHTTPError(err, c)
		}
		t, err := auth.NewLinkShareJWTAuthtoken(share)
		if err != nil {
			_ = s.Rollback()
			return handler.HandleHTTPError(err, c)
		}
		return c.JSON(http.StatusOK, auth.Token{Token: t})
	}

	u, err := user2.GetUserFromClaims(claims)
	if err != nil {
		_ = s.Rollback()
		return handler.HandleHTTPError(err, c)
	}

	user, err := user2.GetUserWithEmail(s, &user2.User{ID: u.ID})
	if err != nil {
		_ = s.Rollback()
		return handler.HandleHTTPError(err, c)
	}

	if err := s.Commit(); err != nil {
		_ = s.Rollback()
		return handler.HandleHTTPError(err, c)
	}

	// Create token
	return auth.NewUserAuthTokenResponse(user, c)
}