/*
   Copyright (c) 2016 VMware, Inc. All Rights Reserved.
   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package api

import (
	"fmt"
	"net/http"
	"os"
	"regexp"
	"strconv"
	"strings"

	"github.com/vmware/harbor/dao"
	"github.com/vmware/harbor/models"
	"github.com/vmware/harbor/utils/log"
)

// UserAPI handles request to /api/users/{}
type UserAPI struct {
	BaseAPI
	currentUserID    int
	userID           int
	SelfRegistration bool
	IsAdmin          bool
	AuthMode         string
}

type passwordReq struct {
	OldPassword string `json:"old_password"`
	NewPassword string `json:"new_password"`
}

// Prepare validates the URL and parms
func (ua *UserAPI) Prepare() {

	authMode := strings.ToLower(os.Getenv("AUTH_MODE"))
	if authMode == "" {
		authMode = "db_auth"
	}
	ua.AuthMode = authMode

	selfRegistration := strings.ToLower(os.Getenv("SELF_REGISTRATION"))
	if selfRegistration == "on" {
		ua.SelfRegistration = true
	}

	if ua.Ctx.Input.IsPost() {
		sessionUserID := ua.GetSession("userId")
		_, _, ok := ua.Ctx.Request.BasicAuth()
		if sessionUserID == nil && !ok {
			return
		}
	}

	ua.currentUserID = ua.ValidateUser()
	id := ua.Ctx.Input.Param(":id")
	if id == "current" {
		ua.userID = ua.currentUserID
	} else if len(id) > 0 {
		var err error
		ua.userID, err = strconv.Atoi(id)
		if err != nil {
			log.Errorf("Invalid user id, error: %v", err)
			ua.CustomAbort(http.StatusBadRequest, "Invalid user Id")
		}
		userQuery := models.User{UserID: ua.userID}
		u, err := dao.GetUser(userQuery)
		if err != nil {
			log.Errorf("Error occurred in GetUser, error: %v", err)
			ua.CustomAbort(http.StatusInternalServerError, "Internal error.")
		}
		if u == nil {
			log.Errorf("User with Id: %d does not exist", ua.userID)
			ua.CustomAbort(http.StatusNotFound, "")
		}
	}

	var err error
	ua.IsAdmin, err = dao.IsAdminRole(ua.currentUserID)
	if err != nil {
		log.Errorf("Error occurred in IsAdminRole:%v", err)
		ua.CustomAbort(http.StatusInternalServerError, "Internal error.")
	}

}

// Get ...
func (ua *UserAPI) Get() {
	if ua.userID == 0 { //list users
		if !ua.IsAdmin {
			log.Errorf("Current user, id: %d does not have admin role, can not list users", ua.currentUserID)
			ua.RenderError(http.StatusForbidden, "User does not have admin role")
			return
		}
		username := ua.GetString("username")
		userQuery := models.User{}
		if len(username) > 0 {
			userQuery.Username = "%" + username + "%"
		}
		userList, err := dao.ListUsers(userQuery)
		if err != nil {
			log.Errorf("Failed to get data from database, error: %v", err)
			ua.RenderError(http.StatusInternalServerError, "Failed to query from database")
			return
		}
		ua.Data["json"] = userList

	} else if ua.userID == ua.currentUserID || ua.IsAdmin {
		userQuery := models.User{UserID: ua.userID}
		u, err := dao.GetUser(userQuery)
		if err != nil {
			log.Errorf("Error occurred in GetUser, error: %v", err)
			ua.CustomAbort(http.StatusInternalServerError, "Internal error.")
		}
		ua.Data["json"] = u
	} else {
		log.Errorf("Current user, id: %d does not have admin role, can not view other user's detail", ua.currentUserID)
		ua.RenderError(http.StatusForbidden, "User does not have admin role")
		return
	}
	ua.ServeJSON()
}

// Put ...
func (ua *UserAPI) Put() {
	ldapAdminUser := (ua.AuthMode == "ldap_auth" && ua.userID == 1 && ua.userID == ua.currentUserID)

	if !(ua.AuthMode == "db_auth" || ldapAdminUser) {
		ua.CustomAbort(http.StatusForbidden, "")
	}
	if !ua.IsAdmin {
		if ua.userID != ua.currentUserID {
			log.Warning("Guests can only change their own account.")
			ua.CustomAbort(http.StatusForbidden, "Guests can only change their own account.")
		}
	}
	user := models.User{UserID: ua.userID}
	ua.DecodeJSONReq(&user)
	err := commonValidate(user)
	if err != nil {
		log.Warning("Bad request in change user profile: %v", err)
		ua.RenderError(http.StatusBadRequest, "change user profile error:"+err.Error())
		return
	}
	userQuery := models.User{UserID: ua.userID}
	u, err := dao.GetUser(userQuery)
	if err != nil {
		log.Errorf("Error occurred in GetUser, error: %v", err)
		ua.CustomAbort(http.StatusInternalServerError, "Internal error.")
	}
	if u == nil {
		log.Errorf("User with Id: %d does not exist", ua.userID)
		ua.CustomAbort(http.StatusNotFound, "")
	}
	if u.Email != user.Email {
		emailExist, err := dao.UserExists(user, "email")
		if err != nil {
			log.Errorf("Error occurred in change user profile: %v", err)
			ua.CustomAbort(http.StatusInternalServerError, "Internal error.")
		}
		if emailExist {
			log.Warning("email has already been used!")
			ua.RenderError(http.StatusConflict, "email has already been used!")
			return
		}
	}
	if err := dao.ChangeUserProfile(user); err != nil {
		log.Errorf("Failed to update user profile, error: %v", err)
		ua.CustomAbort(http.StatusInternalServerError, err.Error())
	}
}

// Post ...
func (ua *UserAPI) Post() {

	if !(ua.AuthMode == "db_auth") {
		ua.CustomAbort(http.StatusForbidden, "")
	}

	if !(ua.SelfRegistration || ua.IsAdmin) {
		log.Warning("Registration can only be used by admin role user when self-registration is off.")
		ua.CustomAbort(http.StatusForbidden, "")
	}

	user := models.User{}
	ua.DecodeJSONReq(&user)
	err := validate(user)
	if err != nil {
		log.Warning("Bad request in Register: %v", err)
		ua.RenderError(http.StatusBadRequest, "register error:"+err.Error())
		return
	}
	userExist, err := dao.UserExists(user, "username")
	if err != nil {
		log.Errorf("Error occurred in Register: %v", err)
		ua.CustomAbort(http.StatusInternalServerError, "Internal error.")
	}
	if userExist {
		log.Warning("username has already been used!")
		ua.RenderError(http.StatusConflict, "username has already been used!")
		return
	}
	emailExist, err := dao.UserExists(user, "email")
	if err != nil {
		log.Errorf("Error occurred in change user profile: %v", err)
		ua.CustomAbort(http.StatusInternalServerError, "Internal error.")
	}
	if emailExist {
		log.Warning("email has already been used!")
		ua.RenderError(http.StatusConflict, "email has already been used!")
		return
	}
	userID, err := dao.Register(user)
	if err != nil {
		log.Errorf("Error occurred in Register: %v", err)
		ua.CustomAbort(http.StatusInternalServerError, "Internal error.")
	}

	ua.Redirect(http.StatusCreated, strconv.FormatInt(userID, 10))
}

// Delete ...
func (ua *UserAPI) Delete() {
	if !ua.IsAdmin {
		log.Warningf("current user, id: %d does not have admin role, can not remove user", ua.currentUserID)
		ua.RenderError(http.StatusForbidden, "User does not have admin role")
		return
	}

	if ua.currentUserID == ua.userID {
		ua.CustomAbort(http.StatusForbidden, "can not delete yourself")
	}

	var err error
	err = dao.DeleteUser(ua.userID)
	if err != nil {
		log.Errorf("Failed to delete data from database, error: %v", err)
		ua.RenderError(http.StatusInternalServerError, "Failed to delete User")
		return
	}
}

// ChangePassword handles PUT to /api/users/{}/password
func (ua *UserAPI) ChangePassword() {
	ldapAdminUser := (ua.AuthMode == "ldap_auth" && ua.userID == 1 && ua.userID == ua.currentUserID)

	if !(ua.AuthMode == "db_auth" || ldapAdminUser) {
		ua.CustomAbort(http.StatusForbidden, "")
	}

	if !ua.IsAdmin {
		if ua.userID != ua.currentUserID {
			log.Error("Guests can only change their own account.")
			ua.CustomAbort(http.StatusForbidden, "Guests can only change their own account.")
		}
	}

	var req passwordReq
	ua.DecodeJSONReq(&req)
	if req.OldPassword == "" {
		log.Error("Old password is blank")
		ua.CustomAbort(http.StatusBadRequest, "Old password is blank")
	}

	queryUser := models.User{UserID: ua.userID, Password: req.OldPassword}
	user, err := dao.CheckUserPassword(queryUser)
	if err != nil {
		log.Errorf("Error occurred in CheckUserPassword: %v", err)
		ua.CustomAbort(http.StatusInternalServerError, "Internal error.")
	}
	if user == nil {
		log.Warning("Password input is not correct")
		ua.CustomAbort(http.StatusForbidden, "old_password_is_not_correct")
	}

	if req.NewPassword == "" {
		ua.CustomAbort(http.StatusBadRequest, "please_input_new_password")
	}
	updateUser := models.User{UserID: ua.userID, Password: req.NewPassword, Salt: user.Salt}
	err = dao.ChangeUserPassword(updateUser, req.OldPassword)
	if err != nil {
		log.Errorf("Error occurred in ChangeUserPassword: %v", err)
		ua.CustomAbort(http.StatusInternalServerError, "Internal error.")
	}
}

// ToggleUserAdminRole handles PUT api/users/{}/sysadmin
func (ua *UserAPI) ToggleUserAdminRole() {
	if !ua.IsAdmin {
		log.Warningf("current user, id: %d does not have admin role, can not update other user's role", ua.currentUserID)
		ua.RenderError(http.StatusForbidden, "User does not have admin role")
		return
	}
	userQuery := models.User{UserID: ua.userID}
	ua.DecodeJSONReq(&userQuery)
	if err := dao.ToggleUserAdminRole(userQuery.UserID, userQuery.HasAdminRole); err != nil {
		log.Errorf("Error occurred in ToggleUserAdminRole: %v", err)
		ua.CustomAbort(http.StatusInternalServerError, "Internal error.")
	}
}

// validate only validate when user register
func validate(user models.User) error {

	if isIllegalLength(user.Username, 0, 20) {
		return fmt.Errorf("Username with illegal length.")
	}
	if isContainIllegalChar(user.Username, []string{",", "~", "#", "$", "%"}) {
		return fmt.Errorf("Username contains illegal characters.")
	}
	if isIllegalLength(user.Password, 0, 20) {
		return fmt.Errorf("Password with illegal length.")
	}
	if err := commonValidate(user); err != nil {
		return err
	}
	return nil
}

//commonValidate validates email, realname, comment information when user register or change their profile
func commonValidate(user models.User) error {

	if len(user.Email) > 0 {
		if m, _ := regexp.MatchString(`^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$`, user.Email); !m {
			return fmt.Errorf("Email with illegal format.")
		}
	} else {
		return fmt.Errorf("Email can't be empty")
	}

	if isIllegalLength(user.Realname, 0, 20) {
		return fmt.Errorf("Realname with illegal length.")
	}

	if isContainIllegalChar(user.Realname, []string{",", "~", "#", "$", "%"}) {
		return fmt.Errorf("Realname contains illegal characters.")
	}
	if isIllegalLength(user.Comment, -1, 30) {
		return fmt.Errorf("Comment with illegal length.")
	}
	return nil

}

func isIllegalLength(s string, min int, max int) bool {
	if min == -1 {
		return (len(s) > max)
	}
	if max == -1 {
		return (len(s) <= min)
	}
	return (len(s) < min || len(s) > max)
}

func isContainIllegalChar(s string, illegalChar []string) bool {
	for _, c := range illegalChar {
		if strings.Index(s, c) >= 0 {
			return true
		}
	}
	return false
}