// Copyright 2014 The Gogs Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package db

import (
	"fmt"
	_ "image/jpeg"
	"os"
	"time"

	"xorm.io/xorm"

	"gogs.io/gogs/internal/repoutil"
	"gogs.io/gogs/internal/userutil"
)

// TODO(unknwon): Delete me once refactoring is done.
func (u *User) BeforeInsert() {
	u.CreatedUnix = time.Now().Unix()
	u.UpdatedUnix = u.CreatedUnix
}

// TODO(unknwon): Delete me once refactoring is done.
func (u *User) AfterSet(colName string, _ xorm.Cell) {
	switch colName {
	case "created_unix":
		u.Created = time.Unix(u.CreatedUnix, 0).Local()
	case "updated_unix":
		u.Updated = time.Unix(u.UpdatedUnix, 0).Local()
	}
}

// deleteBeans deletes all given beans, beans should contain delete conditions.
func deleteBeans(e Engine, beans ...any) (err error) {
	for i := range beans {
		if _, err = e.Delete(beans[i]); err != nil {
			return err
		}
	}
	return nil
}

// FIXME: need some kind of mechanism to record failure. HINT: system notice
func deleteUser(e *xorm.Session, u *User) error {
	// Note: A user owns any repository or belongs to any organization
	//	cannot perform delete operation.

	// Check ownership of repository.
	count, err := getRepositoryCount(e, u)
	if err != nil {
		return fmt.Errorf("GetRepositoryCount: %v", err)
	} else if count > 0 {
		return ErrUserOwnRepos{UID: u.ID}
	}

	// Check membership of organization.
	count, err = u.getOrganizationCount(e)
	if err != nil {
		return fmt.Errorf("GetOrganizationCount: %v", err)
	} else if count > 0 {
		return ErrUserHasOrgs{UID: u.ID}
	}

	// ***** START: Watch *****
	watches := make([]*Watch, 0, 10)
	if err = e.Find(&watches, &Watch{UserID: u.ID}); err != nil {
		return fmt.Errorf("get all watches: %v", err)
	}
	for i := range watches {
		if _, err = e.Exec("UPDATE `repository` SET num_watches=num_watches-1 WHERE id=?", watches[i].RepoID); err != nil {
			return fmt.Errorf("decrease repository watch number[%d]: %v", watches[i].RepoID, err)
		}
	}
	// ***** END: Watch *****

	// ***** START: Star *****
	stars := make([]*Star, 0, 10)
	if err = e.Find(&stars, &Star{UID: u.ID}); err != nil {
		return fmt.Errorf("get all stars: %v", err)
	}
	for i := range stars {
		if _, err = e.Exec("UPDATE `repository` SET num_stars=num_stars-1 WHERE id=?", stars[i].RepoID); err != nil {
			return fmt.Errorf("decrease repository star number[%d]: %v", stars[i].RepoID, err)
		}
	}
	// ***** END: Star *****

	// ***** START: Follow *****
	followers := make([]*Follow, 0, 10)
	if err = e.Find(&followers, &Follow{UserID: u.ID}); err != nil {
		return fmt.Errorf("get all followers: %v", err)
	}
	for i := range followers {
		if _, err = e.Exec("UPDATE `user` SET num_followers=num_followers-1 WHERE id=?", followers[i].UserID); err != nil {
			return fmt.Errorf("decrease user follower number[%d]: %v", followers[i].UserID, err)
		}
	}
	// ***** END: Follow *****

	if err = deleteBeans(e,
		&AccessToken{UserID: u.ID},
		&Collaboration{UserID: u.ID},
		&Access{UserID: u.ID},
		&Watch{UserID: u.ID},
		&Star{UID: u.ID},
		&Follow{FollowID: u.ID},
		&Action{UserID: u.ID},
		&IssueUser{UID: u.ID},
		&EmailAddress{UserID: u.ID},
	); err != nil {
		return fmt.Errorf("deleteBeans: %v", err)
	}

	// ***** START: PublicKey *****
	keys := make([]*PublicKey, 0, 10)
	if err = e.Find(&keys, &PublicKey{OwnerID: u.ID}); err != nil {
		return fmt.Errorf("get all public keys: %v", err)
	}

	keyIDs := make([]int64, len(keys))
	for i := range keys {
		keyIDs[i] = keys[i].ID
	}
	if err = deletePublicKeys(e, keyIDs...); err != nil {
		return fmt.Errorf("deletePublicKeys: %v", err)
	}
	// ***** END: PublicKey *****

	// Clear assignee.
	if _, err = e.Exec("UPDATE `issue` SET assignee_id=0 WHERE assignee_id=?", u.ID); err != nil {
		return fmt.Errorf("clear assignee: %v", err)
	}

	if _, err = e.ID(u.ID).Delete(new(User)); err != nil {
		return fmt.Errorf("Delete: %v", err)
	}

	// FIXME: system notice
	// Note: There are something just cannot be roll back,
	//	so just keep error logs of those operations.

	_ = os.RemoveAll(repoutil.UserPath(u.Name))
	_ = os.Remove(userutil.CustomAvatarPath(u.ID))

	return nil
}

// Deprecated: Use OrgsUsers.CountByUser instead.
//
// TODO(unknwon): Delete me once no more call sites in this file.
func (u *User) getOrganizationCount(e Engine) (int64, error) {
	return e.Where("uid=?", u.ID).Count(new(OrgUser))
}

// DeleteUser completely and permanently deletes everything of a user,
// but issues/comments/pulls will be kept and shown as someone has been deleted.
func DeleteUser(u *User) (err error) {
	sess := x.NewSession()
	defer sess.Close()
	if err = sess.Begin(); err != nil {
		return err
	}

	if err = deleteUser(sess, u); err != nil {
		// Note: don't wrapper error here.
		return err
	}

	if err = sess.Commit(); err != nil {
		return err
	}

	return RewriteAuthorizedKeys()
}

// DeleteInactivateUsers deletes all inactivate users and email addresses.
func DeleteInactivateUsers() (err error) {
	users := make([]*User, 0, 10)
	if err = x.Where("is_active = ?", false).Find(&users); err != nil {
		return fmt.Errorf("get all inactive users: %v", err)
	}
	// FIXME: should only update authorized_keys file once after all deletions.
	for _, u := range users {
		if err = DeleteUser(u); err != nil {
			// Ignore users that were set inactive by admin.
			if IsErrUserOwnRepos(err) || IsErrUserHasOrgs(err) {
				continue
			}
			return err
		}
	}

	_, err = x.Where("is_activated = ?", false).Delete(new(EmailAddress))
	return err
}