// Copyright 2016 The Gogs Authors. All rights reserved.
// Copyright 2018 The Gitea 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 repo

import (
	"context"
	"errors"
	"fmt"
	"time"

	"code.gitea.io/gitea/models/db"
	"code.gitea.io/gitea/modules/log"
	"code.gitea.io/gitea/modules/timeutil"

	"xorm.io/xorm"
)

var (
	// ErrMirrorNotExist mirror does not exist error
	ErrMirrorNotExist = errors.New("Mirror does not exist")
)

// RemoteMirrorer defines base methods for pull/push mirrors.
type RemoteMirrorer interface {
	GetRepository() *Repository
	GetRemoteName() string
}

// Mirror represents mirror information of a repository.
type Mirror struct {
	ID          int64       `xorm:"pk autoincr"`
	RepoID      int64       `xorm:"INDEX"`
	Repo        *Repository `xorm:"-"`
	Interval    time.Duration
	EnablePrune bool `xorm:"NOT NULL DEFAULT true"`

	UpdatedUnix    timeutil.TimeStamp `xorm:"INDEX"`
	NextUpdateUnix timeutil.TimeStamp `xorm:"INDEX"`

	LFS         bool   `xorm:"lfs_enabled NOT NULL DEFAULT false"`
	LFSEndpoint string `xorm:"lfs_endpoint TEXT"`

	Address string `xorm:"-"`
}

func init() {
	db.RegisterModel(new(Mirror))
}

// BeforeInsert will be invoked by XORM before inserting a record
func (m *Mirror) BeforeInsert() {
	if m != nil {
		m.UpdatedUnix = timeutil.TimeStampNow()
		m.NextUpdateUnix = timeutil.TimeStampNow()
	}
}

// AfterLoad is invoked from XORM after setting the values of all fields of this object.
func (m *Mirror) AfterLoad(session *xorm.Session) {
	if m == nil {
		return
	}

	var err error
	m.Repo, err = getRepositoryByID(session, m.RepoID)
	if err != nil {
		log.Error("getRepositoryByID[%d]: %v", m.ID, err)
	}
}

// GetRepository returns the repository.
func (m *Mirror) GetRepository() *Repository {
	return m.Repo
}

// GetRemoteName returns the name of the remote.
func (m *Mirror) GetRemoteName() string {
	return "origin"
}

// ScheduleNextUpdate calculates and sets next update time.
func (m *Mirror) ScheduleNextUpdate() {
	if m.Interval != 0 {
		m.NextUpdateUnix = timeutil.TimeStampNow().AddDuration(m.Interval)
	} else {
		m.NextUpdateUnix = 0
	}
}

func getMirrorByRepoID(e db.Engine, repoID int64) (*Mirror, error) {
	m := &Mirror{RepoID: repoID}
	has, err := e.Get(m)
	if err != nil {
		return nil, err
	} else if !has {
		return nil, ErrMirrorNotExist
	}
	return m, nil
}

// GetMirrorByRepoID returns mirror information of a repository.
func GetMirrorByRepoID(repoID int64) (*Mirror, error) {
	return getMirrorByRepoID(db.GetEngine(db.DefaultContext), repoID)
}

func updateMirror(e db.Engine, m *Mirror) error {
	_, err := e.ID(m.ID).AllCols().Update(m)
	return err
}

// UpdateMirror updates the mirror
func UpdateMirror(m *Mirror) error {
	return updateMirror(db.GetEngine(db.DefaultContext), m)
}

// TouchMirror updates the mirror updatedUnix
func TouchMirror(ctx context.Context, m *Mirror) error {
	m.UpdatedUnix = timeutil.TimeStampNow()
	_, err := db.GetEngine(ctx).ID(m.ID).Cols("updated_unix").Update(m)
	return err
}

// DeleteMirrorByRepoID deletes a mirror by repoID
func DeleteMirrorByRepoID(repoID int64) error {
	_, err := db.GetEngine(db.DefaultContext).Delete(&Mirror{RepoID: repoID})
	return err
}

// MirrorsIterate iterates all mirror repositories.
func MirrorsIterate(f func(idx int, bean interface{}) error) error {
	return db.GetEngine(db.DefaultContext).
		Where("next_update_unix<=?", time.Now().Unix()).
		And("next_update_unix!=0").
		OrderBy("updated_unix ASC").
		Iterate(new(Mirror), f)
}

// InsertMirror inserts a mirror to database
func InsertMirror(mirror *Mirror) error {
	_, err := db.GetEngine(db.DefaultContext).Insert(mirror)
	return err
}

// MirrorRepositoryList contains the mirror repositories
type MirrorRepositoryList []*Repository

func (repos MirrorRepositoryList) loadAttributes(e db.Engine) error {
	if len(repos) == 0 {
		return nil
	}

	// Load mirrors.
	repoIDs := make([]int64, 0, len(repos))
	for i := range repos {
		if !repos[i].IsMirror {
			continue
		}

		repoIDs = append(repoIDs, repos[i].ID)
	}
	mirrors := make([]*Mirror, 0, len(repoIDs))
	if err := e.
		Where("id > 0").
		In("repo_id", repoIDs).
		Find(&mirrors); err != nil {
		return fmt.Errorf("find mirrors: %v", err)
	}

	set := make(map[int64]*Mirror)
	for i := range mirrors {
		set[mirrors[i].RepoID] = mirrors[i]
	}
	for i := range repos {
		repos[i].Mirror = set[repos[i].ID]
	}
	return nil
}

// LoadAttributes loads the attributes for the given MirrorRepositoryList
func (repos MirrorRepositoryList) LoadAttributes() error {
	return repos.loadAttributes(db.GetEngine(db.DefaultContext))
}
