Gitea 2 Gitea migration (#12657)

* first draft

* update gitea sdk to 9e280adb4da

* adapt feat of updated sdk

* releases now works

* break the Reactions loop

* use convertGiteaLabel

* fix endless loop because paggination is not supported there !!!

* rename gitea local uploader files

* pagination can bite you in the ass

* Version Checks

* lint

* docs

* rename gitea sdk import to miss future conficts

* go-swagger: dont scan the sdk structs

* make sure gitea can shutdown gracefully

* make GetPullRequests and GetIssues similar

* rm useles

* Add Test: started ...

* ... add tests ...

* Add tests and Fixing things

* Workaround missing SHA

* Adapt: Ensure that all migration requests are cancellable
(714ab71ddc4260937b1480519d453d2dc4e77dd6)

* LINT: fix misspells in test set

* adapt ListMergeRequestAwardEmoji

* update sdk

* Return error when creating giteadownloader failed

* update sdk

* adapt new sdk

* adopt new features

* check version before err

* adapt: 'migrate service type switch page'

* optimize

* Fix DefaultBranch

* impruve

* handle subPath

* fix test

* Fix ReviewCommentPosition

* test GetReviews

* add DefaultBranch int test set

* rm unused

* Update SDK to v0.13.0

* addopt sdk changes

* found better link

* format template

* Update Docs

* Update Gitea SDK (v0.13.1)

17 files changed, 1083 insertions, 32 deletions

diff --git a/modules/migrations/base/downloader.go b/modules/migrations/base/downloader.go
index 036abf22c9..5c47ed5305 100644
--- a/modules/migrations/base/downloader.go
+++ b/modules/migrations/base/downloader.go
@@ -15,7 +15,7 @@ import (
 
 // AssetDownloader downloads an asset (attachment) for a release
 type AssetDownloader interface {
-	GetAsset(tag string, id int64) (io.ReadCloser, error)
+	GetAsset(relTag string, relID, id int64) (io.ReadCloser, error)
 }
 
 // Downloader downloads the site repo informations
@@ -29,7 +29,7 @@ type Downloader interface {
 	GetLabels() ([]*Label, error)
 	GetIssues(page, perPage int) ([]*Issue, bool, error)
 	GetComments(issueNumber int64) ([]*Comment, error)
-	GetPullRequests(page, perPage int) ([]*PullRequest, error)
+	GetPullRequests(page, perPage int) ([]*PullRequest, bool, error)
 	GetReviews(pullRequestNumber int64) ([]*Review, error)
 }
 
@@ -209,23 +209,24 @@ func (d *RetryDownloader) GetComments(issueNumber int64) ([]*Comment, error) {
 }
 
 // GetPullRequests returns a repository's pull requests with retry
-func (d *RetryDownloader) GetPullRequests(page, perPage int) ([]*PullRequest, error) {
+func (d *RetryDownloader) GetPullRequests(page, perPage int) ([]*PullRequest, bool, error) {
 	var (
 		times = d.RetryTimes
 		prs   []*PullRequest
 		err   error
+		isEnd bool
 	)
 	for ; times > 0; times-- {
-		if prs, err = d.Downloader.GetPullRequests(page, perPage); err == nil {
-			return prs, nil
+		if prs, isEnd, err = d.Downloader.GetPullRequests(page, perPage); err == nil {
+			return prs, isEnd, nil
 		}
 		select {
 		case <-d.ctx.Done():
-			return nil, d.ctx.Err()
+			return nil, false, d.ctx.Err()
 		case <-time.After(time.Second * time.Duration(d.RetryDelay)):
 		}
 	}
-	return nil, err
+	return nil, false, err
 }
 
 // GetReviews returns pull requests reviews
diff --git a/modules/migrations/base/issue.go b/modules/migrations/base/issue.go
index 4e2bf25f17..b9625a23f6 100644
--- a/modules/migrations/base/issue.go
+++ b/modules/migrations/base/issue.go
@@ -23,4 +23,5 @@ type Issue struct {
 	Closed      *time.Time
 	Labels      []*Label
 	Reactions   []*Reaction
+	Assignees   []string
 }
diff --git a/modules/migrations/base/pullrequest.go b/modules/migrations/base/pullrequest.go
index 964512e137..ee612fbb8e 100644
--- a/modules/migrations/base/pullrequest.go
+++ b/modules/migrations/base/pullrequest.go
@@ -31,7 +31,6 @@ type PullRequest struct {
 	MergeCommitSHA string
 	Head           PullRequestBranch
 	Base           PullRequestBranch
-	Assignee       string
 	Assignees      []string
 	IsLocked       bool
 	Reactions      []*Reaction
diff --git a/modules/migrations/base/release.go b/modules/migrations/base/release.go
index 2a223920c7..c9b26ab1da 100644
--- a/modules/migrations/base/release.go
+++ b/modules/migrations/base/release.go
@@ -15,6 +15,7 @@ type ReleaseAsset struct {
 	DownloadCount *int
 	Created       time.Time
 	Updated       time.Time
+	DownloadURL   *string
 }
 
 // Release represents a release
diff --git a/modules/migrations/base/repo.go b/modules/migrations/base/repo.go
index d2052da90d..d26a911854 100644
--- a/modules/migrations/base/repo.go
+++ b/modules/migrations/base/repo.go
@@ -12,8 +12,6 @@ type Repository struct {
 	IsPrivate     bool
 	IsMirror      bool
 	Description   string
-	AuthUsername  string
-	AuthPassword  string
 	CloneURL      string
 	OriginalURL   string
 	DefaultBranch string
diff --git a/modules/migrations/base/review.go b/modules/migrations/base/review.go
index 8051fed653..0a9d03dae9 100644
--- a/modules/migrations/base/review.go
+++ b/modules/migrations/base/review.go
@@ -36,6 +36,7 @@ type ReviewComment struct {
 	TreePath  string
 	DiffHunk  string
 	Position  int
+	Line      int
 	CommitID  string
 	PosterID  int64
 	Reactions []*Reaction
diff --git a/modules/migrations/git.go b/modules/migrations/git.go
index 5c9acb2533..0aad8dbef5 100644
--- a/modules/migrations/git.go
+++ b/modules/migrations/git.go
@@ -66,7 +66,7 @@ func (g *PlainGitDownloader) GetReleases() ([]*base.Release, error) {
 }
 
 // GetAsset returns an asset
-func (g *PlainGitDownloader) GetAsset(_ string, _ int64) (io.ReadCloser, error) {
+func (g *PlainGitDownloader) GetAsset(_ string, _, _ int64) (io.ReadCloser, error) {
 	return nil, ErrNotSupported
 }
 
@@ -81,8 +81,8 @@ func (g *PlainGitDownloader) GetComments(issueNumber int64) ([]*base.Comment, er
 }
 
 // GetPullRequests returns pull requests according page and perPage
-func (g *PlainGitDownloader) GetPullRequests(start, limit int) ([]*base.PullRequest, error) {
-	return nil, ErrNotSupported
+func (g *PlainGitDownloader) GetPullRequests(start, limit int) ([]*base.PullRequest, bool, error) {
+	return nil, false, ErrNotSupported
 }
 
 // GetReviews returns reviews according issue number
diff --git a/modules/migrations/gitea_downloader.go b/modules/migrations/gitea_downloader.go
new file mode 100644
index 0000000000..827cbef5c2
--- /dev/null
+++ b/modules/migrations/gitea_downloader.go
@@ -0,0 +1,671 @@
+// Copyright 2020 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 migrations
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/migrations/base"
+	"code.gitea.io/gitea/modules/structs"
+
+	gitea_sdk "code.gitea.io/sdk/gitea"
+)
+
+var (
+	_ base.Downloader        = &GiteaDownloader{}
+	_ base.DownloaderFactory = &GiteaDownloaderFactory{}
+)
+
+func init() {
+	RegisterDownloaderFactory(&GiteaDownloaderFactory{})
+}
+
+// GiteaDownloaderFactory defines a gitea downloader factory
+type GiteaDownloaderFactory struct {
+}
+
+// New returns a Downloader related to this factory according MigrateOptions
+func (f *GiteaDownloaderFactory) New(ctx context.Context, opts base.MigrateOptions) (base.Downloader, error) {
+	u, err := url.Parse(opts.CloneAddr)
+	if err != nil {
+		return nil, err
+	}
+
+	baseURL := u.Scheme + "://" + u.Host
+	repoNameSpace := strings.TrimPrefix(u.Path, "/")
+	repoNameSpace = strings.TrimSuffix(repoNameSpace, ".git")
+
+	path := strings.Split(repoNameSpace, "/")
+	if len(path) < 2 {
+		return nil, fmt.Errorf("invalid path")
+	}
+
+	repoPath := strings.Join(path[len(path)-2:], "/")
+	if len(path) > 2 {
+		subPath := strings.Join(path[:len(path)-2], "/")
+		baseURL += "/" + subPath
+	}
+
+	log.Trace("Create gitea downloader. BaseURL: %s RepoName: %s", baseURL, repoNameSpace)
+
+	return NewGiteaDownloader(ctx, baseURL, repoPath, opts.AuthUsername, opts.AuthPassword, opts.AuthToken)
+}
+
+// GitServiceType returns the type of git service
+func (f *GiteaDownloaderFactory) GitServiceType() structs.GitServiceType {
+	return structs.GiteaService
+}
+
+// GiteaDownloader implements a Downloader interface to get repository information's
+type GiteaDownloader struct {
+	ctx        context.Context
+	client     *gitea_sdk.Client
+	repoOwner  string
+	repoName   string
+	pagination bool
+	maxPerPage int
+}
+
+// NewGiteaDownloader creates a gitea Downloader via gitea API
+//   Use either a username/password or personal token. token is preferred
+//   Note: Public access only allows very basic access
+func NewGiteaDownloader(ctx context.Context, baseURL, repoPath, username, password, token string) (*GiteaDownloader, error) {
+	giteaClient, err := gitea_sdk.NewClient(
+		baseURL,
+		gitea_sdk.SetToken(token),
+		gitea_sdk.SetBasicAuth(username, password),
+		gitea_sdk.SetContext(ctx),
+	)
+	if err != nil {
+		log.Error(fmt.Sprintf("NewGiteaDownloader: %s", err.Error()))
+		return nil, err
+	}
+
+	path := strings.Split(repoPath, "/")
+
+	paginationSupport := true
+	if err := giteaClient.CheckServerVersionConstraint(">=1.12"); err != nil {
+		paginationSupport = false
+	}
+
+	// set small maxPerPage since we can only guess
+	// (default would be 50 but this can differ)
+	maxPerPage := 10
+	// new gitea instances can tell us what maximum they have
+	if giteaClient.CheckServerVersionConstraint(">=1.13.0") == nil {
+		apiConf, _, err := giteaClient.GetGlobalAPISettings()
+		if err != nil {
+			return nil, err
+		}
+		maxPerPage = apiConf.MaxResponseItems
+	}
+
+	return &GiteaDownloader{
+		ctx:        ctx,
+		client:     giteaClient,
+		repoOwner:  path[0],
+		repoName:   path[1],
+		pagination: paginationSupport,
+		maxPerPage: maxPerPage,
+	}, nil
+}
+
+// SetContext set context
+func (g *GiteaDownloader) SetContext(ctx context.Context) {
+	g.ctx = ctx
+}
+
+// GetRepoInfo returns a repository information
+func (g *GiteaDownloader) GetRepoInfo() (*base.Repository, error) {
+	if g == nil {
+		return nil, errors.New("error: GiteaDownloader is nil")
+	}
+
+	repo, _, err := g.client.GetRepo(g.repoOwner, g.repoName)
+	if err != nil {
+		return nil, err
+	}
+
+	return &base.Repository{
+		Name:          repo.Name,
+		Owner:         repo.Owner.UserName,
+		IsPrivate:     repo.Private,
+		Description:   repo.Description,
+		CloneURL:      repo.CloneURL,
+		OriginalURL:   repo.HTMLURL,
+		DefaultBranch: repo.DefaultBranch,
+	}, nil
+}
+
+// GetTopics return gitea topics
+func (g *GiteaDownloader) GetTopics() ([]string, error) {
+	topics, _, err := g.client.ListRepoTopics(g.repoOwner, g.repoName, gitea_sdk.ListRepoTopicsOptions{})
+	return topics, err
+}
+
+// GetMilestones returns milestones
+func (g *GiteaDownloader) GetMilestones() ([]*base.Milestone, error) {
+	var milestones = make([]*base.Milestone, 0, g.maxPerPage)
+
+	for i := 1; ; i++ {
+		// make sure gitea can shutdown gracefully
+		select {
+		case <-g.ctx.Done():
+			return nil, nil
+		default:
+		}
+
+		ms, _, err := g.client.ListRepoMilestones(g.repoOwner, g.repoName, gitea_sdk.ListMilestoneOption{
+			ListOptions: gitea_sdk.ListOptions{
+				PageSize: g.maxPerPage,
+				Page:     i,
+			},
+			State: gitea_sdk.StateAll,
+		})
+		if err != nil {
+			return nil, err
+		}
+
+		for i := range ms {
+			// old gitea instances dont have this information
+			createdAT := time.Now()
+			var updatedAT *time.Time
+			if ms[i].Closed != nil {
+				createdAT = *ms[i].Closed
+				updatedAT = ms[i].Closed
+			}
+
+			// new gitea instances (>=1.13) do
+			if !ms[i].Created.IsZero() {
+				createdAT = ms[i].Created
+			}
+			if ms[i].Updated != nil && !ms[i].Updated.IsZero() {
+				updatedAT = ms[i].Updated
+			}
+
+			milestones = append(milestones, &base.Milestone{
+				Title:       ms[i].Title,
+				Description: ms[i].Description,
+				Deadline:    ms[i].Deadline,
+				Created:     createdAT,
+				Updated:     updatedAT,
+				Closed:      ms[i].Closed,
+				State:       string(ms[i].State),
+			})
+		}
+		if !g.pagination || len(ms) < g.maxPerPage {
+			break
+		}
+	}
+	return milestones, nil
+}
+
+func (g *GiteaDownloader) convertGiteaLabel(label *gitea_sdk.Label) *base.Label {
+	return &base.Label{
+		Name:        label.Name,
+		Color:       label.Color,
+		Description: label.Description,
+	}
+}
+
+// GetLabels returns labels
+func (g *GiteaDownloader) GetLabels() ([]*base.Label, error) {
+	var labels = make([]*base.Label, 0, g.maxPerPage)
+
+	for i := 1; ; i++ {
+		// make sure gitea can shutdown gracefully
+		select {
+		case <-g.ctx.Done():
+			return nil, nil
+		default:
+		}
+
+		ls, _, err := g.client.ListRepoLabels(g.repoOwner, g.repoName, gitea_sdk.ListLabelsOptions{ListOptions: gitea_sdk.ListOptions{
+			PageSize: g.maxPerPage,
+			Page:     i,
+		}})
+		if err != nil {
+			return nil, err
+		}
+
+		for i := range ls {
+			labels = append(labels, g.convertGiteaLabel(ls[i]))
+		}
+		if !g.pagination || len(ls) < g.maxPerPage {
+			break
+		}
+	}
+	return labels, nil
+}
+
+func (g *GiteaDownloader) convertGiteaRelease(rel *gitea_sdk.Release) *base.Release {
+	r := &base.Release{
+		TagName:         rel.TagName,
+		TargetCommitish: rel.Target,
+		Name:            rel.Title,
+		Body:            rel.Note,
+		Draft:           rel.IsDraft,
+		Prerelease:      rel.IsPrerelease,
+		PublisherID:     rel.Publisher.ID,
+		PublisherName:   rel.Publisher.UserName,
+		PublisherEmail:  rel.Publisher.Email,
+		Published:       rel.PublishedAt,
+		Created:         rel.CreatedAt,
+	}
+
+	for _, asset := range rel.Attachments {
+		size := int(asset.Size)
+		dlCount := int(asset.DownloadCount)
+		r.Assets = append(r.Assets, base.ReleaseAsset{
+			ID:            asset.ID,
+			Name:          asset.Name,
+			Size:          &size,
+			DownloadCount: &dlCount,
+			Created:       asset.Created,
+			DownloadURL:   &asset.DownloadURL,
+		})
+	}
+	return r
+}
+
+// GetReleases returns releases
+func (g *GiteaDownloader) GetReleases() ([]*base.Release, error) {
+	var releases = make([]*base.Release, 0, g.maxPerPage)
+
+	for i := 1; ; i++ {
+		// make sure gitea can shutdown gracefully
+		select {
+		case <-g.ctx.Done():
+			return nil, nil
+		default:
+		}
+
+		rl, _, err := g.client.ListReleases(g.repoOwner, g.repoName, gitea_sdk.ListReleasesOptions{ListOptions: gitea_sdk.ListOptions{
+			PageSize: g.maxPerPage,
+			Page:     i,
+		}})
+		if err != nil {
+			return nil, err
+		}
+
+		for i := range rl {
+			releases = append(releases, g.convertGiteaRelease(rl[i]))
+		}
+		if !g.pagination || len(rl) < g.maxPerPage {
+			break
+		}
+	}
+	return releases, nil
+}
+
+// GetAsset returns an asset
+func (g *GiteaDownloader) GetAsset(_ string, relID, id int64) (io.ReadCloser, error) {
+	asset, _, err := g.client.GetReleaseAttachment(g.repoOwner, g.repoName, relID, id)
+	if err != nil {
+		return nil, err
+	}
+	resp, err := http.Get(asset.DownloadURL)
+	if err != nil {
+		return nil, err
+	}
+
+	// resp.Body is closed by the uploader
+	return resp.Body, nil
+}
+
+func (g *GiteaDownloader) getIssueReactions(index int64) ([]*base.Reaction, error) {
+	var reactions []*base.Reaction
+	if err := g.client.CheckServerVersionConstraint(">=1.11"); err != nil {
+		log.Info("GiteaDownloader: instance to old, skip getIssueReactions")
+		return reactions, nil
+	}
+	rl, _, err := g.client.GetIssueReactions(g.repoOwner, g.repoName, index)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, reaction := range rl {
+		reactions = append(reactions, &base.Reaction{
+			UserID:   reaction.User.ID,
+			UserName: reaction.User.UserName,
+			Content:  reaction.Reaction,
+		})
+	}
+	return reactions, nil
+}
+
+func (g *GiteaDownloader) getCommentReactions(commentID int64) ([]*base.Reaction, error) {
+	var reactions []*base.Reaction
+	if err := g.client.CheckServerVersionConstraint(">=1.11"); err != nil {
+		log.Info("GiteaDownloader: instance to old, skip getCommentReactions")
+		return reactions, nil
+	}
+	rl, _, err := g.client.GetIssueCommentReactions(g.repoOwner, g.repoName, commentID)
+	if err != nil {
+		return nil, err
+	}
+
+	for i := range rl {
+		reactions = append(reactions, &base.Reaction{
+			UserID:   rl[i].User.ID,
+			UserName: rl[i].User.UserName,
+			Content:  rl[i].Reaction,
+		})
+	}
+	return reactions, nil
+}
+
+// GetIssues returns issues according start and limit
+func (g *GiteaDownloader) GetIssues(page, perPage int) ([]*base.Issue, bool, error) {
+	if perPage > g.maxPerPage {
+		perPage = g.maxPerPage
+	}
+	var allIssues = make([]*base.Issue, 0, perPage)
+
+	issues, _, err := g.client.ListRepoIssues(g.repoOwner, g.repoName, gitea_sdk.ListIssueOption{
+		ListOptions: gitea_sdk.ListOptions{Page: page, PageSize: perPage},
+		State:       gitea_sdk.StateAll,
+		Type:        gitea_sdk.IssueTypeIssue,
+	})
+	if err != nil {
+		return nil, false, fmt.Errorf("error while listing issues: %v", err)
+	}
+	for _, issue := range issues {
+
+		var labels = make([]*base.Label, 0, len(issue.Labels))
+		for i := range issue.Labels {
+			labels = append(labels, g.convertGiteaLabel(issue.Labels[i]))
+		}
+
+		var milestone string
+		if issue.Milestone != nil {
+			milestone = issue.Milestone.Title
+		}
+
+		reactions, err := g.getIssueReactions(issue.Index)
+		if err != nil {
+			return nil, false, fmt.Errorf("error while loading reactions: %v", err)
+		}
+
+		var assignees []string
+		for i := range issue.Assignees {
+			assignees = append(assignees, issue.Assignees[i].UserName)
+		}
+
+		allIssues = append(allIssues, &base.Issue{
+			Title:       issue.Title,
+			Number:      issue.Index,
+			PosterID:    issue.Poster.ID,
+			PosterName:  issue.Poster.UserName,
+			PosterEmail: issue.Poster.Email,
+			Content:     issue.Body,
+			Milestone:   milestone,
+			State:       string(issue.State),
+			Created:     issue.Created,
+			Updated:     issue.Updated,
+			Closed:      issue.Closed,
+			Reactions:   reactions,
+			Labels:      labels,
+			Assignees:   assignees,
+			IsLocked:    issue.IsLocked,
+		})
+	}
+
+	isEnd := len(issues) < perPage
+	if !g.pagination {
+		isEnd = len(issues) == 0
+	}
+	return allIssues, isEnd, nil
+}
+
+// GetComments returns comments according issueNumber
+func (g *GiteaDownloader) GetComments(index int64) ([]*base.Comment, error) {
+	var allComments = make([]*base.Comment, 0, g.maxPerPage)
+
+	// for i := 1; ; i++ {
+	// make sure gitea can shutdown gracefully
+	select {
+	case <-g.ctx.Done():
+		return nil, nil
+	default:
+	}
+
+	comments, _, err := g.client.ListIssueComments(g.repoOwner, g.repoName, index, gitea_sdk.ListIssueCommentOptions{ListOptions: gitea_sdk.ListOptions{
+		// PageSize: g.maxPerPage,
+		// Page:     i,
+	}})
+	if err != nil {
+		return nil, fmt.Errorf("error while listing comments: %v", err)
+	}
+
+	for _, comment := range comments {
+		reactions, err := g.getCommentReactions(comment.ID)
+		if err != nil {
+			return nil, fmt.Errorf("error while listing comment creactions: %v", err)
+		}
+
+		allComments = append(allComments, &base.Comment{
+			IssueIndex:  index,
+			PosterID:    comment.Poster.ID,
+			PosterName:  comment.Poster.UserName,
+			PosterEmail: comment.Poster.Email,
+			Content:     comment.Body,
+			Created:     comment.Created,
+			Updated:     comment.Updated,
+			Reactions:   reactions,
+		})
+	}
+
+	// TODO enable pagination vor (gitea >= 1.14) when it got implemented
+	// 	if !g.pagination || len(comments) < g.maxPerPage {
+	//		break
+	//	}
+	//}
+	return allComments, nil
+}
+
+// GetPullRequests returns pull requests according page and perPage
+func (g *GiteaDownloader) GetPullRequests(page, perPage int) ([]*base.PullRequest, bool, error) {
+	if perPage > g.maxPerPage {
+		perPage = g.maxPerPage
+	}
+	var allPRs = make([]*base.PullRequest, 0, perPage)
+
+	prs, _, err := g.client.ListRepoPullRequests(g.repoOwner, g.repoName, gitea_sdk.ListPullRequestsOptions{
+		ListOptions: gitea_sdk.ListOptions{
+			Page:     page,
+			PageSize: perPage,
+		},
+		State: gitea_sdk.StateAll,
+	})
+	if err != nil {
+		return nil, false, fmt.Errorf("error while listing repos: %v", err)
+	}
+	for _, pr := range prs {
+		var milestone string
+		if pr.Milestone != nil {
+			milestone = pr.Milestone.Title
+		}
+
+		var labels = make([]*base.Label, 0, len(pr.Labels))
+		for i := range pr.Labels {
+			labels = append(labels, g.convertGiteaLabel(pr.Labels[i]))
+		}
+
+		var (
+			headUserName string
+			headRepoName string
+			headCloneURL string
+			headRef      string
+			headSHA      string
+		)
+		if pr.Head != nil {
+			if pr.Head.Repository != nil {
+				headUserName = pr.Head.Repository.Owner.UserName
+				headRepoName = pr.Head.Repository.Name
+				headCloneURL = pr.Head.Repository.CloneURL
+			}
+			headSHA = pr.Head.Sha
+			headRef = pr.Head.Ref
+			if headSHA == "" {
+				headCommit, _, err := g.client.GetSingleCommit(g.repoOwner, g.repoName, url.PathEscape(pr.Head.Ref))
+				if err != nil {
+					return nil, false, fmt.Errorf("error while resolving git ref: %v", err)
+				}
+				headSHA = headCommit.SHA
+			}
+		}
+
+		var mergeCommitSHA string
+		if pr.MergedCommitID != nil {
+			mergeCommitSHA = *pr.MergedCommitID
+		}
+
+		reactions, err := g.getIssueReactions(pr.Index)
+		if err != nil {
+			return nil, false, fmt.Errorf("error while loading reactions: %v", err)
+		}
+
+		var assignees []string
+		for i := range pr.Assignees {
+			assignees = append(assignees, pr.Assignees[i].UserName)
+		}
+
+		createdAt := time.Now()
+		if pr.Created != nil {
+			createdAt = *pr.Created
+		}
+		updatedAt := time.Now()
+		if pr.Created != nil {
+			updatedAt = *pr.Updated
+		}
+
+		closedAt := pr.Closed
+		if pr.Merged != nil && closedAt == nil {
+			closedAt = pr.Merged
+		}
+
+		allPRs = append(allPRs, &base.PullRequest{
+			Title:          pr.Title,
+			Number:         pr.Index,
+			PosterID:       pr.Poster.ID,
+			PosterName:     pr.Poster.UserName,
+			PosterEmail:    pr.Poster.Email,
+			Content:        pr.Body,
+			State:          string(pr.State),
+			Created:        createdAt,
+			Updated:        updatedAt,
+			Closed:         closedAt,
+			Labels:         labels,
+			Milestone:      milestone,
+			Reactions:      reactions,
+			Assignees:      assignees,
+			Merged:         pr.HasMerged,
+			MergedTime:     pr.Merged,
+			MergeCommitSHA: mergeCommitSHA,
+			IsLocked:       pr.IsLocked,
+			PatchURL:       pr.PatchURL,
+			Head: base.PullRequestBranch{
+				Ref:       headRef,
+				SHA:       headSHA,
+				RepoName:  headRepoName,
+				OwnerName: headUserName,
+				CloneURL:  headCloneURL,
+			},
+			Base: base.PullRequestBranch{
+				Ref:       pr.Base.Ref,
+				SHA:       pr.Base.Sha,
+				RepoName:  g.repoName,
+				OwnerName: g.repoOwner,
+			},
+		})
+	}
+
+	isEnd := len(prs) < perPage
+	if !g.pagination {
+		isEnd = len(prs) == 0
+	}
+	return allPRs, isEnd, nil
+}
+
+// GetReviews returns pull requests review
+func (g *GiteaDownloader) GetReviews(index int64) ([]*base.Review, error) {
+	if err := g.client.CheckServerVersionConstraint(">=1.12"); err != nil {
+		log.Info("GiteaDownloader: instance to old, skip GetReviews")
+		return nil, nil
+	}
+
+	var allReviews = make([]*base.Review, 0, g.maxPerPage)
+
+	for i := 1; ; i++ {
+		// make sure gitea can shutdown gracefully
+		select {
+		case <-g.ctx.Done():
+			return nil, nil
+		default:
+		}
+
+		prl, _, err := g.client.ListPullReviews(g.repoOwner, g.repoName, index, gitea_sdk.ListPullReviewsOptions{ListOptions: gitea_sdk.ListOptions{
+			Page:     i,
+			PageSize: g.maxPerPage,
+		}})
+		if err != nil {
+			return nil, err
+		}
+
+		for _, pr := range prl {
+
+			rcl, _, err := g.client.ListPullReviewComments(g.repoOwner, g.repoName, index, pr.ID)
+			if err != nil {
+				return nil, err
+			}
+			var reviewComments []*base.ReviewComment
+			for i := range rcl {
+				line := int(rcl[i].LineNum)
+				if rcl[i].OldLineNum > 0 {
+					line = int(rcl[i].OldLineNum) * -1
+				}
+
+				reviewComments = append(reviewComments, &base.ReviewComment{
+					ID:        rcl[i].ID,
+					Content:   rcl[i].Body,
+					TreePath:  rcl[i].Path,
+					DiffHunk:  rcl[i].DiffHunk,
+					Line:      line,
+					CommitID:  rcl[i].CommitID,
+					PosterID:  rcl[i].Reviewer.ID,
+					CreatedAt: rcl[i].Created,
+					UpdatedAt: rcl[i].Updated,
+				})
+			}
+
+			allReviews = append(allReviews, &base.Review{
+				ID:           pr.ID,
+				IssueIndex:   index,
+				ReviewerID:   pr.Reviewer.ID,
+				ReviewerName: pr.Reviewer.UserName,
+				Official:     pr.Official,
+				CommitID:     pr.CommitID,
+				Content:      pr.Body,
+				CreatedAt:    pr.Submitted,
+				State:        string(pr.State),
+				Comments:     reviewComments,
+			})
+		}
+
+		if len(prl) < g.maxPerPage {
+			break
+		}
+	}
+	return allReviews, nil
+}
diff --git a/modules/migrations/gitea_downloader_test.go b/modules/migrations/gitea_downloader_test.go
new file mode 100644
index 0000000000..c52c1225f4
--- /dev/null
+++ b/modules/migrations/gitea_downloader_test.go
@@ -0,0 +1,365 @@
+// Copyright 2020 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 migrations
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"os"
+	"sort"
+	"testing"
+	"time"
+
+	"code.gitea.io/gitea/modules/migrations/base"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func assertEqualIssue(t *testing.T, issueExp, issueGet *base.Issue) {
+	assert.EqualValues(t, issueExp.Number, issueGet.Number)
+	assert.EqualValues(t, issueExp.Title, issueGet.Title)
+	assert.EqualValues(t, issueExp.Content, issueGet.Content)
+	assert.EqualValues(t, issueExp.Milestone, issueGet.Milestone)
+	assert.EqualValues(t, issueExp.PosterID, issueGet.PosterID)
+	assert.EqualValues(t, issueExp.PosterName, issueGet.PosterName)
+	assert.EqualValues(t, issueExp.PosterEmail, issueGet.PosterEmail)
+	assert.EqualValues(t, issueExp.IsLocked, issueGet.IsLocked)
+	assert.EqualValues(t, issueExp.Created.Unix(), issueGet.Created.Unix())
+	assert.EqualValues(t, issueExp.Updated.Unix(), issueGet.Updated.Unix())
+	if issueExp.Closed != nil {
+		assert.EqualValues(t, issueExp.Closed.Unix(), issueGet.Closed.Unix())
+	} else {
+		assert.True(t, issueGet.Closed == nil)
+	}
+	sort.Strings(issueExp.Assignees)
+	sort.Strings(issueGet.Assignees)
+	assert.EqualValues(t, issueExp.Assignees, issueGet.Assignees)
+	assert.EqualValues(t, issueExp.Labels, issueGet.Labels)
+	assert.EqualValues(t, issueExp.Reactions, issueGet.Reactions)
+}
+
+func TestGiteaDownloadRepo(t *testing.T) {
+	// Skip tests if Gitea token is not found
+	giteaToken := os.Getenv("GITEA_TOKEN")
+	if giteaToken == "" {
+		t.Skip("skipped test because GITEA_TOKEN was not in the environment")
+	}
+
+	resp, err := http.Get("https://gitea.com/gitea")
+	if err != nil || resp.StatusCode != 200 {
+		t.Skipf("Can't reach https://gitea.com, skipping %s", t.Name())
+	}
+
+	downloader, err := NewGiteaDownloader(context.Background(), "https://gitea.com", "gitea/test_repo", "", "", giteaToken)
+	if downloader == nil {
+		t.Fatal("NewGitlabDownloader is nil")
+	}
+	if !assert.NoError(t, err) {
+		t.Fatal("NewGitlabDownloader error occur")
+	}
+
+	repo, err := downloader.GetRepoInfo()
+	assert.NoError(t, err)
+	assert.EqualValues(t, &base.Repository{
+		Name:          "test_repo",
+		Owner:         "gitea",
+		IsPrivate:     false,
+		Description:   "Test repository for testing migration from gitea to gitea",
+		CloneURL:      "https://gitea.com/gitea/test_repo.git",
+		OriginalURL:   "https://gitea.com/gitea/test_repo",
+		DefaultBranch: "master",
+	}, repo)
+
+	topics, err := downloader.GetTopics()
+	assert.NoError(t, err)
+	sort.Strings(topics)
+	assert.EqualValues(t, []string{"ci", "gitea", "migration", "test"}, topics)
+
+	labels, err := downloader.GetLabels()
+	assert.NoError(t, err)
+	assert.Len(t, labels, 6)
+	for _, l := range labels {
+		switch l.Name {
+		case "Bug":
+			assertLabelEqual(t, "Bug", "e11d21", "", l)
+		case "documentation":
+			assertLabelEqual(t, "Enhancement", "207de5", "", l)
+		case "confirmed":
+			assertLabelEqual(t, "Feature", "0052cc", "a feature request", l)
+		case "enhancement":
+			assertLabelEqual(t, "Invalid", "d4c5f9", "", l)
+		case "critical":
+			assertLabelEqual(t, "Question", "fbca04", "", l)
+		case "discussion":
+			assertLabelEqual(t, "Valid", "53e917", "", l)
+		default:
+			assert.Error(t, fmt.Errorf("unexpected label: %s", l.Name))
+		}
+	}
+
+	milestones, err := downloader.GetMilestones()
+	assert.NoError(t, err)
+	assert.Len(t, milestones, 2)
+
+	for _, milestone := range milestones {
+		switch milestone.Title {
+		case "V1":
+			assert.EqualValues(t, "Generate Content", milestone.Description)
+			// assert.EqualValues(t, "ToDo", milestone.Created)
+			// assert.EqualValues(t, "ToDo", milestone.Updated)
+			assert.EqualValues(t, 1598985406, milestone.Closed.Unix())
+			assert.True(t, milestone.Deadline == nil)
+			assert.EqualValues(t, "closed", milestone.State)
+		case "V2 Finalize":
+			assert.EqualValues(t, "", milestone.Description)
+			// assert.EqualValues(t, "ToDo", milestone.Created)
+			// assert.EqualValues(t, "ToDo", milestone.Updated)
+			assert.True(t, milestone.Closed == nil)
+			assert.EqualValues(t, 1599263999, milestone.Deadline.Unix())
+			assert.EqualValues(t, "open", milestone.State)
+		default:
+			assert.Error(t, fmt.Errorf("unexpected milestone: %s", milestone.Title))
+		}
+	}
+
+	releases, err := downloader.GetReleases()
+	assert.NoError(t, err)
+	assert.EqualValues(t, []*base.Release{
+		{
+			Name:            "Second Release",
+			TagName:         "v2-rc1",
+			TargetCommitish: "master",
+			Body:            "this repo has:\r\n* reactions\r\n* wiki\r\n* issues  (open/closed)\r\n* pulls (open/closed/merged) (external/internal)\r\n* pull reviews\r\n* projects\r\n* milestones\r\n* labels\r\n* releases\r\n\r\nto test migration against",
+			Draft:           false,
+			Prerelease:      true,
+			Created:         time.Date(2020, 9, 1, 18, 2, 43, 0, time.UTC),
+			Published:       time.Date(2020, 9, 1, 18, 2, 43, 0, time.UTC),
+			PublisherID:     689,
+			PublisherName:   "6543",
+			PublisherEmail:  "6543@noreply.gitea.io",
+		},
+		{
+			Name:            "First Release",
+			TagName:         "V1",
+			TargetCommitish: "master",
+			Body:            "as title",
+			Draft:           false,
+			Prerelease:      false,
+			Created:         time.Date(2020, 9, 1, 17, 30, 32, 0, time.UTC),
+			Published:       time.Date(2020, 9, 1, 17, 30, 32, 0, time.UTC),
+			PublisherID:     689,
+			PublisherName:   "6543",
+			PublisherEmail:  "6543@noreply.gitea.io",
+		},
+	}, releases)
+
+	issues, isEnd, err := downloader.GetIssues(1, 50)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 7, len(issues))
+	assert.True(t, isEnd)
+	assert.EqualValues(t, "open", issues[0].State)
+
+	issues, isEnd, err = downloader.GetIssues(3, 2)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 2, len(issues))
+	assert.False(t, isEnd)
+
+	var (
+		closed4 = time.Date(2020, 9, 1, 15, 49, 34, 0, time.UTC)
+		closed2 = time.Unix(1598969497, 0)
+	)
+
+	assertEqualIssue(t, &base.Issue{
+		Number:      4,
+		Title:       "what is this repo about?",
+		Content:     "",
+		Milestone:   "V1",
+		PosterID:    -1,
+		PosterName:  "Ghost",
+		PosterEmail: "",
+		State:       "closed",
+		IsLocked:    true,
+		Created:     time.Unix(1598975321, 0),
+		Updated:     time.Unix(1598975400, 0),
+		Labels: []*base.Label{{
+			Name:        "Question",
+			Color:       "fbca04",
+			Description: "",
+		}},
+		Reactions: []*base.Reaction{
+			{
+				UserID:   689,
+				UserName: "6543",
+				Content:  "gitea",
+			},
+			{
+				UserID:   689,
+				UserName: "6543",
+				Content:  "laugh",
+			},
+		},
+		Closed: &closed4,
+	}, issues[0])
+	assertEqualIssue(t, &base.Issue{
+		Number:      2,
+		Title:       "Spam",
+		Content:     ":(",
+		Milestone:   "",
+		PosterID:    689,
+		PosterName:  "6543",
+		PosterEmail: "6543@noreply.gitea.io",
+		State:       "closed",
+		IsLocked:    false,
+		Created:     time.Unix(1598919780, 0),
+		Updated:     closed2,
+		Labels: []*base.Label{{
+			Name:        "Invalid",
+			Color:       "d4c5f9",
+			Description: "",
+		}},
+		Reactions: nil,
+		Closed:    &closed2,
+	}, issues[1])
+
+	comments, err := downloader.GetComments(4)
+	assert.NoError(t, err)
+	assert.Len(t, comments, 2)
+	assert.EqualValues(t, 1598975370, comments[0].Created.Unix())
+	assert.EqualValues(t, 1599070865, comments[0].Updated.Unix())
+	assert.EqualValues(t, 1598975393, comments[1].Created.Unix())
+	assert.EqualValues(t, 1598975393, comments[1].Updated.Unix())
+	assert.EqualValues(t, []*base.Comment{
+		{
+			IssueIndex:  4,
+			PosterID:    689,
+			PosterName:  "6543",
+			PosterEmail: "6543@noreply.gitea.io",
+			Created:     comments[0].Created,
+			Updated:     comments[0].Updated,
+			Content:     "a really good question!\n\nIt is the used as TESTSET for gitea2gitea repo migration function",
+		},
+		{
+			IssueIndex:  4,
+			PosterID:    -1,
+			PosterName:  "Ghost",
+			PosterEmail: "",
+			Created:     comments[1].Created,
+			Updated:     comments[1].Updated,
+			Content:     "Oh!",
+		},
+	}, comments)
+
+	prs, isEnd, err := downloader.GetPullRequests(1, 50)
+	assert.NoError(t, err)
+	assert.True(t, isEnd)
+	assert.Len(t, prs, 6)
+	prs, isEnd, err = downloader.GetPullRequests(1, 3)
+	assert.NoError(t, err)
+	assert.False(t, isEnd)
+	assert.Len(t, prs, 3)
+	merged12 := time.Unix(1598982934, 0)
+	assertEqualPulls(t, &base.PullRequest{
+		Number:      12,
+		PosterID:    689,
+		PosterName:  "6543",
+		PosterEmail: "6543@noreply.gitea.io",
+		Title:       "Dont Touch",
+		Content:     "\r\nadd dont touch note",
+		Milestone:   "V2 Finalize",
+		State:       "closed",
+		IsLocked:    false,
+		Created:     time.Unix(1598982759, 0),
+		Updated:     time.Unix(1599023425, 0),
+		Closed:      &merged12,
+		Assignees:   []string{"techknowlogick"},
+		Labels:      []*base.Label{},
+
+		Base: base.PullRequestBranch{
+			CloneURL:  "",
+			Ref:       "master",
+			SHA:       "827aa28a907853e5ddfa40c8f9bc52471a2685fd",
+			RepoName:  "test_repo",
+			OwnerName: "gitea",
+		},
+		Head: base.PullRequestBranch{
+			CloneURL:  "https://gitea.com/6543-forks/test_repo.git",
+			Ref:       "refs/pull/12/head",
+			SHA:       "b6ab5d9ae000b579a5fff03f92c486da4ddf48b6",
+			RepoName:  "test_repo",
+			OwnerName: "6543-forks",
+		},
+		Merged:         true,
+		MergedTime:     &merged12,
+		MergeCommitSHA: "827aa28a907853e5ddfa40c8f9bc52471a2685fd",
+		PatchURL:       "https://gitea.com/gitea/test_repo/pulls/12.patch",
+	}, prs[1])
+
+	reviews, err := downloader.GetReviews(7)
+	assert.NoError(t, err)
+	if assert.Len(t, reviews, 3) {
+		assert.EqualValues(t, 689, reviews[0].ReviewerID)
+		assert.EqualValues(t, "6543", reviews[0].ReviewerName)
+		assert.EqualValues(t, "techknowlogick", reviews[1].ReviewerName)
+		assert.EqualValues(t, "techknowlogick", reviews[2].ReviewerName)
+		assert.False(t, reviews[1].Official)
+		assert.EqualValues(t, "I think this needs some changes", reviews[1].Content)
+		assert.EqualValues(t, "REQUEST_CHANGES", reviews[1].State)
+		assert.True(t, reviews[2].Official)
+		assert.EqualValues(t, "looks good", reviews[2].Content)
+		assert.EqualValues(t, "APPROVED", reviews[2].State)
+
+		// TODO: https://github.com/go-gitea/gitea/issues/12846
+		// assert.EqualValues(t, 9, reviews[1].ReviewerID)
+		// assert.EqualValues(t, 9, reviews[2].ReviewerID)
+
+		assert.Len(t, reviews[0].Comments, 1)
+		assert.EqualValues(t, &base.ReviewComment{
+			ID:        116561,
+			InReplyTo: 0,
+			Content:   "is one `\\newline` to less?",
+			TreePath:  "README.md",
+			DiffHunk:  "@@ -2,3 +2,3 @@\n \n-Test repository for testing migration from gitea 2 gitea\n\\ No newline at end of file\n+Test repository for testing migration from gitea 2 gitea",
+			Position:  0,
+			Line:      4,
+			CommitID:  "187ece0cb6631e2858a6872e5733433bb3ca3b03",
+			PosterID:  689,
+			Reactions: nil,
+			CreatedAt: time.Date(2020, 9, 1, 16, 12, 58, 0, time.UTC),
+			UpdatedAt: time.Date(2020, 9, 1, 16, 12, 58, 0, time.UTC),
+		}, reviews[0].Comments[0])
+	}
+}
+
+func assertEqualPulls(t *testing.T, pullExp, pullGet *base.PullRequest) {
+	assertEqualIssue(t, pull2issue(pullExp), pull2issue(pullGet))
+	assert.EqualValues(t, 0, pullGet.OriginalNumber)
+	assert.EqualValues(t, pullExp.PatchURL, pullGet.PatchURL)
+	assert.EqualValues(t, pullExp.Merged, pullGet.Merged)
+	assert.EqualValues(t, pullExp.MergedTime.Unix(), pullGet.MergedTime.Unix())
+	assert.EqualValues(t, pullExp.MergeCommitSHA, pullGet.MergeCommitSHA)
+	assert.EqualValues(t, pullExp.Base, pullGet.Base)
+	assert.EqualValues(t, pullExp.Head, pullGet.Head)
+}
+
+func pull2issue(pull *base.PullRequest) *base.Issue {
+	return &base.Issue{
+		Number:      pull.Number,
+		PosterID:    pull.PosterID,
+		PosterName:  pull.PosterName,
+		PosterEmail: pull.PosterEmail,
+		Title:       pull.Title,
+		Content:     pull.Content,
+		Milestone:   pull.Milestone,
+		State:       pull.State,
+		IsLocked:    pull.IsLocked,
+		Created:     pull.Created,
+		Updated:     pull.Updated,
+		Closed:      pull.Closed,
+		Labels:      pull.Labels,
+		Reactions:   pull.Reactions,
+		Assignees:   pull.Assignees,
+	}
+}
diff --git a/modules/migrations/gitea.go b/modules/migrations/gitea_uploader.go
index d4ba66fd38..cd1fd5cb8d 100644
--- a/modules/migrations/gitea.go
+++ b/modules/migrations/gitea_uploader.go
@@ -273,9 +273,18 @@ func (g *GiteaLocalUploader) CreateReleases(downloader base.Downloader, releases
 
 			// download attachment
 			err = func() error {
-				rc, err := downloader.GetAsset(rel.TagName, asset.ID)
-				if err != nil {
-					return err
+				var rc io.ReadCloser
+				if asset.DownloadURL == nil {
+					rc, err = downloader.GetAsset(rel.TagName, rel.ID, asset.ID)
+					if err != nil {
+						return err
+					}
+				} else {
+					resp, err := http.Get(*asset.DownloadURL)
+					if err != nil {
+						return err
+					}
+					rc = resp.Body
 				}
 				_, err = storage.Attachments.Save(attach.RelativePath(), rc)
 				return err
@@ -779,8 +788,12 @@ func (g *GiteaLocalUploader) CreateReviews(reviews ...*base.Review) error {
 		}
 
 		for _, comment := range review.Comments {
-			_, _, line, _ := git.ParseDiffHunkString(comment.DiffHunk)
-
+			line := comment.Line
+			if line != 0 {
+				comment.Position = 1
+			} else {
+				_, _, line, _ = git.ParseDiffHunkString(comment.DiffHunk)
+			}
 			headCommitID, err := g.gitRepo.GetRefCommitID(pr.GetGitRefName())
 			if err != nil {
 				return fmt.Errorf("GetRefCommitID[%s]: %v", pr.GetGitRefName(), err)
diff --git a/modules/migrations/gitea_test.go b/modules/migrations/gitea_uploader_test.go
index 8432a1eecd..8432a1eecd 100644
--- a/modules/migrations/gitea_test.go
+++ b/modules/migrations/gitea_uploader_test.go
diff --git a/modules/migrations/github.go b/modules/migrations/github.go
index c053596c17..088e54744d 100644
--- a/modules/migrations/github.go
+++ b/modules/migrations/github.go
@@ -329,7 +329,7 @@ func (g *GithubDownloaderV3) GetReleases() ([]*base.Release, error) {
 }
 
 // GetAsset returns an asset
-func (g *GithubDownloaderV3) GetAsset(_ string, id int64) (io.ReadCloser, error) {
+func (g *GithubDownloaderV3) GetAsset(_ string, _, id int64) (io.ReadCloser, error) {
 	asset, redir, err := g.client.Repositories.DownloadReleaseAsset(g.ctx, g.repoOwner, g.repoName, id, http.DefaultClient)
 	if err != nil {
 		return nil, err
@@ -496,7 +496,7 @@ func (g *GithubDownloaderV3) GetComments(issueNumber int64) ([]*base.Comment, er
 }
 
 // GetPullRequests returns pull requests according page and perPage
-func (g *GithubDownloaderV3) GetPullRequests(page, perPage int) ([]*base.PullRequest, error) {
+func (g *GithubDownloaderV3) GetPullRequests(page, perPage int) ([]*base.PullRequest, bool, error) {
 	opt := &github.PullRequestListOptions{
 		Sort:      "created",
 		Direction: "asc",
@@ -510,7 +510,7 @@ func (g *GithubDownloaderV3) GetPullRequests(page, perPage int) ([]*base.PullReq
 	g.sleep()
 	prs, resp, err := g.client.PullRequests.List(g.ctx, g.repoOwner, g.repoName, opt)
 	if err != nil {
-		return nil, fmt.Errorf("error while listing repos: %v", err)
+		return nil, false, fmt.Errorf("error while listing repos: %v", err)
 	}
 	g.rate = &resp.Rate
 	for _, pr := range prs {
@@ -576,7 +576,7 @@ func (g *GithubDownloaderV3) GetPullRequests(page, perPage int) ([]*base.PullReq
 				PerPage: perPage,
 			})
 			if err != nil {
-				return nil, err
+				return nil, false, err
 			}
 			g.rate = &resp.Rate
 			if len(res) == 0 {
@@ -626,7 +626,7 @@ func (g *GithubDownloaderV3) GetPullRequests(page, perPage int) ([]*base.PullReq
 		})
 	}
 
-	return allPRs, nil
+	return allPRs, len(prs) < perPage, nil
 }
 
 func convertGithubReview(r *github.PullRequestReview) *base.Review {
diff --git a/modules/migrations/github_test.go b/modules/migrations/github_test.go
index 3a1affbc2f..efa8b6ba9b 100644
--- a/modules/migrations/github_test.go
+++ b/modules/migrations/github_test.go
@@ -271,7 +271,7 @@ func TestGitHubDownloadRepo(t *testing.T) {
 	}, comments[:2])
 
 	// downloader.GetPullRequests()
-	prs, err := downloader.GetPullRequests(1, 2)
+	prs, _, err := downloader.GetPullRequests(1, 2)
 	assert.NoError(t, err)
 	assert.EqualValues(t, 2, len(prs))
 
diff --git a/modules/migrations/gitlab.go b/modules/migrations/gitlab.go
index 379a2f2b60..23cd90c747 100644
--- a/modules/migrations/gitlab.go
+++ b/modules/migrations/gitlab.go
@@ -303,7 +303,7 @@ func (g *GitlabDownloader) GetReleases() ([]*base.Release, error) {
 }
 
 // GetAsset returns an asset
-func (g *GitlabDownloader) GetAsset(tag string, id int64) (io.ReadCloser, error) {
+func (g *GitlabDownloader) GetAsset(tag string, _, id int64) (io.ReadCloser, error) {
 	link, _, err := g.client.ReleaseLinks.GetReleaseLink(g.repoID, tag, int(id), gitlab.WithContext(g.ctx))
 	if err != nil {
 		return nil, err
@@ -464,7 +464,7 @@ func (g *GitlabDownloader) GetComments(issueNumber int64) ([]*base.Comment, erro
 }
 
 // GetPullRequests returns pull requests according page and perPage
-func (g *GitlabDownloader) GetPullRequests(page, perPage int) ([]*base.PullRequest, error) {
+func (g *GitlabDownloader) GetPullRequests(page, perPage int) ([]*base.PullRequest, bool, error) {
 	opt := &gitlab.ListProjectMergeRequestsOptions{
 		ListOptions: gitlab.ListOptions{
 			PerPage: perPage,
@@ -479,7 +479,7 @@ func (g *GitlabDownloader) GetPullRequests(page, perPage int) ([]*base.PullReque
 
 	prs, _, err := g.client.MergeRequests.ListProjectMergeRequests(g.repoID, opt, nil, gitlab.WithContext(g.ctx))
 	if err != nil {
-		return nil, fmt.Errorf("error while listing merge requests: %v", err)
+		return nil, false, fmt.Errorf("error while listing merge requests: %v", err)
 	}
 	for _, pr := range prs {
 
@@ -521,7 +521,7 @@ func (g *GitlabDownloader) GetPullRequests(page, perPage int) ([]*base.PullReque
 		for {
 			awards, _, err := g.client.AwardEmoji.ListMergeRequestAwardEmoji(g.repoID, pr.IID, &gitlab.ListAwardEmojiOptions{Page: awardPage, PerPage: perPage}, gitlab.WithContext(g.ctx))
 			if err != nil {
-				return nil, fmt.Errorf("error while listing merge requests awards: %v", err)
+				return nil, false, fmt.Errorf("error while listing merge requests awards: %v", err)
 			}
 			if len(awards) < perPage {
 				break
@@ -569,7 +569,7 @@ func (g *GitlabDownloader) GetPullRequests(page, perPage int) ([]*base.PullReque
 		})
 	}
 
-	return allPRs, nil
+	return allPRs, len(prs) < perPage, nil
 }
 
 // GetReviews returns pull requests review
diff --git a/modules/migrations/gitlab_test.go b/modules/migrations/gitlab_test.go
index 11c3aefeaf..f64d72147c 100644
--- a/modules/migrations/gitlab_test.go
+++ b/modules/migrations/gitlab_test.go
@@ -242,7 +242,7 @@ func TestGitlabDownloadRepo(t *testing.T) {
 		},
 	}, comments[:4])
 
-	prs, err := downloader.GetPullRequests(1, 1)
+	prs, _, err := downloader.GetPullRequests(1, 1)
 	assert.NoError(t, err)
 	assert.Len(t, prs, 1)
 
diff --git a/modules/migrations/migrate.go b/modules/migrations/migrate.go
index 8543a3fc09..191f2a5550 100644
--- a/modules/migrations/migrate.go
+++ b/modules/migrations/migrate.go
@@ -229,7 +229,7 @@ func migrateRepository(downloader base.Downloader, uploader base.Uploader, opts
 		log.Trace("migrating pull requests and comments")
 		var prBatchSize = uploader.MaxBatchInsertSize("pullrequest")
 		for i := 1; ; i++ {
-			prs, err := downloader.GetPullRequests(i, prBatchSize)
+			prs, isEnd, err := downloader.GetPullRequests(i, prBatchSize)
 			if err != nil {
 				return err
 			}
@@ -300,7 +300,7 @@ func migrateRepository(downloader base.Downloader, uploader base.Uploader, opts
 				}
 			}
 
-			if len(prs) < prBatchSize {
+			if isEnd {
 				break
 			}
 		}
diff --git a/modules/structs/repo.go b/modules/structs/repo.go
index a8ca823ef6..c12f8e1c18 100644
--- a/modules/structs/repo.go
+++ b/modules/structs/repo.go
@@ -275,5 +275,6 @@ var (
 	SupportedFullGitService = []GitServiceType{
 		GithubService,
 		GitlabService,
+		GiteaService,
 	}
 )