Add migrate from OneDev (#16356)

* Use context to simplify logic.

* Added migration from OneDev.
This PR adds [OneDev](https://code.onedev.io/) as migration source.

Supported:
- [x] Milestones
- [x] Issues
- [x] Pull Requests
- [x] Comments
- [x] Reviews
- [x] Labels

modules/migrations/base/downloader.go

@@ -13,9 +13,9 @@ import (
 
 // GetCommentOptions represents an options for get comment
 type GetCommentOptions struct {
-	IssueNumber int64
-	Page        int
-	PageSize    int
+	Context  IssueContext
+	Page     int
+	PageSize int
 }
 
 // Downloader downloads the site repo information
@@ -30,7 +30,7 @@ type Downloader interface {
 	GetComments(opts GetCommentOptions) ([]*Comment, bool, error)
 	SupportGetRepoComments() bool
 	GetPullRequests(page, perPage int) ([]*PullRequest, bool, error)
-	GetReviews(pullRequestNumber int64) ([]*Review, error)
+	GetReviews(pullRequestContext IssueContext) ([]*Review, error)
 	FormatCloneURL(opts MigrateOptions, remoteAddr string) (string, error)
 }
 

modules/migrations/base/issue.go

@@ -7,6 +7,25 @@ package base
 
 import "time"
 
+// IssueContext is used to map between local and foreign issue/PR ids.
+type IssueContext interface {
+	LocalID() int64
+	ForeignID() int64
+}
+
+// BasicIssueContext is a 1:1 mapping between local and foreign ids.
+type BasicIssueContext int64
+
+// LocalID gets the local id.
+func (c BasicIssueContext) LocalID() int64 {
+	return int64(c)
+}
+
+// ForeignID gets the foreign id.
+func (c BasicIssueContext) ForeignID() int64 {
+	return int64(c)
+}
+
 // Issue is a standard issue information
 type Issue struct {
 	Number      int64
@@ -25,4 +44,5 @@ type Issue struct {
 	Labels      []*Label
 	Reactions   []*Reaction
 	Assignees   []string
+	Context     IssueContext `yaml:"-"`
 }

modules/migrations/base/null_downloader.go

@@ -50,7 +50,7 @@ func (n NullDownloader) GetIssues(page, perPage int) ([]*Issue, bool, error) {
 	return nil, false, &ErrNotSupported{Entity: "Issues"}
 }
 
-// GetComments returns comments according issueNumber
+// GetComments returns comments according the options
 func (n NullDownloader) GetComments(GetCommentOptions) ([]*Comment, bool, error) {
 	return nil, false, &ErrNotSupported{Entity: "Comments"}
 }
@@ -61,7 +61,7 @@ func (n NullDownloader) GetPullRequests(page, perPage int) ([]*PullRequest, bool
 }
 
 // GetReviews returns pull requests review
-func (n NullDownloader) GetReviews(pullRequestNumber int64) ([]*Review, error) {
+func (n NullDownloader) GetReviews(pullRequestContext IssueContext) ([]*Review, error) {
 	return nil, &ErrNotSupported{Entity: "Reviews"}
 }
 

modules/migrations/base/pullrequest.go

@@ -13,7 +13,6 @@ import (
 // PullRequest defines a standard pull request information
 type PullRequest struct {
 	Number         int64
-	OriginalNumber int64 `yaml:"original_number"`
 	Title          string
 	PosterName     string `yaml:"poster_name"`
 	PosterID       int64  `yaml:"poster_id"`
@@ -34,6 +33,7 @@ type PullRequest struct {
 	Assignees      []string
 	IsLocked       bool `yaml:"is_locked"`
 	Reactions      []*Reaction
+	Context        IssueContext `yaml:"-"`
 }
 
 // IsForkPullRequest returns true if the pull request from a forked repository but not the same repository

modules/migrations/base/retry_downloader.go

@@ -182,14 +182,14 @@ func (d *RetryDownloader) GetPullRequests(page, perPage int) ([]*PullRequest, bo
 }
 
 // GetReviews returns pull requests reviews
-func (d *RetryDownloader) GetReviews(pullRequestNumber int64) ([]*Review, error) {
+func (d *RetryDownloader) GetReviews(pullRequestContext IssueContext) ([]*Review, error) {
 	var (
 		reviews []*Review
 		err     error
 	)
 
 	err = d.retry(func() error {
-		reviews, err = d.Downloader.GetReviews(pullRequestNumber)
+		reviews, err = d.Downloader.GetReviews(pullRequestContext)
 		return err
 	})