feat: implement GitHub API methods and VCS routing (issue #130) (#131)

title

cmd/review-bot/vcs.go

@@ -0,0 +1,361 @@
+package main
+
+// vcs.go defines the vcsClient interface that both gitea.Client (via giteaVCSAdapter)
+// and github.Client (via githubVCSAdapter) satisfy, enabling VCS-type routing in main.go.
+//
+// Interface design:
+//   - Methods cover all PR review operations used by main.go.
+//   - Gitea-specific operations (supersede, comment resolution) are in the separate
+//     giteaExtClient interface. GitHub implementations return ErrNotSupported for those.
+//   - Types are defined here as package-local VCS types; each adapter converts from
+//     its respective client package's types.
+
+import (
+	"context"
+	"errors"
+
+	"gitea.weiker.me/rodin/review-bot/gitea"
+	"gitea.weiker.me/rodin/review-bot/github"
+	"gitea.weiker.me/rodin/review-bot/review"
+)
+
+// ErrNotSupported is returned by VCS methods that have no implementation for
+// a particular VCS backend (e.g., Gitea-specific timeline APIs on GitHub).
+var ErrNotSupported = errors.New("operation not supported on this VCS backend")
+
+// vcsClient is the interface for all PR operations used by main.go.
+// It is implemented by both giteaVCSAdapter and githubVCSAdapter.
+// Interface defined here (in the consumer package) per Go idiom.
+type vcsClient interface {
+	// PR metadata and content
+	GetPullRequest(ctx context.Context, owner, repo string, number int) (*vcsPullRequest, error)
+	GetPullRequestDiff(ctx context.Context, owner, repo string, number int) (string, error)
+	GetPullRequestFiles(ctx context.Context, owner, repo string, number int) ([]vcsChangedFile, error)
+	GetCommitStatuses(ctx context.Context, owner, repo, sha string) ([]vcsCommitStatus, error)
+	GetFileContent(ctx context.Context, owner, repo, filepath string) (string, error)
+	GetFileContentRef(ctx context.Context, owner, repo, filepath, ref string) (string, error)
+	ListContents(ctx context.Context, owner, repo, path string) ([]review.ContentEntry, error)
+	GetAllFilesInPath(ctx context.Context, owner, repo, path string) (map[string]string, error)
+
+	// Review operations
+	PostReview(ctx context.Context, owner, repo string, number int, event, body, commitID string, comments []vcsReviewComment) (*vcsReview, error)
+	ListReviews(ctx context.Context, owner, repo string, number int) ([]vcsReview, error)
+	DeleteReview(ctx context.Context, owner, repo string, number int, reviewID int64) error
+	GetAuthenticatedUser(ctx context.Context) (string, error)
+	RequestReviewer(ctx context.Context, owner, repo string, number int, reviewer string) error
+}
+
+// giteaExtClient extends vcsClient with Gitea-specific operations that have no
+// GitHub equivalent. Code that uses these methods should first do a type assertion.
+type giteaExtClient interface {
+	vcsClient
+	GetTimelineReviewCommentIDForReview(ctx context.Context, owner, repo string, prNum, reviewID int64) (int64, error)
+	EditComment(ctx context.Context, owner, repo string, commentID int64, body string) error
+	ListReviewComments(ctx context.Context, owner, repo string, prNum, reviewID int64) ([]gitea.ReviewComment, error)
+	ResolveComment(ctx context.Context, owner, repo string, commentID int64) error
+}
+
+// --- shared VCS types ---
+
+// vcsPullRequest is VCS-agnostic PR metadata.
+type vcsPullRequest struct {
+	Title string
+	Body  string
+	Head  struct {
+		Sha string
+		Ref string
+	}
+}
+
+// vcsChangedFile is a file changed in a PR.
+type vcsChangedFile struct {
+	Filename string
+	Status   string
+}
+
+// vcsCommitStatus is a CI status entry.
+type vcsCommitStatus struct {
+	Status      string
+	Context     string
+	Description string
+	TargetURL   string
+}
+
+// vcsReviewComment is an inline review comment.
+type vcsReviewComment struct {
+	Path        string
+	NewPosition int64 // Gitea: absolute line; GitHub: diff hunk position
+	Body        string
+}
+
+// vcsReview is a submitted PR review.
+type vcsReview struct {
+	ID       int64
+	Body     string
+	CommitID string
+	User     struct {
+		Login string
+	}
+	State string
+}
+
+// ============================================================
+// giteaVCSAdapter
+// ============================================================
+
+// giteaVCSAdapter wraps gitea.Client to implement vcsClient + giteaExtClient.
+type giteaVCSAdapter struct {
+	c *gitea.Client
+}
+
+func newGiteaVCSAdapter(c *gitea.Client) *giteaVCSAdapter { return &giteaVCSAdapter{c: c} }
+
+func (a *giteaVCSAdapter) GetPullRequest(ctx context.Context, owner, repo string, number int) (*vcsPullRequest, error) {
+	pr, err := a.c.GetPullRequest(ctx, owner, repo, number)
+	if err != nil {
+		return nil, err
+	}
+	r := &vcsPullRequest{Title: pr.Title, Body: pr.Body}
+	r.Head.Sha = pr.Head.Sha
+	r.Head.Ref = pr.Head.Ref
+	return r, nil
+}
+
+func (a *giteaVCSAdapter) GetPullRequestDiff(ctx context.Context, owner, repo string, number int) (string, error) {
+	return a.c.GetPullRequestDiff(ctx, owner, repo, number)
+}
+
+func (a *giteaVCSAdapter) GetPullRequestFiles(ctx context.Context, owner, repo string, number int) ([]vcsChangedFile, error) {
+	files, err := a.c.GetPullRequestFiles(ctx, owner, repo, number)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]vcsChangedFile, len(files))
+	for i, f := range files {
+		out[i] = vcsChangedFile{Filename: f.Filename, Status: f.Status}
+	}
+	return out, nil
+}
+
+func (a *giteaVCSAdapter) GetCommitStatuses(ctx context.Context, owner, repo, sha string) ([]vcsCommitStatus, error) {
+	statuses, err := a.c.GetCommitStatuses(ctx, owner, repo, sha)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]vcsCommitStatus, len(statuses))
+	for i, s := range statuses {
+		out[i] = vcsCommitStatus{Status: s.Status, Context: s.Context, Description: s.Description, TargetURL: s.TargetURL}
+	}
+	return out, nil
+}
+
+func (a *giteaVCSAdapter) GetFileContent(ctx context.Context, owner, repo, filepath string) (string, error) {
+	return a.c.GetFileContent(ctx, owner, repo, filepath)
+}
+
+func (a *giteaVCSAdapter) GetFileContentRef(ctx context.Context, owner, repo, filepath, ref string) (string, error) {
+	return a.c.GetFileContentRef(ctx, owner, repo, filepath, ref)
+}
+
+func (a *giteaVCSAdapter) ListContents(ctx context.Context, owner, repo, path string) ([]review.ContentEntry, error) {
+	entries, err := a.c.ListContents(ctx, owner, repo, path)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]review.ContentEntry, len(entries))
+	for i, e := range entries {
+		out[i] = review.ContentEntry{Name: e.Name, Path: e.Path, Type: e.Type}
+	}
+	return out, nil
+}
+
+func (a *giteaVCSAdapter) GetAllFilesInPath(ctx context.Context, owner, repo, path string) (map[string]string, error) {
+	return a.c.GetAllFilesInPath(ctx, owner, repo, path)
+}
+
+func (a *giteaVCSAdapter) PostReview(ctx context.Context, owner, repo string, number int, event, body, commitID string, comments []vcsReviewComment) (*vcsReview, error) {
+	gc := make([]gitea.ReviewComment, len(comments))
+	for i, c := range comments {
+		gc[i] = gitea.ReviewComment{Path: c.Path, NewPosition: c.NewPosition, Body: c.Body}
+	}
+	r, err := a.c.PostReview(ctx, owner, repo, number, event, body, commitID, gc)
+	if err != nil {
+		return nil, err
+	}
+	out := &vcsReview{ID: r.ID, Body: r.Body, CommitID: r.CommitID, State: r.State}
+	out.User.Login = r.User.Login
+	return out, nil
+}
+
+func (a *giteaVCSAdapter) ListReviews(ctx context.Context, owner, repo string, number int) ([]vcsReview, error) {
+	reviews, err := a.c.ListReviews(ctx, owner, repo, number)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]vcsReview, len(reviews))
+	for i, r := range reviews {
+		out[i] = vcsReview{ID: r.ID, Body: r.Body, CommitID: r.CommitID, State: r.State}
+		out[i].User.Login = r.User.Login
+	}
+	return out, nil
+}
+
+func (a *giteaVCSAdapter) DeleteReview(ctx context.Context, owner, repo string, number int, reviewID int64) error {
+	return a.c.DeleteReview(ctx, owner, repo, number, reviewID)
+}
+
+func (a *giteaVCSAdapter) GetAuthenticatedUser(ctx context.Context) (string, error) {
+	return a.c.GetAuthenticatedUser(ctx)
+}
+
+func (a *giteaVCSAdapter) RequestReviewer(ctx context.Context, owner, repo string, number int, reviewer string) error {
+	return a.c.RequestReviewer(ctx, owner, repo, number, reviewer)
+}
+
+// Gitea-specific extension methods.
+
+func (a *giteaVCSAdapter) GetTimelineReviewCommentIDForReview(ctx context.Context, owner, repo string, prNum, reviewID int64) (int64, error) {
+	return a.c.GetTimelineReviewCommentIDForReview(ctx, owner, repo, int(prNum), reviewID)
+}
+
+func (a *giteaVCSAdapter) EditComment(ctx context.Context, owner, repo string, commentID int64, body string) error {
+	return a.c.EditComment(ctx, owner, repo, commentID, body)
+}
+
+func (a *giteaVCSAdapter) ListReviewComments(ctx context.Context, owner, repo string, prNum, reviewID int64) ([]gitea.ReviewComment, error) {
+	return a.c.ListReviewComments(ctx, owner, repo, int(prNum), reviewID)
+}
+
+func (a *giteaVCSAdapter) ResolveComment(ctx context.Context, owner, repo string, commentID int64) error {
+	return a.c.ResolveComment(ctx, owner, repo, commentID)
+}
+
+// ============================================================
+// githubVCSAdapter
+// ============================================================
+
+// githubVCSAdapter wraps github.Client to implement vcsClient.
+// Gitea-specific extension methods (GetTimelineReviewCommentIDForReview, EditComment,
+// ListReviewComments, ResolveComment) are not available on GitHub and will not be called
+// because main.go gates them with a type assertion to giteaExtClient.
+type githubVCSAdapter struct {
+	c *github.Client
+}
+
+func newGithubVCSAdapter(c *github.Client) *githubVCSAdapter { return &githubVCSAdapter{c: c} }
+
+func (a *githubVCSAdapter) GetPullRequest(ctx context.Context, owner, repo string, number int) (*vcsPullRequest, error) {
+	pr, err := a.c.GetPullRequest(ctx, owner, repo, number)
+	if err != nil {
+		return nil, err
+	}
+	r := &vcsPullRequest{Title: pr.Title, Body: pr.Body}
+	r.Head.Sha = pr.Head.Sha
+	r.Head.Ref = pr.Head.Ref
+	return r, nil
+}
+
+func (a *githubVCSAdapter) GetPullRequestDiff(ctx context.Context, owner, repo string, number int) (string, error) {
+	return a.c.GetPullRequestDiff(ctx, owner, repo, number)
+}
+
+func (a *githubVCSAdapter) GetPullRequestFiles(ctx context.Context, owner, repo string, number int) ([]vcsChangedFile, error) {
+	files, err := a.c.GetPullRequestFiles(ctx, owner, repo, number)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]vcsChangedFile, len(files))
+	for i, f := range files {
+		out[i] = vcsChangedFile{Filename: f.Filename, Status: f.Status}
+	}
+	return out, nil
+}
+
+func (a *githubVCSAdapter) GetCommitStatuses(ctx context.Context, owner, repo, sha string) ([]vcsCommitStatus, error) {
+	statuses, err := a.c.GetCommitStatuses(ctx, owner, repo, sha)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]vcsCommitStatus, len(statuses))
+	for i, s := range statuses {
+		// CommitStatus.Status is tagged as json:"state" — already the normalized "state" value
+		out[i] = vcsCommitStatus{Status: s.Status, Context: s.Context, Description: s.Description, TargetURL: s.TargetURL}
+	}
+	return out, nil
+}
+
+func (a *githubVCSAdapter) GetFileContent(ctx context.Context, owner, repo, filepath string) (string, error) {
+	return a.c.GetFileContent(ctx, owner, repo, filepath)
+}
+
+func (a *githubVCSAdapter) GetFileContentRef(ctx context.Context, owner, repo, filepath, ref string) (string, error) {
+	return a.c.GetFileContentRef(ctx, owner, repo, filepath, ref)
+}
+
+func (a *githubVCSAdapter) ListContents(ctx context.Context, owner, repo, path string) ([]review.ContentEntry, error) {
+	entries, err := a.c.ListContents(ctx, owner, repo, path)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]review.ContentEntry, len(entries))
+	for i, e := range entries {
+		out[i] = review.ContentEntry{Name: e.Name, Path: e.Path, Type: e.Type}
+	}
+	return out, nil
+}
+
+func (a *githubVCSAdapter) GetAllFilesInPath(ctx context.Context, owner, repo, path string) (map[string]string, error) {
+	return a.c.GetAllFilesInPath(ctx, owner, repo, path)
+}
+
+func (a *githubVCSAdapter) PostReview(ctx context.Context, owner, repo string, number int, event, body, commitID string, comments []vcsReviewComment) (*vcsReview, error) {
+	gc := make([]github.ReviewComment, len(comments))
+	for i, c := range comments {
+		// GitHub inline comments use diff hunk "position", not absolute line numbers.
+		// NewPosition from gitea diff parsing gives absolute line numbers, which
+		// will not match GitHub's position values. For initial GitHub support, we
+		// attach comments with Line+Side (absolute line on the RIGHT side) instead.
+		// Comments that cannot be mapped will be omitted (GitHub rejects invalid positions).
+		gc[i] = github.ReviewComment{
+			Path: c.Path,
+			Line: c.NewPosition,
+			Side: "RIGHT",
+			Body: c.Body,
+		}
+	}
+	r, err := a.c.PostReview(ctx, owner, repo, number, event, body, commitID, gc)
+	if err != nil {
+		return nil, err
+	}
+	out := &vcsReview{ID: r.ID, Body: r.Body, State: r.State}
+	out.User.Login = r.User.Login
+	return out, nil
+}
+
+func (a *githubVCSAdapter) ListReviews(ctx context.Context, owner, repo string, number int) ([]vcsReview, error) {
+	reviews, err := a.c.ListReviews(ctx, owner, repo, number)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]vcsReview, len(reviews))
+	for i, r := range reviews {
+		out[i] = vcsReview{ID: r.ID, Body: r.Body, State: r.State}
+		out[i].User.Login = r.User.Login
+	}
+	return out, nil
+}
+
+func (a *githubVCSAdapter) DeleteReview(ctx context.Context, owner, repo string, number int, reviewID int64) error {
+	// GitHub only allows deleting PENDING (draft) reviews. review-bot posts submitted
+	// reviews, so this will return an error for any review we actually posted.
+	// Callers should treat 422 errors here gracefully.
+	return a.c.DeleteReview(ctx, owner, repo, number, reviewID)
+}
+
+func (a *githubVCSAdapter) GetAuthenticatedUser(ctx context.Context) (string, error) {
+	return a.c.GetAuthenticatedUser(ctx)
+}
+
+func (a *githubVCSAdapter) RequestReviewer(ctx context.Context, owner, repo string, number int, reviewer string) error {
+	return a.c.RequestReviewer(ctx, owner, repo, number, reviewer)
+}