Slice 5: Gitea forge - PRs and Merge & clean up

New internal/forge (provider-abstracted, Gitea impl via code.gitea.io/sdk/gitea) with tested remote-URL parsing and read+write ops: list open PRs, and merge-and-cleanup (squash-merge + delete head branch when head/base share a repo). Service resolves repo->owner/repo from remotes (prefers origin) and records a pr-merged event; config gains GITEA_URL/GITEA_TOKEN (forge disabled without both). MCP tools list_prs and merge_and_cleanup_pr (merge tool tells Claude to confirm first, 1.4). HTTP GET /api/repo/prs, POST /api/repo/pr/merge. New <pr-list> component with a confirming Merge & clean up button, hidden when no forge. Verified graceful-disabled path; real merge pending token + a designated PR. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-09-20 08:37:51 -04:00
parent 2b77e15b36
commit 9d1519222c
16 changed files with 657 additions and 13 deletions
@@ -0,0 +1,121 @@
+package forge
+
+import (
+	"context"
+	"fmt"
+	"net/url"
+	"strings"
+
+	"code.gitea.io/sdk/gitea"
+)
+
+// Gitea is a Provider backed by a Gitea/Forgejo instance. It also decides which
+// repos it serves: only those whose remote host matches its base URL.
+type Gitea struct {
+	host   string
+	client *gitea.Client
+}
+
+// NewGitea builds a Gitea provider from a base URL and token. It returns
+// (nil, nil) when not configured (either value empty) so forge features simply
+// stay absent (§8.4 graceful degradation).
+func NewGitea(baseURL, token string) (*Gitea, error) {
+	baseURL = strings.TrimRight(strings.TrimSpace(baseURL), "/")
+	token = strings.TrimSpace(token)
+	if baseURL == "" || token == "" {
+		return nil, nil
+	}
+	u, err := url.Parse(baseURL)
+	if err != nil || u.Hostname() == "" {
+		return nil, fmt.Errorf("invalid GITEA_URL %q", baseURL)
+	}
+	c, err := gitea.NewClient(baseURL, gitea.SetToken(token))
+	if err != nil {
+		return nil, err
+	}
+	return &Gitea{host: u.Hostname(), client: c}, nil
+}
+
+// Handles reports whether a remote host is this Gitea instance.
+func (g *Gitea) Handles(host string) bool {
+	return strings.EqualFold(host, g.host)
+}
+
+// ListPullRequests lists the open PRs of owner/repo.
+func (g *Gitea) ListPullRequests(_ context.Context, owner, repo string) ([]PullRequest, error) {
+	prs, _, err := g.client.ListRepoPullRequests(owner, repo, gitea.ListPullRequestsOptions{State: gitea.StateOpen})
+	if err != nil {
+		return nil, err
+	}
+	out := make([]PullRequest, 0, len(prs))
+	for _, p := range prs {
+		out = append(out, toPR(p))
+	}
+	return out, nil
+}
+
+// MergeAndCleanup merges the PR and deletes its head branch (when the head is in
+// the same repo — never a fork's branch). Callers MUST have confirmed with the
+// user first (§1.4).
+func (g *Gitea) MergeAndCleanup(_ context.Context, owner, repo string, number int64, method MergeMethod) (MergeResult, error) {
+	pr, _, err := g.client.GetPullRequest(owner, repo, number)
+	if err != nil {
+		return MergeResult{}, err
+	}
+	branch := ""
+	if pr.Head != nil {
+		branch = pr.Head.Ref
+	}
+	sameRepo := pr.Head != nil && pr.Base != nil && pr.Head.RepoID == pr.Base.RepoID
+	del := sameRepo && branch != ""
+
+	merged, _, err := g.client.MergePullRequest(owner, repo, number, gitea.MergePullRequestOption{
+		Style:                  toStyle(method),
+		DeleteBranchAfterMerge: &del,
+	})
+	if err != nil {
+		return MergeResult{}, err
+	}
+
+	res := MergeResult{Number: number, Merged: merged, Branch: branch, BranchDeleted: del && merged}
+	// Best-effort fallback in case the merge option didn't delete the branch
+	// (older Gitea). Ignore the error — the branch may already be gone.
+	if merged && del {
+		_, _, _ = g.client.DeleteRepoBranch(owner, repo, branch)
+	}
+	return res, nil
+}
+
+func toPR(p *gitea.PullRequest) PullRequest {
+	pr := PullRequest{
+		Number:    p.Index,
+		Title:     p.Title,
+		Draft:     p.Draft,
+		Mergeable: p.Mergeable,
+		URL:       p.HTMLURL,
+	}
+	if p.Poster != nil {
+		pr.Author = p.Poster.UserName
+	}
+	if p.Head != nil {
+		pr.Head = p.Head.Ref
+	}
+	if p.Base != nil {
+		pr.Base = p.Base.Ref
+	}
+	if p.Head != nil && p.Base != nil {
+		pr.SameRepo = p.Head.RepoID == p.Base.RepoID
+	}
+	return pr
+}
+
+func toStyle(m MergeMethod) gitea.MergeStyle {
+	switch m {
+	case MergeMerge:
+		return gitea.MergeStyleMerge
+	case MergeRebase:
+		return gitea.MergeStyleRebase
+	default:
+		return gitea.MergeStyleSquash
+	}
+}