fix(pr): refuse pr comment and pr attachment on issues

Gitea serves pull request comments and attachments through issue
endpoints, so tea pr comment create 1 posted on issue #1. pr comment and
pr attachment commands now check that the number is a pull request, and
comment IDs that the comment is on one, and point at the issue command
otherwise: "#1 in alice/project is an issue, not a pull request; use tea
issue comment create 1". Issues gain a kind field (issue or pull) in JSON.

Signed-off-by: bircni <bircni@icloud.com>

internal/services/issues.go

@@ -20,6 +20,7 @@ type Issue struct {
 	Ref       string          `json:"ref"`
 	ID        int64           `json:"id"`
 	Number    int64           `json:"number"`
+	Kind      string          `json:"kind"`
 	Title     string          `json:"title"`
 	Body      string          `json:"body"`
 	URL       string          `json:"url"`
@@ -32,6 +33,22 @@ type Issue struct {
 	Comments  int64           `json:"comments"`
 }
 
+// Kinds of Issue: Gitea lists pull requests among issues.
+const (
+	KindIssue = "issue"
+	KindPull  = "pull"
+)
+
+// discussionFrom converts an issue or a pull request listed among issues.
+func discussionFrom(issue *gitea.Issue) Issue {
+	item := issueFrom(issue)
+	item.Kind = KindIssue
+	if issue.PullRequest != nil {
+		item.Kind = KindPull
+	}
+	return item
+}
+
 // IssueMilestone identifies the milestone associated with an issue or pull request.
 type IssueMilestone struct {
 	ID    int64  `json:"id"`
@@ -99,7 +116,7 @@ func (s Issues) List(ctx context.Context, opts ListOptions) ([]Issue, bool, erro
 	if err != nil {
 		return nil, false, err
 	}
-	return convertAll(issues, issueFrom), more, nil
+	return convertAll(issues, discussionFrom), more, nil
 }
 
 // filterValues splits a comma-separated filter, which the SDK joins again.
@@ -112,14 +129,14 @@ func filterValues(value string) []string {
 
 // View retrieves one issue.
 func (s Issues) View(ctx context.Context, number int64) (Issue, error) {
-	return repoConvert(ctx, s.Client, s.Repository, issueFrom, func(ctx context.Context, c *gitea.Client, owner, repo string) (*gitea.Issue, *gitea.Response, error) {
+	return repoConvert(ctx, s.Client, s.Repository, discussionFrom, func(ctx context.Context, c *gitea.Client, owner, repo string) (*gitea.Issue, *gitea.Response, error) {
 		return c.Issues.GetIssue(ctx, owner, repo, number)
 	})
 }
 
 // Create opens an issue.
 func (s Issues) Create(ctx context.Context, options IssueOptions) (Issue, error) {
-	return repoConvert(ctx, s.Client, s.Repository, issueFrom, func(ctx context.Context, c *gitea.Client, owner, repo string) (*gitea.Issue, *gitea.Response, error) {
+	return repoConvert(ctx, s.Client, s.Repository, discussionFrom, func(ctx context.Context, c *gitea.Client, owner, repo string) (*gitea.Issue, *gitea.Response, error) {
 		return c.Issues.CreateIssue(ctx, owner, repo, gitea.CreateIssueOption{
 			Title: options.Title, Body: options.Body, Ref: options.Ref, Assignees: options.Assignees,
 			Deadline: options.Deadline, Milestone: options.Milestone, Labels: options.Labels,
@@ -134,7 +151,7 @@ func (s Issues) SetState(ctx context.Context, number int64, state string) (Issue
 }
 
 func (s Issues) edit(ctx context.Context, number int64, opts gitea.EditIssueOption) (Issue, error) {
-	return repoConvert(ctx, s.Client, s.Repository, issueFrom, func(ctx context.Context, c *gitea.Client, owner, repo string) (*gitea.Issue, *gitea.Response, error) {
+	return repoConvert(ctx, s.Client, s.Repository, discussionFrom, func(ctx context.Context, c *gitea.Client, owner, repo string) (*gitea.Issue, *gitea.Response, error) {
 		return c.Issues.EditIssue(ctx, owner, repo, number, opts)
 	})
 }