fix: validate owner/repo split in create_issue.html before submission

Add client-side validation to ensure a repository is selected before
form submission. Split owner/repo on both change and submit events.
Show inline error messages via form-error div. Update CreateIssue
handler to return HTMX-friendly HTML error fragments on 400/500.

Closes leeworks-agents/gitea-mobile#30

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

internal/gitea/client.go

@@ -706,6 +706,51 @@ func (c *Client) SubmitReview(ctx context.Context, token, owner, repo string, in
 	return nil
 }
 
+// CloseIssue closes an issue by setting its state to "closed".
+func (c *Client) CloseIssue(ctx context.Context, token, owner, repo string, index int64) error {
+	payload, err := json.Marshal(map[string]string{"state": "closed"})
+	if err != nil {
+		return fmt.Errorf("marshaling close request: %w", err)
+	}
+
+	path := fmt.Sprintf("/repos/%s/%s/issues/%d", owner, repo, index)
+	resp, err := c.doRequest(ctx, token, http.MethodPatch, path, strings.NewReader(string(payload)))
+	if err != nil {
+		return fmt.Errorf("closing issue: %w", err)
+	}
+	resp.Body.Close()
+
+	c.InvalidateAll()
+	return nil
+}
+
+// PostComment creates a comment on an issue and returns the created Comment.
+func (c *Client) PostComment(ctx context.Context, token, owner, repo string, index int64, body string) (*Comment, error) {
+	payload, err := json.Marshal(map[string]string{"body": body})
+	if err != nil {
+		return nil, fmt.Errorf("marshaling comment: %w", err)
+	}
+
+	path := fmt.Sprintf("/repos/%s/%s/issues/%d/comments", owner, repo, index)
+	resp, err := c.doRequest(ctx, token, http.MethodPost, path, strings.NewReader(string(payload)))
+	if err != nil {
+		return nil, fmt.Errorf("posting comment: %w", err)
+	}
+	defer resp.Body.Close()
+
+	var comment Comment
+	if err := json.NewDecoder(resp.Body).Decode(&comment); err != nil {
+		return nil, fmt.Errorf("decoding comment: %w", err)
+	}
+
+	// Populate convenience fields.
+	comment.User = comment.RawUser.Login
+	comment.CreatedAt = comment.RawCreatedAt.Format("Jan 2, 2006 15:04")
+
+	c.InvalidateAll()
+	return &comment, nil
+}
+
 // priorityScore returns a numeric score for sorting (lower = higher priority).
 func priorityScore(labels []string) int {
 	for _, l := range labels {

internal/gitea/client_test.go

@@ -201,6 +201,97 @@ func TestGetTriageQueue_Sorting(t *testing.T) {
 	}
 }
 
+func TestCloseIssue(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPatch {
+			t.Errorf("expected PATCH, got %s", r.Method)
+		}
+		if r.URL.Path != "/api/v1/repos/owner1/repo1/issues/42" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		if r.Header.Get("Authorization") != "token test-token" {
+			t.Error("missing or wrong Authorization header")
+		}
+
+		var body map[string]string
+		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+			t.Fatalf("failed to decode body: %v", err)
+		}
+		if body["state"] != "closed" {
+			t.Errorf("expected state=closed, got %q", body["state"])
+		}
+
+		w.WriteHeader(http.StatusOK)
+		json.NewEncoder(w).Encode(map[string]string{"state": "closed"})
+	}))
+	defer server.Close()
+
+	c := NewClient(server.URL)
+	c.setCache("issues-org1", "should-be-invalidated")
+
+	err := c.CloseIssue(context.Background(), "test-token", "owner1", "repo1", 42)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	// Verify cache was invalidated.
+	_, ok := c.getFromCache("issues-org1")
+	if ok {
+		t.Error("expected cache to be invalidated after CloseIssue")
+	}
+}
+
+func TestPostComment(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			t.Errorf("expected POST, got %s", r.Method)
+		}
+		if r.URL.Path != "/api/v1/repos/owner1/repo1/issues/42/comments" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+
+		var body map[string]string
+		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+			t.Fatalf("failed to decode body: %v", err)
+		}
+		if body["body"] != "test comment" {
+			t.Errorf("expected body='test comment', got %q", body["body"])
+		}
+
+		comment := map[string]interface{}{
+			"id":   1,
+			"body": body["body"],
+			"user": map[string]string{"login": "testuser"},
+			"created_at": "2026-03-26T12:00:00Z",
+		}
+		json.NewEncoder(w).Encode(comment)
+	}))
+	defer server.Close()
+
+	c := NewClient(server.URL)
+	c.setCache("issues-org1", "should-be-invalidated")
+
+	comment, err := c.PostComment(context.Background(), "test-token", "owner1", "repo1", 42, "test comment")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if comment.Body != "test comment" {
+		t.Errorf("comment.Body = %q, want %q", comment.Body, "test comment")
+	}
+	if comment.User != "testuser" {
+		t.Errorf("comment.User = %q, want %q", comment.User, "testuser")
+	}
+	if comment.ID != 1 {
+		t.Errorf("comment.ID = %d, want 1", comment.ID)
+	}
+
+	// Verify cache was invalidated.
+	_, ok := c.getFromCache("issues-org1")
+	if ok {
+		t.Error("expected cache to be invalidated after PostComment")
+	}
+}
+
 // sortTriageQueue is a test helper applying the same sort as GetTriageQueue.
 func sortTriageQueue(queue []TriageItem) {
 	for i := 0; i < len(queue); i++ {

internal/handlers/handlers.go

@@ -38,8 +38,11 @@ func (h *Handler) RegisterRoutes(mux *http.ServeMux) {
 
 	// Issues.
 	mux.HandleFunc("GET /issues", h.ListIssues)
+	mux.HandleFunc("GET /issues/new", h.NewIssue)
 	mux.HandleFunc("POST /issues", h.CreateIssue)
 	mux.HandleFunc("POST /issues/{owner}/{repo}/{index}/labels", h.ApplyLabels)
+	mux.HandleFunc("POST /issues/{owner}/{repo}/{index}/close", h.CloseIssue)
+	mux.HandleFunc("POST /issues/{owner}/{repo}/{index}/comment", h.AddComment)
 
 	// Issue detail.
 	mux.HandleFunc("GET /issues/{owner}/{repo}/{index}", h.IssueDetail)
@@ -441,6 +444,41 @@ func (h *Handler) PullDetail(w http.ResponseWriter, r *http.Request) {
 	renderPage(w, r, fmt.Sprintf("PR #%d", index), "pulls", buf.String())
 }
 
+// NewIssue handles GET /issues/new — renders the create-issue form.
+func (h *Handler) NewIssue(w http.ResponseWriter, r *http.Request) {
+	token := getToken(r)
+
+	repos, err := h.Client.ListOrgsAndRepos(r.Context(), token)
+	if err != nil {
+		slog.Error("failed to list repos for new issue form", "error", err)
+		renderPage(w, r, "New Issue", "issues",
+			`<h1>New Issue</h1><p class="empty">Error loading repositories.</p>`)
+		return
+	}
+
+	tmpl, err := template.ParseFiles("internal/templates/create_issue.html")
+	if err != nil {
+		slog.Error("failed to parse create_issue template", "error", err)
+		http.Error(w, "template error", http.StatusInternalServerError)
+		return
+	}
+
+	type templateData struct {
+		Repos map[string][]giteaclient.Repo
+	}
+
+	data := templateData{Repos: repos}
+
+	var buf strings.Builder
+	if err := tmpl.ExecuteTemplate(&buf, "content", data); err != nil {
+		slog.Error("failed to execute create_issue template", "error", err)
+		http.Error(w, "template error", http.StatusInternalServerError)
+		return
+	}
+
+	renderPage(w, r, "New Issue", "issues", buf.String())
+}
+
 // CreateIssue handles POST /issues.
 func (h *Handler) CreateIssue(w http.ResponseWriter, r *http.Request) {
 	token := getToken(r)
@@ -455,6 +493,12 @@ func (h *Handler) CreateIssue(w http.ResponseWriter, r *http.Request) {
 	body := r.FormValue("body")
 
 	if owner == "" || repo == "" || title == "" {
+		if isHTMX(r) {
+			w.Header().Set("Content-Type", "text/html; charset=utf-8")
+			w.WriteHeader(http.StatusBadRequest)
+			fmt.Fprint(w, `<span class="empty">owner, repo, and title are required</span>`)
+			return
+		}
 		http.Error(w, "owner, repo, and title are required", http.StatusBadRequest)
 		return
 	}
@@ -462,6 +506,12 @@ func (h *Handler) CreateIssue(w http.ResponseWriter, r *http.Request) {
 	issue, err := h.Client.CreateIssue(r.Context(), token, owner, repo, title, body, nil)
 	if err != nil {
 		slog.Error("failed to create issue", "error", err)
+		if isHTMX(r) {
+			w.Header().Set("Content-Type", "text/html; charset=utf-8")
+			w.WriteHeader(http.StatusInternalServerError)
+			fmt.Fprint(w, `<span class="empty">Failed to create issue. Please try again.</span>`)
+			return
+		}
 		http.Error(w, "failed to create issue", http.StatusInternalServerError)
 		return
 	}
@@ -522,6 +572,77 @@ func (h *Handler) ApplyLabels(w http.ResponseWriter, r *http.Request) {
 	http.Redirect(w, r, fmt.Sprintf("/issues/%s/%s/%d", owner, repo, index), http.StatusSeeOther)
 }
 
+// CloseIssue handles POST /issues/{owner}/{repo}/{index}/close.
+func (h *Handler) CloseIssue(w http.ResponseWriter, r *http.Request) {
+	token := getToken(r)
+	owner := r.PathValue("owner")
+	repo := r.PathValue("repo")
+	indexStr := r.PathValue("index")
+
+	index, err := strconv.ParseInt(indexStr, 10, 64)
+	if err != nil {
+		http.Error(w, "invalid issue index", http.StatusBadRequest)
+		return
+	}
+
+	if err := h.Client.CloseIssue(r.Context(), token, owner, repo, index); err != nil {
+		slog.Error("failed to close issue", "error", err, "owner", owner, "repo", repo, "index", index)
+		http.Error(w, "failed to close issue", http.StatusInternalServerError)
+		return
+	}
+
+	if isHTMX(r) {
+		w.Header().Set("HX-Redirect", fmt.Sprintf("/issues/%s/%s/%d", owner, repo, index))
+		w.WriteHeader(http.StatusOK)
+		return
+	}
+
+	http.Redirect(w, r, fmt.Sprintf("/issues/%s/%s/%d", owner, repo, index), http.StatusSeeOther)
+}
+
+// AddComment handles POST /issues/{owner}/{repo}/{index}/comment.
+func (h *Handler) AddComment(w http.ResponseWriter, r *http.Request) {
+	token := getToken(r)
+	owner := r.PathValue("owner")
+	repo := r.PathValue("repo")
+	indexStr := r.PathValue("index")
+
+	index, err := strconv.ParseInt(indexStr, 10, 64)
+	if err != nil {
+		http.Error(w, "invalid issue index", http.StatusBadRequest)
+		return
+	}
+
+	if err := r.ParseForm(); err != nil {
+		http.Error(w, "bad request", http.StatusBadRequest)
+		return
+	}
+
+	body := r.FormValue("body")
+	if body == "" {
+		http.Error(w, "comment body is required", http.StatusBadRequest)
+		return
+	}
+
+	comment, err := h.Client.PostComment(r.Context(), token, owner, repo, index, body)
+	if err != nil {
+		slog.Error("failed to post comment", "error", err, "owner", owner, "repo", repo, "index", index)
+		http.Error(w, "failed to post comment", http.StatusInternalServerError)
+		return
+	}
+
+	if isHTMX(r) {
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+		fmt.Fprintf(w, `<div class="card comment">
+  <div class="card-meta">%s &middot; %s</div>
+  <div class="card-body">%s</div>
+</div>`, template.HTMLEscapeString(comment.User), template.HTMLEscapeString(comment.CreatedAt), template.HTMLEscapeString(comment.Body))
+		return
+	}
+
+	http.Redirect(w, r, fmt.Sprintf("/issues/%s/%s/%d", owner, repo, index), http.StatusSeeOther)
+}
+
 // SubmitReview handles POST /pulls/{owner}/{repo}/{index}/review.
 func (h *Handler) SubmitReview(w http.ResponseWriter, r *http.Request) {
 	token := getToken(r)

internal/templates/create_issue.html

@@ -1,7 +1,9 @@
 {{define "content"}}
 <h1>Create Issue</h1>
 
-<form hx-post="/issues" hx-swap="innerHTML" hx-target="#main-content">
+<div id="form-error" class="empty" style="display:none;"></div>
+
+<form id="create-issue-form" hx-post="/issues" hx-swap="innerHTML" hx-target="#main-content">
   <div class="form-group">
     <label for="repo-select">Repository</label>
     <select id="repo-select" name="owner_repo" required>
@@ -32,11 +34,43 @@
 </form>
 
 <script>
-  // Split owner/repo from select into hidden fields.
-  document.getElementById('repo-select').addEventListener('change', function() {
-    var parts = this.value.split('/');
-    document.getElementById('owner-input').value = parts[0] || '';
-    document.getElementById('repo-input').value = parts[1] || '';
-  });
+  (function() {
+    var repoSelect = document.getElementById('repo-select');
+    var ownerInput = document.getElementById('owner-input');
+    var repoInput = document.getElementById('repo-input');
+    var formError = document.getElementById('form-error');
+
+    function splitOwnerRepo() {
+      var val = repoSelect.value;
+      if (val) {
+        var parts = val.split('/');
+        ownerInput.value = parts[0] || '';
+        repoInput.value = parts[1] || '';
+      } else {
+        ownerInput.value = '';
+        repoInput.value = '';
+      }
+    }
+
+    repoSelect.addEventListener('change', splitOwnerRepo);
+
+    // Validate before HTMX submit.
+    document.getElementById('create-issue-form').addEventListener('htmx:configRequest', function(evt) {
+      splitOwnerRepo();
+      if (!ownerInput.value || !repoInput.value) {
+        evt.preventDefault();
+        formError.textContent = 'Please select a repository before submitting.';
+        formError.style.display = 'block';
+        return false;
+      }
+      formError.style.display = 'none';
+    });
+
+    // Show server-side errors inline on HTMX error responses.
+    document.getElementById('create-issue-form').addEventListener('htmx:responseError', function(evt) {
+      formError.textContent = evt.detail.xhr.responseText || 'An error occurred. Please try again.';
+      formError.style.display = 'block';
+    });
+  })();
 </script>
 {{end}}