Harden destructive actions and generation recovery

src/ui/callbacks.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import html
 import json
 
 import gradio as gr
@@ -49,11 +50,15 @@ def ask_question(
         return "Please enter a question.", ""
     page_num = None if page == "All pages" else int(page)
     set_runtime_gemini_api_key(gemini_key)
-    result = answer(
-        question.strip(),
-        k=int(k),
-        filters=build_filters(selected_docs, page_num),
-    )
+    try:
+        result = answer(
+            question.strip(),
+            k=int(k),
+            filters=build_filters(selected_docs, page_num),
+        )
+    except RuntimeError as error:
+        message = _generation_message(error)
+        return message, json.dumps({"error": message}, ensure_ascii=False, indent=2)
     return (
         str(export(result, fmt="md")),
         json.dumps(result.model_dump(), ensure_ascii=False, indent=2),
@@ -67,12 +72,15 @@ def ask_chat(
     selected_docs: list[str],
     page: str,
     gemini_key: str,
+    progress: gr.Progress = PROGRESS,
 ) -> tuple[list[gr.ChatMessage], str, str]:
     user_text = (message or "").strip()
     turns = _normalize_chat_history(history)
     if not user_text:
         return turns, "", ""
+    progress(0.2, desc="Retrieving context…")
     answer_md, raw = ask_question(user_text, k, selected_docs, page, gemini_key)
+    progress(0.9, desc="Formatting answer…")
     turns.append(gr.ChatMessage(role="user", content=user_text))
     turns.append(gr.ChatMessage(role="assistant", content=answer_md))
     return turns, raw, ""
@@ -222,6 +230,41 @@ def delete_selected_docs(
     return filenames, f"Deleted {len(selected)} document(s)."
 
 
+def prepare_delete(
+    selected: list[str],
+) -> tuple[str, dict[str, bool], dict[str, bool], dict[str, bool], dict[str, bool]]:
+    if not selected:
+        raise gr.Error("Select at least one document before deleting.")
+    count = len(selected)
+    names = ", ".join(html.escape(str(name), quote=False) for name in selected[:3])
+    if count > 3:
+        names += f" and {count - 3} more"
+    prompt = (
+        '<div class="delete-confirmation-message">'
+        f"Delete <strong>{names}</strong>? This removes the indexed vectors."
+        " The original PDF remains available for re-indexing.</div>"
+    )
+    return (
+        prompt,
+        gr.update(visible=True),
+        gr.update(visible=True),
+        gr.update(visible=False),
+        gr.update(visible=True),
+    )
+
+
+def reset_delete_confirmation() -> tuple[
+    str, dict[str, bool], dict[str, bool], dict[str, bool], dict[str, bool]
+]:
+    return (
+        "",
+        gr.update(visible=False),
+        gr.update(visible=False),
+        gr.update(visible=True),
+        gr.update(visible=False),
+    )
+
+
 def clear_chat() -> tuple[list[list[str]], str]:
     """Clear the chat history."""
     return [], ""
@@ -234,9 +277,22 @@ def _empty_result_error() -> gr.Error:
 
 
 def _generation_error(error: RuntimeError) -> gr.Error:
+    return gr.Error(_generation_message(error))
+
+
+def _generation_message(error: RuntimeError) -> str:
     if "Missing Gemini API key" in str(error):
-        return gr.Error(
+        return (
             "Gemini API key is missing. Open the Gemini API key section, enter a key, "
             "or set GEMINI_API_KEY before generating."
         )
-    return _empty_result_error()
+    error_text = str(error).lower()
+    if "401" in error_text or "403" in error_text or "unauthorized" in error_text:
+        return "Gemini rejected the API key. Check the key and try again."
+    if "429" in error_text or "rate limit" in error_text:
+        return "Gemini rate limit reached. Wait briefly, then click Generate or Send again."
+    if "timeout" in error_text or "timed out" in error_text:
+        return "Gemini timed out while generating. Check your connection and try again."
+    if "No relevant content" in str(error):
+        return "No relevant content found. Upload documents, select a scope, and try again."
+    return "Generation failed. Check your connection and try Generate or Send again."

src/ui/layout.py

@@ -9,6 +9,8 @@ from src.ui.callbacks import (
     delete_selected_docs,
     generate_flashcard_set_interactive,
     generate_quiz_set_interactive,
+    prepare_delete,
+    reset_delete_confirmation,
     summarize_documents,
 )
 from src.ui.content import (
@@ -119,6 +121,20 @@ def build_demo() -> gr.Blocks:
                         variant="stop",
                         elem_classes="library-delete-btn",
                     )
+                delete_prompt = gr.HTML(visible=False, elem_classes="delete-confirmation")
+                with gr.Row(
+                    visible=False,
+                    elem_classes="delete-confirmation-actions",
+                ) as delete_confirmation_actions:
+                    confirm_delete_btn = gr.Button(
+                        "Confirm delete",
+                        variant="stop",
+                        elem_classes="library-delete-confirm-btn",
+                    )
+                    cancel_delete_btn = gr.Button(
+                        "Cancel",
+                        elem_classes="library-delete-cancel-btn",
+                    )
                 doc_summary = gr.HTML(EMPTY_LIBRARY_HTML, elem_classes="doc-summary")
                 docs = gr.CheckboxGroup(
                     label="Documents",
@@ -278,6 +294,18 @@ def build_demo() -> gr.Blocks:
             api_name="upload_pdf",
         )
         delete_btn.click(
+            fn=prepare_delete,
+            inputs=[docs],
+            outputs=[
+                delete_prompt,
+                confirm_delete_btn,
+                cancel_delete_btn,
+                delete_btn,
+                delete_confirmation_actions,
+            ],
+            api_name="prepare_delete",
+        )
+        confirm_delete_btn.click(
             fn=delete_selected_docs,
             inputs=[docs],
             outputs=[docs, doc_summary],
@@ -286,6 +314,27 @@ def build_demo() -> gr.Blocks:
             fn=refresh_docs,
             inputs=[],
             outputs=[docs, doc_map_state, page, doc_summary, doc_list_md],
+        ).then(
+            fn=reset_delete_confirmation,
+            inputs=[],
+            outputs=[
+                delete_prompt,
+                confirm_delete_btn,
+                cancel_delete_btn,
+                delete_btn,
+                delete_confirmation_actions,
+            ],
+        )
+        cancel_delete_btn.click(
+            fn=reset_delete_confirmation,
+            inputs=[],
+            outputs=[
+                delete_prompt,
+                confirm_delete_btn,
+                cancel_delete_btn,
+                delete_btn,
+                delete_confirmation_actions,
+            ],
         )
         clear_chat_btn.click(
             fn=clear_chat,

static/style.css

@@ -2164,6 +2164,33 @@ body {
   color: #f09ba2 !important;
 }
 
+.delete-confirmation {
+  margin-top: var(--space-3) !important;
+  padding: var(--space-3) var(--space-4) !important;
+  border: 1px solid rgba(224, 98, 108, 0.28) !important;
+  border-radius: var(--radius-card) !important;
+  color: var(--text-secondary) !important;
+  background: rgba(224, 98, 108, 0.06) !important;
+  font-size: 0.8125rem !important;
+  line-height: 1.5 !important;
+}
+
+.delete-confirmation-actions {
+  gap: var(--space-2) !important;
+  margin-top: var(--space-2) !important;
+}
+
+.delete-confirmation-actions > button {
+  flex: 1 1 0 !important;
+  min-width: 0 !important;
+}
+
+.gradio-container .library-delete-confirm-btn {
+  border-color: rgba(224, 98, 108, 0.45) !important;
+  color: #f09ba2 !important;
+  background: rgba(224, 98, 108, 0.1) !important;
+}
+
 .library-document-picker,
 .library-page-picker {
   padding: var(--space-4) !important;

tests/test_ui_contracts.py

@@ -61,8 +61,8 @@ def test_demo_keeps_learning_event_contract() -> None:
         if dependency["backend_fn"]
     }
 
-    assert len(config["components"]) == 97
-    assert len(config["dependencies"]) == 14
+    assert len(config["components"]) == 101
+    assert len(config["dependencies"]) == 17
     assert contracts["refresh_documents"] == (0, 5)
     assert contracts["pages_for_selection"] == (2, 1)
     assert contracts["upload_pdf"] == (1, 6)
@@ -73,6 +73,9 @@ def test_demo_keeps_learning_event_contract() -> None:
     assert contracts["generate_flashcard_set"] == (6, 3)
     assert contracts["clear_chat"] == (0, 1)
     assert contracts["delete_selected_docs"] == (1, 2)
+    assert contracts["prepare_delete"] == (1, 5)
+    assert contracts["reset_delete_confirmation"] == (0, 5)
+    assert contracts["reset_delete_confirmation_1"] == (0, 5)
     assert contracts["lambda"] == (1, 1)
     assert contracts["lambda_1"] == (1, 1)
     assert contracts["lambda_2"] == (1, 1)
@@ -134,6 +137,18 @@ def test_missing_gemini_key_error_names_recovery_action() -> None:
     assert "GEMINI_API_KEY" in str(error)
 
 
+def test_delete_confirmation_escapes_names_and_preserves_restore_path() -> None:
+    from src.ui.callbacks import prepare_delete
+
+    prompt, confirm, cancel, delete, actions = prepare_delete(["<notes>.pdf"])
+
+    assert "&lt;notes&gt;.pdf" in prompt
+    assert confirm["visible"] is True
+    assert cancel["visible"] is True
+    assert delete["visible"] is False
+    assert actions["visible"] is True
+
+
 def test_upload_dropzone_keeps_internal_icon_buttons_scoped() -> None:
     assert ".upload-dropzone button {" not in CSS
     assert ".upload-dropzone > button:not(.icon-button)" in CSS
@@ -448,7 +463,7 @@ def test_library_refresh_keeps_page_scope_disabled(
 def test_refactor_preserves_stylesheet() -> None:
     digest = hashlib.sha256(CSS.encode()).hexdigest()
 
-    assert digest == "d0b59f8197f105ebbad433ba843ac55569e9b1a183e1c9a1d1e1812b0636f4a7"
+    assert digest == "55e1a75fdea3713501f288e6facea4562bb231bc70ba9691f11a755d7a015ba9"
 
 
 def test_mobile_heading_keeps_word_boundary_when_break_is_hidden() -> None: