feat(history): migrate history to SQLite with FTS5 search

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

src/lib/pages/DictationPage.svelte

@@ -2,7 +2,8 @@
   import { onMount, onDestroy } from "svelte";
   import { invoke } from "@tauri-apps/api/core";
   import { listen } from "@tauri-apps/api/event";
-  import { page, settings, templates, addToHistory } from "$lib/stores/page.svelte.js";
+  import { page, settings, templates } from "$lib/stores/page.svelte.js";
+  import { saveTranscript } from "$lib/stores/history.svelte.js";
   import { getTasks, createTask } from "$lib/stores/tasks.svelte.js";
   const tasks = getTasks();
   import Card from "$lib/components/Card.svelte";
@@ -378,7 +379,7 @@
       }
 
       const historyId = crypto.randomUUID();
-      addToHistory({
+      saveTranscript({
         id: historyId,
         date: new Date().toLocaleString("en-GB"),
         source: "live",
@@ -389,6 +390,11 @@
         language: settings.language,
         template: activeTemplate || undefined,
         audioPath,
+        engine: settings.engine,
+        formatMode: settings.formatMode,
+        removeFillers: settings.removeFillers,
+        britishEnglish: settings.britishEnglish,
+        antiHallucination: settings.antiHallucination,
       });
 
       // Extract tasks from transcript
@@ -484,7 +490,7 @@
 
   function saveTypedText() {
     if (!transcript.trim()) return;
-    addToHistory({
+    saveTranscript({
       id: crypto.randomUUID(),
       date: new Date().toLocaleString("en-GB"),
       source: "typed",

src/lib/pages/FilesPage.svelte

@@ -2,7 +2,8 @@
   import { onMount, onDestroy } from "svelte";
   import { invoke } from "@tauri-apps/api/core";
   import { listen } from "@tauri-apps/api/event";
-  import { settings, addToHistory } from "$lib/stores/page.svelte.js";
+  import { settings } from "$lib/stores/page.svelte.js";
+  import { loadHistory } from "$lib/stores/history.svelte.js";
   import Card from "$lib/components/Card.svelte";
   import EmptyState from "$lib/components/EmptyState.svelte";
   import { exportTranscript } from "$lib/utils/export.js";
@@ -91,16 +92,9 @@
 
         segments = [...segments, ...result.segments];
 
-        addToHistory({
-          id: crypto.randomUUID(),
-          date: new Date().toLocaleString("en-GB"),
-          source: fileName,
-          preview: text.slice(0, 120),
-          text,
-          segments: result.segments,
-          duration: result.duration,
-          language: result.language,
-        });
+        // transcribe_file auto-persists to SQLite (Task 2).
+        // Refresh local history state to pick up the new entry.
+        loadHistory();
       } catch (err) {
         error = `Failed: ${fileName} — ${typeof err === "string" ? err : err.message}`;
       }

src/lib/pages/HistoryPage.svelte

@@ -1,8 +1,12 @@
 <script>
-  import { onDestroy } from "svelte";
+  import { onMount, onDestroy } from "svelte";
   import { invoke } from "@tauri-apps/api/core";
-  import { history, saveHistory, deleteFromHistory } from "$lib/stores/page.svelte.js";
+  import { getHistory, loadHistory, deleteTranscript, searchTranscripts } from "$lib/stores/history.svelte.js";
   import { convertFileSrc } from "@tauri-apps/api/core";
+
+  const history = getHistory();
+
+  onMount(() => { loadHistory(); });
   import Card from "$lib/components/Card.svelte";
   import EmptyState from "$lib/components/EmptyState.svelte";
   import { formatTime, formatDuration } from "$lib/utils/time.js";
@@ -17,29 +21,36 @@
   let duration = $state(0);
   let playbackRate = $state(1);
   let animFrameId = null;
+  let searchTimeout = null;
 
   onDestroy(() => {
     stopPlayback();
+    clearTimeout(searchTimeout);
   });
 
-  let filtered = $derived(
-    searchQuery
-      ? history.filter((h) => {
-          const q = searchQuery.toLowerCase();
-          return (
-            (h.text && h.text.toLowerCase().includes(q)) ||
-            (h.preview && h.preview.toLowerCase().includes(q)) ||
-            (h.source && h.source.toLowerCase().includes(q)) ||
-            (h.title && h.title.toLowerCase().includes(q))
-          );
-        })
-      : history
-  );
+  // Debounced FTS5 search — 300ms delay
+  $effect(() => {
+    const q = searchQuery;
+    clearTimeout(searchTimeout);
+    if (!q || !q.trim()) {
+      // Restore full list when search cleared
+      loadHistory();
+      return;
+    }
+    searchTimeout = setTimeout(() => {
+      searchTranscripts(q);
+    }, 300);
+  });
 
-  function clearAll() {
+  // The history array IS the filtered results — FTS5 handles filtering server-side
+  let filtered = $derived(history);
+
+  async function clearAll() {
     if (!confirm("Delete all history? This can't be undone.")) return;
-    history.splice(0);
-    saveHistory();
+    // Delete each transcript from the backend
+    for (const item of [...history]) {
+      await deleteTranscript(item.id);
+    }
     expandedId = null;
     stopPlayback();
   }
@@ -52,21 +63,18 @@
     invoke("copy_to_clipboard", { text: item.text }).catch(() => {});
   }
 
-  function removeItem(item) {
-    const idx = history.indexOf(item);
-    if (idx !== -1) {
-      deleteFromHistory(idx);
-      if (expandedId === item.id) expandedId = null;
-      if (playingId === item.id) stopPlayback();
-    }
+  async function removeItem(item) {
+    await deleteTranscript(item.id);
+    if (expandedId === item.id) expandedId = null;
+    if (playingId === item.id) stopPlayback();
   }
 
   function renameItem(item) {
     const name = prompt("Name this transcript:", item.title || "");
     if (name !== null) {
       item.title = name.trim();
-      item.preview = name.trim() ? `${name.trim()} — ${item.text.slice(0, 80)}` : item.text.slice(0, 120);
-      saveHistory();
+      item.preview = name.trim() ? `${name.trim()} — ${(item.text || '').slice(0, 80)}` : (item.text || '').slice(0, 120);
+      // TODO: Persist rename to SQLite when update_transcript command is added
     }
   }
 

src/lib/stores/history.svelte.js

@@ -0,0 +1,188 @@
+/**
+ * History store backed by SQLite via Tauri commands.
+ * Replaces the localStorage-based history management in page.svelte.js.
+ *
+ * All mutations call the backend first, then update the reactive state
+ * on success. FTS5 search is handled server-side.
+ */
+import { invoke } from '@tauri-apps/api/core';
+
+// Reactive state
+let transcripts = $state([]);
+let loading = $state(false);
+let searchActive = $state(false);
+
+// BroadcastChannel for multi-window sync
+const historyChannel = typeof BroadcastChannel !== 'undefined'
+  ? new BroadcastChannel('kon_history_v2')
+  : null;
+
+if (historyChannel) {
+  historyChannel.onmessage = (event) => {
+    if (event.data.type === 'history_updated') {
+      transcripts.length = 0;
+      transcripts.push(...event.data.transcripts);
+    }
+  };
+}
+
+function broadcastHistory() {
+  if (historyChannel) {
+    historyChannel.postMessage({
+      type: 'history_updated',
+      transcripts: $state.snapshot(transcripts),
+    });
+  }
+}
+
+/**
+ * Load transcription history from the SQLite backend.
+ * @param {number} [limit=100] - Maximum number of results
+ */
+export async function loadHistory(limit = 100) {
+  loading = true;
+  searchActive = false;
+  try {
+    const result = await invoke('list_all_transcripts', { limit });
+    transcripts.length = 0;
+    transcripts.push(...result);
+  } catch (e) {
+    console.error('Failed to load history:', e);
+  } finally {
+    loading = false;
+  }
+}
+
+/**
+ * Save a completed transcription to the SQLite backend.
+ * Also saves segments if provided.
+ *
+ * @param {object} entry - Transcript data matching the save_transcript command params
+ * @returns {Promise<boolean>} Whether the save succeeded
+ */
+export async function saveTranscript(entry) {
+  try {
+    await invoke('save_transcript', {
+      id: entry.id,
+      text: entry.text || '',
+      source: entry.source || 'microphone',
+      title: entry.title || null,
+      audioPath: entry.audioPath || null,
+      duration: entry.duration || 0,
+      engine: entry.engine || null,
+      modelId: entry.modelId || null,
+      inferenceMs: entry.inferenceMs || null,
+      sampleRate: entry.sampleRate || null,
+      audioChannels: entry.audioChannels || null,
+      formatMode: entry.formatMode || null,
+      removeFillers: entry.removeFillers ?? false,
+      britishEnglish: entry.britishEnglish ?? false,
+      antiHallucination: entry.antiHallucination ?? false,
+    });
+
+    // Save segments if provided
+    if (entry.segments && entry.segments.length > 0) {
+      const segmentTuples = entry.segments.map(s => [
+        s.start ?? s.startTime ?? 0,
+        s.end ?? s.endTime ?? 0,
+        s.text || '',
+      ]);
+      await invoke('save_segments', {
+        transcriptId: entry.id,
+        segments: segmentTuples,
+      });
+    }
+
+    // Optimistic local update — add to front of list
+    transcripts.unshift({
+      id: entry.id,
+      text: entry.text,
+      source: entry.source,
+      title: entry.title || null,
+      audioPath: entry.audioPath || null,
+      duration: entry.duration || 0,
+      engine: entry.engine || null,
+      modelId: entry.modelId || null,
+      inferenceMs: entry.inferenceMs || null,
+      sampleRate: entry.sampleRate || null,
+      audioChannels: entry.audioChannels || null,
+      formatMode: entry.formatMode || null,
+      removeFillers: entry.removeFillers ?? false,
+      britishEnglish: entry.britishEnglish ?? false,
+      antiHallucination: entry.antiHallucination ?? false,
+      createdAt: new Date().toISOString(),
+      // Keep original fields for UI compatibility during migration
+      date: entry.date || new Date().toLocaleString('en-GB'),
+      preview: entry.preview || (entry.text || '').slice(0, 120),
+      segments: entry.segments || [],
+      language: entry.language,
+      template: entry.template,
+    });
+
+    broadcastHistory();
+    return true;
+  } catch (e) {
+    console.error('Failed to save transcript:', e);
+    return false;
+  }
+}
+
+/**
+ * Delete a transcript by ID.
+ * @param {string} id - Transcript ID
+ */
+export async function deleteTranscript(id) {
+  try {
+    await invoke('delete_transcript_by_id', { id });
+    const idx = transcripts.findIndex(t => t.id === id);
+    if (idx >= 0) transcripts.splice(idx, 1);
+    broadcastHistory();
+  } catch (e) {
+    console.error('Failed to delete transcript:', e);
+  }
+}
+
+/**
+ * Full-text search across transcripts via FTS5.
+ * Replaces the local state with search results.
+ * @param {string} query - Search query
+ * @param {number} [limit=50] - Maximum results
+ */
+export async function searchTranscripts(query, limit = 50) {
+  if (!query || !query.trim()) {
+    // Empty query — restore full list
+    await loadHistory();
+    return;
+  }
+  loading = true;
+  searchActive = true;
+  try {
+    const result = await invoke('search_all_transcripts', {
+      query: query.trim(),
+      limit,
+    });
+    transcripts.length = 0;
+    transcripts.push(...result);
+  } catch (e) {
+    // FTS5 can throw on malformed queries — fall back to full list
+    console.error('Search failed, falling back to full list:', e);
+    await loadHistory();
+  } finally {
+    loading = false;
+  }
+}
+
+/** Get the reactive transcripts array. */
+export function getHistory() {
+  return transcripts;
+}
+
+/** Whether history is currently loading from the backend. */
+export function getLoading() {
+  return loading;
+}
+
+/** Whether a search filter is currently active. */
+export function isSearchActive() {
+  return searchActive;
+}

src/lib/stores/page.svelte.js

@@ -72,7 +72,9 @@ export function saveProfiles() {
   } catch {}
 }
 
-// ---- History (persisted to localStorage) ----
+// ---- History (DEPRECATED — migrated to history.svelte.js backed by SQLite) ----
+// TODO: Remove localStorage history code after full migration verified.
+// Kept temporarily for backwards compatibility with any unmigrated consumers.
 
 const HISTORY_KEY = "kon_history";