Version history, notes on highlights and bookmarks, "you've studied this", prayer journal

- Earlier versions of a study: the server keeps compressed copies (about one per ten minutes of
  editing, the latest 30); Export shows what differs and puts one back (the replaced copy is kept)
- Notes on highlights and bookmarks: synced, merged without loss, in exports and backups
- Reader verse panel lists your studies and chunks that cover the verse, and opens them
- Prayer journal: requests, who for, linked verses, days prayed, answers; synced, in backups
  and the account export; daily prayer reminder through ntfy
- TODO.md lists the ideas not built yet

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

server/db.js

@@ -1,5 +1,6 @@
 import Database from 'better-sqlite3';
 import { mkdirSync } from 'fs';
+import { MAX_VERSIONS, pack, shouldSnapshot, summarizeProject, unpack } from './versions.js';
 import { join, dirname } from 'path';
 import { fileURLToPath } from 'url';
 
@@ -90,6 +91,15 @@ export function initDb() {
     `);
   }
 
+  // Optional daily prayer reminder, sent to the same ntfy topic.
+  if (!userCols.some((c) => c.name === 'prayer_enabled')) {
+    db.exec(`
+      ALTER TABLE users ADD COLUMN prayer_enabled INTEGER NOT NULL DEFAULT 0;
+      ALTER TABLE users ADD COLUMN prayer_time TEXT;
+      ALTER TABLE users ADD COLUMN last_prayer_date TEXT;
+    `);
+  }
+
   // Reminders fire at the user's own local time, so remember their timezone.
   if (!userCols.some((c) => c.name === 'reminder_tz')) {
     db.exec('ALTER TABLE users ADD COLUMN reminder_tz TEXT');
@@ -125,6 +135,29 @@ export function initDb() {
     );
   `);
 
+  // The prayer journal: one row per account (the whole list as JSON; see server/prayers.js).
+  db.exec(`
+    CREATE TABLE IF NOT EXISTS prayers (
+      user_id    TEXT PRIMARY KEY REFERENCES users(id) ON DELETE CASCADE,
+      data       TEXT NOT NULL,
+      updated_at INTEGER NOT NULL
+    );
+  `);
+
+  // Earlier copies of each study (compressed), for "Restore an earlier version".
+  db.exec(`
+    CREATE TABLE IF NOT EXISTS project_versions (
+      id         INTEGER PRIMARY KEY AUTOINCREMENT,
+      project_id TEXT NOT NULL,
+      state_at   INTEGER NOT NULL,
+      title      TEXT,
+      chunks     INTEGER NOT NULL DEFAULT 0,
+      words      INTEGER NOT NULL DEFAULT 0,
+      data       BLOB NOT NULL
+    );
+    CREATE INDEX IF NOT EXISTS idx_versions_project ON project_versions(project_id, state_at);
+  `);
+
   // Co-teachers: other accounts allowed to edit a study, and the single-use links that let them join.
   db.exec(`
     CREATE TABLE IF NOT EXISTS collaborators (
@@ -239,6 +272,7 @@ function parseUserRow(row) {
     totpEnabled: !!row.totpEnabled,
     reminderEnabled: !!row.reminderEnabled,
     votdEnabled: !!row.votdEnabled,
+    prayerEnabled: !!row.prayerEnabled,
     backupCodeHashes: row.backupCodesRaw ? JSON.parse(row.backupCodesRaw) : [],
   };
 }
@@ -249,7 +283,8 @@ const USER_SELECT = `
          podcast_name AS podcastName,
          ntfy_url AS ntfyUrl, ntfy_topic AS ntfyTopic, reminder_time AS reminderTime,
          reminder_enabled AS reminderEnabled, last_reminder_date AS lastReminderDate, reminder_tz AS reminderTz,
-         votd_enabled AS votdEnabled, votd_time AS votdTime, last_votd_date AS lastVotdDate
+         votd_enabled AS votdEnabled, votd_time AS votdTime, last_votd_date AS lastVotdDate,
+         prayer_enabled AS prayerEnabled, prayer_time AS prayerTime
   FROM users
 `;
 
@@ -297,6 +332,36 @@ export function setVotdSettings(userId, { votdEnabled, votdTime }) {
   db.prepare('UPDATE users SET votd_enabled = ?, votd_time = ? WHERE id = ?').run(votdEnabled ? 1 : 0, votdTime || null, userId);
 }
 
+/** Turns the daily prayer reminder on or off, and says when to send it. */
+export function setPrayerReminder(userId, { prayerEnabled, prayerTime }) {
+  db.prepare('UPDATE users SET prayer_enabled = ?, prayer_time = ? WHERE id = ?').run(prayerEnabled ? 1 : 0, prayerTime || null, userId);
+}
+
+export function getUsersWithPrayerReminder() {
+  return db.prepare(`
+    SELECT id, email, ntfy_url AS ntfyUrl, ntfy_topic AS ntfyTopic, prayer_time AS prayerTime,
+           last_prayer_date AS lastPrayerDate, reminder_tz AS reminderTz
+    FROM users
+    WHERE prayer_enabled = 1 AND ntfy_topic IS NOT NULL AND prayer_time IS NOT NULL
+  `).all();
+}
+
+export function setLastPrayerDate(userId, dateString) {
+  db.prepare('UPDATE users SET last_prayer_date = ? WHERE id = ?').run(dateString, userId);
+}
+
+export function getPrayers(userId) {
+  const row = db.prepare('SELECT data FROM prayers WHERE user_id = ?').get(userId);
+  try { return row ? JSON.parse(row.data) : []; } catch { return []; }
+}
+
+export function setPrayers(userId, list) {
+  db.prepare(`
+    INSERT INTO prayers (user_id, data, updated_at) VALUES (?, ?, ?)
+    ON CONFLICT(user_id) DO UPDATE SET data = excluded.data, updated_at = excluded.updated_at
+  `).run(userId, JSON.stringify(list), Date.now());
+}
+
 /** Every account with the verse of the day turned on and a topic to send it to. */
 export function getUsersWithVotdEnabled() {
   return db.prepare(`
@@ -421,19 +486,19 @@ export function setUserPrefs(userId, prefs) {
 /** The user's bookmarks + highlights: { bookmarks, highlights, updatedAt } (updatedAt 0 = never saved). */
 export function getReaderMarks(userId) {
   const row = db.prepare('SELECT data, updated_at AS updatedAt FROM reader_marks WHERE user_id = ?').get(userId);
-  if (!row) return { bookmarks: {}, highlights: [], updatedAt: 0 };
+  if (!row) return { bookmarks: {}, highlights: [], bookmarkNotes: {}, updatedAt: 0 };
   const data = JSON.parse(row.data);
-  return { bookmarks: data.bookmarks ?? {}, highlights: data.highlights ?? [], updatedAt: row.updatedAt };
+  return { bookmarks: data.bookmarks ?? {}, highlights: data.highlights ?? [], bookmarkNotes: data.bookmarkNotes ?? {}, updatedAt: row.updatedAt };
 }
 
 /** Replaces the user's bookmarks + highlights; returns the new updatedAt (always moves forward). */
-export function setReaderMarks(userId, { bookmarks, highlights }) {
+export function setReaderMarks(userId, { bookmarks, highlights, bookmarkNotes = {} }) {
   const prev = db.prepare('SELECT updated_at AS updatedAt FROM reader_marks WHERE user_id = ?').get(userId);
   const updatedAt = Math.max(Date.now(), (prev?.updatedAt ?? 0) + 1);
   db.prepare(`
     INSERT INTO reader_marks (user_id, data, updated_at) VALUES (?, ?, ?)
     ON CONFLICT(user_id) DO UPDATE SET data = excluded.data, updated_at = excluded.updated_at
-  `).run(userId, JSON.stringify({ bookmarks, highlights }), updatedAt);
+  `).run(userId, JSON.stringify({ bookmarks, highlights, bookmarkNotes }), updatedAt);
   return updatedAt;
 }
 
@@ -553,7 +618,8 @@ export function upsertProject(project, userId) {
   }
 
   // The server's clock decides the version, so a device with a wrong clock can't hide or fake changes.
-  const prev = db.prepare('SELECT last_edited AS lastEdited FROM projects WHERE id = ?').get(project.id);
+  const prev = db.prepare('SELECT last_edited AS lastEdited, data FROM projects WHERE id = ?').get(project.id);
+  if (prev) keepVersion(project.id, prev);
   const lastEdited = Math.max(Date.now(), (prev?.lastEdited ?? 0) + 1);
   const chapterSummary = buildSummary(project);
   const updated = { ...project, lastEdited };
@@ -571,6 +637,48 @@ export function upsertProject(project, userId) {
   return { id: project.id, title: project.title, lastEdited, chapterSummary };
 }
 
+// ---------------------------------------------------------------------------
+// Earlier versions
+// ---------------------------------------------------------------------------
+
+/** Keeps the copy that is about to be replaced (when it's been long enough since the last kept one), then trims the oldest. */
+function keepVersion(projectId, prev, force = false) {
+  const last = db.prepare('SELECT MAX(state_at) AS at FROM project_versions WHERE project_id = ?').get(projectId)?.at;
+  if (!shouldSnapshot({ prevEditedAt: prev.lastEdited, lastKeptAt: last ?? undefined, force })) return;
+  let project;
+  try { project = JSON.parse(prev.data); } catch { return; }
+  if (db.prepare('SELECT 1 FROM project_versions WHERE project_id = ? AND state_at = ?').get(projectId, prev.lastEdited)) return;
+  const { chunks, words } = summarizeProject(project);
+  db.prepare('INSERT INTO project_versions (project_id, state_at, title, chunks, words, data) VALUES (?, ?, ?, ?, ?, ?)')
+    .run(projectId, prev.lastEdited, project.title ?? '', chunks, words, pack(prev.data));
+  db.prepare(`DELETE FROM project_versions WHERE project_id = ? AND id NOT IN (SELECT id FROM project_versions WHERE project_id = ? ORDER BY state_at DESC LIMIT ?)`).run(projectId, projectId, MAX_VERSIONS);
+}
+
+export function listVersions(projectId) {
+  return db.prepare('SELECT id, state_at AS savedAt, title, chunks, words FROM project_versions WHERE project_id = ? ORDER BY state_at DESC').all(projectId);
+}
+
+export function getVersion(projectId, versionId) {
+  const row = db.prepare('SELECT data FROM project_versions WHERE project_id = ? AND id = ?').get(projectId, versionId);
+  if (!row) return null;
+  try { return unpack(row.data); } catch { return null; }
+}
+
+/** Puts an earlier version back as the current one. The copy it replaces is kept first, so a restore can be undone too. */
+export function restoreVersion(projectId, versionId, userId) {
+  const old = getVersion(projectId, versionId);
+  if (!old || !canEditProject(projectId, userId)) return null;
+  return db.transaction(() => {
+    const prev = db.prepare('SELECT last_edited AS lastEdited, data FROM projects WHERE id = ?').get(projectId);
+    if (prev) keepVersion(projectId, prev, true);
+    const lastEdited = Math.max(Date.now(), (prev?.lastEdited ?? 0) + 1);
+    const restored = { ...old, id: projectId, lastEdited };
+    db.prepare('UPDATE projects SET title = ?, last_edited = ?, chapter_summary = ?, data = ? WHERE id = ?')
+      .run(restored.title, lastEdited, buildSummary(restored), JSON.stringify(restored), projectId);
+    return restored;
+  })();
+}
+
 /**
  * Delete a project by id, scoped to userId. No-op if not found/not owned.
  */
@@ -583,6 +691,7 @@ export function deleteProject(id, userId) {
     }
     db.prepare('DELETE FROM collaborators WHERE project_id = ?').run(id);
     db.prepare('DELETE FROM edit_invites WHERE project_id = ?').run(id);
+    db.prepare('DELETE FROM project_versions WHERE project_id = ?').run(id);
   })();
 }
 
@@ -760,6 +869,7 @@ export function adminGetProject(id) {
 
 /** Deletes any project by id, regardless of owner. */
 export function adminDeleteProject(id) {
+  db.prepare('DELETE FROM project_versions WHERE project_id = ?').run(id);
   db.prepare('DELETE FROM projects WHERE id = ?').run(id);
 }