Add study completion, checkpoints, lesson announcements, and lesson-thread defaults

server.js

@@ -61,6 +61,7 @@ const DRAFT_QUESTIONS_FILE = path.join(DATA_DIR, 'questions-draft.json')
 const STUDY_USERS_FILE = path.join(DATA_DIR, 'study-users.json')
 const STUDY_NOTES_FILE = path.join(DATA_DIR, 'study-notes.json') // legacy — kept only for one-time migration
 const STUDY_NOTES_DIR = path.join(DATA_DIR, 'study-notes')
+const STUDY_PROGRESS_DIR = path.join(DATA_DIR, 'study-progress')
 const STUDY_COMMUNITY_FILE = path.join(DATA_DIR, 'study-community.json')
 const REPLY_TEMPLATES_FILE = path.join(DATA_DIR, 'admin-reply-templates.json')
 const REPLY_HISTORY_FILE = path.join(DATA_DIR, 'admin-reply-history.json')
@@ -634,6 +635,8 @@ let studyUsers = []
 let studyUsersWritePromise = Promise.resolve()
 const studyNotesCache = new Map() // userId -> { [sectionId]: string }
 const studyNotesWriteQueues = new Map() // userId -> Promise
+const studyProgressCache = new Map() // userId -> { byStudy: Record<string, { completedSectionIds: string[] }> }
+const studyProgressWriteQueues = new Map() // userId -> Promise
 let studyCommunityPosts = []
 let studyCommunityWritePromise = Promise.resolve()
 let downloadCounts = {}
@@ -2581,6 +2584,58 @@ function queueUserNotesWrite(userId) {
   studyNotesWriteQueues.set(userId, next)
 }
 
+function getUserProgressFilePath(userId) {
+  return path.join(STUDY_PROGRESS_DIR, `${userId}.json`)
+}
+
+function sanitizeStudyProgress(value) {
+  const defaultResult = { byStudy: {}, updatedAt: new Date().toISOString() }
+  if (!value || typeof value !== 'object') return defaultResult
+
+  const progress = { byStudy: {}, updatedAt: typeof value.updatedAt === 'string' ? value.updatedAt : new Date().toISOString() }
+  if (value.byStudy && typeof value.byStudy === 'object') {
+    for (const [studySlug, studyData] of Object.entries(value.byStudy)) {
+      if (typeof studySlug !== 'string' || !studySlug.trim()) continue
+      const completedSectionIds = Array.isArray(studyData?.completedSectionIds)
+        ? studyData.completedSectionIds.filter(id => typeof id === 'string' && id.trim()).map(id => id.trim())
+        : []
+      progress.byStudy[studySlug.trim().toLowerCase()] = {
+        completedSectionIds: Array.from(new Set(completedSectionIds)),
+      }
+    }
+  }
+
+  return progress
+}
+
+async function loadUserProgress(userId) {
+  if (studyProgressCache.has(userId)) return studyProgressCache.get(userId)
+  try {
+    const raw = await readFile(getUserProgressFilePath(userId), 'utf8')
+    const progress = sanitizeStudyProgress(JSON.parse(raw))
+    studyProgressCache.set(userId, progress)
+    return progress
+  } catch {
+    const progress = { byStudy: {}, updatedAt: new Date().toISOString() }
+    studyProgressCache.set(userId, progress)
+    return progress
+  }
+}
+
+function queueUserProgressWrite(userId) {
+  const prev = studyProgressWriteQueues.get(userId) ?? Promise.resolve()
+  const next = prev
+    .then(async () => {
+      const progress = studyProgressCache.get(userId) ?? { byStudy: {}, updatedAt: new Date().toISOString() }
+      await mkdir(STUDY_PROGRESS_DIR, { recursive: true })
+      await writeFile(getUserProgressFilePath(userId), JSON.stringify(progress, null, 2), 'utf8')
+    })
+    .catch(err => {
+      console.error(`[study-progress] failed to write progress for user ${userId}:`, err)
+    })
+  studyProgressWriteQueues.set(userId, next)
+}
+
 async function migrateStudyNotesIfNeeded() {
   try {
     const raw = await readFile(STUDY_NOTES_FILE, 'utf8')
@@ -2941,6 +2996,76 @@ app.put('/api/study-notes/:sectionId', requireStudyAuth, async (req, res) => {
   res.json({ ok: true, note })
 })
 
+app.get('/api/study-progress/:studySlug', requireStudyAuth, async (req, res) => {
+  const user = req.studyUser
+  const studySlug = normalizeStudySlug(req.params.studySlug)
+  if (!studySlug) {
+    res.status(400).json({ message: 'Study slug is required.' })
+    return
+  }
+
+  if (!isStudyUserEnrolled(user, studySlug)) {
+    res.status(403).json({ message: 'Please enroll in this study to view progress.' })
+    return
+  }
+
+  const progress = await loadUserProgress(user.id)
+  const completedSectionIds = progress.byStudy[studySlug]?.completedSectionIds ?? []
+  res.json({ studySlug, completedSectionIds })
+})
+
+app.post('/api/study-progress/:studySlug/:sectionId', requireStudyAuth, async (req, res) => {
+  const user = req.studyUser
+  const studySlug = normalizeStudySlug(req.params.studySlug)
+  const sectionId = normalizeLessonSectionId(req.params.sectionId)
+  if (!studySlug || !sectionId) {
+    res.status(400).json({ message: 'Invalid study slug or section id.' })
+    return
+  }
+
+  if (!isStudyUserEnrolled(user, studySlug)) {
+    res.status(403).json({ message: 'Please enroll in this study to update progress.' })
+    return
+  }
+
+  const progress = await loadUserProgress(user.id)
+  const studyProgress = progress.byStudy[studySlug] ?? { completedSectionIds: [] }
+  if (!studyProgress.completedSectionIds.includes(sectionId)) {
+    studyProgress.completedSectionIds = [...studyProgress.completedSectionIds, sectionId]
+  }
+  progress.byStudy[studySlug] = studyProgress
+  progress.updatedAt = new Date().toISOString()
+  studyProgressCache.set(user.id, progress)
+  queueUserProgressWrite(user.id)
+
+  res.json({ ok: true, studySlug, completedSectionIds: studyProgress.completedSectionIds })
+})
+
+app.delete('/api/study-progress/:studySlug/:sectionId', requireStudyAuth, async (req, res) => {
+  const user = req.studyUser
+  const studySlug = normalizeStudySlug(req.params.studySlug)
+  const sectionId = normalizeLessonSectionId(req.params.sectionId)
+  if (!studySlug || !sectionId) {
+    res.status(400).json({ message: 'Invalid study slug or section id.' })
+    return
+  }
+
+  if (!isStudyUserEnrolled(user, studySlug)) {
+    res.status(403).json({ message: 'Please enroll in this study to update progress.' })
+    return
+  }
+
+  const progress = await loadUserProgress(user.id)
+  const studyProgress = progress.byStudy[studySlug] ?? { completedSectionIds: [] }
+  studyProgress.completedSectionIds = studyProgress.completedSectionIds.filter(id => id !== sectionId)
+  progress.byStudy[studySlug] = studyProgress
+  progress.updatedAt = new Date().toISOString()
+  studyProgressCache.set(user.id, progress)
+  queueUserProgressWrite(user.id)
+
+  res.json({ ok: true, studySlug, completedSectionIds: studyProgress.completedSectionIds })
+})
+
 app.get('/api/study-community', requireStudyAuth, async (req, res) => {
   const user = req.studyUser
   const studySlug = normalizeStudySlug(typeof req.query?.studySlug === 'string' ? req.query.studySlug : '')
@@ -3154,6 +3279,7 @@ app.post('/api/study-account/change-password', studyAuthRateLimiter, requireStud
 app.get('/api/study-account/overview', requireStudyAuth, async (req, res) => {
   const user = req.studyUser
   const notes = await loadUserNotes(user.id)
+  const progress = await loadUserProgress(user.id)
   const noteEntries = Object.entries(notes)
 
   const studies = getStudyCatalog().map(study => {
@@ -3161,13 +3287,14 @@ app.get('/api/study-account/overview', requireStudyAuth, async (req, res) => {
       ? (cachedSiteContent.studies.find(item => normalizeStudySlug(item?.slug) === study.slug)?.sections?.length ?? 0)
       : 0
     const noteCount = noteEntries.filter(([key, value]) => key.startsWith(`${study.slug}--`) && typeof value === 'string' && value.trim()).length
+    const completedLessons = progress.byStudy[study.slug]?.completedSectionIds?.length ?? 0
     return {
       slug: study.slug,
       title: study.title,
       status: study.status,
       enrolled: isStudyUserEnrolled(user, study.slug),
       totalLessons,
-      completedLessons: noteCount,
+      completedLessons,
       noteCount,
     }
   })