From c2a5d730a0a4d90379b376a4205cb80ac43092de Mon Sep 17 00:00:00 2001
From: kinga <kingamazur33@gmail.com>
Date: Sat, 25 Apr 2026 20:30:50 +0200
Subject: [PATCH 1/4] feat(flashcard-assistant): add flashcard assistant API
 and UI component for enhanced user interaction with flashcards

---
 LearningPlatform/app/(public)/login/page.tsx  |  33 ++-
 .../dashboard/flashcards/study/page.tsx       |  17 ++
 .../app/api/flashcard-assistant/route.ts      |  84 ++++++
 .../student/flashcard-assistant-fab.tsx       | 193 ++++++++++++++
 .../student/lesson-assistant-fab.tsx          | 240 ++++++++++++------
 .../lib/flashcard-assistant-prompt.ts         |  12 +
 LearningPlatform/lib/public-routes.ts         |   1 +
 7 files changed, 503 insertions(+), 77 deletions(-)
 create mode 100644 LearningPlatform/app/api/flashcard-assistant/route.ts
 create mode 100644 LearningPlatform/components/student/flashcard-assistant-fab.tsx
 create mode 100644 LearningPlatform/lib/flashcard-assistant-prompt.ts

diff --git a/LearningPlatform/app/(public)/login/page.tsx b/LearningPlatform/app/(public)/login/page.tsx
index ae9b619..c395d3b 100644
--- a/LearningPlatform/app/(public)/login/page.tsx
+++ b/LearningPlatform/app/(public)/login/page.tsx
@@ -15,6 +15,22 @@ import { Home } from 'lucide-react';
 import { cn } from '@/lib/utils';
 import { heroMarketingAuthInputClass, heroMarketingGlassText } from '@/lib/hero-marketing-classes';
 
+async function getInfraStatusMessage(): Promise<string | null> {
+  try {
+    // Add a timestamp to bypass any browser/proxy caching of old health responses.
+    const res = await fetch(`/api/health?t=${Date.now()}`, { cache: 'no-store' });
+    if (res.ok) return null;
+
+    // Health endpoint returns 503 for DB/Payload connectivity issues.
+    if (res.status >= 500) {
+      return 'Cannot connect to the server/database right now. Please try again in a moment.';
+    }
+    return null;
+  } catch {
+    return 'Cannot reach the backend right now. Check your connection and try again.';
+  }
+}
+
 function LoginForm() {
   const isDark = useIsDark();
   const router = useRouter();
@@ -40,6 +56,14 @@ function LoginForm() {
     setIsLoading(true);
 
     try {
+      // Fast-fail before credential check so infra outages are not mislabeled
+      // as "invalid email/password".
+      const precheckInfraMessage = await getInfraStatusMessage();
+      if (precheckInfraMessage) {
+        setError(precheckInfraMessage);
+        return;
+      }
+
       const result = await signIn('credentials', {
         email,
         password,
@@ -47,7 +71,14 @@ function LoginForm() {
       });
 
       if (result?.error) {
-        setError('Invalid email or password');
+        const infraMessage = await getInfraStatusMessage();
+        if (infraMessage) {
+          setError(infraMessage);
+        } else if (result.error.toLowerCase().includes('too many')) {
+          setError('Too many login attempts. Please try again later.');
+        } else {
+          setError('Invalid email or password');
+        }
       } else {
         router.push(safeCallbackUrl);
         router.refresh();
diff --git a/LearningPlatform/app/(student)/(shell)/dashboard/flashcards/study/page.tsx b/LearningPlatform/app/(student)/(shell)/dashboard/flashcards/study/page.tsx
index 7e14c99..16f3dbd 100644
--- a/LearningPlatform/app/(student)/(shell)/dashboard/flashcards/study/page.tsx
+++ b/LearningPlatform/app/(student)/(shell)/dashboard/flashcards/study/page.tsx
@@ -36,6 +36,7 @@ import {
 } from 'lucide-react'
 import { cn } from '@/lib/utils'
 import { FlashcardRichText } from '@/components/student/flashcard-markdown'
+import { FlashcardAssistantFab } from '@/components/student/flashcard-assistant-fab'
 
 // --- Types ---
 
@@ -79,6 +80,14 @@ function humanizeSlug(slug: string): string {
     .join(' ')
 }
 
+function isTypingTarget(target: EventTarget | null): boolean {
+  if (!(target instanceof HTMLElement)) return false
+  const tag = target.tagName
+  if (tag === 'INPUT' || tag === 'TEXTAREA' || tag === 'SELECT') return true
+  if (target.isContentEditable) return true
+  return Boolean(target.closest('[contenteditable="true"], [role="textbox"]'))
+}
+
 function studyQuery(
   mode: string,
   tagSlug: string,
@@ -280,6 +289,8 @@ function StudyPage() {
 
   useEffect(() => {
     function onKey(e: KeyboardEvent) {
+      if (isTypingTarget(e.target)) return
+
       if (e.key === ' ' || e.key === 'Enter') {
         if (phase === 'question') {
           e.preventDefault()
@@ -747,6 +758,12 @@ function StudyPage() {
         )}
       </main>
 
+      <FlashcardAssistantFab
+        enabled={Boolean(card)}
+        cardFront={card?.question ?? ''}
+        cardBack={card?.answer ?? ''}
+      />
+
       <style>{`
         .katex { font-size: 1.1em; }
         .katex-display { max-width: 100%; overflow-x: auto; overflow-y: hidden; padding: 0.25rem 0; }
diff --git a/LearningPlatform/app/api/flashcard-assistant/route.ts b/LearningPlatform/app/api/flashcard-assistant/route.ts
new file mode 100644
index 0000000..45806c2
--- /dev/null
+++ b/LearningPlatform/app/api/flashcard-assistant/route.ts
@@ -0,0 +1,84 @@
+import { NextResponse } from 'next/server'
+import { z } from 'zod'
+import Anthropic from '@anthropic-ai/sdk'
+import type { TextBlock } from '@anthropic-ai/sdk/resources/messages'
+import { requireProUser } from '@/lib/auth-helpers'
+import { checkRateLimit } from '@/lib/rate-limit'
+import { FLASHCARD_ASSISTANT_SYSTEM_PROMPT } from '@/lib/flashcard-assistant-prompt'
+import {
+  type LessonAssistantModelPreset,
+  resolveLessonAssistantModelId,
+} from '@/lib/lesson-assistant-models'
+
+const bodySchema = z.object({
+  question: z.string().min(1).max(4000),
+  cardFront: z.string().min(1).max(12000),
+  cardBack: z.string().min(1).max(12000),
+  modelPreset: z.enum(['haiku', 'sonnet']).optional(),
+})
+
+export async function POST(req: Request) {
+  try {
+    const user = await requireProUser()
+    const rate = await checkRateLimit({
+      request: req,
+      key: 'flashcard-assistant',
+      limit: 20,
+      windowMs: 60_000,
+      identityFallback: user.id,
+    })
+    if (!rate.allowed) {
+      const sec = Math.max(1, Math.ceil(rate.retryAfter / 1000))
+      return NextResponse.json(
+        { error: 'Too many requests', retryAfterMs: rate.retryAfter },
+        { status: 429, headers: { 'Retry-After': String(sec) } },
+      )
+    }
+
+    const payload = await req.json().catch(() => null)
+    const parsed = bodySchema.safeParse(payload)
+    if (!parsed.success) {
+      return NextResponse.json({ error: 'Invalid request' }, { status: 400 })
+    }
+
+    const { question, cardFront, cardBack, modelPreset: rawPreset } = parsed.data
+    const modelPreset: LessonAssistantModelPreset = rawPreset ?? 'haiku'
+    const model = resolveLessonAssistantModelId(modelPreset)
+
+    const apiKey = process.env.ANTHROPIC_API_KEY?.trim()
+    if (!apiKey) {
+      return NextResponse.json({ error: 'Flashcard assistant is not configured' }, { status: 503 })
+    }
+
+    let userMsg = `--- Flashcard front ---\n${cardFront.trim()}\n\n--- Flashcard back ---\n${cardBack.trim()}\n\n`
+    userMsg += `--- Question ---\n${question.trim()}`
+
+    const client = new Anthropic({ apiKey })
+    const resp = await client.messages.create({
+      model,
+      max_tokens: 4096,
+      system: FLASHCARD_ASSISTANT_SYSTEM_PROMPT,
+      messages: [{ role: 'user', content: userMsg }],
+    })
+
+    const answer = resp.content
+      .filter((b): b is TextBlock => b.type === 'text')
+      .map((b) => b.text)
+      .join('\n')
+      .trim()
+
+    return NextResponse.json({ answer }, { headers: { 'Cache-Control': 'private, no-store' } })
+  } catch (error) {
+    if (error instanceof Error) {
+      if (error.message === 'Unauthorized') {
+        return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+      }
+      if (error.message === 'Forbidden') {
+        return NextResponse.json({ error: 'Forbidden' }, { status: 403 })
+      }
+    }
+    console.error('[POST /api/flashcard-assistant]', error)
+    return NextResponse.json({ error: 'Internal server error' }, { status: 500 })
+  }
+}
+
diff --git a/LearningPlatform/components/student/flashcard-assistant-fab.tsx b/LearningPlatform/components/student/flashcard-assistant-fab.tsx
new file mode 100644
index 0000000..529d433
--- /dev/null
+++ b/LearningPlatform/components/student/flashcard-assistant-fab.tsx
@@ -0,0 +1,193 @@
+'use client'
+
+import { useEffect, useId, useState } from 'react'
+import { MessageSquareText, X } from 'lucide-react'
+import { Button } from '@/components/ui/button'
+import { Textarea } from '@/components/ui/textarea'
+import { Label } from '@/components/ui/label'
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from '@/components/ui/select'
+import { studentGlassCard } from '@/lib/student-glass-styles'
+import { cn } from '@/lib/utils'
+import type { LessonAssistantModelPreset } from '@/lib/lesson-assistant-models'
+import { TheoryMarkdown } from '@/components/student/markdown-theory-body'
+import { useLessonTheoryTextSize } from '@/lib/lesson-theory-text-size'
+
+export function FlashcardAssistantFab({
+  enabled,
+  cardFront,
+  cardBack,
+}: {
+  enabled: boolean
+  cardFront: string
+  cardBack: string
+}) {
+  const questionInputId = useId()
+  const tier = useLessonTheoryTextSize()
+  const [open, setOpen] = useState(false)
+  const [question, setQuestion] = useState('')
+  const [answer, setAnswer] = useState('')
+  const [loading, setLoading] = useState(false)
+  const [error, setError] = useState<string | null>(null)
+  const [modelPreset, setModelPreset] = useState<LessonAssistantModelPreset>('haiku')
+  const [composerCollapsed, setComposerCollapsed] = useState(false)
+
+  useEffect(() => {
+    setAnswer('')
+    setError(null)
+    setComposerCollapsed(false)
+  }, [cardFront, cardBack])
+
+  async function submit() {
+    const q = question.trim()
+    if (!q || loading) return
+    setLoading(true)
+    setError(null)
+    setAnswer('')
+    try {
+      const res = await fetch('/api/flashcard-assistant', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          question: q,
+          cardFront,
+          cardBack,
+          modelPreset,
+        }),
+      })
+      const data = (await res.json().catch(() => ({}))) as { answer?: string; error?: string }
+      if (res.status === 429) {
+        setError('Too many requests. Please wait a moment and try again.')
+        return
+      }
+      if (!res.ok) {
+        setError(data.error ?? 'Something went wrong.')
+        return
+      }
+      setAnswer((data.answer ?? '').trim())
+      setComposerCollapsed(true)
+    } catch {
+      setError('Network error. Please try again.')
+    } finally {
+      setLoading(false)
+    }
+  }
+
+  if (!enabled) return null
+
+  return (
+    <>
+      {open ? (
+        <aside
+          className={cn(
+            'fixed bottom-4 right-4 z-30 flex w-[min(96vw,34rem)] min-w-0 flex-col gap-3 rounded-xl border-0 p-4 shadow-none',
+            studentGlassCard,
+            'max-h-[calc(100dvh-2rem)]',
+          )}
+        >
+          <div className="flex items-start justify-between gap-2 border-b border-border pb-3">
+            <h2 className="text-base font-semibold leading-snug text-foreground">Ask about this flashcard</h2>
+            <Button type="button" variant="ghost" size="icon" className="shrink-0" onClick={() => setOpen(false)}>
+              <X className="h-5 w-5" aria-hidden />
+              <span className="sr-only">Close assistant</span>
+            </Button>
+          </div>
+
+          {!composerCollapsed ? (
+            <>
+              <div className="space-y-2">
+                <Label htmlFor="flashcard-assistant-model" className="text-sm font-medium text-foreground">
+                  Model
+                </Label>
+                <Select
+                  value={modelPreset}
+                  onValueChange={(v) => setModelPreset(v as LessonAssistantModelPreset)}
+                  disabled={loading}
+                >
+                  <SelectTrigger id="flashcard-assistant-model" className="w-full">
+                    <SelectValue />
+                  </SelectTrigger>
+                  <SelectContent position="popper">
+                    <SelectItem value="haiku">Haiku 4.5 — faster, lower cost</SelectItem>
+                    <SelectItem value="sonnet">Sonnet 4.5 — richer answers</SelectItem>
+                  </SelectContent>
+                </Select>
+              </div>
+
+              <div className="space-y-1.5">
+                <Label htmlFor={questionInputId} className="sr-only">
+                  Your question
+                </Label>
+                <Textarea
+                  id={questionInputId}
+                  placeholder="Your question…"
+                  value={question}
+                  onChange={(e) => setQuestion(e.target.value)}
+                  onKeyDown={(e) => {
+                    if (e.key === 'Enter' && !e.shiftKey) {
+                      e.preventDefault()
+                      void submit()
+                    }
+                  }}
+                  className="min-h-[88px] resize-y text-base"
+                  disabled={loading}
+                />
+              </div>
+
+              <Button
+                type="button"
+                variant="hero"
+                className="auth-hero-cta w-full"
+                onClick={() => void submit()}
+                disabled={loading || !question.trim()}
+              >
+                {loading ? 'Thinking…' : 'Ask'}
+              </Button>
+            </>
+          ) : (
+            <div className="flex items-center justify-between gap-2 rounded-md border bg-muted/20 px-3 py-2">
+              <p className="line-clamp-2 text-sm text-muted-foreground">
+                {question.trim() ? `Question: ${question.trim()}` : 'Previous question'}
+              </p>
+              <Button type="button" variant="outline" size="sm" onClick={() => setComposerCollapsed(false)} className="shrink-0">
+                Ask another
+              </Button>
+            </div>
+          )}
+
+          {error ? <p className="text-sm text-destructive">{error}</p> : null}
+
+          <div className="overflow-y-auto rounded-md border bg-muted/20 px-3 py-2 md:max-h-[calc(100dvh-16rem)]">
+            {answer ? (
+              <TheoryMarkdown markdown={answer} tier={tier} className="min-w-0" />
+            ) : (
+              <p className="text-sm text-muted-foreground">Answer will appear here.</p>
+            )}
+          </div>
+        </aside>
+      ) : null}
+
+      {!open ? (
+        <button
+          type="button"
+          onClick={() => setOpen(true)}
+          className={cn(
+            'fixed z-30 flex h-14 w-14 items-center justify-center rounded-full border bg-primary text-primary-foreground shadow-lg transition hover:opacity-95',
+            'focus-visible:outline focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-ring',
+            'bottom-[max(1.25rem,env(safe-area-inset-bottom))] right-[max(1.25rem,env(safe-area-inset-right))]',
+          )}
+          aria-label="Open flashcard assistant"
+          aria-expanded={false}
+        >
+          <MessageSquareText className="h-7 w-7" aria-hidden />
+        </button>
+      ) : null}
+    </>
+  )
+}
+
diff --git a/LearningPlatform/components/student/lesson-assistant-fab.tsx b/LearningPlatform/components/student/lesson-assistant-fab.tsx
index a05924f..0a8dba7 100644
--- a/LearningPlatform/components/student/lesson-assistant-fab.tsx
+++ b/LearningPlatform/components/student/lesson-assistant-fab.tsx
@@ -1,6 +1,6 @@
 'use client'
 
-import { useCallback, useEffect, useId, useState, type ReactNode } from 'react'
+import { useCallback, useEffect, useId, useLayoutEffect, useRef, useState, type ReactNode } from 'react'
 import { MessageSquareText, X, Highlighter } from 'lucide-react'
 import { Button } from '@/components/ui/button'
 import { Textarea } from '@/components/ui/textarea'
@@ -69,6 +69,58 @@ export function LessonAssistantShell({
   const [loading, setLoading] = useState(false)
   const [error, setError] = useState<string | null>(null)
   const [modelPreset, setModelPreset] = useState<LessonAssistantModelPreset>('haiku')
+  const [composerCollapsed, setComposerCollapsed] = useState(false)
+
+  const leftColumnRef = useRef<HTMLDivElement>(null)
+  const rightColumnRef = useRef<HTMLDivElement>(null)
+  const lastLeftScrollRef = useRef(0)
+  const lastRightScrollRef = useRef(0)
+  const pendingWindowScrollRef = useRef<number | null>(null)
+
+  /** Styled scrollbars for column panes (WebKit + Firefox). */
+  const columnScrollbarClass = cn(
+    '[scrollbar-width:thin]',
+    '[scrollbar-color:hsl(var(--muted-foreground)/0.35)_transparent]',
+    '[&::-webkit-scrollbar]:w-2',
+    '[&::-webkit-scrollbar]:h-2',
+    '[&::-webkit-scrollbar-thumb]:rounded-full',
+    '[&::-webkit-scrollbar-thumb]:bg-muted-foreground/30',
+    '[&::-webkit-scrollbar-thumb]:hover:bg-muted-foreground/45',
+    '[&::-webkit-scrollbar-track]:bg-transparent',
+  )
+
+  const captureColumnScrollPositions = useCallback(() => {
+    lastLeftScrollRef.current = leftColumnRef.current?.scrollTop ?? 0
+    lastRightScrollRef.current = rightColumnRef.current?.scrollTop ?? 0
+  }, [])
+
+  const setOpenPreserveScroll = useCallback(
+    (next: boolean) => {
+      if (typeof window !== 'undefined') {
+        pendingWindowScrollRef.current = window.scrollY
+        if (!next) {
+          captureColumnScrollPositions()
+        }
+      }
+      setOpen(next)
+    },
+    [captureColumnScrollPositions],
+  )
+
+  useLayoutEffect(() => {
+    const winY = pendingWindowScrollRef.current
+    pendingWindowScrollRef.current = null
+    if (typeof window === 'undefined' || winY == null) return
+
+    window.scrollTo({ top: winY })
+
+    if (open) {
+      requestAnimationFrame(() => {
+        leftColumnRef.current?.scrollTo({ top: lastLeftScrollRef.current })
+        rightColumnRef.current?.scrollTo({ top: lastRightScrollRef.current })
+      })
+    }
+  }, [open])
 
   const refreshSelection = useCallback(() => {
     const root = document.getElementById(THEORY_ROOT_ID)
@@ -87,11 +139,11 @@ export function LessonAssistantShell({
   useEffect(() => {
     if (!open) return
     const onKey = (e: KeyboardEvent) => {
-      if (e.key === 'Escape') setOpen(false)
+      if (e.key === 'Escape') setOpenPreserveScroll(false)
     }
     window.addEventListener('keydown', onKey)
     return () => window.removeEventListener('keydown', onKey)
-  }, [open])
+  }, [open, setOpenPreserveScroll])
 
   async function submit() {
     const q = question.trim()
@@ -122,6 +174,7 @@ export function LessonAssistantShell({
         return
       }
       setAnswer((data.answer ?? '').trim())
+      setComposerCollapsed(true)
     } catch {
       setError('Network error. Please try again.')
     } finally {
@@ -147,19 +200,32 @@ export function LessonAssistantShell({
   const wideOpen = open
 
   return (
-    <div className={cn(shellBase, wideOpen ? 'max-w-[90rem]' : 'max-w-4xl')}>
-      <div className="mb-8 min-w-0">{lessonHeader}</div>
-
+    <div
+      className={cn(
+        shellBase,
+        wideOpen
+          ? 'max-w-[90rem] md:h-[calc(100dvh-6.5rem)] md:overflow-hidden md:py-4'
+          : 'max-w-4xl',
+      )}
+    >
       {open ? (
-        <div className="grid grid-cols-1 items-start gap-8 md:grid-cols-2 md:gap-8 lg:gap-10">
-          <div className="min-w-0">{lessonBody}</div>
+        <div className="grid grid-cols-1 items-stretch gap-8 md:grid-cols-2 md:gap-8 lg:gap-10 md:h-full md:min-h-0">
+          <div
+            ref={leftColumnRef}
+            className={cn('min-w-0 md:min-h-0 md:overflow-y-auto md:pr-1', columnScrollbarClass)}
+          >
+            <div className="mb-8 min-w-0">{lessonHeader}</div>
+            {lessonBody}
+          </div>
 
+          <div
+            ref={rightColumnRef}
+            className={cn('min-w-0 md:min-h-0 md:overflow-y-auto', columnScrollbarClass)}
+          >
           <aside
             className={cn(
               'flex w-full min-w-0 flex-col gap-3 rounded-xl border-0 p-4 shadow-none',
               studentGlassCard,
-              'min-h-0 max-h-[min(90dvh,40rem)] md:max-h-[calc(100dvh-5.5rem)]',
-              'md:sticky md:top-6',
             )}
             aria-labelledby={panelTitleId}
           >
@@ -168,7 +234,7 @@ export function LessonAssistantShell({
                 <h2 id={panelTitleId} className="text-base font-semibold leading-snug text-foreground">
                   Ask about this lesson
                 </h2>
-                <Button type="button" variant="ghost" size="icon" className="shrink-0" onClick={() => setOpen(false)}>
+                <Button type="button" variant="ghost" size="icon" className="shrink-0" onClick={() => setOpenPreserveScroll(false)}>
                   <X className="h-5 w-5" aria-hidden />
                   <span className="sr-only">Close assistant</span>
                 </Button>
@@ -177,77 +243,95 @@ export function LessonAssistantShell({
               <p className="text-sm text-muted-foreground">
                 Select text in the theory, then capture it. Your question is sent with full lesson context.
               </p>
+              {!composerCollapsed ? (
+                <>
+                  <div className="space-y-2">
+                    <Label htmlFor="lesson-assistant-model" className="text-sm font-medium text-foreground">
+                      Model
+                    </Label>
+                    <Select
+                      value={modelPreset}
+                      onValueChange={(v) => setModelPreset(v as LessonAssistantModelPreset)}
+                      disabled={loading}
+                    >
+                      <SelectTrigger id="lesson-assistant-model" className="w-full">
+                        <SelectValue />
+                      </SelectTrigger>
+                      <SelectContent position="popper">
+                        <SelectItem value="haiku">Haiku 4.5 — faster, lower cost</SelectItem>
+                        <SelectItem value="sonnet">Sonnet 4.5 — richer answers</SelectItem>
+                      </SelectContent>
+                    </Select>
+                  </div>
 
-              <div className="space-y-2">
-                <Label htmlFor="lesson-assistant-model" className="text-sm font-medium text-foreground">
-                  Model
-                </Label>
-                <Select
-                  value={modelPreset}
-                  onValueChange={(v) => setModelPreset(v as LessonAssistantModelPreset)}
-                  disabled={loading}
-                >
-                  <SelectTrigger id="lesson-assistant-model" className="w-full">
-                    <SelectValue />
-                  </SelectTrigger>
-                  <SelectContent position="popper">
-                    <SelectItem value="haiku">Haiku 4.5 — faster, lower cost</SelectItem>
-                    <SelectItem value="sonnet">Sonnet 4.5 — richer answers</SelectItem>
-                  </SelectContent>
-                </Select>
-              </div>
+                  <Button type="button" variant="outline" size="sm" onClick={refreshSelection} className="w-fit gap-1.5">
+                    <Highlighter className="h-4 w-4" aria-hidden />
+                    Use page selection
+                  </Button>
 
-              <Button type="button" variant="outline" size="sm" onClick={refreshSelection} className="w-fit gap-1.5">
-                <Highlighter className="h-4 w-4" aria-hidden />
-                Use page selection
-              </Button>
+                  {selectedText ? (
+                    <div className="max-h-24 overflow-y-auto rounded-md border border-dashed bg-muted/40 px-3 py-2 text-sm text-muted-foreground">
+                      {selectedText}
+                    </div>
+                  ) : null}
 
-              {selectedText ? (
-                <div className="max-h-24 overflow-y-auto rounded-md border border-dashed bg-muted/40 px-3 py-2 text-sm text-muted-foreground">
-                  {selectedText}
-                </div>
-              ) : null}
-
-              <div className="space-y-1.5">
-                <Label htmlFor={questionInputId} className="sr-only">
-                  Your question
-                </Label>
-                <Textarea
-                  id={questionInputId}
-                  placeholder="Your question…"
-                  value={question}
-                  onChange={(e) => setQuestion(e.target.value)}
-                  onKeyDown={(e) => {
-                    if (e.key === 'Enter' && !e.shiftKey) {
-                      e.preventDefault()
-                      void submit()
-                    }
-                  }}
-                  aria-describedby={`${questionInputId}-hint`}
-                  className="min-h-[88px] resize-y text-base"
-                  disabled={loading}
-                />
-                <p id={`${questionInputId}-hint`} className="text-xs text-muted-foreground">
-                  <kbd className="rounded border bg-muted px-1 py-0.5 font-mono text-[0.7rem]">Enter</kbd> to send ·{' '}
-                  <kbd className="rounded border bg-muted px-1 py-0.5 font-mono text-[0.7rem]">Shift</kbd> +{' '}
-                  <kbd className="rounded border bg-muted px-1 py-0.5 font-mono text-[0.7rem]">Enter</kbd> for new line
-                </p>
-              </div>
+                  <div className="space-y-1.5">
+                    <Label htmlFor={questionInputId} className="sr-only">
+                      Your question
+                    </Label>
+                    <Textarea
+                      id={questionInputId}
+                      placeholder="Your question…"
+                      value={question}
+                      onChange={(e) => setQuestion(e.target.value)}
+                      onKeyDown={(e) => {
+                        if (e.key === 'Enter' && !e.shiftKey) {
+                          e.preventDefault()
+                          void submit()
+                        }
+                      }}
+                      aria-describedby={`${questionInputId}-hint`}
+                      className="min-h-[88px] resize-y text-base"
+                      disabled={loading}
+                    />
+                    <p id={`${questionInputId}-hint`} className="text-xs text-muted-foreground">
+                      <kbd className="rounded border bg-muted px-1 py-0.5 font-mono text-[0.7rem]">Enter</kbd> to send ·{' '}
+                      <kbd className="rounded border bg-muted px-1 py-0.5 font-mono text-[0.7rem]">Shift</kbd> +{' '}
+                      <kbd className="rounded border bg-muted px-1 py-0.5 font-mono text-[0.7rem]">Enter</kbd> for new line
+                    </p>
+                  </div>
 
-              <Button
-                type="button"
-                variant="hero"
-                className="auth-hero-cta w-full"
-                onClick={() => void submit()}
-                disabled={loading || !question.trim()}
-              >
-                {loading ? 'Thinking…' : 'Ask'}
-              </Button>
+                  <Button
+                    type="button"
+                    variant="hero"
+                    className="auth-hero-cta w-full"
+                    onClick={() => void submit()}
+                    disabled={loading || !question.trim()}
+                  >
+                    {loading ? 'Thinking…' : 'Ask'}
+                  </Button>
+                </>
+              ) : (
+                <div className="flex items-center justify-between gap-2 rounded-md border bg-muted/20 px-3 py-2">
+                  <p className="line-clamp-2 text-sm text-muted-foreground">
+                    {question.trim() ? `Question: ${question.trim()}` : 'Previous question'}
+                  </p>
+                  <Button
+                    type="button"
+                    variant="outline"
+                    size="sm"
+                    onClick={() => setComposerCollapsed(false)}
+                    className="shrink-0"
+                  >
+                    Ask another
+                  </Button>
+                </div>
+              )}
 
               {error ? <p className="text-sm text-destructive">{error}</p> : null}
             </div>
 
-            <div className="min-h-0 flex-1 overflow-y-auto rounded-md border bg-muted/20 px-3 py-2">
+            <div className="min-h-[14rem] rounded-md border bg-muted/20 px-3 py-2">
               {answer ? (
                 <TheoryMarkdown markdown={answer} tier={tier} className="min-w-0" />
               ) : (
@@ -255,15 +339,19 @@ export function LessonAssistantShell({
               )}
             </div>
           </aside>
+          </div>
         </div>
       ) : (
-        <div className="min-w-0">{lessonBody}</div>
+        <>
+          <div className="mb-8 min-w-0">{lessonHeader}</div>
+          <div className="min-w-0">{lessonBody}</div>
+        </>
       )}
 
       {!open ? (
         <button
           type="button"
-          onClick={() => setOpen(true)}
+          onClick={() => setOpenPreserveScroll(true)}
           className={cn(
             'fixed z-30 flex h-14 w-14 items-center justify-center rounded-full border bg-primary text-primary-foreground shadow-lg transition hover:opacity-95',
             'focus-visible:outline focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-ring',
diff --git a/LearningPlatform/lib/flashcard-assistant-prompt.ts b/LearningPlatform/lib/flashcard-assistant-prompt.ts
new file mode 100644
index 0000000..8dd223e
--- /dev/null
+++ b/LearningPlatform/lib/flashcard-assistant-prompt.ts
@@ -0,0 +1,12 @@
+export const FLASHCARD_ASSISTANT_SYSTEM_PROMPT = `
+You are a concise learning assistant for flashcards.
+
+Rules:
+- Use the flashcard front/back as the primary context.
+- If user selected an excerpt, prioritize that exact excerpt first.
+- Answer clearly and directly; use bullet points when useful.
+- If the question goes beyond the flashcard, still help, but clearly label what is from flashcard context vs extra context.
+- Keep responses practical and study-friendly.
+- Use Markdown.
+`.trim()
+
diff --git a/LearningPlatform/lib/public-routes.ts b/LearningPlatform/lib/public-routes.ts
index faa035d..dcb8b78 100644
--- a/LearningPlatform/lib/public-routes.ts
+++ b/LearningPlatform/lib/public-routes.ts
@@ -12,6 +12,7 @@ export const PUBLIC_PATHS = [
   '/register',
   '/admin/login',
   '/api/ping',
+  '/api/health',
 ] as const
 
 /** Path prefixes accessible without authentication. */

From 34e8fa8b1bbfd54bf4a981a47e3059e325126778 Mon Sep 17 00:00:00 2001
From: kinga <kingamazur33@gmail.com>
Date: Sat, 25 Apr 2026 20:55:23 +0200
Subject: [PATCH 2/4] fix(auth-and-dashboard): harden local login and progress
 loading

Switch login infra checks to a lightweight public healthz probe with short client-side caching, reset flashcard assistant drafts on card change, and add compatibility fallbacks when archivedAt is missing in local course progress schemas.
---
 LearningPlatform/app/(public)/login/page.tsx  | 31 +++++++++++++------
 .../app/actions/course-progress.ts            | 18 ++++++++---
 LearningPlatform/app/api/healthz/route.ts     | 15 +++++++++
 .../student/flashcard-assistant-fab.tsx       |  1 +
 LearningPlatform/lib/public-routes.ts         |  2 +-
 LearningPlatform/lib/started-courses.ts       | 16 +++++++---
 6 files changed, 64 insertions(+), 19 deletions(-)
 create mode 100644 LearningPlatform/app/api/healthz/route.ts

diff --git a/LearningPlatform/app/(public)/login/page.tsx b/LearningPlatform/app/(public)/login/page.tsx
index c395d3b..02eaae6 100644
--- a/LearningPlatform/app/(public)/login/page.tsx
+++ b/LearningPlatform/app/(public)/login/page.tsx
@@ -15,19 +15,30 @@ import { Home } from 'lucide-react';
 import { cn } from '@/lib/utils';
 import { heroMarketingAuthInputClass, heroMarketingGlassText } from '@/lib/hero-marketing-classes';
 
+const INFRA_STATUS_CACHE_TTL_MS = 30_000;
+let lastInfraStatusCheckAt = 0;
+let lastInfraStatusMessage: string | null = null;
+
 async function getInfraStatusMessage(): Promise<string | null> {
-  try {
-    // Add a timestamp to bypass any browser/proxy caching of old health responses.
-    const res = await fetch(`/api/health?t=${Date.now()}`, { cache: 'no-store' });
-    if (res.ok) return null;
+  const now = Date.now();
+  if (now - lastInfraStatusCheckAt < INFRA_STATUS_CACHE_TTL_MS) {
+    return lastInfraStatusMessage;
+  }
 
-    // Health endpoint returns 503 for DB/Payload connectivity issues.
-    if (res.status >= 500) {
-      return 'Cannot connect to the server/database right now. Please try again in a moment.';
-    }
-    return null;
+  try {
+    const res = await fetch('/api/healthz', { cache: 'no-store' });
+    const message =
+      res.ok || res.status < 500
+        ? null
+        : 'Cannot connect to the server/database right now. Please try again in a moment.';
+    lastInfraStatusCheckAt = now;
+    lastInfraStatusMessage = message;
+    return message;
   } catch {
-    return 'Cannot reach the backend right now. Check your connection and try again.';
+    const message = 'Cannot reach the backend right now. Check your connection and try again.';
+    lastInfraStatusCheckAt = now;
+    lastInfraStatusMessage = message;
+    return message;
   }
 }
 
diff --git a/LearningPlatform/app/actions/course-progress.ts b/LearningPlatform/app/actions/course-progress.ts
index 2e5ffd2..9ab248e 100644
--- a/LearningPlatform/app/actions/course-progress.ts
+++ b/LearningPlatform/app/actions/course-progress.ts
@@ -28,10 +28,20 @@ export async function getAllCourseProgress() {
     throw new Error('Unauthorized')
   }
 
-  return prisma.courseProgress.findMany({
-    where: { userId: session.user.id, archivedAt: null },
-    orderBy: { lastActivityAt: 'desc' },
-  })
+  // Backward-compatible: some local DB/schema snapshots do not include archivedAt yet.
+  const whereWithArchiveFilter: Record<string, unknown> = { userId: session.user.id }
+  whereWithArchiveFilter.archivedAt = null
+  try {
+    return await prisma.courseProgress.findMany({
+      where: whereWithArchiveFilter as never,
+      orderBy: { lastActivityAt: 'desc' },
+    })
+  } catch {
+    return prisma.courseProgress.findMany({
+      where: { userId: session.user.id },
+      orderBy: { lastActivityAt: 'desc' },
+    })
+  }
 }
 
 /**
diff --git a/LearningPlatform/app/api/healthz/route.ts b/LearningPlatform/app/api/healthz/route.ts
new file mode 100644
index 0000000..1aeca74
--- /dev/null
+++ b/LearningPlatform/app/api/healthz/route.ts
@@ -0,0 +1,15 @@
+import { NextResponse } from 'next/server'
+import { prisma } from '@/lib/prisma'
+
+/**
+ * Lightweight public readiness probe for login precheck.
+ * Returns only ok/error without exposing internal diagnostics.
+ */
+export async function GET() {
+  try {
+    await prisma.$queryRaw`SELECT 1`
+    return NextResponse.json({ ok: true }, { status: 200 })
+  } catch {
+    return NextResponse.json({ ok: false }, { status: 503 })
+  }
+}
diff --git a/LearningPlatform/components/student/flashcard-assistant-fab.tsx b/LearningPlatform/components/student/flashcard-assistant-fab.tsx
index 529d433..d6b4b31 100644
--- a/LearningPlatform/components/student/flashcard-assistant-fab.tsx
+++ b/LearningPlatform/components/student/flashcard-assistant-fab.tsx
@@ -38,6 +38,7 @@ export function FlashcardAssistantFab({
   const [composerCollapsed, setComposerCollapsed] = useState(false)
 
   useEffect(() => {
+    setQuestion('')
     setAnswer('')
     setError(null)
     setComposerCollapsed(false)
diff --git a/LearningPlatform/lib/public-routes.ts b/LearningPlatform/lib/public-routes.ts
index dcb8b78..1fa43ba 100644
--- a/LearningPlatform/lib/public-routes.ts
+++ b/LearningPlatform/lib/public-routes.ts
@@ -12,7 +12,7 @@ export const PUBLIC_PATHS = [
   '/register',
   '/admin/login',
   '/api/ping',
-  '/api/health',
+  '/api/healthz',
 ] as const
 
 /** Path prefixes accessible without authentication. */
diff --git a/LearningPlatform/lib/started-courses.ts b/LearningPlatform/lib/started-courses.ts
index f69f255..0ade8ac 100644
--- a/LearningPlatform/lib/started-courses.ts
+++ b/LearningPlatform/lib/started-courses.ts
@@ -19,10 +19,18 @@ function courseIdFromLessonField(lesson: { id: string | number; course: unknown
 export async function getOrderedStartedCourseIds(userId: string, payload: Payload): Promise<string[]> {
   const archivedCourseRows =
     typeof prisma.courseProgress?.findMany === 'function'
-      ? await prisma.courseProgress.findMany({
-          where: { userId, archivedAt: { not: null } },
-          select: { courseId: true },
-        })
+      ? await (async () => {
+          const whereWithArchiveFilter: Record<string, unknown> = { userId }
+          whereWithArchiveFilter.archivedAt = { not: null }
+          try {
+            return await prisma.courseProgress.findMany({
+              where: whereWithArchiveFilter as never,
+              select: { courseId: true },
+            })
+          } catch {
+            return []
+          }
+        })()
       : []
   const archivedCourseIds = new Set(archivedCourseRows.map((r) => r.courseId))
 

From d85df6989c4b7a3b842bb11835646c8f6ed2625d Mon Sep 17 00:00:00 2001
From: kinga <kingamazur33@gmail.com>
Date: Sat, 25 Apr 2026 21:01:11 +0200
Subject: [PATCH 3/4] chore(tsconfig): remove unnecessary .next/dev/types
 exclusion for cleaner TypeScript configuration

---
 LearningPlatform/tsconfig.json | 1 -
 1 file changed, 1 deletion(-)

diff --git a/LearningPlatform/tsconfig.json b/LearningPlatform/tsconfig.json
index 07a9a1d..816c25b 100644
--- a/LearningPlatform/tsconfig.json
+++ b/LearningPlatform/tsconfig.json
@@ -37,7 +37,6 @@
     "**/*.ts",
     "**/*.tsx",
     ".next/types/**/*.ts",
-    ".next/dev/types/**/*.ts",
     "**/*.mts"
   ],
   "exclude": [

From bedb1da67667ba3f62956b1e0e669b9d716fde0d Mon Sep 17 00:00:00 2001
From: kinga <kingamazur33@gmail.com>
Date: Sat, 25 Apr 2026 21:08:05 +0200
Subject: [PATCH 4/4] fix(flashcard-assistant): ensure unique key for
 FlashcardAssistantFab component to prevent rendering issues

---
 .../(shell)/dashboard/flashcards/study/page.tsx          | 1 +
 .../components/student/flashcard-assistant-fab.tsx       | 9 +--------
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/LearningPlatform/app/(student)/(shell)/dashboard/flashcards/study/page.tsx b/LearningPlatform/app/(student)/(shell)/dashboard/flashcards/study/page.tsx
index 16f3dbd..980a524 100644
--- a/LearningPlatform/app/(student)/(shell)/dashboard/flashcards/study/page.tsx
+++ b/LearningPlatform/app/(student)/(shell)/dashboard/flashcards/study/page.tsx
@@ -759,6 +759,7 @@ function StudyPage() {
       </main>
 
       <FlashcardAssistantFab
+        key={card?.id ?? 'no-card'}
         enabled={Boolean(card)}
         cardFront={card?.question ?? ''}
         cardBack={card?.answer ?? ''}
diff --git a/LearningPlatform/components/student/flashcard-assistant-fab.tsx b/LearningPlatform/components/student/flashcard-assistant-fab.tsx
index d6b4b31..5901fca 100644
--- a/LearningPlatform/components/student/flashcard-assistant-fab.tsx
+++ b/LearningPlatform/components/student/flashcard-assistant-fab.tsx
@@ -1,6 +1,6 @@
 'use client'
 
-import { useEffect, useId, useState } from 'react'
+import { useId, useState } from 'react'
 import { MessageSquareText, X } from 'lucide-react'
 import { Button } from '@/components/ui/button'
 import { Textarea } from '@/components/ui/textarea'
@@ -37,13 +37,6 @@ export function FlashcardAssistantFab({
   const [modelPreset, setModelPreset] = useState<LessonAssistantModelPreset>('haiku')
   const [composerCollapsed, setComposerCollapsed] = useState(false)
 
-  useEffect(() => {
-    setQuestion('')
-    setAnswer('')
-    setError(null)
-    setComposerCollapsed(false)
-  }, [cardFront, cardBack])
-
   async function submit() {
     const q = question.trim()
     if (!q || loading) return