How Synapse
is built

// 3 calls fire in parallel - cards appear as each resolves
void _fetchAll() {
  for (var i = 0; i < 3; i++) {
    _fetchCard(i, _returnTypes[i]); // ['book','movie','serie']
  }
}

// On manual Refresh: library + all previously shown items sent as
// exclusions; forceRefresh=true bypasses the 24 h server cache.
final existing = [...libraryItems, ..._seenItems];
final result = await ApiService.discoverSingle(
  title: book.title, creator: book.author,
  type: book.type.name, returnType: returnType,
  existing: existing, forceRefresh: isRefresh,
);

// forceRefresh=true deletes the cache entry so the AI is called fresh.
// Without it, the 24 h server cache returns an instant response.
if (!forceRefresh) {
  const cached = cacheGet(key)
  if (cached) return cached
} else {
  _discoverCache.delete(key) // evict stale entry
}
// Exclusion list = library + every card shown this session
const exclusions = existing.map(
  e => `- "${e.title}" by ${e.creator} (${e.type})`
).join('\n')
const result = await discoverModel.generateContent(
  buildDiscoverSinglePrompt(title, creator, type, returnType, existing)
)
cacheSet(key, item)

// Guard: skip if already have today's cached suggestions
if (db.hasTodaySuggestions) { _loadCachedIfAvailable(); return; }

// Serialize: id + title + topic joined with body
final notes = db.notes.map((n) => {
  'id': n.id, 'title': n.title,
  'content': [n.topic, n.body].where((s) => s.isNotEmpty).join('\n'),
}).toList();

final raw = await ApiService.getSuggestions(notes);
await db.saveDailySuggestions(raw); // cached in _settingsBox

// Filter before display
if (db.areLinked(fromId, toId))       continue; // already connected
if (db.isDismissedPair(fromId, toId)) continue; // user dismissed before

const MAX_NOTES = 60, MAX_CONTENT = 400 // chars per note

const formatted = notes
  .slice(0, MAX_NOTES)
  .map(n => `[${n.id}] ${n.title}\n${n.content.slice(0, MAX_CONTENT)}`)
  .join('\n\n---\n\n')

// Validate IDs in the response match IDs we actually sent
suggestions = parsed.suggestions
  .filter(s => noteIds.has(s.source_note_id)
             && noteIds.has(s.target_note_id)
             && s.source_note_id !== s.target_note_id)
  .slice(0, 3)