import type { Database } from 'bun:sqlite';

// ---------------------------------------------------------------------------
// Snapshot freshness
// ---------------------------------------------------------------------------

function maxSnapshotAgeMs(): number {
  const raw = Number(process.env.MAX_MEMBERS_SNAPSHOT_AGE_MS);
  return Number.isFinite(raw) && raw > 0 ? raw : 24 * 60 * 60 * 1000; // 24h default
}

export function isSnapshotFresh(
  db: Database,
  groupId: string,
  nowMs: number = Date.now()
): boolean {
  try {
    const row = db
      .prepare(`SELECT last_verified FROM groups WHERE id = ?`)
      .get(groupId) as { last_verified?: string | null } | undefined;
    const lv = row?.last_verified ? String(row.last_verified) : null;
    if (!lv) return false;
    const iso = lv.includes('T') ? lv : lv.replace(' ', 'T') + 'Z';
    const ms = Date.parse(iso);
    if (!Number.isFinite(ms)) return false;
    return nowMs - ms <= maxSnapshotAgeMs();
  } catch {
    return false;
  }
}

// ---------------------------------------------------------------------------
// Membership queries
// ---------------------------------------------------------------------------

export function isUserActiveInGroup(
  db: Database,
  userId: string,
  groupId: string
): boolean {
  if (!userId || !groupId) return false;
  const row = db
    .prepare(
      `SELECT 1 FROM group_members WHERE group_id = ? AND user_id = ? AND is_active = 1 LIMIT 1`
    )
    .get(groupId, userId);
  return !!row;
}

export function getActiveGroupIdsForUser(
  db: Database,
  userId: string
): string[] {
  if (!userId) return [];
  const rows = db
    .prepare(
      `SELECT gm.group_id AS id
       FROM group_members gm
       JOIN groups g ON g.id = gm.group_id
       WHERE gm.user_id = ? AND gm.is_active = 1 AND g.active = 1
         AND COALESCE(g.is_community,0) = 0
         AND COALESCE(g.archived,0) = 0`
    )
    .all(userId) as Array<{ id: string }>;
  return [...new Set(rows.map(r => String(r.id)))];
}

export function getFreshMemberGroupsForUser(
  db: Database,
  userId: string
): string[] {
  return getActiveGroupIdsForUser(db, userId).filter(gid =>
    isSnapshotFresh(db, gid)
  );
}