/**
 * Typed API client for the FamilySync backend.
 *
 * credentials: 'include' is required so the OIDC session cookie is sent with
 * every cross-origin request (Vite dev proxy routes to :3000; production is
 * same-origin via Pangolin).
 *
 * 401 responses mean the session has expired — the browser will follow the
 * 302 redirect to Authelia on the next API call automatically (full-page nav).
 */

// ── /api/me ────────────────────────────────────────────────────────────────

export interface MeUser {
  id: number
  displayName: string | null
  color: string
}

export interface MeResponse {
  user: MeUser
}

export async function fetchMe(): Promise<MeResponse> {
  const res = await fetch('/api/me', {
    credentials: 'include',
  })

  if (!res.ok) {
    // 302 → browser follows redirect to Authelia automatically.
    // For 4xx/5xx, throw so React Query can surface the error.
    throw new Error(`GET /api/me failed: ${res.status}`)
  }

  return res.json() as Promise<MeResponse>
}

// ── /api/events (windowed — Phase 2) ─────────────────────────────────────

/**
 * A single concrete occurrence of a calendar event.
 *
 * Mirrors the CalendarOccurrence shape produced by the backend's
 * expandOccurrences() helper (apps/api/src/broker/expand.ts).
 *
 * calendarId and ownerUserId are both present:
 *   calendarId    — DB calendar-row id (do NOT use for Schedule-X routing)
 *   ownerUserId   — DB user id (use for Schedule-X calendarId routing)
 *   isShared      — true when this event belongs to the shared-family calendar
 *
 * hydrateEvents() uses isShared/ownerUserId — never String(calendarId) —
 * to build the Schedule-X calendarId that keys into buildCalendarConfig().
 */
export interface CalendarOccurrence {
  id: string            // `${uid}::${dtstart_iso}` — stable identity
  uid: string
  calendarId: number    // DB calendar-row id — do NOT use for SX calendarId routing
  calendarName: string
  ownerUserId: number   // DB user id — the correct Schedule-X routing key
  color: string         // hex from users.color or shared-family constant
  isShared: boolean     // true → 'shared' slot; false → String(ownerUserId) slot
  title: string
  start: string         // 'YYYY-MM-DD' for allDay:true; ISO 8601 with IANA tz for timed
  end: string
  allDay: boolean
  location: string | null
  description: string | null
}

export interface OccurrencesResponse {
  occurrences: CalendarOccurrence[]
}

/**
 * Fetch windowed calendar occurrences.
 *
 * The ?start=&end= window is mandatory — an unwindowed call would expand 500+
 * cached events with all their recurring occurrences (RESEARCH.md Pitfall 5).
 *
 * @param start ISO date string 'YYYY-MM-DD' — window start (inclusive)
 * @param end   ISO date string 'YYYY-MM-DD' — window end (exclusive)
 */
export async function fetchEvents(
  start: string,
  end: string,
): Promise<OccurrencesResponse> {
  const res = await fetch(`/api/events?start=${start}&end=${end}`, {
    credentials: 'include',
  })

  if (!res.ok) {
    throw new Error(`GET /api/events failed: ${res.status}`)
  }

  return res.json() as Promise<OccurrencesResponse>
}

// Phase 1 legacy types (CalendarEvent, EventsResponse, fetchEventsLegacy) removed in Plan 05
// when the Phase 1 broker-proof component was retired.