import type { Card, Session } from './types'

const SESSION_KEY = 'sapbg-session'

async function post(path: string, body: unknown): Promise<Session> {
  const res = await fetch(path, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(body),
  })
  const data = await res.json()
  if (!res.ok) throw new Error(data.error ?? 'request failed')
  return data as Session
}

export type BotDifficulty = 'easy' | 'medium' | 'hard'

export function createGame(name: string): Promise<Session> {
  return post('/api/games', { name })
}

export function joinGame(code: string, name: string): Promise<Session> {
  return post('/api/join', { code, name })
}

export async function fetchCatalog(packs?: string[]): Promise<Card[]> {
  const query = (packs ?? [])
    .map((p) => `pack=${encodeURIComponent(p)}`)
    .join('&')
  const res = await fetch(query ? `/api/catalog?${query}` : '/api/catalog')
  if (!res.ok) throw new Error('failed to load catalog')
  return (await res.json()) as Card[]
}

// debugReportURL builds the link to a game's debug report — the full state,
// battles and event log, enough to replay the situation in a test. Served only
// when the server runs with DEBUG on. `text` renders it for reading; otherwise
// it downloads as JSON, which is the form a test can replay.
export function debugReportURL(session: Session, format: 'json' | 'text', note?: string): string {
  const params = new URLSearchParams({
    game: session.gameId,
    player: session.playerId,
    token: session.token,
    format,
  })
  if (note) params.set('note', note)
  return `/api/debug/report?${params}`
}

export async function fetchDebugReportText(session: Session, note?: string): Promise<string> {
  const res = await fetch(debugReportURL(session, 'text', note))
  if (!res.ok) throw new Error('failed to fetch the debug report')
  return res.text()
}

export function loadSession(): Session | null {
  try {
    const raw = localStorage.getItem(SESSION_KEY)
    return raw ? (JSON.parse(raw) as Session) : null
  } catch {
    return null
  }
}

export function saveSession(s: Session) {
  localStorage.setItem(SESSION_KEY, JSON.stringify(s))
}

export function clearSession() {
  localStorage.removeItem(SESSION_KEY)
}