// ============ save.js — localStorage slots, autosave, export/import ============
import { serialize, deserialize } from '../game/state.js';
import { download } from '../core/util.js';

const KEY = 'arcane_tycoon_save_';
const SLOTS = ['auto', 'slot1', 'slot2', 'slot3'];

export function listSaves() {
  const out = [];
  for (const s of SLOTS) {
    try {
      const raw = localStorage.getItem(KEY + s);
      if (!raw) { out.push({ slot: s, exists: false }); continue; }
      const d = JSON.parse(raw);
      out.push({
        slot: s, exists: true,
        parkName: d.park?.name || 'Park',
        scenario: d.scenario,
        date: `Y${d.time?.year} M${(d.time?.month ?? 0) + 1}`,
        cash: d.cash,
        guests: d.guests?.length ?? 0,
        savedAt: d.savedAt,
      });
    } catch {
      out.push({ slot: s, exists: false });
    }
  }
  return out;
}

export function saveTo(state, slot) {
  const data = serialize(state);
  data.savedAt = Date.now();
  try {
    localStorage.setItem(KEY + slot, JSON.stringify(data));
    return true;
  } catch (e) {
    console.error('save failed', e);
    return false;
  }
}

export function loadFrom(slot) {
  try {
    const raw = localStorage.getItem(KEY + slot);
    if (!raw) return null;
    return deserialize(JSON.parse(raw));
  } catch (e) {
    console.error('load failed', e);
    return null;
  }
}

export function hasAutosave() {
  try { return !!localStorage.getItem(KEY + 'auto'); } catch { return false; }
}

export function autosave(state) {
  return saveTo(state, 'auto');
}

export function exportSave(state) {
  const data = serialize(state);
  data.savedAt = Date.now();
  const name = (state.park.name || 'park').replace(/\W+/g, '_').toLowerCase();
  download(`arcane-tycoon-${name}.json`, JSON.stringify(data));
}

export function importSaveText(text) {
  try {
    const data = JSON.parse(text);
    if (!data.version) throw new Error('Not an Arcane Tycoon save');
    return deserialize(data);
  } catch (e) {
    console.error('import failed', e);
    return null;
  }
}