'use strict';

/**
 * 智能问数智能体 · 跨主体对比工具
 * ----------------------------------------------------------------------------
 * cross_entity：湖内全部主体（多账号/多食堂）本期 vs 基期核心指标对比，
 * 供「跨校对比」「哪家餐厅更好」类问题。窗口锚定当前主体的湖内区间，
 * 无本期数据的主体自动滤除并说明。
 */

const { ymdDash } = require('./lake.js');

const z2 = (n) => String(n).padStart(2, '0');
function dayShift(ymd, delta) {
  const d = new Date(Number(ymd.slice(0, 4)), Number(ymd.slice(4, 6)) - 1, Number(ymd.slice(6, 8)));
  d.setDate(d.getDate() + delta);
  return `${d.getFullYear()}${z2(d.getMonth() + 1)}${z2(d.getDate())}`;
}

function entitySanitize(args, ctx) {
  const a = args || {};
  const { dateRange } = ctx;
  const dates = ctx.svc.store.datesInLake(ctx.entityKey);
  let from = /^\d{8}$/.test(String(a.from || '')) ? String(a.from) : '';
  let to = /^\d{8}$/.test(String(a.to || '')) ? String(a.to) : '';
  from = from && from >= dateRange.from && from <= dateRange.to ? from : '';
  to = to && to >= dateRange.from && to <= dateRange.to ? to : '';
  if (!from || !to || from > to) {
    if (!dates.length) return { empty: true };
    to = dates[dates.length - 1];
    from = dates[Math.max(0, dates.length - 7)];
  }
  const len = Math.max(1, Math.round(
    (new Date(Number(to.slice(0, 4)), Number(to.slice(4, 6)) - 1, Number(to.slice(6, 8)))
      - new Date(Number(from.slice(0, 4)), Number(from.slice(4, 6)) - 1, Number(from.slice(6, 8)))) / 86400000) + 1);
  const prevTo = dayShift(from, -1);
  const prevFrom = dayShift(prevTo, -(len - 1));
  return { from, to, prevFrom, prevTo, empty: false };
}

function windowTotals(svc, key, from, to) {
  const rows = svc.store.queryRows(key, { from, to, scope: 'shop' });
  const s = svc.summarizeRows(rows);
  return { gross: s.grossAmt, orders: s.validOrderCnt, days: s.dayCount, hasData: rows.length > 0 };
}

function entityHandler(ctx, args) {
  const { svc } = ctx;
  if (args.empty) return { summary: '当前主体湖内暂无数据，无法跨主体对比。', data: { empty: true } };
  const { from, to, prevFrom, prevTo } = args;
  const entities = svc.store.listEntities();
  const out = [];
  const skipped = [];
  for (const e of entities) {
    const cur = windowTotals(svc, e.key, from, to);
    if (!cur.hasData) { skipped.push(e.name || e.key); continue; }
    const prev = windowTotals(svc, e.key, prevFrom, prevTo);
    out.push({
      key: e.key,
      name: e.name || e.key,
      shopCount: e.shopCount || 0,
      cur,
      prev,
      grossDeltaPct: prev.gross > 0 ? +(((cur.gross - prev.gross) / prev.gross) * 100).toFixed(1) : null,
    });
  }
  out.sort((a, b) => b.cur.gross - a.cur.gross);
  const lines = [`跨主体对比（本期 ${ymdDash(from)} ~ ${ymdDash(to)} vs 上期 ${ymdDash(prevFrom)} ~ ${ymdDash(prevTo)}，按本期营业额降序）：`];
  for (const e of out) {
    const delta = e.grossDeltaPct == null ? '上期无数据' : `环比 ${e.grossDeltaPct >= 0 ? '+' : ''}${e.grossDeltaPct}%`;
    lines.push(`  ${e.name}（${e.shopCount} 店）：营业额 ${Math.round(e.cur.gross)} / 有效订单 ${Math.round(e.cur.orders)}（${delta}）`);
  }
  if (skipped.length) lines.push(`本期无数据未纳入：${skipped.join('、')}`);
  if (!out.length) lines.push('湖内没有任何主体在本期有数据。');
  return { summary: lines.join('\n'), data: { from, to, prevFrom, prevTo, entities: out, skipped } };
}

module.exports = { entitySanitize, entityHandler };