import { readFileSync, existsSync } from 'fs';

type EnvMap = Record<string, string>;

function loadDotEnv(path: string): EnvMap {
  const out: EnvMap = {};
  if (!existsSync(path)) return out;
  const text = readFileSync(path, 'utf-8');
  for (const line of text.split('\n')) {
    const trimmed = line.trim();
    if (!trimmed || trimmed.startsWith('#')) continue;
    const idx = trimmed.indexOf('=');
    if (idx === -1) continue;
    const key = trimmed.slice(0, idx).trim();
    const value = trimmed.slice(idx + 1).trim();
    out[key] = value;
  }
  return out;
}

async function login(baseUrl: string, email: string, password: string): Promise<string> {
  const res = await fetch(`${baseUrl}/auth/login`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ email, password }),
  });
  const data = await res.json() as any;
  if (!res.ok || !data?.data?.token) {
    throw new Error(data?.error || 'GoodDays login failed');
  }
  return data.data.token;
}

async function getMysticalDaily(baseUrl: string, token: string, payload: any) {
  const res = await fetch(`${baseUrl}/api/mystical/daily`, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Authorization': `Bearer ${token}`,
    },
    body: JSON.stringify(payload),
  });
  const data = await res.json() as any;
  if (!res.ok || data?.success === false) {
    throw new Error(data?.error || 'GoodDays mystical daily failed');
  }
  return data;
}

async function getUnifiedEvents(baseUrl: string, token: string, userId: string, startDate: string, endDate: string) {
  const url = new URL(`${baseUrl}/api/unified-events`);
  url.searchParams.set('userId', userId);
  url.searchParams.set('startDate', startDate);
  url.searchParams.set('endDate', endDate);
  const res = await fetch(url.toString(), {
    method: 'GET',
    headers: token ? { 'Authorization': `Bearer ${token}` } : {},
  });
  const data = await res.json() as any;
  if (!res.ok || data?.success === false) {
    throw new Error(data?.error || 'GoodDays unified-events failed');
  }
  return data;
}

function parseDateFromMessage(message: string): { year: number; month: number; day: number; hour?: number } {
  const now = new Date();
  const dateMatch = message.match(/(\d{4})-(\d{1,2})-(\d{1,2})/);
  const hourMatch = message.match(/(?:hour|小時|時|點)\s*[:：]?\s*(\d{1,2})/i);
  if (dateMatch) {
    return {
      year: Number(dateMatch[1]),
      month: Number(dateMatch[2]),
      day: Number(dateMatch[3]),
      hour: hourMatch ? Number(hourMatch[1]) : undefined,
    };
  }
  return {
    year: now.getFullYear(),
    month: now.getMonth() + 1,
    day: now.getDate(),
    hour: hourMatch ? Number(hourMatch[1]) : undefined,
  };
}

function formatYmd(year: number, month: number, day: number): string {
  return `${year}-${String(month).padStart(2, '0')}-${String(day).padStart(2, '0')}`;
}

function addDays(year: number, month: number, day: number, offset: number): { year: number; month: number; day: number } {
  const d = new Date(year, month - 1, day);
  d.setDate(d.getDate() + offset);
  return { year: d.getFullYear(), month: d.getMonth() + 1, day: d.getDate() };
}

function detectIntent(message: string): 'events' | 'mystical' {
  const m = message.toLowerCase();
  if (/(行程|事件|日程|schedule|calendar|待會|今天有什麼安排|未來48小時)/i.test(m)) return 'events';
  return 'mystical';
}

function summarizeEvents(events: any[]): string {
  if (!Array.isArray(events) || events.length === 0) return '• 目前沒有查到符合條件的事件';
  return events.slice(0, 20).map((evt: any, idx: number) => {
    const title = evt?.title || evt?.name || evt?.summary || `事件 ${idx + 1}`;
    const start = evt?.startDate || evt?.start || evt?.start_time || evt?.date || '未知時間';
    const end = evt?.endDate || evt?.end || evt?.end_time || '';
    return `• ${title}${start ? `｜${start}` : ''}${end ? ` → ${end}` : ''}`;
  }).join('\n');
}

export async function handler(ctx: any) {
  const workspace = ctx.env?.OPENCLAW_WORKSPACE || `${process.env.HOME}/.openclaw/workspace`;
  const env = {
    ...loadDotEnv(`${workspace}/.env`),
    ...process.env,
  } as EnvMap;

  const baseUrl = env.GOODDAYS_BASE_URL;
  const email = env.GOODDAYS_EMAIL;
  const password = env.GOODDAYS_PASSWORD;
  const userId = env.GOODDAYS_USER_ID;
  const message = ctx.message?.text || ctx.message?.content || '';

  if (!baseUrl || !email || !password) {
    return { reply: '缺少 GoodDays 設定，請先檢查 workspace/.env。' };
  }

  try {
    const token = await login(baseUrl, email, password);
    const datePayload = parseDateFromMessage(message);
    const intent = detectIntent(message);

    if (intent === 'events') {
      const startDate = formatYmd(datePayload.year, datePayload.month, datePayload.day);
      const plusOne = addDays(datePayload.year, datePayload.month, datePayload.day, 1);
      const endDate = formatYmd(plusOne.year, plusOne.month, plusOne.day);
      const result = await getUnifiedEvents(baseUrl, token, userId, startDate, endDate);
      const events = result?.data || [];
      return {
        reply:
          `📅 GoodDays 行程查詢\n\n` +
          `區間：${startDate} ~ ${endDate}\n` +
          `${summarizeEvents(events)}`,
        metadata: {
          engine: 'gooddays-calendar',
          endpoint: '/api/unified-events',
          startDate,
          endDate,
          count: Array.isArray(events) ? events.length : 0,
          result,
        },
      };
    }

    const payload = { ...datePayload, userId };
    if (payload.hour == null) delete (payload as any).hour;

    const result = await getMysticalDaily(baseUrl, token, payload);
    const d = result?.data || {};
    const goodHours = d?.good_hours?.good_hours_display || '未提供';
    const isGoodNow = d?.good_hours?.is_good_hour;
    const ganzhi = d?.ganzhi?.day || '未知';
    const lunar = d?.lunar?.full_date || '未知';
    const dongong = d?.dongong?.note || '未提供';
    const twelve = d?.twelve_star?.description || '未提供';

    return {
      reply:
        `📅 GoodDays 今日資訊\n\n` +
        `日期：${payload.year}-${String(payload.month).padStart(2, '0')}-${String(payload.day).padStart(2, '0')}` +
        `${payload.hour != null ? ` ${payload.hour}:00` : ''}` +
        `\n干支：${ganzhi}` +
        `\n農曆：${lunar}` +
        `\n吉時：${goodHours}` +
        `\n此刻是否吉時：${isGoodNow === true ? '是' : isGoodNow === false ? '否' : '未知'}` +
        `\n董公：${dongong}` +
        `\n十二建星：${twelve}`,
      metadata: {
        engine: 'gooddays-calendar',
        endpoint: '/api/mystical/daily',
        payload,
        result,
      },
    };
  } catch (error: any) {
    return {
      reply: `❌ GoodDays 查詢失敗：${error?.message || String(error)}`,
      metadata: { error: error?.message || String(error) },
    };
  }
}