import { parseHourMinute } from './schedule-intent.mjs';
import {
  addLocalDays,
  getLocalParts,
  normalizeTimezone,
  startOfLocalDay,
  zonedTimeToEpochMs,
} from './schedule-time.mjs';

function normalizeText(text) {
  return String(text ?? '')
    .replace(/^(?:嗯|那个|就是|然后|呃|能不能|请|帮我|麻烦|嗨)+/u, '')
    .replace(/\s+/g, '')
    .trim();
}

const EXECUTE_VERBS = /(?:做|生成|制作|创建|写|执行|跑|更新|整理|汇总|推送|发送|发给|发|看看|检查|监控|瞧瞧)/u;
const SCHEDULE_MARKERS = /(?:定时(?:自动)?任务|scheduled\s*task|scheduled\s*automation|cron\s*job|recurring\s*task)/iu;
const RECURRENCE_MARKERS = /(?:每天|每日|每周|定时|到点|届时|自动)/u;

const WEEKDAY_LABELS = [
  ['周日', '周天', '星期日', '星期天'],
  ['周一', '星期一'],
  ['周二', '星期二'],
  ['周三', '星期三'],
  ['周四', '星期四'],
  ['周五', '星期五'],
  ['周六', '星期六'],
];

const META_TASK_SPEC_PATTERNS = [
  /^我要?(?:做|创建|设置|弄)?(?:一个|个)?(?:定时(?:自动)?)?执行(?:任务)?$/u,
  /^帮我?(?:做|创建|设置|弄)?(?:一个|个)?(?:定时(?:自动)?)?执行(?:任务)?$/u,
  /^请?(?:帮我)?(?:做|创建|设置|弄)?(?:一个|个)?(?:定时(?:自动)?)?执行(?:任务)?$/u,
  /^定时(?:自动)?执行(?:任务)?$/u,
  /^执行(?:任务)?$/u,
  /^做(?:一个|个)?(?:定时(?:自动)?)?(?:执行)?任务$/u,
  /^创建(?:一个|个)?定时(?:自动)?执行(?:任务)?$/u,
  /^想(?:要)?(?:做|创建|设置)?(?:一个|个)?(?:定时(?:自动)?)?执行(?:任务)?$/u,
];

function isMetaScheduledTaskSpec(spec) {
  const normalized = String(spec ?? '').replace(/\s+/g, '').trim();
  if (!normalized) return true;
  return META_TASK_SPEC_PATTERNS.some((pattern) => pattern.test(normalized));
}

function wantsScheduledTaskAutomation(compact) {
  if (SCHEDULE_MARKERS.test(compact)) return true;
  if (RECURRENCE_MARKERS.test(compact)
    && /(?:看看|检查|监控|瞧瞧).{0,20}(?:有没有|是否有)/u.test(compact)) {
    return true;
  }
  if (!RECURRENCE_MARKERS.test(compact)) return false;
  if (!EXECUTE_VERBS.test(compact)) return false;
  // Pure reminders/digests stay on schedule-assistant or wechat schedule handler.
  if (/(?:提醒我|闹钟|待办记录|待办列表|待办清单|当天待办|一天的待办)/u.test(compact)) return false;
  if (/(?:待办|代办|带办|代拜).{0,8}(?:记录|列表|清单|摘要|汇总)/u.test(compact)) {
    // 「待办摘要页面 / 待办汇总 HTML」仍是定时自动任务，不是纯 digest 推送。
    if (!/(?:页面|网页|html|h5)/iu.test(compact)) return false;
  }
  return true;
}

function parseWeekday(compact) {
  for (let index = 0; index < WEEKDAY_LABELS.length; index += 1) {
    if (WEEKDAY_LABELS[index].some((label) => compact.includes(label))) {
      return index;
    }
  }
  return null;
}

function extractScheduledTaskSpec(text) {
  const original = String(text ?? '').trim();
  if (!original) return null;
  let spec = original
    .replace(/^(?:不是|别是|并非)(?:待办|代办|提醒|日程|闹钟)[，,、:：\s]*/u, '')
    .replace(
      /^(?:帮我)?(?:设|设置|创建|添加|想创建)(?:一个|个)?(?:定时(?:自动)?任务|定时执行任务)?[:：,，、\s]*/u,
      '',
    )
    .replace(
      /(?:一次|单次|仅一次|once|每天|每日|weekly|每周|daily|定时|到点|届时|自动)/giu,
      ' ',
    )
    .replace(
      /(?:今天|今日|今晚|明天|后天|早上|上午|清晨|下午|晚上)?[0-9零一二两三四五六七八九十]{1,3}(?:点|:|：)(半|[0-9]{1,2}分?)?/gu,
      ' ',
    )
    .replace(/(?:周[一二三四五六日天]|星期[一二三四五六日天])/gu, ' ')
    .replace(/(?:帮我|请|麻烦)/gu, ' ')
    .replace(/^执行[，,、:：\s]+/u, '')
    .replace(/[，,、:：\s]+执行$/u, '')
    .replace(/\s+/g, ' ')
    .trim();
  if (!spec || spec.length < 3) return null;
  if (isMetaScheduledTaskSpec(spec)) return null;
  if (!EXECUTE_VERBS.test(spec.replace(/\s+/g, ''))) return null;
  return spec;
}

function formatRunAtLocal(epochMs, timezone) {
  const parts = getLocalParts(epochMs, timezone);
  return `${parts.year}-${String(parts.month).padStart(2, '0')}-${String(parts.day).padStart(2, '0')} ${String(parts.hour).padStart(2, '0')}:${String(parts.minute).padStart(2, '0')}`;
}

function resolveOnceRunAtLocal(text, compact, { timezone, now = Date.now() } = {}) {
  const time = parseHourMinute(text);
  if (!time) return null;

  let dayOffset = 0;
  if (/后天/u.test(compact)) dayOffset = 2;
  else if (/明天/u.test(compact)) dayOffset = 1;
  else if (/(?:今晚|今天|今日)/u.test(compact)) dayOffset = 0;

  const todayStart = startOfLocalDay(now, timezone);
  let targetDayStart = addLocalDays(todayStart, dayOffset, timezone);
  let parts = getLocalParts(targetDayStart, timezone);
  let runAt = zonedTimeToEpochMs(
    {
      year: parts.year,
      month: parts.month,
      day: parts.day,
      hour: time.hour,
      minute: time.minute,
      second: 0,
    },
    timezone,
  );
  if (runAt <= now) {
    targetDayStart = addLocalDays(targetDayStart, 1, timezone);
    parts = getLocalParts(targetDayStart, timezone);
    runAt = zonedTimeToEpochMs(
      {
        year: parts.year,
        month: parts.month,
        day: parts.day,
        hour: time.hour,
        minute: time.minute,
        second: 0,
      },
      timezone,
    );
  }
  return formatRunAtLocal(runAt, timezone);
}

export function shouldUseScheduledTaskAutomation(text) {
  const compact = normalizeText(text);
  if (!compact) return false;
  return wantsScheduledTaskAutomation(compact);
}

export function parseScheduledTaskIntent(text, { now = Date.now(), timezone = 'Asia/Shanghai' } = {}) {
  const compact = normalizeText(text);
  const original = String(text ?? '').trim();
  if (!compact) return { action: 'none' };

  const wantsCancel = /(?:取消|停止|关闭|删除).{0,16}(?:定时|自动|每日|每天)/u.test(compact)
    || /(?:取消|停止|关闭|删除).{0,16}(?:新闻|天气).{0,8}任务/u.test(compact)
    || /(?:cancel|stop|disable).{0,12}(?:scheduled|automation|task)/iu.test(compact);
  if (wantsCancel) {
    return { action: 'cancel_scheduled_task' };
  }

  const wantsList = /(?:查看|看看|列出|我的).{0,12}(?:定时|自动).{0,12}(?:任务|自动化)/u.test(compact)
    || /(?:list|show).{0,12}(?:scheduled|automation).{0,12}tasks/iu.test(compact);
  if (wantsList) {
    return { action: 'list_scheduled_tasks' };
  }

  if (!wantsScheduledTaskAutomation(compact)) {
    return { action: 'none' };
  }

  const tz = normalizeTimezone(timezone);

  const recurrence = /(?:一次|单次|仅一次|once)/iu.test(compact)
    ? 'once'
    : /(?:每周|weekly)/iu.test(compact)
      ? 'weekly'
      : /(?:每天|每日|daily)/u.test(compact)
        ? 'daily'
        : null;

  const time = parseHourMinute(original);
  const weekday = recurrence === 'weekly' ? parseWeekday(compact) : null;
  const runAtLocal = recurrence === 'once' || (!recurrence && time)
    ? resolveOnceRunAtLocal(original, compact, { timezone: tz, now })
    : null;
  const taskSpec = extractScheduledTaskSpec(original);
  const hasTaskSpec = Boolean(taskSpec);

  const needsClarification = [];
  if (recurrence === 'weekly' && weekday == null) {
    needsClarification.push('weekday');
  }
  if (recurrence === 'once' || (!recurrence && /(?:今晚|今天|明天|后天)/u.test(compact))) {
    if (!runAtLocal) needsClarification.push('schedule');
  } else if (recurrence === 'daily' || recurrence === 'weekly' || recurrence == null) {
    if (!time) needsClarification.push('schedule');
  } else if (!time && !runAtLocal && !/(?:明天|后天|今天|今晚|\d{1,2}[点:：]|[零一二两三四五六七八九十]{1,3}点)/u.test(compact)) {
    needsClarification.push('schedule');
  }
  if (!hasTaskSpec) {
    needsClarification.push('task_spec');
  }

  const resolvedRecurrence = recurrence ?? (runAtLocal ? 'once' : 'daily');

  if (needsClarification.length > 0) {
    return {
      action: 'create_scheduled_task',
      needsClarification,
      recurrence: resolvedRecurrence,
      hour: time?.hour ?? null,
      minute: time?.minute ?? 0,
      weekday,
      runAtLocal,
      taskSpec,
    };
  }

  return {
    action: 'create_scheduled_task',
    recurrence: resolvedRecurrence,
    hour: time?.hour ?? null,
    minute: time?.minute ?? 0,
    weekday,
    runAtLocal,
    taskSpec,
    title: taskSpec?.slice(0, 80) ?? null,
  };
}

export function buildScheduledTaskCreatePayload(intent, {
  userId,
  sourceChannel = 'agent',
  sourceSessionId = null,
  sourceMessageId = null,
  sourceText = null,
  timezone = 'Asia/Shanghai',
  notifyChannel = 'both',
} = {}) {
  if (!userId) throw new Error('缺少用户');
  if (intent?.action !== 'create_scheduled_task') {
    throw new Error('不是创建定时自动任务意图');
  }
  if (intent.needsClarification?.length) {
    throw new Error('创建定时任务前仍需澄清信息');
  }
  const taskSpec = String(intent.taskSpec ?? '').trim();
  if (!taskSpec) throw new Error('缺少 taskSpec（执行内容）');

  return {
    userId,
    title: intent.title ?? taskSpec.slice(0, 80),
    taskSpec,
    recurrence: intent.recurrence ?? 'daily',
    runAtLocal: intent.recurrence === 'once' ? intent.runAtLocal : null,
    hour: intent.recurrence === 'once' ? null : intent.hour,
    minute: intent.minute ?? 0,
    weekday: intent.recurrence === 'weekly' ? intent.weekday : null,
    timezone: normalizeTimezone(timezone),
    notifyChannel,
    sourceChannel,
    sourceSessionId,
    sourceMessageId,
    sourceText,
  };
}

export function formatScheduledTaskCreateReply(task, { workerWarning = null } = {}) {
  const recurrenceLabel = task.recurrence === 'once'
    ? '一次性'
    : task.recurrence === 'weekly'
      ? '每周'
      : '每天';
  const timeLabel = task.recurrence === 'once'
    ? intentRunAtLabel(task)
    : `${String(task.hour).padStart(2, '0')}:${String(task.minute ?? 0).padStart(2, '0')}`;
  const lines = [
    `已设置${recurrenceLabel}定时任务：${task.title}`,
    `执行内容：${task.taskSpec}`,
    `执行时间：${timeLabel}（${task.timezone || 'Asia/Shanghai'}）`,
    '到点会自动执行并通过服务号/站内推送结果。',
  ];
  if (workerWarning) {
    lines.push(`⚠️ ${workerWarning}`);
  }
  return lines.join('\n');
}

function intentRunAtLabel(task) {
  if (task.nextRunAt) {
    return formatRunAtLocal(Number(task.nextRunAt), task.timezone);
  }
  return '待确认';
}

export function formatScheduledTaskClarification(intent) {
  const missing = intent?.needsClarification ?? [];
  if (missing.includes('task_spec') && missing.includes('schedule')) {
    return '可以。请告诉我具体执行时间和任务内容，例如“每天 6 点帮我做今日新闻页面”或“今晚 21:45 执行做新闻页面”。';
  }
  if (missing.includes('task_spec')) {
    return '可以。到点需要自动执行什么？例如“搜索并生成今日新闻页面”。';
  }
  if (missing.includes('weekday')) {
    return '可以。这是每周任务，请告诉我是周几、几点执行，例如“每周一 7 点整理待办摘要”。';
  }
  if (missing.includes('schedule')) {
    return '可以。请告诉我想几点执行，例如“每天 6 点”或“今晚 21:45”。';
  }
  return '可以。请补充定时任务的执行时间和具体内容。';
}

export function isScheduledTaskIntent(intent) {
  return intent?.action && intent.action !== 'none';
}

export function formatScheduledTaskListReply(tasks = []) {
  if (!tasks.length) return '你当前没有进行中的定时自动任务。';
  const lines = ['你的定时自动任务：'];
  for (const task of tasks.slice(0, 10)) {
    const when = task.recurrence === 'once'
      ? formatRunAtLocal(Number(task.nextRunAt), task.timezone)
      : `${String(task.hour).padStart(2, '0')}:${String(task.minute ?? 0).padStart(2, '0')}`;
    lines.push(`- ${task.title}（${task.recurrence} ${when}）`);
  }
  return lines.join('\n');
}

export {
  extractScheduledTaskSpec,
  isMetaScheduledTaskSpec,
  parseWeekday,
  resolveOnceRunAtLocal,
};