import { isScheduleIntent, parseScheduleIntent } from '../../schedule-intent.mjs';

function normalizeHour(value) {
  const hour = Number(value);
  return Number.isInteger(hour) && hour >= 0 && hour <= 23 ? hour : null;
}

function normalizeMinute(value) {
  const minute = Number(value);
  return Number.isInteger(minute) && minute >= 0 && minute <= 59 ? minute : null;
}

function normalizeThresholdCents(value) {
  const parsed = Number(value);
  if (!Number.isFinite(parsed) || parsed < 0) return null;
  return Math.round(parsed * 100);
}

function parseJsonReply(reply) {
  const text = String(reply ?? '').trim();
  if (!text) return null;
  const fenced = text.match(/```(?:json)?\s*([\s\S]*?)```/i);
  const candidate = fenced?.[1] ?? text;
  try {
    return JSON.parse(candidate);
  } catch {
    return null;
  }
}

function normalizeLlmScheduleIntent(payload) {
  const action = String(payload?.action ?? 'none').trim();
  if (!action) return { action: 'none' };

  if (action === 'create_todo') {
    const title = String(payload?.title ?? '').trim();
    return title ? { action, title } : { action, needsClarification: ['todo_title'] };
  }

  if (action === 'create_daily_todo_digest') {
    const hour = normalizeHour(payload?.hour);
    const minute = normalizeMinute(payload?.minute ?? 0);
    if (hour == null || minute == null) {
      return { action, needsClarification: ['digest_time'] };
    }
    return { action, hour, minute };
  }

  if (action === 'create_balance_alert') {
    const thresholdCents = normalizeThresholdCents(payload?.thresholdYuan);
    return thresholdCents == null
      ? { action, needsClarification: ['threshold'] }
      : { action, thresholdCents };
  }

  if (action === 'query_schedule' || action === 'schedule_agent') {
    return { action };
  }

  return { action: 'none' };
}

async function parseScheduleIntentWithLlm({ text, llmProviderService, logger = console }) {
  if (!llmProviderService || typeof llmProviderService.createChatCompletion !== 'function') {
    return { action: 'none' };
  }

  const result = await llmProviderService.createChatCompletion({
    temperature: 0,
    messages: [
      {
        role: 'system',
        content: [
          '你是公众号提醒助手，只做意图识别。',
          '请严格输出 JSON，不要输出解释。',
          '允许 action: create_todo, create_daily_todo_digest, create_balance_alert, query_schedule, schedule_agent, none。',
          'create_todo 需要 title。',
          'create_daily_todo_digest 需要 hour(0-23) 和 minute(0-59)。',
          'create_balance_alert 需要 thresholdYuan 数字。',
          '如果用户在说具体时间提醒、一次性闹钟、某天某时提醒，返回 schedule_agent。',
          '不确定时返回 none。',
        ].join('\n'),
      },
      {
        role: 'user',
        content: text,
      },
    ],
  });

  if (!result?.ok) {
    logger?.warn?.('[wechat-schedule-llm] parse skipped:', result?.message ?? 'unknown');
    return { action: 'none' };
  }

  return normalizeLlmScheduleIntent(parseJsonReply(result.reply));
}

async function resolveScheduleIntent({
  text,
  wechatScheduleLlmConfigService,
  llmProviderService,
  logger,
}) {
  const ruleIntent = parseScheduleIntent(text);
  if (isScheduleIntent(ruleIntent)) return ruleIntent;

  if (!wechatScheduleLlmConfigService || !llmProviderService) return ruleIntent;

  let enabled = false;
  try {
    enabled = await wechatScheduleLlmConfigService.isScheduleLlmEnabled();
  } catch (err) {
    logger?.warn?.(
      '[wechat-schedule-llm] config load failed:',
      err instanceof Error ? err.message : err,
    );
  }
  if (!enabled) return ruleIntent;

  return parseScheduleIntentWithLlm({ text, llmProviderService, logger });
}

export async function handleWechatScheduleIntent({
  intent,
  user,
  scheduleService,
  wechatScheduleLlmConfigService = null,
  llmProviderService = null,
  logger = console,
}) {
  if (!scheduleService) return null;
  const scheduleIntent = await resolveScheduleIntent({
    text: intent.agentText,
    wechatScheduleLlmConfigService,
    llmProviderService,
    logger,
  });
  if (!isScheduleIntent(scheduleIntent) || scheduleIntent.action === 'schedule_agent') return null;

  const timezone = process.env.H5_DEFAULT_TIMEZONE || 'Asia/Shanghai';

  if (scheduleIntent.action === 'create_todo') {
    if (scheduleIntent.needsClarification?.includes('todo_title')) {
      return '可以。你想让我记哪一条待办？例如“帮我记一下 跟段吃饭”。';
    }
    const item = await scheduleService.createItem({
      userId: user.userId,
      kind: 'task',
      title: scheduleIntent.title,
      timezone,
      sourceChannel: 'wechat',
      sourceMessageId: intent.msgId || null,
      sourceText: intent.agentText,
      metadata: {
        source: 'wechat_mp',
      },
    });
    return `已记录到待办列表：${item.title}，未设置提醒。`;
  }

  if (scheduleIntent.action === 'create_daily_todo_digest') {
    if (scheduleIntent.needsClarification?.includes('digest_time')) {
      return '可以。你想每天几点收到当天待办记录？比如“每天早上 7 点发给我”。';
    }
    const subscription = await scheduleService.createDailyTodoDigest({
      userId: user.userId,
      hour: scheduleIntent.hour,
      minute: scheduleIntent.minute,
      timezone,
      channel: 'wechat',
      sourceChannel: 'wechat',
      sourceMessageId: intent.msgId || null,
      sourceText: intent.agentText,
    });
    const minuteText = subscription.minute === 0 ? '' : `${String(subscription.minute).padStart(2, '0')}分`;
    return `已设置：我会每天早上 ${subscription.hour}点${minuteText} 通过服务号把当天待办记录发给你。`;
  }

  if (scheduleIntent.action === 'create_balance_alert') {
    if (scheduleIntent.needsClarification?.includes('threshold')) {
      return '可以。你想在余额低于多少时提醒我？例如“余额低于 20 元提醒我”。';
    }
    const subscription = await scheduleService.createBalanceLowAlert({
      userId: user.userId,
      thresholdCents: scheduleIntent.thresholdCents,
      channel: 'wechat',
      sourceChannel: 'wechat',
      sourceMessageId: intent.msgId || null,
      sourceText: intent.agentText,
    });
    return `已设置：当余额低于 ${(subscription.thresholdCents / 100).toFixed(2)} 元时，我会通过服务号提醒你。`;
  }

  if (scheduleIntent.action === 'query_schedule') {
    return scheduleService.buildTodoDigestText({
      userId: user.userId,
      timezone,
    });
  }

  return null;
}