import {
  buildScheduledTaskCreatePayload,
  formatScheduledTaskClarification,
  formatScheduledTaskCreateReply,
  formatScheduledTaskListReply,
  isScheduledTaskIntent,
  parseScheduledTaskIntent,
} from '../../scheduled-task-intent.mjs';
import {
  isScheduledTaskWorkerEnabled,
  scheduledTaskWorkerDisabledMessage,
} from '../../scheduled-task-worker-config.mjs';

const WEEKDAY_NAMES = ['周日', '周一', '周二', '周三', '周四', '周五', '周六'];

export async function handleWechatScheduledTaskIntent({
  intent,
  user,
  scheduledTaskService,
  env = process.env,
  logger = console,
}) {
  if (!scheduledTaskService) return null;

  const timezone = env.H5_DEFAULT_TIMEZONE || 'Asia/Shanghai';
  const taskIntent = parseScheduledTaskIntent(intent.agentText, {
    timezone,
  });
  if (!isScheduledTaskIntent(taskIntent)) return null;

  try {
    if (taskIntent.action === 'list_scheduled_tasks') {
      const tasks = await scheduledTaskService.listTasks({
        userId: user.userId,
        status: 'active',
        limit: 20,
      });
      return formatScheduledTaskListReply(tasks);
    }

    if (taskIntent.action === 'cancel_scheduled_task') {
      const titleMatch = String(intent.agentText ?? '')
        .replace(/(?:取消|停止|关闭|删除|我的|定时|自动|任务)/gu, ' ')
        .trim();
      if (!titleMatch) {
        return '请告诉我要取消哪一条定时任务，或提供任务名称关键词。';
      }
      const task = await scheduledTaskService.cancelTask({
        userId: user.userId,
        titleMatch,
      });
      return `已取消定时任务：${task.title}`;
    }

    if (taskIntent.action === 'create_scheduled_task') {
      if (taskIntent.needsClarification?.length) {
        return formatScheduledTaskClarification(taskIntent);
      }
      const payload = buildScheduledTaskCreatePayload(taskIntent, {
        userId: user.userId,
        sourceChannel: 'wechat',
        sourceMessageId: intent.msgId || null,
        sourceText: intent.agentText,
        timezone,
      });
      const task = await scheduledTaskService.createTask(payload);
      const workerWarning = isScheduledTaskWorkerEnabled(env)
        ? null
        : scheduledTaskWorkerDisabledMessage(env);
      let reply = formatScheduledTaskCreateReply(task, { workerWarning });
      if (task.recurrence === 'weekly' && task.weekday != null) {
        reply = reply.replace(
          /执行时间：/,
          `执行时间：${WEEKDAY_NAMES[Number(task.weekday)] ?? ''} `,
        );
      }
      return reply;
    }
  } catch (err) {
    logger.warn?.(
      '[wechat-scheduled-task] preflight failed:',
      err instanceof Error ? err.message : err,
    );
    return `定时任务设置失败：${err instanceof Error ? err.message : String(err)}`;
  }

  return null;
}