import type { DevTask, DevTaskStatus } from './dev-task';
import { canStartDevTask, canTransition } from './dev-task';

export interface DevTaskWorkflowResult {
  ok: boolean;
  patch?: Partial<DevTask>;
  message?: string;
}

export interface DevTaskTransitionOptions {
  now?: Date;
  delayReason?: string;
}

export function normalizeDevTaskOnCreate(task: DevTask): DevTask {
  return {
    ...task,
    status: 'todo',
    actualStartAt: undefined,
    actualEndAt: undefined,
  };
}

export function applyDevTaskTransition(
  task: DevTask,
  to: DevTaskStatus,
  options: DevTaskTransitionOptions = {},
): DevTaskWorkflowResult {
  if (!canTransition(task.status, to)) {
    return { ok: false, message: `不允许从「${task.status}」流转到「${to}」` };
  }

  if (to === 'submitted' && task.isBlocked) {
    return { ok: false, message: '任务仍处于阻塞中，请先解除阻塞后再提测' };
  }

  const nowIso = (options.now ?? new Date()).toISOString();
  if (to === 'in_progress' && !canStartDevTask(task)) {
    return { ok: false, message: '开始开发前需要先领取并填写预计开始和预计截止时间' };
  }

  const patch: Partial<DevTask> = {
    status: to,
    aiDraft: false,
  };

  if (to === 'in_progress' && !task.actualStartAt) {
    patch.actualStartAt = nowIso;
    if (options.delayReason?.trim()) patch.delayReason = options.delayReason.trim();
  }

  if (to === 'submitted') {
    patch.actualEndAt = nowIso;
  }

  return { ok: true, patch };
}