const CHECKPOINT_STATUS_LABELS = {
  pending: '待开始',
  running: '进行中',
  awaiting_approval: '待确认',
  approved: '已完成',
  skipped: '已跳过',
  failed: '失败',
};

export function buildGoalContextEnvelope(goal) {
  if (!goal) return '';
  const checkpoints = Array.isArray(goal.checkpoints) ? goal.checkpoints : [];
  const current = checkpoints.find((item) => item.id === goal.currentCheckpointId)
    ?? checkpoints.find((item) => item.status === 'running')
    ?? checkpoints.find((item) => item.status === 'pending');
  const completed = checkpoints.filter((item) =>
    ['approved', 'awaiting_approval'].includes(item.status));
  const awaiting = checkpoints.find((item) => item.status === 'awaiting_approval');

  const lines = [
    '【Goal Context】',
    `目标：${goal.title}`,
  ];
  if (current) {
    const statusLabel = CHECKPOINT_STATUS_LABELS[current.status] ?? current.status;
    lines.push(`当前阶段：${current.title}（${statusLabel}）`);
  }
  if (completed.length) {
    lines.push('已完成摘要：');
    for (const checkpoint of completed) {
      if (checkpoint.outputSummary) {
        lines.push(`- ${checkpoint.outputSummary}`);
      } else {
        lines.push(`- ${checkpoint.title}`);
      }
    }
  }
  if (awaiting) {
    lines.push(`待你确认：${awaiting.description || awaiting.title}`);
  }
  return lines.join('\n');
}