#!/usr/bin/env bash
# 自动合并：CI全绿+已审批后自动squash merge PR到develop
# 短作业模式：只检查一次，不满足条件就退出，由pr-auto-scan定时兜底
# 环境变量：GITHUB_TOKEN, MERGE_TOKEN, PR_NUMBER, PR_HEAD_SHA, BASE_REF, GITHUB_API_URL, GITHUB_REPOSITORY
set -eu

echo "PR #${PR_NUMBER} - 检查CI状态+审批并自动合并到${BASE_REF}"
echo
echo "模式: 短作业（只检查一次，不满足则退出，由pr-auto-scan定时兜底）"
echo

# 只合develop分支
if [ "$BASE_REF" != "develop" ]; then
  echo "Skip: 目标分支不是develop"
  exit 0
fi

# 判断是否纯前端改动
FILES=$(curl -s -H "Authorization: token ${GITHUB_TOKEN}" \
  "${GITHUB_API_URL}/repos/${GITHUB_REPOSITORY}/pulls/${PR_NUMBER}/files?limit=300" \
  | python3 -c "import sys,json; [print(f['filename']) for f in json.load(sys.stdin)]")
TOTAL=$(echo "$FILES" | grep -cv '^$' || true)
FRONTEND_COUNT=$(echo "$FILES" | grep -c '^apps/web/' || true)
BACKEND_COUNT=$((TOTAL - FRONTEND_COUNT))
echo "变更文件: ${TOTAL} 个 (前端: ${FRONTEND_COUNT}, 后端/公共: ${BACKEND_COUNT})"
echo

# 使用统一的CI Gate门禁（单一检查点，自动处理前端/后端/全栈跳过逻辑）
CONTEXTS=(
  "CI/CD Pipeline / CI Gate (pull_request)"
)
echo "检查CI Gate统一门禁"
echo

# 等待30秒后开始轮询，最多10分钟
echo "等待30秒让CI启动..."
sleep 30

# 405计数器（单次运行内重试）
MERGE_405_COUNT=0
MAX_405_RETRIES=3

check_and_merge() {
  ALL_SUCCESS=true
  ANY_FAILED=false
  ANY_PENDING=false

  echo "--- 检查CI状态 ($(date '+%H:%M:%S')) ---"

  # 检查CI状态
  for ctx in "${CONTEXTS[@]}"; do
    STATE=$(python3 scripts/check_ci_status.py "$GITHUB_TOKEN" "$GITHUB_REPOSITORY" "$PR_HEAD_SHA" "$ctx")
    echo "  CI: ${ctx##*/}: $STATE"
    if [ "$STATE" != "success" ]; then
      ALL_SUCCESS=false
    fi
    if [ "$STATE" = "failure" ] || [ "$STATE" = "error" ]; then
      ANY_FAILED=true
    fi
    if [ "$STATE" = "pending" ]; then
      ANY_PENDING=true
    fi
  done

  # CI有失败 → 不合并，直接退出
  if [ "$ANY_FAILED" = "true" ]; then
    echo
    echo "❌ CI有失败项，不自动合并"
    exit 0
  fi

  # CI未全绿（pending中）→ 退出，等下次触发
  if [ "$ALL_SUCCESS" != "true" ]; then
    echo
    echo "⏳ CI尚未全绿（仍有pending），等待重试..."
    echo "   （当前第${attempt}次轮询，最多${MAX_ATTEMPTS}次）"
    return 1
  fi

  # CI全绿 → 合并
  echo
  echo "✅ CI全绿，执行自动合并"
  echo "等待30秒冷却，给Gitea内部状态同步时间..."
  sleep 30

  # 幂等检查：PR是否还是open
  PR_STATE=$(curl -s -H "Authorization: token ${MERGE_TOKEN}" \
    "${GITHUB_API_URL}/repos/${GITHUB_REPOSITORY}/pulls/${PR_NUMBER}" \
    | python3 -c "import sys,json; print(json.load(sys.stdin).get('state',''))")

  if [ "$PR_STATE" != "open" ]; then
    echo "PR状态为 ${PR_STATE}，无需合并"
    exit 0
  fi

  # 执行squash merge
  HTTP_CODE=$(curl -s -o /tmp/merge_resp.json -w "%{http_code}" \
    -X POST \
    -H "Authorization: token ${MERGE_TOKEN}" \
    -H "Content-Type: application/json" \
    -d '{"do":"squash","merge_title_field":"","merge_message_field":"","delete_branch_after_merge":true,"force_merge":false}' \
    "${GITHUB_API_URL}/repos/${GITHUB_REPOSITORY}/pulls/${PR_NUMBER}/merge")

  echo "合并API HTTP状态: $HTTP_CODE"

  if [ "$HTTP_CODE" = "200" ]; then
    echo "✅ 自动合并成功"
    exit 0
  elif [ "$HTTP_CODE" = "405" ]; then
    MERGE_405_COUNT=$((MERGE_405_COUNT + 1))
    echo "⚠️  合并返回405（第${MERGE_405_COUNT}次），可能CI状态尚未同步或有未解决的门禁"
    cat /tmp/merge_resp.json 2>/dev/null || true
    echo
    if [ "$MERGE_405_COUNT" -ge "$MAX_405_RETRIES" ]; then
      echo "⚠️  连续${MAX_405_RETRIES}次合并返回405，放弃本次自动合并"
      echo "   （pr-auto-scan会继续尝试，需人工确认是否有冲突或门禁问题）"
      curl -s -X POST \
        -H "Authorization: token ${MERGE_TOKEN}" \
        -H "Content-Type: application/json" \
        -d '{"body": "Auto merge skipped after multiple 405 errors: PR may have conflicts or unresolved checks. Please review manually. This is not a CI failure."}' \
        "${GITHUB_API_URL}/repos/${GITHUB_REPOSITORY}/issues/${PR_NUMBER}/comments" > /dev/null 2>&1 || true
      exit 0
    fi
    echo "30秒后重试..."
    sleep 30
    return 1  # 重试
  else
    echo "❌ 自动合并失败 (HTTP $HTTP_CODE)"
    cat /tmp/merge_resp.json 2>/dev/null || true
    curl -s -X POST \
      -H "Authorization: token ${MERGE_TOKEN}" \
      -H "Content-Type: application/json" \
      -d "{\"body\": \"Auto merge failed (HTTP ${HTTP_CODE}), please check manually.\"}" \
      "${GITHUB_API_URL}/repos/${GITHUB_REPOSITORY}/issues/${PR_NUMBER}/comments" > /dev/null 2>&1 || true
    exit 1
  fi
}

# 轮询等待CI就绪+审批完成，最多10分钟（60次x10秒）
MAX_ATTEMPTS=60
for attempt in $(seq 1 $MAX_ATTEMPTS); do
  if check_and_merge; then
    exit 0
  fi
  
  # 检查PR是否还open（可能已被手动合并或关闭）
  PR_STATE=$(curl -s -H "Authorization: token ${MERGE_TOKEN}" \
    "${GITHUB_API_URL}/repos/${GITHUB_REPOSITORY}/pulls/${PR_NUMBER}" \
    | python3 -c "import sys,json; print(json.load(sys.stdin).get('state',''))" 2>/dev/null || echo "?")
  
  if [ "$PR_STATE" != "open" ]; then
    echo "PR状态为 ${PR_STATE}，无需继续等待"
    exit 0
  fi
  
  if [ $attempt -lt $MAX_ATTEMPTS ]; then
    sleep 10
  fi
done

echo
echo "⏰ 等待10分钟后仍未满足合并条件，退出。pr-auto-scan定时扫描会继续重试。"
exit 0