#!/bin/bash

set -euo pipefail

GITEA_SERVER="$1"
REPOSITORY="$2"
PACKAGE_NAME="$3"
TOKEN="$4"
KEEP_COUNT="$5"
DRY_RUN="${6:-false}"

# 參數驗證
if [[ -z "$GITEA_SERVER" ]] || [[ -z "$REPOSITORY" ]] || [[ -z "$PACKAGE_NAME" ]] || [[ -z "$TOKEN" ]] || [[ -z "$KEEP_COUNT" ]]; then
  echo "❌ 錯誤：缺少必要參數"
  echo "使用方式: $0 <gitea-server> <repository> <package-name> <token> <keep-count> [dry-run]"
  exit 1
fi

echo "開始清理舊映像，保留最新 $KEEP_COUNT 個版本"

# 提取 owner 名稱
OWNER=$(echo "$REPOSITORY" | cut -d'/' -f1)

echo "Owner: $OWNER"
echo "Package: $PACKAGE_NAME"

# 獲取所有 container 版本並按創建時間排序
echo "正在獲取映像版本列表..."
VERSIONS_JSON=$(curl -s -w "\nHTTP_STATUS:%{http_code}" \
  "$GITEA_SERVER/api/v1/packages/$OWNER/container/$PACKAGE_NAME?token=$TOKEN" \
  -H "Accept: application/json")

HTTP_STATUS=$(echo "$VERSIONS_JSON" | grep -o "HTTP_STATUS:[0-9]*" | cut -d: -f2)
VERSIONS_JSON=$(echo "$VERSIONS_JSON" | sed '/HTTP_STATUS:/d')

# 檢查是否成功獲取版本列表
if [[ "$HTTP_STATUS" != "200" ]] || [[ -z "$VERSIONS_JSON" ]] || [[ "$VERSIONS_JSON" == "null" ]]; then
  echo "❌ 錯誤：無法獲取 container 版本列表 (HTTP Status: $HTTP_STATUS)"
  exit 1
fi

# 獲取並排序所有版本 (按創建時間降序)
SORTED_VERSIONS=$(echo "$VERSIONS_JSON" | jq -e 'sort_by(.created_at) | reverse')

if [[ $? -ne 0 ]]; then
  echo "❌ 錯誤：無法解析版本資料"
  exit 1
fi

# 計算總數量
TOTAL_COUNT=$(echo "$SORTED_VERSIONS" | jq 'length')
echo "目前總共有 $TOTAL_COUNT 個映像版本"

# 如果總數量小於等於保留數量，則無需清理
if [[ $TOTAL_COUNT -le $KEEP_COUNT ]]; then
  echo "✅ 映像數量 ($TOTAL_COUNT) 未超過保留數量 ($KEEP_COUNT)，無需清理"
  exit 0
fi

# 計算需要刪除的數量
DELETE_COUNT=$((TOTAL_COUNT - KEEP_COUNT))
echo "需要刪除 $DELETE_COUNT 個舊映像"

# 獲取要刪除的版本 (跳過前 keep-count 個)
TO_DELETE=$(echo "$SORTED_VERSIONS" | jq -c ".[$KEEP_COUNT:][]")

# 初始化刪除計數器
DELETED_COUNT=0
FAILED_COUNT=0

# 處理每個要刪除的版本
while IFS= read -r version; do
  if [[ -z "$version" ]] || [[ "$version" == "null" ]]; then
    continue
  fi
  
  VERSION_ID=$(echo "$version" | jq -r '.id')
  VERSION_NAME=$(echo "$version" | jq -r '.version')
  CREATED_AT=$(echo "$version" | jq -r '.created_at')
  
  if [[ -z "$VERSION_ID" ]] || [[ "$VERSION_ID" == "null" ]]; then
    continue
  fi
  
  echo "準備刪除: ID=$VERSION_ID, Version=$VERSION_NAME, Created=$CREATED_AT"
  
  if [[ "$DRY_RUN" == "true" ]]; then
    echo "🔍 [模擬執行] 會刪除映像版本: $VERSION_NAME (ID: $VERSION_ID)"
    DELETED_COUNT=$((DELETED_COUNT + 1))
  else
    # 實際刪除
    DELETE_RESPONSE=$(curl -s -w "\nHTTP_STATUS:%{http_code}" \
      -X DELETE "$GITEA_SERVER/api/v1/packages/$OWNER/container/$PACKAGE_NAME/$VERSION_NAME?token=$TOKEN" \
      -H "Accept: application/json")
    
    DELETE_HTTP_STATUS=$(echo "$DELETE_RESPONSE" | grep -o "HTTP_STATUS:[0-9]*" | cut -d: -f2)
    
    if [[ "$DELETE_HTTP_STATUS" == "204" ]] || [[ "$DELETE_HTTP_STATUS" == "200" ]]; then
      echo "✅ 成功刪除映像版本: $VERSION_NAME (ID: $VERSION_ID)"
      DELETED_COUNT=$((DELETED_COUNT + 1))
    else
      echo "❌ 刪除失敗映像版本: $VERSION_NAME (ID: $VERSION_ID), HTTP狀態: $DELETE_HTTP_STATUS"
      FAILED_COUNT=$((FAILED_COUNT + 1))
    fi
  fi
done <<< "$TO_DELETE"

# 檢查是否有刪除失敗的情況
if [[ $FAILED_COUNT -gt 0 ]]; then
  echo ""
  echo "❌ 錯誤：有 $FAILED_COUNT 個映像版本刪除失敗"
  exit 1
fi

# 輸出最終結果
echo ""
echo "========================================="
if [[ "$DRY_RUN" == "true" ]]; then
  echo "🔍 [模擬執行] 總共會刪除 $DELETED_COUNT 個映像版本"
  echo "✅ 模擬執行完成"
else
  echo "✅ 清理完成，成功刪除了 $DELETED_COUNT 個映像版本"
  
  # 驗證結果
  if [[ $DELETED_COUNT -gt 0 ]]; then
    echo ""
    echo "正在驗證剩餘映像數量..."
    VERIFY_JSON=$(curl -s "$GITEA_SERVER/api/v1/packages/$OWNER/container/$PACKAGE_NAME?token=$TOKEN" \
      -H "Accept: application/json")
    NEW_TOTAL_COUNT=$(echo "$VERIFY_JSON" | jq 'length')
    echo "📊 目前剩餘 $NEW_TOTAL_COUNT 個映像版本（預期: $KEEP_COUNT）"
  fi
fi
echo "========================================="