#!/bin/bash
# Docker镜像构建与推送脚本 - 处理registry不稳定问题
# 特性：
#   1. 构建+推送镜像（缓存只读模式）保证成功
#   2. 单独尝试推送缓存，失败不影响主构建
#   3. 缓存推送自动重试3次
#   4. zstd压缩减小缓存体积
set -eu

usage() {
  echo "Usage: $0 <dockerfile> <image_tag> <cache_ref> [build_args...]"
  echo "  dockerfile:   Dockerfile路径"
  echo "  image_tag:    完整镜像标签 (registry/repo:tag)"
  echo "  cache_ref:    缓存引用 (registry/repo-cache:branch)"
  echo "  build_args:   额外的--build-arg参数 (可选)"
  exit 1
}

if [ $# -lt 3 ]; then
  usage
fi

DOCKERFILE="$1"
IMAGE_TAG="$2"
CACHE_REF="$3"
shift 3
BUILD_ARGS=""
for arg in "$@"; do
  BUILD_ARGS="$BUILD_ARGS --build-arg $arg"
done

CACHE_FROM="type=registry,ref=${CACHE_REF},ignore-error=true"
CACHE_TO="type=registry,ref=${CACHE_REF},mode=min,compression=zstd,oci-mediatypes=true"

echo "========================================"
echo "构建镜像: $IMAGE_TAG"
echo "Dockerfile: $DOCKERFILE"
echo "缓存引用: $CACHE_REF"
echo "========================================"

# Step 1: 构建并推送镜像（只读缓存，保证主构建成功）
echo ""
echo "[1/2] 构建并推送镜像 (只读缓存模式)..."
docker buildx build \
  $BUILD_ARGS \
  --cache-from "$CACHE_FROM" \
  -f "$DOCKERFILE" \
  -t "$IMAGE_TAG" \
  --push \
  .
echo "✅ 镜像构建并推送成功: $IMAGE_TAG"

# Step 2: 尝试推送缓存（失败不影响，重试3次）
echo ""
echo "[2/2] 尝试推送缓存到 registry (最多重试3次)..."
CACHE_PUSH_SUCCESS=false
for attempt in 1 2 3; do
  echo "  缓存推送尝试 $attempt/3..."
  if docker buildx build \
    $BUILD_ARGS \
    --cache-from "$CACHE_FROM" \
    --cache-to "$CACHE_TO" \
    -f "$DOCKERFILE" \
    -t "$IMAGE_TAG" \
    --push \
    . 2>&1 | tail -5; then
    CACHE_PUSH_SUCCESS=true
    echo "  ✅ 缓存推送成功 (第$attempt次尝试)"
    break
  else
    echo "  ⚠️  缓存推送失败 (第$attempt次尝试)，等待后重试..."
    sleep $((attempt * 5))
  fi
done

if [ "$CACHE_PUSH_SUCCESS" = false ]; then
  echo ""
  echo "⚠️  缓存推送最终失败，跳过（不影响构建结果）"
  echo "   下一次构建将使用旧缓存或无缓存构建"
fi

echo ""
echo "========================================"
echo "✅ 构建完成: $IMAGE_TAG"
echo "========================================"