name: Build container image

on:
 # pull_request:
   # branches:
    #  - main
 # schedule:
  #  - cron: '05 12 * * 2,5'
  workflow_dispatch:

env:
  IMAGE_DESC: "Custom Fedora bootc image"
  IMAGE_NAME: "${{ github.event.repository.name }}"
  DEFAULT_TAG: "stable"

concurrency:
  group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
  cancel-in-progress: true

jobs:
  build_push:
    name: Build and push image
    runs-on: ubuntu-24.04

    permissions:
      contents: read
      packages: write
      id-token: write

    steps:
      - name: Prepare environment
        run: |
          # Extrahiert die reine Domain/Host aus der Gitea-URL
          REGISTRY_HOST=$(echo "${{ github.server_url }}" | awk -F/ '{print $3}')
          OWNER_LOWER="${{ github.repository_owner }}"
          NAME_LOWER="${{ env.IMAGE_NAME }}"

          echo "REGISTRY_HOST=${REGISTRY_HOST}" >> ${GITHUB_ENV}
          echo "IMAGE_REGISTRY=${REGISTRY_HOST}/${OWNER_LOWER,,}" >> ${GITHUB_ENV}
          echo "IMAGE_NAME=${NAME_LOWER,,}" >> ${GITHUB_ENV}

      - name: Determine image tag
        run: |
          BRANCH="${GITHUB_REF_NAME}"
          if [[ "$BRANCH" == "main" ]]; then
            echo "IMAGE_TAG=${DEFAULT_TAG}" >> ${GITHUB_ENV}
            echo "IS_TEST_BUILD=false" >> ${GITHUB_ENV}
          else
            SANITIZED=$(echo "$BRANCH" | sed 's/[^a-zA-Z0-9._-]/-/g' | head -c 50)
            echo "IMAGE_TAG=test-${SANITIZED}" >> ${GITHUB_ENV}
            echo "IS_TEST_BUILD=true" >> ${GITHUB_ENV}
          fi

      - name: Checkout
        uses: actions/checkout@v7.0.1

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v4.2.0

      - name: Image Metadata
        id: metadata
        uses: docker/metadata-action@v6.2.0
        with:
          images: ${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=raw,value=${{ env.IMAGE_TAG }}
            type=raw,value=${{ env.IMAGE_TAG }}.{{date 'YYYYMMDD'}},enable=${{ env.IS_TEST_BUILD == 'false' }}
            type=raw,value={{date 'YYYYMMDD'}},enable=${{ env.IS_TEST_BUILD == 'false' }}
            type=sha,enable=${{ github.event_name == 'pull_request' }}
            type=ref,event=pr
          labels: |
            org.opencontainers.image.created={{date 'YYYY-MM-DDTHH:mm:ssZ'}}
            org.opencontainers.image.description=${{ env.IMAGE_DESC }}
            org.opencontainers.image.documentation=${{ github.server_url }}/${{ github.repository }}
            org.opencontainers.image.source=${{ github.server_url }}/${{ github.repository }}
            org.opencontainers.image.title=${{ env.IMAGE_NAME }}
            org.opencontainers.image.url=${{ github.server_url }}/${{ github.repository }}
            org.opencontainers.image.vendor=${{ github.repository_owner }}
            org.opencontainers.image.version=${{ env.IMAGE_TAG }}.{{date 'YYYYMMDD'}}
            containers.bootc=1
            ostree.bootable=1

      - name: Login to Gitea Container Registry
        uses: docker/login-action@v4.6.0
        with:
          registry: ${{ env.REGISTRY_HOST }}
          username: ${{ github.repository_owner }}
          password: ${{ secrets.REGISTRY }}     

      # 1. Buildx baut das Image mit Registry-Cache und exportiert ein lokaes OCI-Archiv
      - name: Build Image to OCI Archive (Docker Buildx)
        uses: docker/build-push-action@v7.3.0
        id: build_image
        with:
          context: .
          file: ./Containerfile
          tags: ${{ steps.metadata.outputs.tags }}
          labels: ${{ steps.metadata.outputs.labels }}
          outputs: type=oci,dest=./oci-image.tar
          cache-from: type=registry,ref=${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_NAME }}:buildcache
          cache-to: type=registry,ref=${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_NAME }}:buildcache,mode=max

      # 2. OCI-Archiv entpacken
      - name: Extract OCI Layout
        run: |
          mkdir -p ./oci-image
          tar -xf ./oci-image.tar -C ./oci-image
          rm ./oci-image.tar

    # 3. OCI-Image mit Chunkah verarbeiten (Binary via Docker-Container extrahieren)
      - name: Process OCI Image with Chunkah
        run: |
          # 1. Fertiges Binary aus dem offiziellen Quay.io-Image auf den Runner kopieren
          docker create --name temp-chunkah quay.io/coreos/chunkah:latest
          docker cp temp-chunkah:/usr/bin/chunkah /tmp/chunkah
          docker rm temp-chunkah
          chmod +x /tmp/chunkah

          # 2. Chunkah nativ auf dem OCI-Ordner ausführen (ohne Container-Layer)
          /tmp/chunkah chunk --max-layers =128 ./oci-image

      # 4. Skopeo nativ installieren
      - name: Install Skopeo
        if: github.event_name != 'pull_request'
        run: |
          sudo apt-get update && sudo apt-get install -y skopeo

      # 5. Gechunketes Image mit Skopeo pushen & Digest erfassen
      - name: Push Chunked Image via Skopeo
        if: github.event_name != 'pull_request'
        run: |
          echo "${{ secrets.REGISTRY }}" | skopeo login "${{ env.REGISTRY_HOST }}" -u "${{ github.repository_owner }}" --password-stdin

          for TAG_REF in ${{ steps.metadata.outputs.tags }}; do
            echo "Pushe gechunketes Image nach: docker://${TAG_REF}"
            skopeo copy \
              --dest-compress-format zstd:chunked \
              --digestfile /tmp/digest.txt \
              oci:./oci-image "docker://${TAG_REF}"
          done

          echo "IMAGE_DIGEST=$(cat /tmp/digest.txt)" >> ${GITHUB_ENV}

      - name: Install envsubst dependencies
        if: github.event_name != 'pull_request' && env.IS_TEST_BUILD == 'false'
        run: |
          sudo apt-get update && sudo apt-get install -y gettext

      - name: Install Cosign
        if: github.event_name != 'pull_request' && env.IS_TEST_BUILD == 'false'
        uses: sigstore/cosign-installer@v4.1.2

      # 6. Container Image signieren (nutzt direkt den von Skopeo erzeugten Digest)
      - name: Sign container image
        if: github.event_name != 'pull_request' && env.IS_TEST_BUILD == 'false'
        env:
          COSIGN_PRIVATE_KEY: ${{ secrets.SIGNING_SECRET }}
          COSIGN_PASSWORD: ""
        run: |
          echo "${{ secrets.REGISTRY }}" | cosign login "${{ env.REGISTRY_HOST }}" -u "${{ github.repository_owner }}" --password-stdin
          
          IMAGE_REF="${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_NAME }}@${{ env.IMAGE_DIGEST }}"
          echo "Signiere Manifest via Digest: ${IMAGE_REF}"
          
          cosign sign -y \
            --key env://COSIGN_PRIVATE_KEY \
            --recursive \
            --use-signing-config=false \
            --new-bundle-format=false \
            --registry-referrers-mode=legacy \
            "${IMAGE_REF}"
          
      - name: Post-Build Cleanup
        if: always()
        run: |
          echo "Räume temporäre Dateien und Buildx-Cache auf..."
          rm -rf ./oci-image /tmp/digest.txt || true
          docker buildx prune -a -f || true