name: Build container image

on:
  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:

      # ------------------------------------------------------------
      # Environment
      # ------------------------------------------------------------

      - name: Prepare environment
        run: |
          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}"

      # ------------------------------------------------------------
      # Image tag
      # ------------------------------------------------------------

      - 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

      # ------------------------------------------------------------
      # Checkout
      # ------------------------------------------------------------

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

      # ------------------------------------------------------------
      # Buildx
      # ------------------------------------------------------------

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

      # ------------------------------------------------------------
      # Image metadata
      # ------------------------------------------------------------

      - 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

      # ------------------------------------------------------------
      # Registry login
      # ------------------------------------------------------------

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

      # ------------------------------------------------------------
      # Prepare OCI output
      # ------------------------------------------------------------

      - name: Prepare OCI archive
        run: |
          rm -rf "${{ github.workspace }}/oci-layout.tar"

      # ------------------------------------------------------------
      # Build image
      # ------------------------------------------------------------

      - name: Build Image (Docker Buildx OCI-Export)
        uses: docker/build-push-action@v7.3.0
        id: build_image
        with:
          context: .
          file: ./Containerfile

          push: false
          pull: true

          tags: ${{ steps.metadata.outputs.tags }}
          labels: ${{ steps.metadata.outputs.labels }}

          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

          outputs: type=oci,dest=${{ github.workspace }}/oci-layout.tar,tar=true

      # ------------------------------------------------------------
      # Install Skopeo
      # ------------------------------------------------------------

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

      # ------------------------------------------------------------
      # Push image via Skopeo
      # ------------------------------------------------------------

      - name: Push Image via Skopeo (zstd:chunked)
        if: github.event_name != 'pull_request'
        run: |
          set -e

          TAGS="${{ steps.metadata.outputs.tags }}"

          for TAG in $TAGS; do
            echo "Pushe ${TAG} via Skopeo mit zstd:chunked..."

            skopeo copy \
              --dest-creds "${{ github.repository_owner }}:${{ secrets.REGISTRY }}" \
              --dest-compress-format zstd:chunked \
              "oci-archive:${{ github.workspace }}/oci-layout.tar" \
              "docker://${TAG}"
          done

      # ------------------------------------------------------------
      # Install envsubst
      # ------------------------------------------------------------

      - 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

      # ------------------------------------------------------------
      # Install Cosign
      # ------------------------------------------------------------

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

      # ------------------------------------------------------------
      # Sign image
      # ------------------------------------------------------------

      - name: Sign container image (Recursive Digest)
        if: github.event_name != 'pull_request' && env.IS_TEST_BUILD == 'false'
        env:
          COSIGN_PRIVATE_KEY: ${{ secrets.SIGNING_SECRET }}
          COSIGN_PASSWORD: ""
        run: |
          set -e

          echo "${{ secrets.REGISTRY }}" \
            | cosign login "${{ env.REGISTRY_HOST }}" \
                -u "${{ github.repository_owner }}" \
                --password-stdin

          echo "Frage finalen Registry-Digest via Skopeo ab..."

          OUTER_DIGEST=$(
            skopeo inspect \
              --creds "${{ github.repository_owner }}:${{ secrets.REGISTRY }}" \
              "docker://${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_NAME }}:stable" \
              | jq -r .Digest
          )

          echo "Registry digest: ${OUTER_DIGEST}"

          IMAGE_REF="${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_NAME }}@${OUTER_DIGEST}"

          echo "Signiere Image rekursiv:"
          echo "${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}"

      # ------------------------------------------------------------
      # Cleanup
      # ------------------------------------------------------------

      - name: Post-Build Cleanup
        if: always()
        run: |
          echo "Räume temporäre Dateien und Buildx-Cache auf..."

          rm -f "${{ github.workspace }}/oci-layout.tar"

          docker buildx prune -a -f || true