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: |
          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@v4.2.2

      - name: Image Metadata
        id: metadata
        uses: docker/metadata-action@v5.7.0
        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 }}//raw/commit/${{ github.sha }}/README.md
            org.opencontainers.image.source=${{ github.server_url }}/${{ github.repository }}/src/commit/${{ github.sha }}/Containerfile
            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: Build and Push Image (Buildah unprivileged)
        id: build_image
        run: |
          # Metadaten in Dateien schreiben, damit sie im Tar-Stream landen
          cat << 'EOF' > labels.txt
          ${{ steps.metadata.outputs.labels }}
          EOF

          cat << 'EOF' > tags.txt
          ${{ steps.metadata.outputs.tags }}
          EOF

          # Buildah-Container starten und Image im RAM-Dateisystem bauen
          BUILD_OUTPUT=$(tar -cf - . | docker run -i --rm \
            --cap-add=SYS_ADMIN \
            --security-opt seccomp=unconfined \
            --security-opt apparmor=unconfined \
            --security-opt label=disable \
            --tmpfs /var/lib/containers:exec \
            --ulimit nofile=1048576:1048576 \
            quay.io/buildah/stable:latest \
            bash -c '
              mkdir /src && tar -xf - -C /src

              # Labels sauber in ein Bash-Array einlesen (verhindert Escaping-Fehler)
              declare -a LABEL_ARGS
              while IFS= read -r line || [ -n "$line" ]; do
                [ -z "$line" ] && continue
                LABEL_ARGS+=("--label" "$line")
              done < /src/labels.txt

              FIRST_TAG=$(head -n 1 /src/tags.txt)

              # 1. Image mit den dynamischen OCI-Labels bauen
              buildah --storage-driver=vfs --isolation=chroot bud \
                "${LABEL_ARGS[@]}" \
                -t "$FIRST_TAG" \
                -f /src/Containerfile /src

              # 2. Wenn kein PR, direkt aus Buildah in die Gitea-Registry pushen
              if [ "${{ github.event_name }}" != "pull_request" ]; then
                PUSH_OUT=$(buildah --storage-driver=vfs push --creds "${{ github.repository_owner }}:${{ secrets.REGISTRY }}" "$FIRST_TAG" "docker://$FIRST_TAG")
                echo "$PUSH_OUT"

                # Alle weiteren von metadata-action generierten Tags pushen
                while IFS= read -r tag || [ -n "$tag" ]; do
                  [ -z "$tag" ] && continue
                  if [ "$tag" != "$FIRST_TAG" ]; then
                    buildah --storage-driver=vfs tag "$FIRST_TAG" "$tag"
                    buildah --storage-driver=vfs push --creds "${{ github.repository_owner }}:${{ secrets.REGISTRY }}" "$tag" "docker://$tag"
                  fi
                done < /src/tags.txt

                # Den echten Image-Digest aus den Push-Logs für Cosign extrahieren
                DIGEST=$(echo "$PUSH_OUT" | grep -oE "sha256:[a-f0-9]{64}" | tail -n 1)
                echo "CONTAINER_DIGEST=${DIGEST}"
              fi
            ')

          # Log-Ausgabe für das Gitea Actions UI
          echo "$BUILD_OUTPUT"

          # Digest an den Runner-Schritt übergeben, falls gepusht wurde
          if [ "${{ github.event_name }}" != "pull_request" ]; then
            IMAGE_DIGEST=$(echo "$BUILD_OUTPUT" | grep "CONTAINER_DIGEST=" | cut -d= -f2)
            echo "digest=${IMAGE_DIGEST}" >> $GITHUB_OUTPUT
          fi

      - name: Install gettext (provides envsubst)
        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 via official Action
        if: github.event_name != 'pull_request' && env.IS_TEST_BUILD == 'false'
        uses: sigstore/cosign-installer@v4.1.2

      - name: Sign container image
        if: github.event_name != 'pull_request' && env.IS_TEST_BUILD == 'false'
        env:
          COSIGN_PRIVATE_KEY: ${{ secrets.SIGNING_SECRET }}
          COSIGN_PASSWORD: ""
        run: |
          # 1. Cosign an der Gitea-Registry anmelden
          cosign login "${{ env.REGISTRY_HOST }}" -u "${{ github.repository_owner }}" -p "${{ secrets.REGISTRY }}"

          # 2. Den reinen Digest aus dem Buildah-Schritt holen
          IMAGE_DIGEST="${{ steps.build_image.outputs.digest }}"
          IMAGE_REF="${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_NAME }}@${IMAGE_DIGEST}"

          echo "Signiere exklusiv via Digest: ${IMAGE_REF}"

          # 3. Signierung ausführen
          cosign sign -y \
            --key env://COSIGN_PRIVATE_KEY \
            --use-signing-config=false \
            --new-bundle-format=false \
            --tlog-upload=false \
            --registry-referrers-mode=legacy \
            "${IMAGE_REF}"