name: Container build + GHCR push

# Builds the root Dockerfile, generates an image SBOM, and pushes to GHCR:
#   * Pull-request:    build + smoke-test only (no push, no registry login).
#   * Push to main:    build + push SHA-tagged image to ghcr.io/szl-holdings/a11oy.
#   * Release published: push semver + latest tags, sign with cosign keyless.
#
# L1 fix (2026-05-31): REVISION build-arg is now passed as github.sha so that
# the runtime ENV A11OY_GIT_SHA is populated in the container and /healthz
# returns the real deployed SHA. Reference: red-team finding L1.
#
# Cosign keyless verification (no stored key; GitHub OIDC + Fulcio + Rekor):
#   cosign verify \
#     --certificate-identity-regexp \
#       "https://github.com/szl-holdings/a11oy/.github/workflows/docker-build.yml.*" \
#     --certificate-oidc-issuer https://token.actions.githubusercontent.com \
#     ghcr.io/szl-holdings/a11oy:<tag>
#
# References:
#   docker/build-push-action: https://github.com/docker/build-push-action
#   anchore/sbom-action:       https://github.com/anchore/sbom-action
#   cosign keyless:            https://docs.sigstore.dev/cosign/signing/overview/
#
# Authored for SZL Holdings. Signed-off per repository DCO.

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]
  release:
    types: [published]

permissions:
  contents: read

env:
  IMAGE: ghcr.io/szl-holdings/a11oy

jobs:
  build:
    name: Build image + SBOM (push on main + release)
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write       # push to GHCR on main and release
      id-token: write        # cosign keyless OIDC token
    steps:
      - name: Checkout
        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3.10.0

      - name: Derive image version and tags
        id: ver
        run: |
          SHA7="${GITHUB_SHA::7}"
          BUILD_DATE="$(date -u +%Y-%m-%dT%H:%M:%SZ)"
          if [ "${{ github.event_name }}" = "release" ]; then
            VERSION="${{ github.event.release.tag_name }}"
            TAGS="${{ env.IMAGE }}:${VERSION}
          ${{ env.IMAGE }}:latest
          ${{ env.IMAGE }}:sha-${SHA7}"
          elif [ "${{ github.event_name }}" = "push" ]; then
            VERSION="0.0.0-dev-${SHA7}"
            TAGS="${{ env.IMAGE }}:sha-${SHA7}"
          else
            VERSION="0.0.0-pr-${SHA7}"
            TAGS="${{ env.IMAGE }}:pr-${SHA7}"
          fi
          echo "version=${VERSION}"      >> "$GITHUB_OUTPUT"
          echo "sha7=${SHA7}"            >> "$GITHUB_OUTPUT"
          echo "build_date=${BUILD_DATE}" >> "$GITHUB_OUTPUT"
          # Multi-line value — use heredoc to avoid quoting issues.
          {
            echo "tags<<EOF"
            echo "${TAGS}"
            echo "EOF"
          } >> "$GITHUB_OUTPUT"

      # Log in on push-to-main and on release; skip for PRs.
      - name: Log in to GHCR
        if: github.event_name != 'pull_request'
        uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3.4.0
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Build image (push on main + release; load on PR)
        id: build
        uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4 # v6.15.0
        with:
          context: .
          file: Dockerfile
          build-args: |
            VERSION=${{ steps.ver.outputs.version }}
            REVISION=${{ github.sha }}
            BUILD_DATE=${{ steps.ver.outputs.build_date }}
          push: ${{ github.event_name != 'pull_request' }}
          load: ${{ github.event_name == 'pull_request' }}
          tags: ${{ steps.ver.outputs.tags }}
          cache-from: type=gha
          cache-to: type=gha,mode=max
          # FIX (Yachay, empire-reliability 2026-06-01): docker/build-push-action@v6
          # defaults to provenance:true, which exports an OCI attestation manifest.
          # Pushing that referrers index to ghcr.io/szl-holdings/* returns 403 Forbidden
          # on the attestation blob HEAD (org GHCR rejects the auto-created attestation
          # index). Image SBOM is already produced by the dedicated anchore/syft step,
          # so disabling buildx attestations is the root-cause fix, not a workaround.
          provenance: false
          sbom: false

      - name: Smoke test image (PR builds — loaded into local daemon)
        if: github.event_name == 'pull_request'
        run: |
          TAG="${{ env.IMAGE }}:pr-${{ steps.ver.outputs.sha7 }}"
          echo "=== --version ==="
          docker run --rm "${TAG}" --version
          echo "=== --help ==="
          docker run --rm "${TAG}" --help

      # FIX (Yachay, empire-reliability 2026-06-01): the SBOM step previously always
      # referenced the pushed main tag `:sha-<sha7>`. On pull_request builds the image
      # is NOT pushed to GHCR (push:false) — it is `load`ed into the local Docker daemon
      # under tag `:pr-<sha7>`. Syft therefore tried to pull `ghcr.io/.../a11oy:sha-<sha7>`
      # which does not exist for PRs and returned `unauthorized` (registry has no such
      # manifest + no PR login), failing every PR run. Root-cause fix: scan the
      # locally-loaded PR image on PRs and the pushed SHA tag on push-to-main.
      - name: Generate image SBOM (CycloneDX) via Syft — push to main
        if: github.event_name == 'push'
        uses: anchore/sbom-action@df80a981bc6edbc4e220a492d3cbe9f5547a6e75 # v0.17.9
        with:
          image: ${{ env.IMAGE }}:sha-${{ steps.ver.outputs.sha7 }}
          format: cyclonedx-json
          output-file: a11oy-image-sbom.cyclonedx.json
          upload-artifact: true

      - name: Generate image SBOM (CycloneDX) via Syft — PR (local image)
        if: github.event_name == 'pull_request'
        uses: anchore/sbom-action@df80a981bc6edbc4e220a492d3cbe9f5547a6e75 # v0.17.9
        with:
          image: ${{ env.IMAGE }}:pr-${{ steps.ver.outputs.sha7 }}
          format: cyclonedx-json
          output-file: a11oy-image-sbom.cyclonedx.json
          upload-artifact: true

      - name: Install cosign (release only)
        if: github.event_name == 'release'
        uses: sigstore/cosign-installer@dc72c7d5c4d10cd6bcb8cf6e3fd625a9e5e537da # v3.7.0

      - name: Sign image with cosign keyless (release only)
        if: github.event_name == 'release'
        env:
          COSIGN_EXPERIMENTAL: "1"
        run: |
          DIGEST="${{ steps.build.outputs.digest }}"
          cosign sign --yes "${{ env.IMAGE }}@${DIGEST}"
          echo "Signed ${{ env.IMAGE }}@${DIGEST} (keyless OIDC)."

      - name: Generate + attach image SBOM on release (signed)
        if: github.event_name == 'release'
        uses: anchore/sbom-action@df80a981bc6edbc4e220a492d3cbe9f5547a6e75 # v0.17.9
        with:
          image: ${{ env.IMAGE }}:${{ steps.ver.outputs.version }}
          format: cyclonedx-json
          output-file: a11oy-image-sbom.cyclonedx.json
          upload-artifact: true