name: Docker Images Builder

on:
  workflow_dispatch:
    inputs:
      gh_ref:
        description: 'Name of the branch or ref'
        type: string
        required: true
        default: 'develop'
  workflow_call:
    inputs:
      gh_ref:
        description: 'Name of the branch or ref'
        type: string
        required: true
        default: 'develop'

concurrency:
  group: ${{ github.workflow }}-${{ inputs.gh_ref }}
  cancel-in-progress: true

env:
  ALL_IMAGES: backend frontend exporter storybook mcp
  # All runner instances live on the same server, so the bundle is
  # downloaded from S3 once and shared between build jobs through this
  # host-local directory. Each build job falls back to S3 if the file is
  # missing (e.g. if runners ever move to separate machines).
  BUNDLE_CACHE: /var/tmp/penpot-bundle-cache

jobs:
  # ── 1. Resolve the build key and check the whole set at once ───────────
  prepare:
    name: Prepare
    runs-on: penpot-runner-02
    timeout-minutes: 15
    outputs:
      gh_ref: ${{ steps.vars.outputs.gh_ref }}
      bundle_version: ${{ steps.vars.outputs.bundle_version }}
      build_key: ${{ steps.vars.outputs.build_key }}
      exists: ${{ steps.check.outputs.exists }}

    steps:
      - name: Checkout code
        uses: actions/checkout@v6
        with:
          ref: ${{ inputs.gh_ref }}

      - name: Extract some useful variables
        id: vars
        env:
          AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
          AWS_DEFAULT_REGION: ${{ secrets.AWS_REGION }}
        run: |
          GH_REF="${{ inputs.gh_ref || github.ref_name }}"
          echo "gh_ref=$GH_REF" >> $GITHUB_OUTPUT

          BUNDLE_VERSION=$(aws s3api head-object \
            --bucket ${{ secrets.S3_BUCKET }} \
            --key "penpot-$GH_REF.zip" \
            --query 'Metadata."bundle-version"' \
            --output text)
          echo "bundle_version=$BUNDLE_VERSION" >> $GITHUB_OUTPUT

          # Image content = bundle + docker build context, so the build key
          # combines both.
          CTX_HASH=$(git rev-parse "HEAD:docker/images" | cut -c1-12)
          echo "build_key=${BUNDLE_VERSION}-${CTX_HASH}" >> $GITHUB_OUTPUT

      # The image set is a single block, so a single set-level check is
      # enough: `promote` drops a marker object in S3 only after every
      # image was built AND every branch tag was moved. Marker present
      # means there is nothing at all to do for this build key.
      - name: Check if this image set is already built
        id: check
        env:
          AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
          AWS_DEFAULT_REGION: ${{ secrets.AWS_REGION }}
        run: |
          if aws s3api head-object \
               --bucket ${{ secrets.S3_BUCKET }} \
               --key "markers/images-${{ steps.vars.outputs.build_key }}" \
               > /dev/null 2>&1; then
            echo "exists=true" >> $GITHUB_OUTPUT
            {
              echo "### ⏭️ Image set build skipped"
              echo ""
              echo "The whole set was already built and promoted for \`${{ steps.vars.outputs.build_key }}\`."
            } >> "$GITHUB_STEP_SUMMARY"
          else
            echo "exists=false" >> $GITHUB_OUTPUT

            # Stage the bundle in the host-local cache, once, for all the
            # build jobs. Download to a temp name and mv for atomicity;
            # prune stale bundles while at it.
            mkdir -p "$BUNDLE_CACHE"
            find "$BUNDLE_CACHE" -type f -mtime +1 -delete || true
            ZIP="$BUNDLE_CACHE/penpot-${{ steps.vars.outputs.build_key }}.zip"
            if [ ! -f "$ZIP" ]; then
              aws s3 cp "s3://${{ secrets.S3_BUCKET }}/penpot-${{ steps.vars.outputs.gh_ref }}.zip" "$ZIP.$$.tmp"
              mv "$ZIP.$$.tmp" "$ZIP"
            fi
          fi

  # ── 2. One build per image, in parallel, only when needed ──────────────
  build:
    name: Build ${{ matrix.image }}
    runs-on: penpot-runner-02
    timeout-minutes: 60
    needs: prepare
    if: needs.prepare.outputs.exists == 'false'
    strategy:
      fail-fast: true
      # 4 runner slots are available for build jobs on this server; cap the
      # matrix at 3 so short jobs (prepare and other workflows' checks)
      # never queue behind long builds.
      max-parallel: 3
      matrix:
        image: [backend, frontend, exporter, storybook, mcp]

    steps:
      - name: Set common environment variables
        run: |
          # Each job execution will use its own docker configuration.
          echo "DOCKER_CONFIG=${{ runner.temp }}/.docker-${{ github.run_id }}-${{ github.job }}-${{ matrix.image }}" >> $GITHUB_ENV

      - name: Checkout code
        uses: actions/checkout@v6
        with:
          ref: ${{ inputs.gh_ref }}

      - name: Login to Docker Registry
        uses: docker/login-action@v4
        with:
          registry: ${{ secrets.DOCKER_REGISTRY }}
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}

      # To avoid the “429 Too Many Requests” error when downloading
      # images from DockerHub for unregistered users.
      # https://docs.docker.com/docker-hub/usage/
      - name: Login to DockerHub Registry
        uses: docker/login-action@v4
        with:
          username: ${{ secrets.PUB_DOCKER_USERNAME }}
          password: ${{ secrets.PUB_DOCKER_PASSWORD }}

      # Images now build FROM Docker Hardened Images (dhi.io). DHI
      # is free (Apache 2.0, no subscription), but pulling from it
      # still requires an authenticated login -- a separate `docker
      # login` against a different registry host, even though it
      # reuses the same PUB_DOCKER_* credentials as the DockerHub
      # login above.
      - name: Login to Docker Hardened Images registry (base image pull)
        uses: docker/login-action@v4
        with:
          registry: dhi.io
          username: ${{ secrets.PUB_DOCKER_USERNAME }}
          password: ${{ secrets.PUB_DOCKER_PASSWORD }}

      # Bundle staged once by `prepare` on this host; the S3 fallback only
      # triggers if the cache is unavailable (runners on another machine,
      # cache pruned mid-run, ...).
      - name: Prepare Penpot bundle
        env:
          AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
          AWS_DEFAULT_REGION: ${{ secrets.AWS_REGION }}
        run: |
          ZIP="$BUNDLE_CACHE/penpot-${{ needs.prepare.outputs.build_key }}.zip"
          if [ ! -f "$ZIP" ]; then
            echo "Bundle not found in host cache; falling back to S3."
            mkdir -p "$BUNDLE_CACHE"
            aws s3 cp "s3://${{ secrets.S3_BUCKET }}/penpot-${{ needs.prepare.outputs.gh_ref }}.zip" "$ZIP.$$.tmp"
            mv "$ZIP.$$.tmp" "$ZIP"
          fi
          # Extract only the bundle this job needs.
          pushd docker/images
          unzip -q "$ZIP" "penpot/${{ matrix.image }}/*"
          mv "penpot/${{ matrix.image }}" "bundle-${{ matrix.image }}"
          popd

      - name: Set up QEMU (stable)
        uses: docker/setup-qemu-action@v4
        with:
          platforms: linux/amd64,linux/arm64

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

      - name: Extract metadata (tags, labels)
        id: meta
        uses: docker/metadata-action@v6
        with:
          images: ${{ matrix.image }}
          labels: |
            bundle_version=${{ needs.prepare.outputs.bundle_version }}

      - name: Build and push Docker image
        uses: docker/build-push-action@v7
        with:
          context: ./docker/images/
          file: ./docker/images/Dockerfile.${{ matrix.image }}
          platforms: linux/amd64,linux/arm64
          push: true
          provenance: mode=max
          sbom: true
          # Immutable tag only; branch tags are moved atomically for the
          # whole image set by the `promote` job.
          tags: ${{ secrets.DOCKER_REGISTRY }}/${{ matrix.image }}:build-${{ needs.prepare.outputs.build_key }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=registry,ref=${{ secrets.DOCKER_REGISTRY }}/${{ matrix.image }}:buildcache
          cache-to: type=registry,ref=${{ secrets.DOCKER_REGISTRY }}/${{ matrix.image }}:buildcache,mode=max

  # ── 3. Move the branch tags of ALL images together ─────────────────────
  # Runs only when every build succeeded (default `needs` semantics); if
  # the set was already complete, `build` is skipped and so is this job —
  # the S3 marker guarantees the branch tags were already moved.
  promote:
    name: Promote image set
    runs-on: penpot-runner-02
    timeout-minutes: 10
    needs: [prepare, build]

    steps:
      - name: Set common environment variables
        run: |
          echo "DOCKER_CONFIG=${{ runner.temp }}/.docker-${{ github.run_id }}-${{ github.job }}" >> $GITHUB_ENV

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

      - name: Login to Docker Registry
        uses: docker/login-action@v4
        with:
          registry: ${{ secrets.DOCKER_REGISTRY }}
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}

      - name: Point branch tags to the new build key
        run: |
          set -e
          for image in $ALL_IMAGES; do
            docker buildx imagetools create \
              -t "${{ secrets.DOCKER_REGISTRY }}/$image:${{ needs.prepare.outputs.gh_ref }}" \
              "${{ secrets.DOCKER_REGISTRY }}/$image:build-${{ needs.prepare.outputs.build_key }}"
          done

      # The marker is written LAST: its presence certifies that all five
      # images exist and all branch tags point to this build key.
      - name: Write set-completed marker
        env:
          AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
          AWS_DEFAULT_REGION: ${{ secrets.AWS_REGION }}
        run: |
          echo "${{ github.run_id }}" | aws s3 cp - \
            "s3://${{ secrets.S3_BUCKET }}/markers/images-${{ needs.prepare.outputs.build_key }}"
          {
            echo "### ✅ Image set promoted"
            echo ""
            echo "All \`:${{ needs.prepare.outputs.gh_ref }}\` tags now point to \`build-${{ needs.prepare.outputs.build_key }}\`."
          } >> "$GITHUB_STEP_SUMMARY"

  # ── 4. Single failure notification for the whole workflow ─────────────
  notify:
    name: Notify failure
    runs-on: penpot-runner-02
    timeout-minutes: 5
    needs: [prepare, build, promote]
    if: failure()

    steps:
      - name: Notify Mattermost
        uses: mattermost/action-mattermost-notify@ae31bb6f9e26a54336e79696f108a2c91cf55b4e # v2.1.0
        with:
          MATTERMOST_WEBHOOK_URL: ${{ secrets.MATTERMOST_WEBHOOK }}
          MATTERMOST_CHANNEL: bot-alerts-cicd
          TEXT: |
            ❌ 🐳 *[PENPOT] Error building/promoting the penpot docker image set.*
            📄 Triggered from ref: `${{ needs.prepare.outputs.gh_ref || inputs.gh_ref }}`
            📦 Bundle: `${{ needs.prepare.outputs.bundle_version || 'n/a' }}`
            🔗 Run: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}
            @infra