# Build and publish per-channel container images to GHCR.
#
# WHY this exists: pilot dev workstations sit behind an inspecting proxy
# (Zscaler) that resets npm's many small fetches mid-install, so building the
# image FROM SOURCE on a pilot box is unreliable. These runners
# (arc-runner-set) install npm cleanly - the CI `frontend` job already proves
# it - so we build the image ONCE here and pilots pull the finished image.
# A single image pull is one resumable HTTPS stream, far more robust through
# the proxy than hundreds of npm requests.
#
# Channels are mapped to how THIS repo actually ships, which is not how the
# branch this came from ships. Upstream, main is a release branch and dev-be is
# the trunk. Here main IS the trunk - it runs hundreds of commits past the last
# release - and releases are tags (ADR-007). Publishing main as :stable would
# put unreleased work behind a word that promises the opposite, to sites that
# have no way to know:
#
#   tag v*  -> ghcr.io/<owner>/shopdb-flask:stable  (badge off)  the release
#   main    -> ghcr.io/<owner>/shopdb-flask:edge    (DEV badge)  the trunk
#
# The image also carries a short-SHA tag for traceability and rollback.
#
# Automatic publishing is OFF until someone confirms the GHCR package exists
# under this owner and decides who may pull it. Re-enable by uncommenting the
# push: block below; workflow_dispatch works meanwhile.

name: publish-images

on:
  # push:
  #   tags:
  #     - 'v*'
  #   branches:
  #     - main
  # Manual rebuild/publish of the current ref's channel image.
  workflow_dispatch:

# One in-flight publish per branch; a newer push supersedes an older one.
concurrency:
  group: publish-images-${{ github.ref }}
  cancel-in-progress: true

jobs:
  build-and-push:
    runs-on: arc-runner-set
    permissions:
      contents: read
      packages: write
    steps:
      - uses: actions/checkout@v5

      # Lowercase the owner: GHCR repository paths must be lowercase, but
      # github.repository_owner can carry uppercase (e.g. ge-aero is fine, but
      # this keeps the workflow correct for any owner casing).
      - name: Resolve image name and channel tag
        id: meta
        run: |
          owner="$(echo '${{ github.repository_owner }}' | tr '[:upper:]' '[:lower:]')"
          image="ghcr.io/${owner}/shopdb-flask"
          # A tag is a release, anything else is the trunk. Deliberately not
          # keyed on the branch name: a release here is a tag, so keying on
          # "main" would label the trunk stable.
          if [ "${{ github.ref_type }}" = "tag" ]; then
            channel="stable"
          else
            channel="edge"
          fi
          echo "image=${image}" >> "$GITHUB_OUTPUT"
          echo "channel=${channel}" >> "$GITHUB_OUTPUT"
          echo "sha=$(git rev-parse --short HEAD)" >> "$GITHUB_OUTPUT"

      - name: Log in to GHCR
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Set up Buildx
        uses: docker/setup-buildx-action@v3

      - name: Build and push channel image
        uses: docker/build-push-action@v6
        with:
          context: .
          push: true
          tags: |
            ${{ steps.meta.outputs.image }}:${{ steps.meta.outputs.channel }}
            ${{ steps.meta.outputs.image }}:${{ steps.meta.outputs.channel }}-${{ steps.meta.outputs.sha }}
          # Reuse the channel tag as a cache source/target so subsequent builds
          # only redo layers that actually changed.
          cache-from: type=registry,ref=${{ steps.meta.outputs.image }}:${{ steps.meta.outputs.channel }}
          cache-to: type=inline