name: Release image

# Builds and pushes the multi-arch image to GHCR, the registry the installer
# defaults to.
#
# The Gitea registry is on a VPN, which a GitHub runner can never reach, so CI
# does not touch it at all: `scripts/mirror-gitea.sh` copies a release into it
# from the VPN side, in parallel and after the fact. Keeping the two apart is
# what makes a registry outage unable to fail a release.
on:
  release:
    types: [published]
  workflow_dispatch:

permissions:
  contents: read
  packages: write

concurrency:
  group: release-image
  cancel-in-progress: false

jobs:
  image:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - uses: docker/setup-qemu-action@v3

      - uses: docker/setup-buildx-action@v3

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

      # The version the app reports on Settings > General when the build
      # isn't a published release.
      - name: Read the source version
        id: source
        run: |
          set -euo pipefail
          echo "version=$(sed -n -E 's/^[[:space:]]*"version": "([^"]+)",?$/\1/p' package.json | head -n1)" >> "$GITHUB_OUTPUT"

      # The same four tags for every kind of build: a release gets its own
      # version plus the moving `latest` and `major.minor`, so that
      # scripts/mirror-gitea.sh can copy whichever of them still belong to
      # it, and a dispatch build gets the commit tag only, since it is not a
      # release and must not move `latest`.
      - name: Work out image tags
        id: tags
        env:
          EVENT: ${{ github.event_name }}
          RELEASE_TAG: ${{ github.event.release.tag_name }}
          SOURCE_VERSION: ${{ steps.source.outputs.version }}
        run: |
          set -euo pipefail
          sha="sha-${GITHUB_SHA::12}"
          if [ "$EVENT" = "release" ] && [ -n "$RELEASE_TAG" ]; then
            version="$RELEASE_TAG"
            minor="$(printf '%s' "$version" | sed -E 's/^v?([0-9]+)\.([0-9]+).*/\1.\2/')"
            tags="$(printf '%s\n' \
              "ghcr.io/moduletrace/cobble:latest" \
              "ghcr.io/moduletrace/cobble:${version}" \
              "ghcr.io/moduletrace/cobble:${minor}" \
              "ghcr.io/moduletrace/cobble:${sha}")"
          else
            version="$SOURCE_VERSION"
            tags="ghcr.io/moduletrace/cobble:${sha}"
          fi
          {
            echo "version=$version"
            echo "tags<<EOF"
            echo "$tags"
            echo "EOF"
          } >> "$GITHUB_OUTPUT"

      # The only push CI makes. The installer defaults to this registry, so
      # this step failing has to fail the release.
      - name: Build and push to GHCR
        uses: docker/build-push-action@v6
        with:
          context: .
          file: ./Dockerfile
          platforms: linux/amd64,linux/arm64
          push: true
          build-args: |
            COBBLE_VERSION=${{ steps.tags.outputs.version }}
          tags: ${{ steps.tags.outputs.tags }}
          provenance: false
          sbom: false
          cache-from: type=gha
          cache-to: type=gha,mode=max