name: Release

# Publishes the four service images to GHCR after a merge into main, and again
# under semver tags when a v* tag is pushed. The deploy host only pulls, so
# nothing has to be built on the server.
on:
  push:
    branches: [main]
    tags: ['v*']
  workflow_dispatch:

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

env:
  REGISTRY: ghcr.io

jobs:
  # Nothing is published unless the full suite passes first.
  ci:
    uses: ./.github/workflows/ci.yml

  # GHCR rejects an uppercase path, and this repository is "lucasrguerra/LambdaMail".
  # Lowercasing github.repository here keeps the workflow fork-safe instead of
  # hardcoding the owner.
  prepare:
    name: Namespace das imagens
    runs-on: ubuntu-latest
    outputs:
      namespace: ${{ steps.namespace.outputs.value }}
    steps:
      - id: namespace
        run: echo "value=${GITHUB_REPOSITORY,,}" >> "$GITHUB_OUTPUT"

  # Each architecture is built on a runner of its own kind. QEMU emulation
  # would also work, but it makes the Go and Next builds roughly an order of
  # magnitude slower.
  build:
    name: Build ${{ matrix.service }} (${{ matrix.platform }})
    needs: [ci, prepare]
    runs-on: ${{ matrix.runner }}
    permissions:
      contents: read
      packages: write
    strategy:
      fail-fast: false
      matrix:
        # Both are axes, so this is a cross product: four services on two
        # architectures is eight jobs. Declaring platform only under `include`
        # would not multiply anything - include can add keys to existing
        # combinations, but it cannot create the combinations themselves.
        service: [protocols, auth, storage, webmail]
        platform: [linux/amd64, linux/arm64]
        include:
          - platform: linux/amd64
            runner: ubuntu-latest
            arch: amd64
          - platform: linux/arm64
            runner: ubuntu-24.04-arm
            arch: arm64
    steps:
      - uses: actions/checkout@v4

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

      - name: Autentica no GHCR
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Metadados
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ needs.prepare.outputs.namespace }}/${{ matrix.service }}

      # Pushed by digest only: the tags are attached later, once both
      # architectures exist and can be joined into a single manifest list.
      - name: Build e push por digest
        id: build
        uses: docker/build-push-action@v6
        with:
          context: services/${{ matrix.service }}
          platforms: ${{ matrix.platform }}
          labels: ${{ steps.meta.outputs.labels }}
          outputs: type=image,name=${{ env.REGISTRY }}/${{ needs.prepare.outputs.namespace }}/${{ matrix.service }},push-by-digest=true,name-canonical=true,push=true
          cache-from: type=gha,scope=${{ matrix.service }}-${{ matrix.arch }}
          cache-to: type=gha,mode=max,scope=${{ matrix.service }}-${{ matrix.arch }}

      - name: Exporta o digest
        run: |
          mkdir -p /tmp/digests
          # The output already carries the `sha256:` prefix; the file name must
          # not, since the merge step prepends it again.
          digest='${{ steps.build.outputs.digest }}'
          touch "/tmp/digests/${digest#sha256:}"

      - name: Guarda o digest
        uses: actions/upload-artifact@v4
        with:
          # Slashes are not allowed in artifact names, hence the arch alias.
          name: digest-${{ matrix.service }}-${{ matrix.arch }}
          path: /tmp/digests/*
          retention-days: 1
          if-no-files-found: error

  publish:
    name: Publica ${{ matrix.service }}
    needs: [build, prepare]
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    strategy:
      fail-fast: false
      matrix:
        service: [protocols, auth, storage, webmail]
    steps:
      - uses: actions/checkout@v4

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

      - name: Autentica no GHCR
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Recupera os digests
        uses: actions/download-artifact@v4
        with:
          pattern: digest-${{ matrix.service }}-*
          merge-multiple: true
          path: /tmp/digests

      # `latest` is what compose pulls. The semver tags only materialise on a
      # v* tag push and make it possible to pin or roll back to an exact
      # release; the sha tag does the same for any main build.
      - name: Metadados
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ needs.prepare.outputs.namespace }}/${{ matrix.service }}
          tags: |
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=semver,pattern={{major}}
            type=raw,value=latest
            type=sha,format=long

      # Joins both architectures under one manifest list, so `docker pull`
      # resolves to the right one automatically.
      - name: Cria o manifesto multi-arquitetura
        working-directory: /tmp/digests
        run: |
          docker buildx imagetools create \
            $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< '${{ steps.meta.outputs.json }}') \
            $(printf '${{ env.REGISTRY }}/${{ needs.prepare.outputs.namespace }}/${{ matrix.service }}@sha256:%s ' *)

      - name: Confere o resultado
        run: |
          docker buildx imagetools inspect \
            "${{ env.REGISTRY }}/${{ needs.prepare.outputs.namespace }}/${{ matrix.service }}:latest" \
            --format '{{json .Manifest}}' \
            | jq -r '.manifests[] | select(.platform.os == "linux") | "\(.platform.os)/\(.platform.architecture)"'

      - name: Resumo
        run: |
          {
            echo "### ${{ matrix.service }} publicado (linux/amd64 e linux/arm64)"
            echo
            echo '```'
            echo "${{ steps.meta.outputs.tags }}"
            echo '```'
          } >> "$GITHUB_STEP_SUMMARY"