name: Docker

on:
  push:
    branches: [main]
    tags: ["v*.*.*"]
  pull_request:
    branches: [main]
  # Manual republish (e.g. base-image refresh without a version bump).
  # Must be dispatched FROM A TAG REF: metadata-action only derives semver
  # image tags from the git tag, so a branch dispatch is rejected below.
  workflow_dispatch:

permissions:
  contents: read

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: ${{ github.event_name == 'pull_request' }}

jobs:
  # Fail fast with a clear message instead of silently pushing a bare
  # `latest` (or nothing) when someone dispatches from a branch.
  guard-dispatch:
    if: github.event_name == 'workflow_dispatch' && !startsWith(github.ref, 'refs/tags/v')
    runs-on: ubuntu-latest
    steps:
      - run: |
          echo "::error::Manual runs must be dispatched from a v*.*.* tag ref (use the 'Run workflow' ref selector). Branch refs produce no semver image tags."
          exit 1

  # Catch tag/code drift before anything is published (root.go has drifted
  # from tags before).
  verify-version:
    if: startsWith(github.ref, 'refs/tags/v')
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Check tag matches cmd/root.go version
        run: |
          TAG_VERSION="${GITHUB_REF_NAME#v}"
          CODE_VERSION=$(sed -nE 's/^[[:space:]]*version[[:space:]]*=[[:space:]]*"([0-9]+\.[0-9]+\.[0-9]+)".*/\1/p' cmd/root.go)
          echo "tag=v${TAG_VERSION} code=${CODE_VERSION}"
          if [ "$TAG_VERSION" != "$CODE_VERSION" ]; then
            echo "::error::Git tag v${TAG_VERSION} does not match version \"${CODE_VERSION}\" in cmd/root.go. Bump cmd/root.go before tagging."
            exit 1
          fi

  # PR / main validation: build only, single platform (multi-arch under QEMU
  # roughly doubles CI time for no extra signal; tag builds cover arm64).
  build:
    if: github.event_name == 'pull_request' || (github.event_name == 'push' && github.ref == 'refs/heads/main')
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4

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

      - name: Build (no push)
        uses: docker/build-push-action@v6
        with:
          context: .
          platforms: linux/amd64
          push: false
          cache-from: type=gha
          cache-to: type=gha,mode=max

  # Publish on version tags (and manual dispatch from a tag ref).
  # No fork-secrets concern: this never runs for pull_request events.
  publish:
    if: startsWith(github.ref, 'refs/tags/v')
    needs: verify-version
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v3

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

      - name: Log in to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      # `latest` is applied automatically on semver tags (latest=auto).
      # Caveat: it follows the most recently pushed tag, not the highest
      # version — we only tag forward, never backport.
      - name: Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: karust/openserp
          tags: |
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}

      # The pinned chromedp/headless-shell digest is a multi-arch OCI index
      # (amd64 + arm64/v8), and the builder stage cross-compiles via
      # $BUILDPLATFORM, so only the small final-stage apt layer runs under QEMU.
      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          context: .
          platforms: linux/amd64,linux/arm64
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max