name: Docker image

# Phase 5 / spec §15.5 — multi-arch image builds.
#
# Pushes to ghcr.io on release tags and when invoked by release automation.

on:
  workflow_call:
    inputs:
      ref:
        description: "Git ref to build when invoked as a reusable workflow."
        required: false
        type: string
        default: ""
      release_version:
        description: "Stable Docker tag to publish when invoked from release automation."
        required: false
        type: string
        default: ""
      publish_latest:
        description: "Whether to also publish :latest when invoked from release automation."
        required: false
        type: boolean
        default: false
  push:
    tags: ['v*.*.*']

jobs:
  build-and-push:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
      id-token: write
    steps:
      - name: Check out repository
        uses: actions/checkout@v4
        with:
          ref: ${{ inputs.ref || github.sha }}

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v3
        with:
          platforms: linux/amd64,linux/arm64

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

      - name: Log in to GitHub Container Registry
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ghcr.io/${{ github.repository_owner }}/od
          # spec §15.1 tag scheme:
          #   - vX.Y.Z push             → :X.Y.Z + :latest
          #   - workflow_call (stable)  → :<release_version> + optional :latest
          tags: |
            type=semver,pattern={{version}}
            type=raw,value=${{ inputs.release_version }},enable=${{ inputs.release_version != '' }}
            type=raw,value=latest,enable=${{ startsWith(github.ref, 'refs/tags/v') }}
            type=raw,value=latest,enable=${{ inputs.publish_latest == true }}

      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          context: .
          file: deploy/Dockerfile
          # spec §15.1 — multi-arch single manifest
          platforms: linux/amd64,linux/arm64
          # Tags and release workflow calls publish.
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          # The in-tree Dockerfile uses node:24-alpine + apk for build
          # tooling; we keep that default so the workflow doesn't drift
          # from local builds. Spec §15.1 nominates bookworm-slim as
          # the canonical base; switching is a follow-up that needs
          # the Dockerfile's apk lines re-cast for apt.
          cache-from: type=gha
          cache-to: type=gha,mode=max