name: Docker Build

on:
  push:
    branches:
      - main
  release:
    types: published
  workflow_call:
    inputs:
      ref:
        description: 'Git reference'
        required: true
        type: string
      tag:
        description: 'Docker tag'
        required: true
        type: string

permissions:
  contents: read
  packages: write

jobs:
  build:
    name: Build Docker Image
    runs-on: ubuntu-24.04
    steps:
    - name: Define variables on push to `main`
      if: github.event_name == 'push'
      run: |
        {
          echo "CHECKOUT_REF=main"
          echo "DOCKER_TAG=latest"
          echo "OUTPUT_TYPE=type=registry"
        } >> "$GITHUB_ENV"
    - name: Define variables on release event
      if: github.event_name == 'release'
      run: |
        {
          echo "CHECKOUT_REF=${{ github.event.release.tag_name }}"
          echo "DOCKER_TAG=${{ github.event.release.tag_name }}"
          echo "OUTPUT_TYPE=type=registry"
        } >> "$GITHUB_ENV"
    - name: Define variables on workflow call
      if: github.event_name != 'push' && github.event_name != 'release'
      run: |
        {
          echo "CHECKOUT_REF=${{ inputs.ref }}"
          echo "DOCKER_TAG=${{ inputs.tag }}"
          echo "OUTPUT_TYPE=type=local,dest=artifacts"
        } >> "$GITHUB_ENV"
    - uses: actions/checkout@v4
      with:
        ref: ${{ env.CHECKOUT_REF }}
    - name: Set lowercase repository name
      run: echo "REPOSITORY_LC=${REPOSITORY,,}" >> "$GITHUB_ENV"
      env:
        REPOSITORY: ${{ github.repository }}
    - name: Set up Docker Buildx
      uses: docker/setup-buildx-action@v3
    - name: Login to GitHub registry
      uses: docker/login-action@v3
      with:
        username: ${{ github.actor }}
        password: ${{ secrets.GITHUB_TOKEN }}
        registry: ghcr.io
    - uses: docker/build-push-action@v6
      with:
        context: .
        tags: ghcr.io/${{ env.REPOSITORY_LC }}:${{ env.DOCKER_TAG }}
        platforms: linux/amd64
        outputs: ${{ env.OUTPUT_TYPE }}
    - name: Rename binary artifact
      if: contains(env.OUTPUT_TYPE, 'local')
      run: mv artifacts/usr/bin/swiftlint artifacts/usr/bin/swiftlint_linux_amd64
    - name: Upload binary artifact
      if: contains(env.OUTPUT_TYPE, 'local')
      uses: actions/upload-artifact@v4
      with:
        name: swiftlint_linux_amd64
        path: artifacts/usr/bin/swiftlint_linux_amd64
        if-no-files-found: error
        retention-days: 2