name: Build and Push Docker Image
description: >
    A reusable GitHub Action to build and push Docker images to a specified container registry.
inputs:
  registry:
    description: 'Container registry host (e.g., ghcr.io, docker.io)'
    required: true
  username:
    description: 'Username for the container registry'
    required: true
  password:
    description: 'Password or token for the container registry'
    required: true
  image_name:
    description: 'Name of the Docker image (e.g., myuser/myimage)'
    required: true
  context_path:
    description: 'Path to the build context'
    required: false
    default: '.'
  dockerfile_path:
    description: 'Path to the Dockerfile'
    required: false
    default: './Dockerfile'
  platforms:
    description: 'Target platforms for the Docker image (e.g., linux/amd64,linux/arm64)'
    required: false
    default: 'linux/amd64'
  cache_ref:
    description: 'Reference for build cache'
    required: false
    default: ''
  github_token:
    description: 'GitHub token for metadata extraction'
    required: true

runs:
  using: "composite"
  steps:
    - name: Checkout repository
      uses: actions/checkout@v5

    - name: Define branch helpers
      id: branch
      run: |
        DEFAULT="${{ github.event.repository.default_branch }}"
        CURRENT="${{ github.ref_name }}"
        if [ "$DEFAULT" = "$CURRENT" ]; then
          echo "is_default_branch=true" >> $GITHUB_OUTPUT
        else
          echo "is_default_branch=false" >> $GITHUB_OUTPUT
        fi

    - name: Extract Docker metadata
      id: meta
      uses: docker/metadata-action@v5
      with:
        github-token: ${{ inputs.github_token }}
        images: ${{ inputs.registry }}/${{ inputs.image_name }}
        tags: |
          type=ref,event=branch
          type=ref,event=tag
          type=sha
          type=raw,value=latest,enable=${{ steps.branch.outputs.is_default_branch }}

    - name: Set up QEMU  # for multi-platform builds
      uses: docker/setup-qemu-action@v3

    - name: Set up Docker Buildx  # for advanced builds
      uses: docker/setup-buildx-action@v3

    - name: Log in to registry
      uses: docker/login-action@v3
      with:
        registry: ${{ inputs.registry }}
        username: ${{ inputs.username }}
        password: ${{ inputs.password }}

    - name: Build and push Docker image
      uses: docker/build-push-action@v5
      with:
        context: ${{ inputs.context_path }}
        file: ${{ inputs.dockerfile_path }}
        push: true
        platforms: ${{ inputs.platforms }}
        tags: ${{ steps.meta.outputs.tags }}
        labels: ${{ steps.meta.outputs.labels }}
        cache-from: type=registry,ref=${{ inputs.cache_ref }}
        cache-to: type=registry,ref=${{ inputs.cache_ref }},mode=max

    - name: Image details
      run: |
        echo "Image pushed: ${{ inputs.registry }}/${{ inputs.image_name }}"
        echo "Labels: ${{ steps.meta.outputs.labels }}"
        echo "Tags: ${{ steps.meta.outputs.tags }}"
        echo "Digest: ${{ steps.meta.outputs.digest }}"