name: Docker Build + Push
description: Build and push Docker images for Gitea Actions using the docker daemon at DOCKER_HOST
author: eric

inputs:
  dockerfile:
    description: Path to Dockerfile (relative to build context)
    default: Dockerfile
  context:
    description: Build context path (relative to repo root)
    default: .
  image-name:
    description: Full image name (e.g. registry/image or image)
    required: true
  tags:
    description: Additional tags as CSV appended to defaults
    default: ""
  registry:
    description: Docker registry for login (e.g. ghcr.io)
    default: ""
  registry-username:
    description: Docker registry username
    default: ""
  registry-password:
    description: Docker registry password (use secrets.DOCKER_PASSWORD)
    default: ""
  push:
    description: Push images to registry after build
    default: "false"
  build-args:
    description: Build args as CSV KEY=VALUE
    default: ""

outputs:
  image:
    description: Full image name with tag
    value: ${{ steps.meta.outputs.image }}
  tag:
    description: The primary tag used (date-SHA)
    value: ${{ steps.meta.outputs.tag }}
  digest:
    description: Image digest (only available after push)
    value: ${{ steps.push-digest.outputs.digest }}

runs:
  using: composite
  env:
    DOCKER_HOST: tcp://docker.local:2375
    DOCKER_BUILDKIT: "1"

  steps:
    - name: Compute metadata
      id: meta
      shell: bash
      run: |
        # Generate tags
        TAGS="latest"
        if [ -n "${{ inputs.tags }}" ]; then
          TAGS="$TAGS,${{ inputs.tags }}"
        fi

        SHORT_SHA="$(git rev-parse --short HEAD 2>/dev/null || echo 'local')"
        DATE_TAG="$(date +%Y-%m-%d)"
        TAG="$DATE_TAG-$SHORT_SHA"
        TAGS="$TAGS,$TAG"

        # Add git tag if this is a tag push
        if [[ "${{ github.ref }}" == refs/tags/* ]]; then
          TAG_NAME="${{ github.ref_name }}"
          TAGS="$TAGS,$TAG_NAME"
        fi

        echo "image=${{ inputs.image-name }}" >> $GITHUB_OUTPUT
        echo "tag=$TAG" >> $GITHUB_OUTPUT
        echo "tags=$TAGS" >> $GITHUB_OUTPUT

    - name: Log in to Docker registry
      shell: bash
      run: |
        if [ -n "${{ inputs.registry }}" ] && [ -n "${{ inputs.registry-password }}" ]; then
          echo "${{ inputs.registry-password }}" | docker login ${{ inputs.registry }} -u ${{ inputs.registry-username }} --password-stdin
        fi

    - name: Build image
      id: build
      shell: bash
      run: |
        BUILD_ARGS_FLAG=""
        if [ -n "${{ inputs.build-args }}" ]; then
          for arg in $(echo "${{ inputs.build-args }}" | tr ',' ' '); do
            BUILD_ARGS_FLAG="$BUILD_ARGS_FLAG --build-arg=$arg"
          done
        fi

        set -x
        docker build \
          --tag "${{ inputs.image-name }}:${{ steps.meta.outputs.tag }}" \
          --tag "${{ inputs.image-name }}:latest" \
          $(for t in $(echo ${{ steps.meta.outputs.tags }} | tr ',' ' '); do echo -n "--tag ${{ inputs.image-name }}:$t "; done) \
          --file ${{ inputs.context }}/${{ inputs.dockerfile }} \
          $BUILD_ARGS_FLAG \
          ${{ inputs.context }}

    - name: Push image
      id: push
      if: inputs.push == 'true'
      shell: bash
      run: |
        set -x
        docker push "${{ inputs.image-name }}:${{ steps.meta.outputs.tag }}"
        docker push "${{ inputs.image-name }}:latest"
        for t in $(echo ${{ steps.meta.outputs.tags }} | tr ',' ' '); do
          docker push "${{ inputs.image-name }}:$t"
        done

    - name: Get image digest
      id: push-digest
      shell: bash
      if: inputs.push == 'true'
      run: |
        DIGEST="$(docker inspect "${{ inputs.image-name }}:${{ steps.meta.outputs.tag }}" --format '{{.Digest}}' 2>/dev/null)"
        echo "digest=$DIGEST" >> $GITHUB_OUTPUT