name: Build and Push Docker Images

on:
  push:
    branches:
      - main
      - develop
    tags:
      - 'v*'
  pull_request:
    branches:
      - main
      - develop
  pull_request_target:
    types: [labeled]
  workflow_dispatch:

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}

jobs:
  # Security check for fork PRs
  security-check:
    runs-on: ubuntu-latest
    if: github.event_name == 'pull_request'
    permissions:
      pull-requests: read
    outputs:
      is_fork: ${{ steps.check.outputs.is_fork }}
    steps:
      - name: Check if PR is from fork
        id: check
        run: |
          if [ "${{ github.event.pull_request.head.repo.full_name }}" != "${{ github.repository }}" ]; then
            echo "is_fork=true" >> $GITHUB_OUTPUT
            echo "::warning::This PR is from a fork. Builds from forks require manual approval for security."
          else
            echo "is_fork=false" >> $GITHUB_OUTPUT
          fi

  build-and-push:
    needs: security-check
    # Run on push/tag events (security-check is skipped but that's ok)
    # For PRs, only run on non-fork PRs or manually approved fork PRs
    if: |
      always() && (
        github.event_name == 'push' ||
        github.event_name == 'workflow_dispatch' ||
        (github.event_name == 'pull_request' && needs.security-check.result == 'success' && needs.security-check.outputs.is_fork == 'false') ||
        (github.event_name == 'pull_request_target' && contains(github.event.pull_request.labels.*.name, 'safe-to-build'))
      )
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write

    strategy:
      matrix:
        include:
          - service: web
            dockerfile: docker/web/Dockerfile
            context: .
          - service: caddy
            dockerfile: docker/caddy/Dockerfile
            context: .

    steps:
      - name: Checkout repository
        uses: actions/checkout@v5
        with:
          # For pull_request_target, checkout the PR head
          ref: ${{ github.event_name == 'pull_request_target' && github.event.pull_request.head.sha || '' }}

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

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

      - name: Extract metadata (tags, labels)
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}-${{ matrix.service }}
          tags: |
            type=ref,event=branch
            type=ref,event=pr
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=semver,pattern={{major}}
            type=sha
            type=raw,value=latest,enable={{is_default_branch}}

      - name: Build and push Docker image
        id: build
        uses: docker/build-push-action@v6
        with:
          context: ${{ matrix.context }}
          file: ${{ matrix.dockerfile }}
          push: ${{ github.event_name != 'pull_request' && github.event_name != 'pull_request_target' }}
          load: ${{ github.event_name == 'pull_request' || github.event_name == 'pull_request_target' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max
          # Build amd64 images on pushes; PR builds stay single-platform
          platforms: ${{ (github.event_name != 'pull_request' && github.event_name != 'pull_request_target') && 'linux/amd64' || '' }}
          # SBOM and provenance create manifest lists, incompatible with load (PRs)
          sbom: ${{ github.event_name != 'pull_request' && github.event_name != 'pull_request_target' }}
          provenance: ${{ github.event_name != 'pull_request' && github.event_name != 'pull_request_target' }}