# Docker CI/CD Reusable Workflow
# Builds, scans, and pushes container images with attestations
#
# Features:
# - OIDC authentication (no secrets required for GHCR)
# - Multi-platform builds (linux/amd64, linux/arm64)
# - SBOM generation and attestation
# - Trivy vulnerability scanning
# - Build provenance attestation
# - Smart caching with GitHub Actions cache
#
# Usage:
#   jobs:
#     docker:
#       uses: ghndrx/github-actions-library/.github/workflows/docker-ci.yml@main
#       with:
#         image-name: my-app
#         push: ${{ github.event_name != 'pull_request' }}
#       permissions:
#         contents: read
#         packages: write
#         id-token: write
#         attestations: write

name: Docker CI

on:
  workflow_call:
    inputs:
      image-name:
        description: 'Image name (without registry prefix)'
        required: true
        type: string
      context:
        description: 'Docker build context path'
        required: false
        type: string
        default: '.'
      dockerfile:
        description: 'Path to Dockerfile'
        required: false
        type: string
        default: 'Dockerfile'
      push:
        description: 'Push image to registry'
        required: false
        type: boolean
        default: false
      platforms:
        description: 'Target platforms (comma-separated)'
        required: false
        type: string
        default: 'linux/amd64,linux/arm64'
      build-args:
        description: 'Build arguments (newline-separated KEY=value)'
        required: false
        type: string
        default: ''
      target:
        description: 'Docker build target stage'
        required: false
        type: string
        default: ''
      scan-severity:
        description: 'Trivy scan severity threshold (CRITICAL,HIGH,MEDIUM,LOW)'
        required: false
        type: string
        default: 'CRITICAL,HIGH'
      fail-on-vuln:
        description: 'Fail workflow if vulnerabilities found'
        required: false
        type: boolean
        default: false
      generate-sbom:
        description: 'Generate SBOM attestation'
        required: false
        type: boolean
        default: true
      generate-provenance:
        description: 'Generate build provenance attestation'
        required: false
        type: boolean
        default: true
    outputs:
      image-digest:
        description: 'Image digest (sha256:...)'
        value: ${{ jobs.build.outputs.digest }}
      image-tags:
        description: 'Generated image tags (JSON array)'
        value: ${{ jobs.build.outputs.tags }}
      sbom-attestation-id:
        description: 'SBOM attestation bundle ID'
        value: ${{ jobs.build.outputs.sbom-id }}

jobs:
  build:
    name: Build & Push
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
      id-token: write
      attestations: write
    outputs:
      digest: ${{ steps.build.outputs.digest }}
      tags: ${{ steps.meta.outputs.tags }}
      sbom-id: ${{ steps.sbom-attest.outputs.bundle-id }}

    steps:
      - name: Checkout
        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2

      - name: Set up QEMU
        uses: docker/setup-qemu-action@49b3bc8e6bdd4a60e6116a5414239cba5943d3cf # v3.2.0

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@c47758b77c9736f4b2ef4073d4d51994fabfe349 # v3.7.1

      - name: Log in to GitHub Container Registry
        if: inputs.push
        uses: docker/login-action@9780b0c442fbb1117ed29e0efdff1e18412f7567 # v3.3.0
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@8e5442c4ef9f78752691e2d8f8d19755c6f78e81 # v5.5.1
        with:
          images: ghcr.io/${{ github.repository_owner }}/${{ inputs.image-name }}
          tags: |
            # Branch name
            type=ref,event=branch
            # PR number
            type=ref,event=pr
            # Semantic version tags
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=semver,pattern={{major}},enable=${{ !startsWith(github.ref, 'refs/tags/v0.') }}
            # Short SHA
            type=sha,prefix=sha-,format=short
            # Latest on default branch
            type=raw,value=latest,enable=${{ github.ref == format('refs/heads/{0}', github.event.repository.default_branch) }}

      - name: Build and push
        id: build
        uses: docker/build-push-action@4f58ea79222b3b9dc2c8bbdd6debcef730109a75 # v6.9.0
        with:
          context: ${{ inputs.context }}
          file: ${{ inputs.context }}/${{ inputs.dockerfile }}
          platforms: ${{ inputs.platforms }}
          push: ${{ inputs.push }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          build-args: ${{ inputs.build-args }}
          target: ${{ inputs.target }}
          cache-from: type=gha
          cache-to: type=gha,mode=max
          provenance: ${{ inputs.generate-provenance }}
          sbom: ${{ inputs.generate-sbom }}

      - name: Generate SBOM attestation
        if: inputs.push && inputs.generate-sbom
        id: sbom-attest
        uses: actions/attest-sbom@115c3be05ff3974bcbd596578934b3f9ce39bf68 # v2.1.0
        with:
          subject-name: ghcr.io/${{ github.repository_owner }}/${{ inputs.image-name }}
          subject-digest: ${{ steps.build.outputs.digest }}
          sbom-path: ${{ runner.temp }}/sbom.spdx.json
        continue-on-error: true

      - name: Run Trivy vulnerability scanner
        uses: aquasecurity/trivy-action@18f2510ee396bbf400402947b394f2dd8c87dbb0 # v0.29.0
        with:
          image-ref: ghcr.io/${{ github.repository_owner }}/${{ inputs.image-name }}@${{ steps.build.outputs.digest }}
          format: 'sarif'
          output: 'trivy-results.sarif'
          severity: ${{ inputs.scan-severity }}
          exit-code: ${{ inputs.fail-on-vuln && '1' || '0' }}
        if: inputs.push

      - name: Upload Trivy scan results
        uses: github/codeql-action/upload-sarif@48ab28a6f5dbc2a99bf1e0131198dd8f1df78169 # v3.28.0
        with:
          sarif_file: 'trivy-results.sarif'
        if: inputs.push && always()

      - name: Output summary
        if: always()
        run: |
          echo "## 🐳 Docker Build Summary" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "| Property | Value |" >> $GITHUB_STEP_SUMMARY
          echo "|----------|-------|" >> $GITHUB_STEP_SUMMARY
          echo "| Image | \`ghcr.io/${{ github.repository_owner }}/${{ inputs.image-name }}\` |" >> $GITHUB_STEP_SUMMARY
          echo "| Digest | \`${{ steps.build.outputs.digest }}\` |" >> $GITHUB_STEP_SUMMARY
          echo "| Platforms | ${{ inputs.platforms }} |" >> $GITHUB_STEP_SUMMARY
          echo "| Pushed | ${{ inputs.push }} |" >> $GITHUB_STEP_SUMMARY
          echo "| Provenance | ${{ inputs.generate-provenance }} |" >> $GITHUB_STEP_SUMMARY
          echo "| SBOM | ${{ inputs.generate-sbom }} |" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "### Tags" >> $GITHUB_STEP_SUMMARY
          echo '```' >> $GITHUB_STEP_SUMMARY
          echo "${{ steps.meta.outputs.tags }}" >> $GITHUB_STEP_SUMMARY
          echo '```' >> $GITHUB_STEP_SUMMARY