name: Docker Build, Scan & Publish

on:
  workflow_call:
    inputs:
      images:
        description: >
          JSON array of images to build.
          Each item: { name, context, dockerfile, target, cache_ref }
        required: true
        type: string

      registry_host:
        required: true
        type: string

      build_args:
        required: false
        type: string
        default: ""

      trivy_severity:
        required: false
        type: string
        default: "CRITICAL"

    secrets:
      registry_user:
        required: true
      registry_password:
        required: true
      ci_token:
        required: true
      ssh_private_key:
        required: false
      ssh_known_hosts:
        required: false

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Start ssh-agent
        if: ${{ secrets.ssh_private_key != '' }}
        uses: webfactory/ssh-agent@v0.9.0
        with:
          ssh-private-key: ${{ secrets.ssh_private_key }}

      - name: Add SSH known hosts
        if: ${{ secrets.ssh_known_hosts != '' }}
        run: |
          mkdir -p ~/.ssh
          printf '%s\n' "${{ secrets.ssh_known_hosts }}" >> ~/.ssh/known_hosts
          chmod 644 ~/.ssh/known_hosts

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

      - name: Install Trivy
        run: |
          curl -sfL https://raw.githubusercontent.com/aquasecurity/trivy/main/contrib/install.sh | sudo sh -s -- -b /usr/local/bin
          trivy --version

      - name: Login to registry
        uses: docker/login-action@v3
        with:
          registry: ${{ inputs.registry_host }}
          username: ${{ secrets.registry_user }}
          password: ${{ secrets.registry_password }}

      - name: Build, scan and push images
        env:
          IMAGES: ${{ inputs.images }}
          BUILD_ARGS: ${{ inputs.build_args }}
          CI_TOKEN: ${{ secrets.ci_token }}
          TRIVY_SEVERITY: ${{ inputs.trivy_severity }}
        run: |
          set -euo pipefail

          SSH_FLAGS=""
          if [ -n "${SSH_AUTH_SOCK:-}" ]; then
            SSH_FLAGS="--ssh default"
          fi

          echo "$IMAGES" | jq -c '.[]' | while read -r img; do
            IMAGE_NAME=$(echo "$img" | jq -r '.name')
            FULL_IMAGE="${{ inputs.registry_host }}/${IMAGE_NAME}"
            CACHE_REF="${{ inputs.registry_host }}/$(echo "$img" | jq -r '.cache_ref')"
            CONTEXT=$(echo "$img" | jq -r '.context')
            DOCKERFILE=$(echo "$img" | jq -r '.dockerfile')
            TARGET=$(echo "$img" | jq -r '.target')
            RAW_REF="${{ github.ref }}"
            SHA_FULL="${{ github.sha }}"
            SHA_SHORT="${SHA_FULL:0:12}"

            echo "==== Building $FULL_IMAGE ===="

            TAGS=()
            TAGS+=("$FULL_IMAGE:sha-$SHA_SHORT")
            if [[ "$RAW_REF" =~ ^refs/tags/v([0-9]+)\.([0-9]+)\.([0-9]+)$ ]]; then
              TAGS+=("$FULL_IMAGE:v${BASH_REMATCH[1]}.${BASH_REMATCH[2]}.${BASH_REMATCH[3]}")
              TAGS+=("$FULL_IMAGE:v${BASH_REMATCH[1]}.${BASH_REMATCH[2]}")
              TAGS+=("$FULL_IMAGE:v${BASH_REMATCH[1]}")
              TAGS+=("$FULL_IMAGE:latest")
            fi

            TAG_ARGS=$(printf -- "--tag %s " "${TAGS[@]}")
            BUILD_ARG_FLAGS=""
            if [ -n "$BUILD_ARGS" ]; then
              BUILD_ARG_FLAGS=$(printf -- "--build-arg %s " $BUILD_ARGS)
            fi

            TARGET_FLAG=""
            if [ -n "$TARGET" ] && [ "$TARGET" != "null" ]; then
              TARGET_FLAG="--target $TARGET"
            fi

            docker buildx build \
              --file "$DOCKERFILE" \
              $TARGET_FLAG \
              --cache-from "type=registry,ref=$CACHE_REF" \
              --cache-to "type=registry,ref=$CACHE_REF,mode=max" \
              $SSH_FLAGS \
              --load \
              $TAG_ARGS \
              $BUILD_ARG_FLAGS \
              "$CONTEXT"

            echo "==== Trivy scan for $FULL_IMAGE ===="
            trivy image \
              --severity "$TRIVY_SEVERITY" \
              --exit-code 1 \
              "${TAGS[0]}"

            echo "==== Pushing $FULL_IMAGE ===="
            for tag in "${TAGS[@]}"; do
              docker push "$tag"
            done
          done