name: Build and Publish Docker Image

on:
  push:
    branches: [main, master]
    paths: # run only when this file changed at all
      - "unshackle/core/__init__.py"
  pull_request: {} # optional – delete if you don’t build on PRs
  workflow_dispatch: {} # manual override

jobs:
  detect-version-change:
    runs-on: ubuntu-latest
    outputs:
      changed: ${{ steps.vdiff.outputs.changed }}
      version: ${{ steps.vdiff.outputs.version }}

    steps:
      - uses: actions/checkout@v4
        with: { fetch-depth: 2 } # we need the previous commit :contentReference[oaicite:1]{index=1}

      - name: Extract & compare version
        id: vdiff
        shell: bash
        run: |
          current=$(grep -oP '__version__ = "\K[^"]+' unshackle/core/__init__.py)
          prev=$(git show HEAD^:unshackle/core/__init__.py \
                 | grep -oP '__version__ = "\K[^"]+' || echo '')
          echo "version=$current"   >>"$GITHUB_OUTPUT"
          echo "changed=$([ "$current" != "$prev" ] && echo true || echo false)" >>"$GITHUB_OUTPUT"
          echo "Current=$current  Previous=$prev"

  build-and-push:
    needs: detect-version-change
    if: needs.detect-version-change.outputs.changed == 'true' # only run when bumped :contentReference[oaicite:2]{index=2}
    runs-on: ubuntu-latest
    permissions: { contents: read, packages: write }

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

      - name: Extract version from __init__.py
        id: version
        run: |
          VERSION=$(grep -oP '__version__ = "\K[^"]+' unshackle/core/__init__.py)
          echo "version=$VERSION" >> $GITHUB_OUTPUT
          echo "major_minor=$(echo $VERSION | cut -d. -f1-2)" >> $GITHUB_OUTPUT
          echo "major=$(echo $VERSION | cut -d. -f1)" >> $GITHUB_OUTPUT
          echo "Extracted version: $VERSION"

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

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

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

      - name: Show planned tags
        run: |
          echo "Planning to create the following tags:"
          echo "${{ steps.meta.outputs.tags }}"

      - name: Build and push Docker image
        uses: docker/build-push-action@v5
        with:
          context: .
          platforms: linux/amd64,linux/arm64
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

      - name: Test Docker image
        if: github.event_name != 'pull_request'
        run: |
          docker run --rm ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest env check