auto-release.yml

name: Auto Release on Release Branch

on:
  pull_request:
    types: [closed]
    branches:
      - release

permissions:
  contents: write

jobs:
  auto-release:
    # Only run if PR was merged to release branch (not just closed)
    if: github.event.pull_request.merged == true
    runs-on: ubuntu-latest
    
    steps:
      - name: Checkout code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0  # Fetch all history for versioning
      
      - name: Setup Zig
        uses: goto-bus-stop/setup-zig@v2
        with:
          version: 0.14.1
      
      - name: Read VERSION file
        id: get_version
        run: |
          VERSION=$(cat VERSION)
          echo "version=$VERSION" >> $GITHUB_OUTPUT
          echo "tag=v$VERSION" >> $GITHUB_OUTPUT
      
      - name: Check if tag exists
        id: check_tag
        run: |
          if git rev-parse "v${{ steps.get_version.outputs.version }}" >/dev/null 2>&1; then
            echo "exists=true" >> $GITHUB_OUTPUT
            echo "⚠️ Tag v${{ steps.get_version.outputs.version }} already exists"
          else
            echo "exists=false" >> $GITHUB_OUTPUT
            echo "✅ Tag v${{ steps.get_version.outputs.version }} does not exist"
          fi
      
      - name: Run tests
        if: steps.check_tag.outputs.exists == 'false'
        run: zig build test
      
      - name: Build library
        if: steps.check_tag.outputs.exists == 'false'
        run: zig build
      
      - name: Update build.zig.zon version
        if: steps.check_tag.outputs.exists == 'false'
        run: |
          VERSION="${{ steps.get_version.outputs.version }}"
          sed -i "s/\.version = \".*\"/\.version = \"$VERSION\"/" build.zig.zon
      
      - name: Generate changelog
        if: steps.check_tag.outputs.exists == 'false'
        id: changelog
        run: |
          VERSION="${{ steps.get_version.outputs.version }}"
          
          # Get previous tag
          PREV_TAG=$(git describe --tags --abbrev=0 2>/dev/null || echo "")
          
          if [ -z "$PREV_TAG" ]; then
            echo "## 🎉 Initial Release" > CHANGELOG.md
            echo "" >> CHANGELOG.md
            echo "First release of zig-poseidon - A Zig implementation of Poseidon2 hash function." >> CHANGELOG.md
            echo "" >> CHANGELOG.md
            echo "### Features" >> CHANGELOG.md
            echo "- BabyBear field (p = 2³¹ - 2²⁷ + 1) for Ethereum Lean chain" >> CHANGELOG.md
            echo "- KoalaBear field (p = 2³¹ - 2²⁴ + 1) for plonky3 and Rust hash-sig compatibility" >> CHANGELOG.md
            echo "- Generic Montgomery form implementation" >> CHANGELOG.md
            echo "- Compression mode for Merkle Trees" >> CHANGELOG.md
            echo "- Comprehensive test suite" >> CHANGELOG.md
          else
            echo "## Changes since $PREV_TAG" > CHANGELOG.md
            echo "" >> CHANGELOG.md
            git log "$PREV_TAG"..HEAD --pretty=format:"- %s (%h)" >> CHANGELOG.md
          fi
          
          cat CHANGELOG.md
      
      - name: Create Git tag
        if: steps.check_tag.outputs.exists == 'false'
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"
          git tag -a "${{ steps.get_version.outputs.tag }}" -m "Release ${{ steps.get_version.outputs.tag }}"
          git push origin "${{ steps.get_version.outputs.tag }}"
      
      - name: Create GitHub Release
        if: steps.check_tag.outputs.exists == 'false'
        uses: softprops/action-gh-release@v1
        with:
          tag_name: ${{ steps.get_version.outputs.tag }}
          name: Release ${{ steps.get_version.outputs.tag }}
          body_path: CHANGELOG.md
          draft: false
          prerelease: false
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      
      - name: Calculate tarball hash
        if: steps.check_tag.outputs.exists == 'false'
        id: tarball_hash
        run: |
          VERSION="${{ steps.get_version.outputs.version }}"
          TARBALL_URL="https://github.com/${{ github.repository }}/archive/v${VERSION}.tar.gz"
          
          # Download and calculate hash
          curl -L "$TARBALL_URL" -o release.tar.gz
          HASH=$(zig fetch release.tar.gz 2>&1 | grep -o '12[0-9a-f]*' || echo "")
          
          if [ -z "$HASH" ]; then
            echo "⚠️ Could not calculate hash automatically"
            echo "📦 Users can get the hash by running:"
            echo "   zig fetch --save $TARBALL_URL"
          else
            echo "hash=$HASH" >> $GITHUB_OUTPUT
            echo "📦 Tarball hash: $HASH"
          fi
      
      - name: Post release information
        if: steps.check_tag.outputs.exists == 'false'
        run: |
          echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
          echo "🎉 Release ${{ steps.get_version.outputs.tag }} created successfully!"
          echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
          echo ""
          echo "📦 To use this release in your project's build.zig.zon:"
          echo ""
          echo ".dependencies = .{"
          echo "    .poseidon = .{"
          echo "        .url = \"https://github.com/${{ github.repository }}/archive/${{ steps.get_version.outputs.tag }}.tar.gz\","
          echo "        .hash = \"${{ steps.tarball_hash.outputs.hash }}\","
          echo "    },"
          echo "},"
          echo ""
          echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
      
      - name: Skip release (tag exists)
        if: steps.check_tag.outputs.exists == 'true'
        run: |
          echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
          echo "⚠️  Skipping release - tag ${{ steps.get_version.outputs.tag }} already exists"
          echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
          echo ""
          echo "To create a new release:"
          echo "1. Update the VERSION file with a new version number"
          echo "2. Commit the change"
          echo "3. Create and merge a PR"
          echo ""
          echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"