auto-release.yml

name: Auto Versioned Release

on:
  push:
    branches: [main]

permissions:
  contents: write

jobs:
  release:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout Code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0 

      - name: Get latest tag from remote
        id: get_tag
        run: |
          # Fetch all tags to ensure we see tags even if they aren't in this branch's history
          git fetch --tags --force
          
          # Find the highest version tag using natural version sorting
          # Filters for tags starting with 'v'
          tag=$(git tag -l "v*" --sort=-v:refname | head -n 1)
          
          # If no tag is found, start at v1.0.0
          if [ -z "$tag" ]; then
            tag="v1.0.0"
          fi
          
          echo "latest_tag=$tag" >> $GITHUB_OUTPUT
          echo "Found latest tag: $tag"

      - name: Bump version (semantic roll over)
        id: bump
        run: |
          tag="${{ steps.get_tag.outputs.latest_tag }}"
          base=${tag#v}
          IFS='.' read -r major minor patch <<< "$base"

          # Logic: Rolls over to next decimal place if value is 9
          if [ "$patch" -lt 9 ]; then
            patch=$((patch + 1))
          else
            patch=0
            if [ "$minor" -lt 9 ]; then
              minor=$((minor + 1))
            else
              minor=0
              major=$((major + 1))
            fi
          fi

          new_tag="v${major}.${minor}.${patch}"
          echo "new_tag=$new_tag" >> $GITHUB_OUTPUT
          echo "New calculated tag: $new_tag"

      - name: Generate changelog
        id: changelog
        run: |
          prev=${{ steps.get_tag.outputs.latest_tag }}
          
          # If the latest_tag was the fallback v1.0.0 and doesn't actually exist in git
          if git rev-parse "$prev" >/dev/null 2>&1; then
            log=$(git log $prev..HEAD --pretty=format:"- %s")
          else
            log=$(git log --pretty=format:"- %s")
          fi

          # Handle empty logs
          if [ -z "$log" ]; then log="- No changes documented."; fi

          echo "changelog<<EOF" >> $GITHUB_OUTPUT
          echo "$log" >> $GITHUB_OUTPUT
          echo "EOF" >> $GITHUB_OUTPUT

      - name: Create and Push Tag
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"
          git tag ${{ steps.bump.outputs.new_tag }}
          git push origin ${{ steps.bump.outputs.new_tag }}

      - name: Create GitHub Release
        uses: softprops/action-gh-release@v2
        with:
          tag_name: ${{ steps.bump.outputs.new_tag }}
          name: "${{ steps.bump.outputs.new_tag }}"
          body: |
            ## Changes since last release
            ${{ steps.changelog.outputs.changelog }}
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}