name: Scala (sbt) tests
on: [push, pull_request]

jobs:
  scala-test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      # Find an sbt project (first build.sbt found). If none, we skip gracefully.
      - name: Detect sbt project
        id: detect
        shell: bash
        run: |
          set -e
          FILE=$(git ls-files '**/build.sbt' | head -n1 || true)
          if [ -z "$FILE" ]; then
            echo "found=false" >> "$GITHUB_OUTPUT"
            exit 0
          fi
          DIR=$(dirname "$FILE")
          echo "found=true" >> "$GITHUB_OUTPUT"
          echo "dir=$DIR"   >> "$GITHUB_OUTPUT"

      - name: Set up Java (for sbt)
        if: steps.detect.outputs.found == 'true'
        uses: actions/setup-java@v4
        with:
          distribution: temurin
          java-version: '11'          # or 17/21 to match your project
          cache: sbt
          # Limit cache scan to the detected project to avoid the "no file matched" error
          cache-dependency-path: |
            ${{ steps.detect.outputs.dir }}/build.sbt
            ${{ steps.detect.outputs.dir }}/project/build.properties
            ${{ steps.detect.outputs.dir }}/project/**/*.scala
            ${{ steps.detect.outputs.dir }}/project/**/*.sbt

      - name: Set up sbt
        if: steps.detect.outputs.found == 'true'
        uses: sbt/setup-sbt@v1

      - name: Run tests
        if: steps.detect.outputs.found == 'true'
        working-directory: ${{ steps.detect.outputs.dir }}
        run: sbt -batch -v test

      - name: Skip (no sbt project found)
        if: steps.detect.outputs.found != 'true'
        run: echo "No sbt project found; skipping Scala tests."