.github/workflows/sync-labels.yml

# Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/sync-labels.md
name: Sync Labels

# See: https://docs.github.com/en/actions/reference/events-that-trigger-workflows
on:
  push:
    paths:
      - ".github/workflows/sync-labels.ya?ml"
      - ".github/label-configuration-files/*.ya?ml"
  pull_request:
    paths:
      - ".github/workflows/sync-labels.ya?ml"
      - ".github/label-configuration-files/*.ya?ml"
  schedule:
    # Run daily at 8 AM UTC to sync with changes to shared label configurations.
    - cron: "0 8 * * *"
  workflow_dispatch:
  repository_dispatch:

env:
  CONFIGURATIONS_FOLDER: .github/label-configuration-files
  CONFIGURATIONS_ARTIFACT: label-configuration-files

jobs:
  check:
    runs-on: ubuntu-latest

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

      - name: Download JSON schema for labels configuration file
        id: download-schema
        uses: carlosperate/download-file-action@v2
        with:
          file-url: https://raw.githubusercontent.com/arduino/tooling-project-assets/main/workflow-templates/assets/sync-labels/arduino-tooling-gh-label-configuration-schema.json
          location: ${{ runner.temp }}/label-configuration-schema

      - name: Install JSON schema validator
        run: |
          sudo npm install \
            --global \
            ajv-cli \
            ajv-formats

      - name: Validate local labels configuration
        run: |
          # See: https://github.com/ajv-validator/ajv-cli#readme
          ajv validate \
            --all-errors \
            -c ajv-formats \
            -s "${{ steps.download-schema.outputs.file-path }}" \
            -d "${{ env.CONFIGURATIONS_FOLDER }}/*.{yml,yaml}"

  download:
    needs: check
    runs-on: ubuntu-latest

    strategy:
      matrix:
        filename:
          # Filenames of the shared configurations to apply to the repository in addition to the local configuration.
          # https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/sync-labels
          - universal.yml
          - tooling.yml

    steps:
      - name: Download
        uses: carlosperate/download-file-action@v2
        with:
          file-url: https://raw.githubusercontent.com/arduino/tooling-project-assets/main/workflow-templates/assets/sync-labels/${{ matrix.filename }}

      - name: Pass configuration files to next job via workflow artifact
        uses: actions/upload-artifact@v3
        with:
          path: |
            *.yaml
            *.yml
          if-no-files-found: error
          name: ${{ env.CONFIGURATIONS_ARTIFACT }}

  sync:
    needs: download
    runs-on: ubuntu-latest

    steps:
      - name: Set environment variables
        run: |
          # See: https://docs.github.com/en/actions/reference/workflow-commands-for-github-actions#setting-an-environment-variable
          echo "MERGED_CONFIGURATION_PATH=${{ runner.temp }}/labels.yml" >> "$GITHUB_ENV"

      - name: Determine whether to dry run
        id: dry-run
        if: >
          github.event_name == 'pull_request' ||
          (
            (
              github.event_name == 'push' ||
              github.event_name == 'workflow_dispatch'
            ) &&
            github.ref != format('refs/heads/{0}', github.event.repository.default_branch)
          )
        run: |
          # Use of this flag in the github-label-sync command will cause it to only check the validity of the
          # configuration.
          echo "::set-output name=flag::--dry-run"

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

      - name: Download configuration files artifact
        uses: actions/download-artifact@v3
        with:
          name: ${{ env.CONFIGURATIONS_ARTIFACT }}
          path: ${{ env.CONFIGURATIONS_FOLDER }}

      - name: Remove unneeded artifact
        uses: geekyeggo/delete-artifact@v2
        with:
          name: ${{ env.CONFIGURATIONS_ARTIFACT }}

      - name: Merge label configuration files
        run: |
          # Merge all configuration files
          shopt -s extglob
          cat "${{ env.CONFIGURATIONS_FOLDER }}"/*.@(yml|yaml) > "${{ env.MERGED_CONFIGURATION_PATH }}"

      - name: Install github-label-sync
        run: sudo npm install --global github-label-sync

      - name: Sync labels
        env:
          GITHUB_ACCESS_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          # See: https://github.com/Financial-Times/github-label-sync
          github-label-sync \
            --labels "${{ env.MERGED_CONFIGURATION_PATH }}" \
            ${{ steps.dry-run.outputs.flag }} \
            ${{ github.repository }}