name: Changelog preview

on:
  pull_request:
    branches:
      - master
    types: [opened, synchronize]

jobs:
  generate_changelog_preview:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
        with:
          ref: develop
          # pulls all commits (needed for semantic release to correctly version)
          fetch-depth: '0'
      # pulls all tags (needed for semantic release to correctly version)
      - run: git fetch --depth=1 origin +refs/tags/*:refs/tags/*
      - name: Use Node.js ${{ matrix.node-version }}
        uses: actions/setup-node@v2
        with:
          node-version: ${{ matrix.node-version }}
          registry-url: 'https://registry.npmjs.org'
      - name: Installation
        run: yarn --frozen-lockfile && yarn bootstrap-ci
      - name: Generate Changelog
        id: generate_changelog
        run: |
          GITHUB_REF='refs/heads/develop' yarn extract-changelog
          echo "Changelog script finished! Checking if there are changes..."
          CHANGELOG_PREVIEW=$(cat NEXT_RELEASE_CHANGELOG.md || true)

          if [[ ! -z "${CHANGELOG_PREVIEW}" ]]; then
            echo "Changelog found! Writing header to the file..."
            echo '# Next releases' | cat - NEXT_RELEASE_CHANGELOG.md > NEXT_RELEASE_CHANGELOG.tmp.md && mv NEXT_RELEASE_CHANGELOG.tmp.md NEXT_RELEASE_CHANGELOG.md

            echo "Changelog file ready! Setting up outputs"
            CHANGELOG_PREVIEW=$(cat NEXT_RELEASE_CHANGELOG.md)
            
            CHANGELOG_PREVIEW_ESCAPED="${CHANGELOG_PREVIEW//'%'/'%25'}"
            CHANGELOG_PREVIEW_ESCAPED="${CHANGELOG_PREVIEW_ESCAPED//$'\n'/'%0A'}"
            CHANGELOG_PREVIEW_ESCAPED="${CHANGELOG_PREVIEW_ESCAPED//$'\r'/'%0D'}"

            echo "::set-output name=exists::true"
            echo "::set-output name=preview::$CHANGELOG_PREVIEW_ESCAPED"
          fi
      - uses: marocchino/sticky-pull-request-comment@v2
        if: steps.generate_changelog.outputs.exists == 'true'
        with:
          header: changelog_preview
          message: ${{ steps.generate_changelog.outputs.preview }}
      - uses: marocchino/sticky-pull-request-comment@v2
        if: steps.generate_changelog.outputs.exists != 'true'
        with:
          header: changelog_preview
          message: No changelog generated for the current changes on this pull request.