name: '[CI/CD] Markdown linter'
on:
  pull_request:
    branches:
      - main
    paths:
      - '**.md'
permissions:
  contents: read
jobs:
  markdown-linter:
    runs-on: ubuntu-latest
    steps:
      - name: Install mardownlint
        run: npm install -g markdownlint-cli@0.33.0
      - name: Checkout project
        uses: actions/checkout@v3
      - name: Execute markdownlint
        run: |
          # Using the Github API to detect the files changed as git merge-base stops working when the branch is behind
          # and jitterbit/get-changed-files does not support pull_request_target
          URL="https://api.github.com/repos/${{ github.repository }}/pulls/${{ github.event.pull_request.number }}/files"
          files_changed_data=$(curl -s --header 'authorization: Bearer ${{ secrets.GITHUB_TOKEN }}' -X GET -G "$URL")
          files_changed="$(echo "$files_changed_data" | jq -r '.[] | .filename')"
          md_files="$(echo "$files_changed" | grep -o ".*\.md$" | sort | uniq || true)"
          # Create an empty file, useful when the PR changes ignored files
          touch ${{runner.temp}}/output
          exit_code=0
          markdownlint -o ${{runner.temp}}/output ${md_files[@]} || exit_code=$?
          while read -r line; do
            # line format:
            #   file:row[:column] message
            # white space inside brackets is intentional to detect the message for the notice.
            message="${line#*[ ]}"
            file_row_column="${line%%[ ]*}"
            # Split by ':'
            readarray -d : -t strarr < <(printf '%s' "$file_row_column")
            if [[ "${#strarr[@]}" -eq 3 ]]; then
              echo "::warning file=${strarr[0]},line=${strarr[1]},col=${strarr[2]}::${message}"
            elif [[ "${#strarr[@]}" -eq 2 ]]; then
              echo "::warning file=${strarr[0]},line=${strarr[1]}::${message}"
            else
              echo "::warning:: Error processing: ${line}"
            fi
          done < ${{runner.temp}}/output
          if [[ $exit_code -ne 0 ]]; then
            echo "::error:: Please review linter messages"
            exit "$exit_code"
          fi