# This workflow checks for any changes in .qhelp files in pull requests.
# For any changed files, it renders them to markdown in a file called `comment_body.txt`.
# It then checks if there's an existing comment on the pull request generated by
# this workflow, and writes the comment ID to `comment_id.txt`.
# It also writes the PR number to `pr_number.txt`.
# These three files are uploaded as an artifact.

# When this workflow completes, the workflow "Post PR comment" runs.
# It downloads the artifact and adds a comment to the PR with the rendered
# QHelp.

# The task is split like this because creating PR comments requires extra
# permissions that we don't want to expose to PRs from external forks.

# For more info see:
# https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#workflow_run
# https://docs.github.com/en/actions/security-guides/automatic-token-authentication#permissions-for-the-github_token
name: Render QHelp changes

permissions:
  contents: read
  pull-requests: read

on:
  pull_request:
    branches:
      - main
      - "rc/*"
    paths:
      - "**/*.qhelp"

jobs:
  qhelp:
    runs-on: ubuntu-latest
    steps:
      - run: echo "${PR_NUMBER}" > pr_number.txt
        env:
          PR_NUMBER: ${{ github.event.number }}
      - uses: actions/upload-artifact@v3
        with:
          name: comment
          path: pr_number.txt
          if-no-files-found: error
          retention-days: 1

      - uses: actions/checkout@v4
        with:
          fetch-depth: 2
          persist-credentials: false
      - uses: ./.github/actions/fetch-codeql
      - name: Determine changed files
        id: changes
        run: |
          (git diff -z --name-only --diff-filter=ACMRT HEAD~1 HEAD | grep -z '.qhelp$' | grep -z -v '.inc.qhelp';
           git diff -z --name-only --diff-filter=ACMRT HEAD~1 HEAD | grep -z '.inc.qhelp$' | xargs --null -rn1 basename -z | xargs --null -rn1 git grep -z -l) |
           grep -z '.qhelp$' | grep -z -v '^-' | sort -z -u > "${RUNNER_TEMP}/paths.txt"

      - name: QHelp preview
        run: |
          EXIT_CODE=0
          echo "QHelp previews:" > comment_body.txt
          while read -r -d $'\0' path; do
            if [ ! -f "${path}" ]; then
               exit 1
            fi
            echo "<details> <summary>${path}</summary>"
            echo
            codeql generate query-help --format=markdown -- "./${path}" 2> errors.txt || EXIT_CODE="$?"
            if [ -s errors.txt ]; then
               echo "# errors/warnings:"
               echo '```'
               cat errors.txt
               cat errors.txt 1>&2
               echo '```'
            fi
            echo "</details>"
          done < "${RUNNER_TEMP}/paths.txt" >> comment_body.txt
          exit "${EXIT_CODE}"

      - if: ${{ !cancelled() }}
        uses: actions/upload-artifact@v3
        with:
          name: comment
          path: comment_body.txt
          if-no-files-found: error
          retention-days: 1

      - name: Save ID of existing QHelp comment (if it exists)
        run: |
          # Find the latest comment starting with "QHelp previews"
          COMMENT_PREFIX="QHelp previews"
          gh api "repos/${GITHUB_REPOSITORY}/issues/${PR_NUMBER}/comments" --paginate | jq --arg prefix "${COMMENT_PREFIX}" '[.[] | select(.body|startswith($prefix)) | .id] | max' > comment_id.txt
        env:
          GITHUB_TOKEN: ${{ github.token }}
          PR_NUMBER: ${{ github.event.number }}

      - uses: actions/upload-artifact@v3
        with:
          name: comment
          path: comment_id.txt
          if-no-files-found: error
          retention-days: 1