name: Check PR Template

on:
  pull_request_target: # zizmor: ignore[dangerous-triggers]
    types: [opened, edited]

permissions: {}

jobs:
  parse:
    runs-on: ubuntu-latest
    if: ${{ github.event.pull_request.head.repo.fork == true }}
    permissions:
      contents: read
    outputs:
      uses_template: ${{ steps.check.outputs.uses_template }}
    steps:
      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
        with:
          sparse-checkout: .github/pull_request_template.md
          sparse-checkout-cone-mode: false
          persist-credentials: false

      - name: Check required sections
        id: check
        env:
          BODY: ${{ github.event.pull_request.body }}
        run: |
          OK=true
          while IFS= read -r header; do
            printf '%s\n' "$BODY" | grep -qF "$header" || OK=false
          done < <(sed '/<!--/,/-->/d' .github/pull_request_template.md | grep "^## ")
          echo "uses_template=$OK" >> "$GITHUB_OUTPUT"

  act:
    runs-on: ubuntu-latest
    needs: parse
    permissions:
      pull-requests: write
    steps:
      - name: Close PR
        if: ${{ needs.parse.outputs.uses_template == 'false' && github.event.pull_request.state != 'closed' }}
        env:
          GH_TOKEN: ${{ github.token }}
          NODE_ID: ${{ github.event.pull_request.node_id }}
        run: |
          gh api graphql \
            -f prId="$NODE_ID" \
            -f body="This PR has been automatically closed as the description doesn't follow our template. After you edit it to match the template, the PR will automatically be reopened." \
            -f query='
              mutation CommentAndClosePR($prId: ID!, $body: String!) {
                addComment(input: {
                  subjectId: $prId,
                  body: $body
                }) {
                  __typename
                }
                closePullRequest(input: {
                  pullRequestId: $prId
                }) {
                  __typename
                }
              }'

      - name: Reopen PR (sections now present, PR closed)
        if: ${{ needs.parse.outputs.uses_template == 'true' && github.event.pull_request.state == 'closed' }}
        env:
          GH_TOKEN: ${{ github.token }}
          NODE_ID: ${{ github.event.pull_request.node_id }}
        run: |
          gh api graphql \
            -f prId="$NODE_ID" \
            -f query='
              mutation ReopenPR($prId: ID!) {
                reopenPullRequest(input: {
                  pullRequestId: $prId
                }) {
                  __typename
                }
              }'