name: GitHub - Autoclose Invalid PRs
on:
  pull_request_target:
    branches:
      - 'main'
    paths:
      - '.gitignore'

jobs:
  autoclose:
    runs-on: ubuntu-22.04
    steps:
      - uses: actions/github-script@d7906e4ad0b1822421a7e6a35d5ca353c962f410 # v6
        with:
          github-token: ${{secrets.GITHUB_TOKEN}}
          script: |
            const files = await github.rest.pulls.listFiles({
              owner: context.payload.repository.owner.login,
              repo: context.payload.repository.name,
              pull_number: context.payload.pull_request.number,
            });
            if (
              files.data.length !== 1 ||
              (files.data[0].filename !== ".gitignore" &&
              // We've had four PRs make this same (irrelevant) change already.
                !(files.data[0].filename === "664ef4623946e65e18d59764.md" &&
                  files.data[0].patch.includes("return re.sub('(?<!\d)1', '', equation_string.strip('+'))")
                )
              )
            ) {
              return;
            }
            const creator = context.payload.sender.login;
            const opts = github.rest.issues.listForRepo.endpoint.merge({
              ...context.issue,
              creator,
              state: 'all'
            });
            const issues = await github.paginate(opts);

            // iterate through issues
            for (const issue of issues) {
              // if the issue is this one, keep looking
              if (issue.number === context.issue.number) {
                continue;
              }

              // if the issue is actually a PR, they're not a first timer
              if (issue.pull_request) {
                return // Creator is already a contributor.
              }
            }
            core.setFailed("Invalid PR detected.");
            github.rest.issues.createComment({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: "Thank you for opening this pull request.\n\nThis is a standard message notifying you that we've reviewed your pull request and have decided not to merge it. We would welcome future pull requests from you.\n\nThank you and happy coding.",
            });
            await github.rest.pulls.update({
              owner: context.payload.repository.owner.login,
              repo: context.payload.repository.name,
              pull_number: context.payload.pull_request.number,
              state: "closed"
            });
            await github.rest.issues.addLabels({
              owner: context.payload.repository.owner.login,
              repo: context.payload.repository.name,
              issue_number: context.issue.number,
              labels: ["spam"]
            });