name: PR Burst Guard

on:
  pull_request_target:
    types: [opened, reopened]

# Process one author's ledger serially. A newer pending event replaces an older
# pending event; each run reads all PR states instead of relying on event counts.
concurrency:
  group: pr-burst-${{ github.repository }}-${{ github.event.pull_request.user.id }}
  cancel-in-progress: false

permissions:
  contents: read
  pull-requests: write
  issues: write

jobs:
  moderate:
    runs-on: ubuntu-latest
    timeout-minutes: 10
    steps:
      # pull_request_target's SHA is the trusted default branch, never a PR head.
      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
        with:
          ref: ${{ github.sha }}
          persist-credentials: false
          sparse-checkout: |
            .github/pr-burst-policy.json
            scripts/ci/pr-burst-guard.js
          sparse-checkout-cone-mode: false
      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
        with:
          node-version: '20.x'
      - name: Enforce PR submission policy
        env:
          GITHUB_TOKEN: ${{ github.token }}
          PR_MODERATION_BLOCK_TOKEN: ${{ secrets.PR_MODERATION_BLOCK_TOKEN }}
        run: node scripts/ci/pr-burst-guard.js