name: Check documentation links

# check the links of the documentation weekly; external links break without any change in this repository
on:
  schedule:
    - cron: '17 4 * * 1'
  workflow_dispatch:

permissions:
  contents: read

concurrency:
  group: ${{ github.workflow }}
  cancel-in-progress: true

jobs:
  check_docs_links:
    if: github.repository == 'nlohmann/json'
    runs-on: ubuntu-latest
    timeout-minutes: 30
    steps:
      - name: Harden Runner
        uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
        with:
          egress-policy: audit

      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
        with:
          persist-credentials: false

      - name: Install virtual environment
        run: make install_venv -C docs/mkdocs

      - name: Check links
        shell: bash  # adds -o pipefail, so tee does not hide the exit code
        run: make link_check -C docs/mkdocs 2>&1 | tee link_check.log

      - name: Summarize broken links
        if: failure()
        run: |
          {
            echo '### Broken documentation links'
            echo '```'
            grep 'invalid url' link_check.log || true
            echo '```'
          } >> "$GITHUB_STEP_SUMMARY"