name: CodeQL

# Advanced setup so we can control when analysis runs. The "Require code
# scanning results" ruleset rule waits for a SARIF upload; if a PR doesn't
# touch code (locale-only, workflow-only) and the workflow never runs, the
# check sits pending forever. We always run a job per language and either do
# the real analysis (when relevant paths changed) or upload an empty SARIF so
# the check reports cleanly.
#
# Parity with the previous default setup:
#   - languages: actions, javascript-typescript
#     (javascript and typescript are subsumed by javascript-typescript)
#   - query suite: default
#   - threat model: remote
#   - schedule: weekly

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]
  schedule:
    # Weekly run, matches previous default setup cadence.
    - cron: "0 6 * * 1"

permissions: {}

jobs:
  analyze:
    name: Analyze (${{ matrix.language }})
    runs-on: ubuntu-latest
    permissions:
      security-events: write
      contents: read
      actions: read
      pull-requests: read # dorny/paths-filter calls the PRs API on pull_request events

    strategy:
      fail-fast: false
      matrix:
        include:
          - language: actions
            paths-filter: |
              code:
                - '.github/workflows/**'
                - '.github/actions/**'
          - language: javascript-typescript
            paths-filter: |
              code:
                - '**/*.ts'
                - '**/*.tsx'
                - '**/*.js'
                - '**/*.jsx'
                - '**/*.mjs'
                - '**/*.cjs'
                - '**/package.json'
                - '**/pnpm-lock.yaml'

    steps:
      - name: Checkout
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false

      # On push and schedule, always analyze. On pull_request, only analyze
      # when paths relevant to this language changed.
      - name: Detect relevant changes
        id: changes
        if: github.event_name == 'pull_request'
        uses: dorny/paths-filter@7b450fff21473bca461d4b92ce414b9d0420d706 # v4.0.2
        with:
          filters: ${{ matrix.paths-filter }}

      - name: Decide whether to analyze
        id: decide
        env:
          EVENT_NAME: ${{ github.event_name }}
          CHANGED: ${{ steps.changes.outputs.code }}
        run: |
          if [ "$EVENT_NAME" != "pull_request" ] || [ "$CHANGED" = "true" ]; then
            echo "analyze=true" >> "$GITHUB_OUTPUT"
          else
            echo "analyze=false" >> "$GITHUB_OUTPUT"
          fi

      - name: Initialize CodeQL
        if: steps.decide.outputs.analyze == 'true'
        uses: github/codeql-action/init@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
        with:
          languages: ${{ matrix.language }}

      - name: Perform CodeQL analysis
        if: steps.decide.outputs.analyze == 'true'
        uses: github/codeql-action/analyze@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
        with:
          category: "/language:${{ matrix.language }}"

      # When skipped, upload an empty SARIF so the "Require code scanning
      # results" rule on the branch ruleset sees a result and passes the PR.
      - name: Write empty SARIF
        if: steps.decide.outputs.analyze != 'true'
        env:
          LANGUAGE: ${{ matrix.language }}
        run: |
          cat > empty.sarif <<EOF
          {
            "version": "2.1.0",
            "\$schema": "https://json.schemastore.org/sarif-2.1.0.json",
            "runs": [
              {
                "tool": {
                  "driver": {
                    "name": "CodeQL",
                    "semanticVersion": "0.0.0",
                    "rules": []
                  }
                },
                "results": [],
                "automationDetails": {
                  "id": "/language:${LANGUAGE}/"
                }
              }
            ]
          }
          EOF

      - name: Upload empty SARIF
        if: steps.decide.outputs.analyze != 'true'
        uses: github/codeql-action/upload-sarif@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
        with:
          sarif_file: empty.sarif
          category: "/language:${{ matrix.language }}"