name: Update README Stats

on:
  schedule:
    - cron: '0 6 * * *'   # nightly at 06:00 UTC
  workflow_dispatch:
  push:
    branches: [main]
    paths:
      - 'backend/**'
      - 'agents/**'
      - '.github/workflows/readme-stats.yml'

permissions:
  contents: write

jobs:
  update-stats:
    name: Refresh dynamic README section
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          token: ${{ secrets.GITHUB_TOKEN }}

      - name: Gather repository statistics
        id: stats
        run: |
          PY_FILES=$(find . -name "*.py" -not -path "./.git/*" | wc -l)
          JS_FILES=$(find . -name "*.js" -not -path "./.git/*" | wc -l)
          AGENT_FILES=$(find ./agents -name "*.py" 2>/dev/null | wc -l)
          ROUTER_FILES=$(find ./backend/app/routers -name "*.py" 2>/dev/null | wc -l)
          WORKFLOW_FILES=$(find ./.github/workflows -name "*.yml" | wc -l)
          LAST_COMMIT=$(git log -1 --format="%ai" | cut -d' ' -f1)

          echo "py_files=$PY_FILES" >> $GITHUB_OUTPUT
          echo "js_files=$JS_FILES" >> $GITHUB_OUTPUT
          echo "agent_files=$AGENT_FILES" >> $GITHUB_OUTPUT
          echo "router_files=$ROUTER_FILES" >> $GITHUB_OUTPUT
          echo "workflow_files=$WORKFLOW_FILES" >> $GITHUB_OUTPUT
          echo "last_commit=$LAST_COMMIT" >> $GITHUB_OUTPUT

      - name: Update README dynamic section
        run: |
          python3 - <<'PY'
          import re

          py_files   = "${{ steps.stats.outputs.py_files }}"
          js_files   = "${{ steps.stats.outputs.js_files }}"
          agent_files = "${{ steps.stats.outputs.agent_files }}"
          router_files = "${{ steps.stats.outputs.router_files }}"
          workflow_files = "${{ steps.stats.outputs.workflow_files }}"
          last_commit = "${{ steps.stats.outputs.last_commit }}"

          block = (
              "<!-- DYNAMIC_STATS_START -->\n"
              "| Metric | Count |\n"
              "|--------|-------|\n"
              f"| Python files | {py_files} |\n"
              f"| JavaScript files | {js_files} |\n"
              f"| Agent modules | {agent_files} |\n"
              f"| API routers | {router_files} |\n"
              f"| CI/CD workflows | {workflow_files} |\n"
              f"| Last updated | {last_commit} |\n"
              "<!-- DYNAMIC_STATS_END -->"
          )

          with open("README.md", "r") as f:
              content = f.read()

          updated = re.sub(
              r"<!-- DYNAMIC_STATS_START -->.*?<!-- DYNAMIC_STATS_END -->",
              block,
              content,
              flags=re.DOTALL,
          )

          with open("README.md", "w") as f:
              f.write(updated)

          print("README stats updated")
          PY

      - name: Commit updated README
        run: |
          git config user.name "BlackRoad Bot"
          git config user.email "bot@blackroad.io"
          git add README.md
          if git diff --cached --quiet; then
            echo "No changes to commit"
          else
            git commit -m "docs: auto-update README stats [skip ci]"
            git push
          fi