name: Generate Cached Results

on:
  push:
    branches: [main]
  # Allow manual trigger for testing
  workflow_dispatch:

jobs:
  generate-cache:
    runs-on: ubuntu-latest
    steps:
      - name: Free disk space
        run: |
          sudo rm -rf /usr/share/dotnet
          sudo rm -rf /opt/ghc
          sudo rm -rf /usr/local/share/boost
          docker system prune -af

      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          token: ${{ secrets.GITHUB_TOKEN }}

      - name: Setup Python
        uses: actions/setup-python@v5
        with:
          python-version: '3.10'
          cache: 'pip'

      - name: Install dependencies
        run: |
           pip install git+https://github.com/embeddings-benchmark/mteb.git

      - name: Generate cached results
        run: |
          python scripts/generate_cached_results.py
        env:
          PYTHONUNBUFFERED: 1

      - name: Configure Git
        run: |
          git config --global user.name "github-actions[bot]"
          git config --global user.email "github-actions[bot]@users.noreply.github.com"

      - name: Update cached-data branch
        env:
          GIT_LFS_SKIP_SMUDGE: "1"
        run: |
          # Check if __cached_results.json.gz was created
          if [ ! -f "__cached_results.json.gz" ]; then
            echo "❌ Cached results file not found"
            exit 1
          fi

          # Get file size for logging
          FILE_SIZE=$(stat -f%z __cached_results.json.gz 2>/dev/null || stat -c%s __cached_results.json.gz)
          echo "📦 Generated cache file: $(echo "scale=1; $FILE_SIZE/1024/1024" | bc -l)MB"

          # Move the generated file outside repository before rebuilding branch
          CACHE_TMP_PATH="$RUNNER_TEMP/__cached_results.json.gz"
          mv __cached_results.json.gz "$CACHE_TMP_PATH"
          README_TMP_PATH="$RUNNER_TEMP/cached-data-README.md"

          # Preserve README.md from cached-data branch (if it exists) without modifications
          if git ls-remote --exit-code --heads origin cached-data >/dev/null 2>&1; then
            git fetch origin cached-data:refs/remotes/origin/cached-data
            if git cat-file -e origin/cached-data:README.md 2>/dev/null; then
              git show origin/cached-data:README.md > "$README_TMP_PATH"
            fi
          fi

          # Rebuild cached-data as a fresh orphan branch so history always has one commit
          git checkout --orphan cached-data
          git rm -rf . 2>/dev/null || true

          # Restore and stage cache file
          mv "$CACHE_TMP_PATH" __cached_results.json.gz
          git add __cached_results.json.gz

          # Restore preserved README.md exactly as it was in cached-data
          if [ -f "$README_TMP_PATH" ]; then
            cp "$README_TMP_PATH" README.md
            git add README.md
          fi

          # Commit with timestamp and file size
          TIMESTAMP=$(date -u '+%Y-%m-%d %H:%M:%S UTC')
          COMMIT_MSG="Update cached results - $TIMESTAMP ($(echo "scale=1; $FILE_SIZE/1024/1024" | bc -l)MB)"
          git commit -m "$COMMIT_MSG"

          # Force push keeps remote branch as a single-commit history
          git push origin cached-data --force
          echo "✅ Successfully replaced cached-data branch with a single commit"

      - name: Report status
        if: always()
        run: |
          if [ -f "__cached_results.json.gz" ]; then
            FILE_SIZE=$(stat -f%z __cached_results.json.gz 2>/dev/null || stat -c%s __cached_results.json.gz)
            echo "✅ Workflow completed. Cache file size: $(echo "scale=1; $FILE_SIZE/1024/1024" | bc -l)MB"
          else
            echo "❌ Workflow failed - no cache file generated"
          fi