name: cloud-train

# Runs the pure-CPU JavaScript trainer (node trainer.js -> lib/training.js).
# No GPU, no Python, no audiocraft — just Node. Persists checkpoint progress
# back to the repo so training is incremental across runs.

on:
  workflow_dispatch:
    inputs:
      steps:
        description: "Training steps to run this invocation"
        required: false
        default: "400"
  schedule:
    - cron: "0 */6 * * *"   # every 6h (cheap CPU loop; adjust cadence as you like)

permissions:
  contents: write

concurrency:
  group: cloud-train
  cancel-in-progress: false

jobs:
  train:
    runs-on: ubuntu-latest
    timeout-minutes: 10
    steps:
      - name: checkout
        uses: actions/checkout@v4

      - name: node
        uses: actions/setup-node@v4
        with:
          node-version: "20"

      - name: install deps
        run: npm ci || npm install

      - name: train (CPU, pure-JS — no GPU)
        env:
          STEPS: ${{ github.event.inputs.steps || '400' }}
        run: npm run train

      - name: commit progress
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
          git add checkpoints/ data/ 2>/dev/null || true
          if git diff --cached --quiet; then
            echo "no checkpoint changes to commit"
          else
            git commit -m "cloud-train: advance training to step $(node -e "console.log(require('./checkpoints/meta.json').step)") [skip ci]"
            git push
          fi

      - name: upload checkpoints artifact
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: checkpoints-${{ github.run_id }}
          path: checkpoints/**
          if-no-files-found: warn