name: NPM Publish

on:
  push:
    branches:
      - main

permissions:
  contents: read
  packages: write

jobs:
  build-and-publish:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Setup Node.js with caching
        uses: actions/setup-node@v4
        with:
          node-version: '20'
          registry-url: 'https://registry.npmjs.org'
          cache: 'npm' # Enables npm dependency caching
          cache-dependency-path: '**/package-lock.json' # Cache key based on lockfile

      - name: Install dependencies
        run: npm ci

      - name: Build
        run: npm run build

      - name: Check version change
        id: check_version
        run: |
          CURRENT_VERSION=$(node -p "require('./package.json').version")
          PREV_VERSION=$(git show HEAD^:package.json | grep '"version":' | sed -E 's/.*"version": *"([^"]+)".*/\1/')
          if [ "$CURRENT_VERSION" != "$PREV_VERSION" ]; then
            echo "Version changed from $PREV_VERSION to $CURRENT_VERSION"
            echo "version_changed=true" >> $GITHUB_OUTPUT
          else
            echo "Version unchanged: $CURRENT_VERSION"
            echo "version_changed=false" >> $GITHUB_OUTPUT
          fi

      - name: Publish to npm
        if: steps.check_version.outputs.version_changed == 'true'
        run: npm publish
        env:
          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}