name: Bump version on PR merge

on:
  pull_request:
    branches: [master]
    types: [closed]

permissions:
  contents: write

jobs:
  bump:
    # Only run when the PR was actually merged (not just closed)
    if: github.event.pull_request.merged == true

    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v5
        with:
          # fetch-depth 2 so HEAD~1 resolves to the pre-merge master commit
          fetch-depth: 2
          # Use a PAT so the pushed bump commit can trigger deploy.yml
          token: ${{ secrets.RELEASE_BOT_TOKEN }}

      - name: Set up Node
        uses: actions/setup-node@v6
        with:
          node-version: "24.x"
          cache: npm

      - name: Get PR diff
        run: git diff HEAD~1 HEAD > /tmp/pr.diff

      - name: AI-detect bump type from diff
        id: bump
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          TYPE=$(node scripts/detect-bump-type.js --diff-file /tmp/pr.diff)
          echo "type=$TYPE" >> "$GITHUB_OUTPUT"
          echo "AI-determined bump type: $TYPE"

      - name: Extract base version (master before this PR merged)
        id: base
        run: |
          BASE=$(git show HEAD~1:public/versioning.js \
            | grep -oP 'const VERSION = "\K[\d.]+')
          echo "version=$BASE" >> "$GITHUB_OUTPUT"
          echo "Base version: $BASE"

      - name: Run version bump script
        run: |
          node scripts/bump-version.js ${{ steps.bump.outputs.type }} \
            --base-version ${{ steps.base.outputs.version }}

      - name: Commit and push bump
        run: |
          NEW_VERSION=$(node -e "
            const m = require('fs')
              .readFileSync('public/versioning.js', 'utf8')
              .match(/const VERSION = \"([\d.]+)\"/);
            console.log(m[1]);
          ")

          git config user.name  "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"
          git add public/versioning.js package.json package-lock.json src/index.html

          if ! git diff --cached --quiet; then
            git commit -m "chore: bump version to $NEW_VERSION"
            git push
            echo "Pushed version bump → $NEW_VERSION"
          else
            echo "Nothing changed, skipping commit."
          fi