deploy.yml

name: CI & Deploy

on:
  push:
    branches: [ "main" ]
  pull_request:
    branches: [ "main" ]

env:
  CARGO_TERM_COLOR: always

jobs:

  build:
    runs-on: ubuntu-latest

    steps:
    # Checkout code
    - uses: actions/checkout@v4

    # Cache Cargo registry (dependencies)
    - name: Cache Cargo registry
      uses: actions/cache@v4
      with:
        path: ~/.cargo/registry
        key: ${{ runner.os }}-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
        restore-keys: |
          ${{ runner.os }}-cargo-registry-

    # Cache Cargo git index
    - name: Cache Cargo git index
      uses: actions/cache@v4
      with:
        path: ~/.cargo/git
        key: ${{ runner.os }}-cargo-git-${{ hashFiles('**/Cargo.lock') }}
        restore-keys: |
          ${{ runner.os }}-cargo-git-
          
    # Cache mdBook binary
    - name: Cache mdBook binary
      uses: actions/cache@v4
      with:
        path: ~/.cargo/bin/mdbook
        key: ${{ runner.os }}-mdbook-${{ hashFiles('**/Cargo.lock') }}
        restore-keys: |
          ${{ runner.os }}-mdbook-

    # Install markdown book
    - name: Install mdBook
      run: |
        if ! command -v mdbook &> /dev/null; then
          cargo install mdbook --no-default-features --features search --vers "^0.4" --locked;
        else
          echo "mdBook is already installed, skipping installation."
        fi

    # Run mdBook Rust code tests
    - name: Test Rust code
      run: mdbook test


  deploy:
    needs: build
    runs-on: ubuntu-latest
    
    if: github.ref == 'refs/heads/main'
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      # Restore the mdBook binary from the cache
      - name: Restore mdBook binary
        uses: actions/cache@v4
        with:
          path: ~/.cargo/bin/mdbook
          key: ${{ runner.os }}-mdbook-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-mdbook-

      # Build the book and deploy to GitHub Pages
      - name: Deploy to GitHub Pages
        run: |
          # Build the mdBook
          mdbook build
          
          # Create (or update) the gh-pages worktree
          git worktree add gh-pages || true
          git config user.name "Deploy from CI"
          git config user.email "deploy@ci"

          cd gh-pages
          # Remove previous gh-pages history and files
          git update-ref -d refs/heads/gh-pages || true
          rm -rf *
          # Copy the built book from the default location ("book" directory)
          mv ../book/* .

          git add .
          git commit -m "Deploy ${GITHUB_SHA} to gh-pages"
          git push --force --set-upstream origin gh-pages