# Builds the Russian (master) and English (english_version) editions of the
# mdBook and deploys them as one GitHub Pages site:
#
#   /APS/        ← Russian
#   /APS/en/     ← English
#
name: Deploy mdBook site to Pages

on:
  push:
    branches: ["master", "english_version"]
  workflow_dispatch:

permissions:
  contents: read
  pages:    write
  id-token: write

concurrency:
  group: "pages"
  cancel-in-progress: false

jobs:
  build:
    runs-on: ubuntu-latest
    env:
      MDBOOK_VERSION: 0.4.36

    steps:
      # ── 1. Checkout master (Russian) ──────────────────────────────────────
      - name: Checkout master (Russian)
        uses: actions/checkout@v4
        # checks out into $GITHUB_WORKSPACE (i.e. the working directory)

      # ── 2. Install mdBook ─────────────────────────────────────────────────
      - name: Install mdBook
        run: |
          curl --proto '=https' --tlsv1.2 https://sh.rustup.rs -sSf | sh -s -- -y
          source "$HOME/.cargo/env"
          cargo install --version "${MDBOOK_VERSION}" mdbook

      # ── 3. Build Russian version ──────────────────────────────────────────
      - name: Prepare Russian sources
        run: |
          chmod +x .github/prepare.sh
          .github/prepare.sh

      - name: Build Russian (mdbook → ./book/)
        run: |
          source "$HOME/.cargo/env"
          mdbook build

      # ── 4. Checkout English branch ────────────────────────────────────────
      - name: Checkout english_version branch
        uses: actions/checkout@v4
        with:
          ref:  english_version
          path: english_src      # checked out next to the working directory

      # ── 5. Build English version ──────────────────────────────────────────
      - name: Prepare English sources
        run: |
          cd english_src

          chmod +x .github/prepare.sh
          .github/prepare.sh

          # Use the dedicated English book.toml (sets site-url = "/APS/en/")
          cp .github/book_en.toml book.toml

          # Copy language-switcher theme files from the master checkout
          cp -r ../.github/theme ./theme

      - name: Build English (mdbook → english_src/book/)
        run: |
          source "$HOME/.cargo/env"
          cd english_src
          mdbook build

      # ── 6. Merge artifacts ────────────────────────────────────────────────
      - name: Merge English build into Russian book/en/
        run: |
          mkdir -p book/en
          cp -r english_src/book/. book/en/

      # ── 7. Deploy ─────────────────────────────────────────────────────────
      - name: Setup Pages
        id: pages
        uses: actions/configure-pages@v5

      - name: Upload Pages artifact
        uses: actions/upload-pages-artifact@v3
        with:
          path: ./book

  deploy:
    environment:
      name: github-pages
      url:  ${{ steps.deployment.outputs.page_url }}
    runs-on: ubuntu-latest
    needs: build
    steps:
      - name: Deploy to GitHub Pages
        id: deployment
        uses: actions/deploy-pages@v4