name: deploy-book

# Based on:
# https://jupyterbook.org/en/stable/publish/gh-pages.html

# Run on a push to any branch, then deploy books from all branches.
on:
  push:
    branches:
    - '*'
    # If your git repository has the Jupyter Book within some-subfolder next to
    # unrelated files, you can make this run only if a file within that specific
    # folder has been modified.
    #
    # paths:
    # - some-subfolder/**
  workflow_dispatch:

jobs:
  get-branches:
    runs-on: ubuntu-latest
    outputs:
      branches: ${{ steps.set-branches.outputs.branches }}
    permissions:
      contents: read
    steps:
    - uses: actions/checkout@v4
      with:
        fetch-depth: 0
    - id: set-branches
      name: Collect all remote branch names for the matrix
      run: |
        branches=$(git branch -r | sed 's,\s*origin/,,g' | jq -Rn '[inputs]')
        echo "branches=$(echo $branches)" >> $GITHUB_OUTPUT

  build-books:
    runs-on: ubuntu-latest
    needs: get-branches
    permissions:
      pages: write
      id-token: write
    strategy:
      # If one branch fails, we may still want to deploy the other
      fail-fast: false
      matrix:
        branch: ${{ fromJson(needs.get-branches.outputs.branches) }}
    steps:
    - name: Checkout to branch
      uses: actions/checkout@v4
      with:
        ref: ${{ matrix.branch }}

    - name: Cache page build
      id: cache-html
      uses: actions/cache@v4
      with:
        path: "book/_build/html"
        key: html-build-${{ hashFiles('book/**', 'figures/**', 'requirements.txt') }}

    - if: ${{ steps.cache-html.outputs.cache-hit != 'true' }}
      name: Set up Python 3.11
      uses: actions/setup-python@v5
      with:
        python-version: 3.11
        cache: 'pip'

    - if: ${{ steps.cache-html.outputs.cache-hit != 'true' }}
      name: Install dependencies
      run: |
        pip install -r requirements.txt

    - if: ${{ steps.cache-html.outputs.cache-hit != 'true' }}
      name: Preprocess & build the book from branch
      run: |
        jupyter-book build book/

    - name: Upload the built book HTML as an artifact
      uses: actions/upload-artifact@v4
      with:
        name: ${{ matrix.branch }}
        path: "book/_build/html"

  deploy-books:
    # Run after build-books, even if it failed
    if: always()
    needs: build-books
    runs-on: ubuntu-latest
    permissions:
      pages: write
      id-token: write
    steps:
    - uses: actions/checkout@v4

    - run: |
        mkdir final/

    - name: Download all book artifacts
      uses: actions/download-artifact@v4
      with:
        path: "final/"

    - name: Symlink `book` to `main`
      run: |
        if test -d final/main; then
          ln -s main final/book
        fi

    - name: Load root page to redirect to `book/`
      run: |
        cp redirect.html final/index.html

    - name: Upload final Pages artifact
      uses: actions/upload-pages-artifact@v3
      with:
        path: "final/"
    
    - name: Deploy to GitHub Pages
      id: deployment
      uses: actions/deploy-pages@v4


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