name: Deploy MkDocs

on:
  push:
    branches:
      - main

permissions:
  contents: write

jobs:
  deploy:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout code
        uses: actions/checkout@v2
        with:
          fetch-depth: 0 

      - name: Setup Python
        uses: actions/setup-python@v4
        with:
          python-version: '3.10'

      - name: Calculate requirements hash
        id: req-hash
        run: echo "hash=$(sha256sum requirements-doc.txt | awk '{print $1}')" >> $GITHUB_ENV

      - name: Setup cache for pip
        uses: actions/cache@v3
        with:
          path: |
            ~/.cache/pip
            .cache
          key: ${{ runner.os }}-pip-${{ env.hash }}
          restore-keys: |
            ${{ runner.os }}-pip-

      - name: Install Requirements
        if: steps.cache.outputs.cache-hit != 'true'
        run: |
          sudo apt-get update &&
          sudo apt-get install pngquant &&
          pip install -r requirements-doc.txt

      - name: Fetch documentation branch
        run: git fetch origin gh-pages --depth=1
        
      - name: Build and deploy MkDocs
        run: mkdocs gh-deploy --force