name: Generate docs

on: push

jobs:
  build-sources:
    name: Generate docs
    runs-on: ubuntu-20.04
    if: github.ref != 'master'
    steps:
      - uses: actions/checkout@v2
      - run: date +%F > todays-date
      - name: Restore cache for today's nightly.
        uses: actions/cache@v2
        with:
          path: build
          key: ${{ runner.os }}-appimage-${{ hashFiles('todays-date') }}

      - name: Restore cache for tree-sitter
        uses: actions/cache@v2
        with:
          path: _ts
          key: ${{ runner.os }}-ts-${{ hashFiles('todays-date') }}

      - name: Prepare
        run: |
          test -d build || {
            mkdir -p build
            wget https://github.com/neovim/neovim/releases/download/nightly/nvim.appimage
            chmod +x nvim.appimage
            mv nvim.appimage ./build/nvim
          }
          test -d _ts || {
            # Pining version. Not sure if we should actually do that
            mkdir -p _ts
            wget https://github.com/tree-sitter/tree-sitter/releases/download/0.17.3/tree-sitter-linux-x64.gz
            gzip -d tree-sitter-linux-x64
            chmod +x tree-sitter-linux-x64
            mv tree-sitter-linux-x64 ./_ts/tree-sitter
          }
          mkdir -p ~/.local/share/nvim/site/pack/vendor/start
          git clone --depth 1 https://github.com/tjdevries/tree-sitter-lua ~/.local/share/nvim/site/pack/vendor/start/tree-sitter-lua
          ln -s $(pwd) ~/.local/share/nvim/site/pack/vendor/start

      - name: Build parser
        run: |
          # We have to build the parser every single time to keep up with parser changes
          export PATH="${PWD}/_ts/:${PATH}"
          cd ~/.local/share/nvim/site/pack/vendor/start/tree-sitter-lua
          mkdir -p build parser
          make build_parser
          ln -s ../build/parser.so parser/lua.so
          cd

      # inspired by nvim-lspconfigs
      - name: Generating docs
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          COMMIT_MSG: |
            [Actions] Generate Documentation
            skip-checks: true
        run: |
          export PATH="${PWD}/build/:${PATH}"
          git config user.email "actions@github"
          git config user.name "Github Actions"
          git remote set-url origin https://x-access-token:${GITHUB_TOKEN}@github.com/${GITHUB_REPOSITORY}.git
          make docgen
          git add doc/
          # Only commit and push if we have changes
          git diff --quiet && git diff --staged --quiet || (git commit -m "${COMMIT_MSG}"; git push origin HEAD:${GITHUB_REF})