name: deploy-docs

on:
  push:
    branches:
      - main
    paths:
      - .github/workflows/docs.yml
      - docs/**

env:
  CARGO_TARGET_DIR: ~/cargo-target-dir

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
        with:
          fetch-depth: 0

      - name: Environment preparation
        id: prep
        run: |
          set -x

          rustup toolchain update --no-self-update stable
          rustup default stable
          rustup component add clippy rustfmt
          rustup show

          rustc --version | awk '{print $2}' | tee RUSTC_VER
          echo "rustc_ver=$(cat RUSTC_VER)" >> $GITHUB_OUTPUT

      - name: Get latest versions of mdbook with plugins
        id: get-version
        run: |
          set -x

          curl -SsL https://crates.io/api/v1/crates/mdbook | jq -r .crate.max_stable_version | tee MDBOOK_VER
          curl -SsL https://crates.io/api/v1/crates/mdbook-admonish | jq -r .crate.max_stable_version | tee MDBOOK_ADMONISH_VER
          curl -SsL https://crates.io/api/v1/crates/mdbook-pagetoc | jq -r .crate.max_stable_version | tee MDBOOK_PAGETOC_VER
          echo "mdbook_ver=$(cat MDBOOK_VER)" >> $GITHUB_OUTPUT
          echo "mdbook_admonish_ver=$(cat MDBOOK_ADMONISH_VER)" >> $GITHUB_OUTPUT
          echo "mdbook_pagetoc_ver=$(cat MDBOOK_PAGETOC_VER)" >> $GITHUB_OUTPUT

      - name: Cache for mdbook
        id: cache-mdbook
        uses: actions/cache@v3
        with:
          path: ~/.cargo/bin/mdbook
          key: ${{ github.workflow }}|${{ runner.os }}|cargo|00|${{ steps.prep.outputs.rustc_ver }}|mdbook|${{ steps.get-version.outputs.mdbook_ver }}
      - name: Cache for mdbook-admonish
        id: cache-mdbook-admonish
        uses: actions/cache@v3
        with:
          path: ~/.cargo/bin/mdbook-admonish
          key: ${{ github.workflow }}|${{ runner.os }}|cargo|00|${{ steps.prep.outputs.rustc_ver }}|mdbook-admonish|${{ steps.get-version.outputs.mdbook_admonish_ver }}
      - name: Cache for mdbook-pagetoc
        id: cache-mdbook-pagetoc
        uses: actions/cache@v3
        with:
          path: ~/.cargo/bin/mdbook-pagetoc
          key: ${{ github.workflow }}|${{ runner.os }}|cargo|00|${{ steps.prep.outputs.rustc_ver }}|mdbook-pagetoc|${{ steps.get-version.outputs.mdbook_pagetoc_ver }}

      - name: Install mdbook
        if: steps.cache-mdbook.outputs.cache-hit != 'true'
        run: cargo install mdbook --version ${{ steps.get-version.outputs.mdbook_ver }}
      - name: Install mdbook-admonish
        if: steps.cache-mdbook-admonish.outputs.cache-hit != 'true'
        run: cargo install mdbook-admonish --version ${{ steps.get-version.outputs.mdbook_admonish_ver }}
      - name: Install mdbook-pagetoc
        if: steps.cache-mdbook-pagetoc.outputs.cache-hit != 'true'
        run: cargo install mdbook-pagetoc --version ${{ steps.get-version.outputs.mdbook_pagetoc_ver }}

      - name: Deploy GitHub Pages
        run: |
          set -x
          export PATH="$HOME/.cargo/bin:$PATH"

          cd docs
          mdbook build

          git branch gh-pages
          git worktree add gh-pages gh-pages
          git config user.name "GitHub Action"
          git config user.email "action@github.com"

          cd gh-pages
          git update-ref -d refs/heads/gh-pages

          mv .git ../dotgit
          find . -name . -o -prune -exec rm -rf -- {} +
          mv ../dotgit .git
          mv ../book/* .

          git add .
          git commit -m "Deploy $GITHUB_SHA to gh-pages"
          git push -f -u origin gh-pages