name: rust-toolchain
description: |
  Install a Rust toolchain using rustup.
  See https://rust-lang.github.io/rustup/concepts/toolchains.html#toolchain-specification
  for more information about toolchains.
inputs:
  toolchain:
    description: |
      Rust toolchain name.
      See https://rust-lang.github.io/rustup/concepts/toolchains.html#toolchain-specification
    required: false
  target:
    description: Target triple to install for this toolchain
    required: false
  components:
    description: Space-separated list of components to be additionally installed for a new toolchain
    required: false
outputs:
  rustc_version:
    description: The rustc version installed
    value: ${{ steps.rustc-version.outputs.version }}

runs:
  using: composite
  steps:
    - name: Cache rustup toolchains
      uses: actions/cache@v3
      with:
        path: |
          ~/.rustup
          !~/.rustup/tmp
          !~/.rustup/downloads
        # Requires repo to be cloned if toolchain is not specified
        key: ${{ runner.os }}-rustup-${{ inputs.toolchain || hashFiles('**/rust-toolchain.toml') }}
    - name: Install Rust toolchain
      shell: bash
      run: |
        if ! command -v rustup &> /dev/null ; then
            curl --proto '=https' --tlsv1.2 --retry 10 --retry-connrefused -fsSL "https://sh.rustup.rs" | sh -s -- --default-toolchain none -y
            echo "${CARGO_HOME:-$HOME/.cargo}/bin" >> $GITHUB_PATH
        fi
    - shell: bash
      run: |
        set -x
        ${{ inputs.toolchain && format('rustup override set {0}', inputs.toolchain) }}
        ${{ inputs.target && format('rustup target add {0}', inputs.target) }}
        ${{ inputs.components && format('rustup component add {0}', inputs.components) }}
        cargo --version
        rustc --version
    - id: rustc-version
      shell: bash
      run: |
        echo "version=$(rustc --version)" >> $GITHUB_OUTPUT