name: "CI"

on:
  pull_request:
  push:

jobs:

  tests:
    needs: [check_cachix]
    strategy:
      matrix:
        os: [ubuntu-latest, macos-latest]
    runs-on: ${{ matrix.os }}
    timeout-minutes: 60
    steps:
    - uses: actions/checkout@v2.4.0
      with:
        fetch-depth: 0
    - uses: cachix/install-nix-action@v16
    - run: echo CACHIX_NAME="$(echo $GITHUB_REPOSITORY-install-tests | tr "[A-Z]/" "[a-z]-")" >> $GITHUB_ENV
    - uses: cachix/cachix-action@v10
      if: needs.check_cachix.outputs.secret == 'true'
      with:
        name: '${{ env.CACHIX_NAME }}'
        signingKey: '${{ secrets.CACHIX_SIGNING_KEY }}'
        authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
    - run: nix-build -A checks.$(nix-instantiate --eval -E '(builtins.currentSystem)')

  check_cachix:
    name: Cachix secret present for installer tests
    runs-on: ubuntu-latest
    outputs:
      secret: ${{ steps.secret.outputs.secret }}
    steps:
      - name: Check for Cachix secret
        id: secret
        env:
          _CACHIX_SECRETS: ${{ secrets.CACHIX_SIGNING_KEY }}${{ secrets.CACHIX_AUTH_TOKEN }}
        run: echo "::set-output name=secret::${{ env._CACHIX_SECRETS != '' }}"

  installer:
    needs: [tests, check_cachix]
    if: github.event_name == 'push' && needs.check_cachix.outputs.secret == 'true'
    runs-on: ubuntu-latest
    outputs:
      installerURL: ${{ steps.prepare-installer.outputs.installerURL }}
    steps:
    - uses: actions/checkout@v2.4.0
      with:
        fetch-depth: 0
    - run: echo CACHIX_NAME="$(echo $GITHUB_REPOSITORY-install-tests | tr "[A-Z]/" "[a-z]-")" >> $GITHUB_ENV
    - uses: cachix/install-nix-action@v16
    - uses: cachix/cachix-action@v10
      with:
        name: '${{ env.CACHIX_NAME }}'
        signingKey: '${{ secrets.CACHIX_SIGNING_KEY }}'
        authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
    - id: prepare-installer
      run: scripts/prepare-installer-for-github-actions

  installer_test:
    needs: [installer, check_cachix]
    if: github.event_name == 'push' && needs.check_cachix.outputs.secret == 'true'
    strategy:
      matrix:
        os: [ubuntu-latest, macos-latest]
    runs-on: ${{ matrix.os }}
    steps:
    - uses: actions/checkout@v2.4.0
    - run: echo CACHIX_NAME="$(echo $GITHUB_REPOSITORY-install-tests | tr "[A-Z]/" "[a-z]-")" >> $GITHUB_ENV
    - uses: cachix/install-nix-action@v16
      with:
        install_url: '${{needs.installer.outputs.installerURL}}'
        install_options: "--tarball-url-prefix https://${{ env.CACHIX_NAME }}.cachix.org/serve"
    - run: nix-instantiate -E 'builtins.currentTime' --eval

  docker_push_image:
    needs: [check_cachix, tests]
    if: >-
      github.event_name == 'push' &&
      github.ref_name == 'master' &&
      needs.check_cachix.outputs.secret == 'true'
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2.4.0
      with:
        fetch-depth: 0
    - uses: cachix/install-nix-action@v16
    - run: echo CACHIX_NAME="$(echo $GITHUB_REPOSITORY-install-tests | tr "[A-Z]/" "[a-z]-")" >> $GITHUB_ENV
    - run: echo NIX_VERSION="$(nix-instantiate --eval -E '(import ./default.nix).defaultPackage.${builtins.currentSystem}.version' | tr -d \")" >> $GITHUB_ENV
    - uses: cachix/cachix-action@v10
      if: needs.check_cachix.outputs.secret == 'true'
      with:
        name: '${{ env.CACHIX_NAME }}'
        signingKey: '${{ secrets.CACHIX_SIGNING_KEY }}'
        authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
    - run: nix-build -A checks.$(nix-instantiate --eval -E 'builtins.currentSystem' --json).dockerImage
    - run: docker load -i ./result/image.tar.gz
    - run: docker tag nix:$NIX_VERSION nixos/nix:$NIX_VERSION
    - name: Login to Docker Hub
      uses: docker/login-action@v1
      with:
        username: ${{ secrets.DOCKERHUB_USERNAME }}
        password: ${{ secrets.DOCKERHUB_TOKEN }}
    - run: docker push nixos/nix:$NIX_VERSION