name: Updater

on:
  schedule:
  - cron: '0 2 * * *'
  workflow_dispatch: {}

jobs:
  generate_matrix:
    runs-on: ubuntu-20.04
    outputs:
      matrix: ${{ steps.gen_matrix.outputs.matrix }}
    steps:
    - name: Clone repository
      uses: actions/checkout@v3
      with:
        token: '${{ secrets.GITHUB_TOKEN }}'
    - name: Install nix
      uses: cachix/install-nix-action@v16
      with:
        extra_nix_config: |
          auto-optimise-store = true
          access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
          experimental-features = nix-command flakes
          substituters = https://cache.nixos.org/ https://nix-community.cachix.org
          trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs=
        install_url: https://releases.nixos.org/nix/nix-2.7.0/install
    - id: gen_matrix
      run: |
        matrix=$(nix flake show --json | jq -c '.packages."x86_64-linux" | keys')
        printf "%s" "$matrix" | jq
        printf "::set-output name=matrix::%s" "$matrix"
    
  update_flake:
    runs-on: ubuntu-20.04
    steps:
    - name: Clone repository
      uses: actions/checkout@v3
      with:
        token: '${{ secrets.GITHUB_TOKEN }}'
    - name: Install nix
      uses: cachix/install-nix-action@v16
      with:
        extra_nix_config: |
          auto-optimise-store = true
          access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
          experimental-features = nix-command flakes
          substituters = https://cache.nixos.org/ https://nix-community.cachix.org
          trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs=
        install_url: https://releases.nixos.org/nix/nix-2.7.0/install
    - name: Set up git
      run: |
        git config user.email gitbot@nobbz.dev
        git config user.name "Git Bot"
    - name: Update the flake
      run: nix flake update
    - name: Store flake.lock
      uses: actions/upload-artifact@v3
      with:
        name: flake_lock
        path: flake.lock

  build_flake:
    runs-on: ubuntu-20.04
    needs: [generate_matrix, update_flake]
    strategy:
      fail-fast: false
      max-parallel: 5
      matrix:
        package: ${{fromJson(needs.generate_matrix.outputs.matrix)}}
    steps:
    # - name: Prepare store folder
    #   run: sudo mkdir -p /nix
    # - name: Free diskspace
    #   uses: easimon/maximize-build-space@master
    #   with:
    #     build-mount-path: /nix
    #     remove-dotnet: true
    #     remove-android: true
    #     remove-haskell: true
    - name: Clone repository
      uses: actions/checkout@v3
      with:
        token: '${{ secrets.GITHUB_TOKEN }}'
    - name: Install nix
      uses: cachix/install-nix-action@v16
      with:
        extra_nix_config: |
          auto-optimise-store = true
          access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
          experimental-features = nix-command flakes
          substituters = https://cache.nixos.org/ https://nix-community.cachix.org
          trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs=
        install_url: https://releases.nixos.org/nix/nix-2.7.0/install
    - name: Set up cachix
      uses: cachix/cachix-action@master # pathsToPush, please update once we have v11!
      with:
        name: nobbz
        signingKey: '${{ secrets.CACHIX_SIGNING_KEY }}'
        pathsToPush: result
    - name: Restore flake.lock
      uses: actions/download-artifact@v3
      with:
        name: flake_lock
    - name: Build everything
      run: nix build .#${{ matrix.package }}

  push_update:
    runs-on: ubuntu-20.04
    permissions: write-all
    needs: [update_flake, build_flake]
    steps:
    - name: Clone repository
      uses: actions/checkout@v3
      with:
        token: '${{ secrets.GITHUB_TOKEN }}'
    - name: Restore flake.lock
      uses: actions/download-artifact@v3
      with:
        name: flake_lock
    - name: Set up git
      run: |
        git config user.email gitbot@nobbz.dev
        git config user.name "Git Bot"
    - name: Create and merge PR
      run: |
        git switch -c updates-${{ github.run_id }}
        git commit -am "flake.lock: Update"
        git push -u origin updates-${{ github.run_id }}
        PR=$(gh pr create \
          --assignee NobbZ \
          --base master \
          --body "Automatic flake update on $(date -I)" \
          --fill \
          --label bot \
          --title "Auto update $(date -I)")
        gh pr merge $PR --merge --delete-branch
      env:
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}