name: Update

on:
  workflow_dispatch:
  schedule:
    - cron:  '0 0 * * SUN' # every sunday

jobs:
  update:
    name: Pull in latest lib from Nixpkgs
    runs-on: ubuntu-latest
    steps:

    - name: Procure Nix
      uses: cachix/install-nix-action@v21

    - name: Checkout
      uses: actions/checkout@v2
      with:
        ref: master
        path: nixpkgs-lib

    - name: Checkout nixpkgs repo
      uses: actions/checkout@v2
      with:
        ref: master
        repository: NixOS/nixpkgs
        path: nixpkgs
        fetch-depth: 0 # complete history

    - name: Procure git-filter-repo from nixpkgs
      run: "nix profile install nixpkgs#git-filter-repo"


    - name: Filter nixpkgs on ./lib
      run: |
        cd ./nixpkgs
        git filter-repo --path lib --force

    - name: Update nixpkgs.lib
      run: |
        cd ./nixpkgs-lib
        git remote add other ../nixpkgs/
        git fetch other master
        git config --local user.email "41898282+github-actions[bot]@users.noreply.github.com"
        git config --local user.name "github-actions[bot]"
        git merge -X theirs --allow-unrelated-histories other/master

    - name: Push changes
      uses: ad-m/github-push-action@master
      with:
        github_token: ${{ secrets.GITHUB_TOKEN }}
        directory: nixpkgs-lib
        branch: master