# This action periodically merges base branches into staging branches.
# This is done to
#  * prevent conflicts or rather resolve them early
#  * make all potential breakage happen on the staging branch
#  * and make sure that all major rebuilds happen before the staging
#    branch get’s merged back into its base branch.

name: "Periodic Merges (24h)"


on:
  schedule:
    # * is a special character in YAML so you have to quote this string
    # Merge every 24 hours
    - cron:  '0 0 * * *'

jobs:
  periodic-merge:
    if: github.repository_owner == 'NixOS'
    runs-on: ubuntu-latest
    strategy:
      # don't fail fast, so that all pairs are tried
      fail-fast: false
      # certain branches need to be merged in order, like master->staging-next->staging
      # and disabling parallelism ensures the order of the pairs below.
      max-parallel: 1
      matrix:
        pairs:
          - from: master
            into: haskell-updates
          - from: release-21.11
            into: staging-next-21.11
          - from: staging-next-21.11
            into: staging-21.11
          - from: release-22.05
            into: staging-next-22.05
          - from: staging-next-22.05
            into: staging-22.05
    name: ${{ matrix.pairs.from }} → ${{ matrix.pairs.into }}
    steps:
      - uses: actions/checkout@v3

      - name: ${{ matrix.pairs.from }} → ${{ matrix.pairs.into }}
        uses: devmasx/merge-branch@1.4.0
        with:
          type: now
          from_branch: ${{ matrix.pairs.from }}
          target_branch: ${{ matrix.pairs.into }}
          github_token: ${{ secrets.GITHUB_TOKEN }}

      - name: Comment on failure
        uses: peter-evans/create-or-update-comment@v2
        if: ${{ failure() }}
        with:
          issue-number: 105153
          body: |
            Periodic merge from `${{ matrix.pairs.from }}` into `${{ matrix.pairs.into }}` has [failed](https://github.com/NixOS/nixpkgs/actions/runs/${{ github.run_id }}).