# WARNING:
# When extending this action, be aware that $GITHUB_TOKEN allows write access to
# the GitHub repository. This means that it should not evaluate user input in a
# way that allows code injection.

name: Backport

on:
  pull_request_target:
    types: [closed, labeled]

permissions:
  contents: read
  issues: write # adding the 'has: port to stable' and 'has: backport failed' label
  pull-requests: write # creating backport pull requests

defaults:
  run:
    shell: bash

jobs:
  backport:
    name: Backport Pull Request
    if: vars.NIXPKGS_CI_CLIENT_ID && github.event.pull_request.merged == true && (github.event.action != 'labeled' || startsWith(github.event.label.name, 'backport'))
    runs-on: ubuntu-slim
    timeout-minutes: 3
    steps:
      # Use a GitHub App to create the PR so that CI gets triggered
      # The App is scoped to Repository > Contents and Pull Requests: write for Nixpkgs
      - uses: actions/create-github-app-token@bcd2ba49218906704ab6c1aa796996da409d3eb1 # v3.2.0
        id: app-token
        with:
          client-id: ${{ vars.NIXPKGS_CI_CLIENT_ID }}
          private-key: ${{ secrets.NIXPKGS_CI_APP_PRIVATE_KEY }}
          permission-contents: write
          permission-pull-requests: write
          permission-workflows: write

      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          ref: ${{ github.event.pull_request.head.sha }}
          token: ${{ steps.app-token.outputs.token }}
          persist-credentials: true

      - name: Log current API rate limits
        env:
          GH_TOKEN: ${{ steps.app-token.outputs.token }}
        run: gh api /rate_limit | jq

      - name: Create backport PRs
        id: backport
        uses: korthout/backport-action@66065406958f46e82238fd59546f5a99e69e22aa # v4.5.2
        with:
          # Config README: https://github.com/korthout/backport-action#backport-action
          add_author_as_reviewer: true
          copy_labels_pattern: 'severity:\ssecurity'
          github_token: ${{ steps.app-token.outputs.token }}
          pull_description: |-
            Bot-based backport to `${target_branch}`, triggered by a label in #${pull_number}.

            **Before merging, ensure that this backport is [acceptable for the release](https://github.com/NixOS/nixpkgs/blob/master/CONTRIBUTING.md#changes-acceptable-for-releases).**

            Even as a non-committer, if you find that it is not acceptable, leave a comment.

            > [!TIP]
            > If you maintain all packages touched by this pull request, and they are all located under `pkgs/by-name/*`, you can comment **`@NixOS/nixpkgs-merge-bot merge`** to automatically merge this PR using the [`nixpkgs-merge-bot`](https://github.com/NixOS/nixpkgs/blob/master/ci/README.md#nixpkgs-merge-bot).

      - name: Log current API rate limits
        env:
          GH_TOKEN: ${{ steps.app-token.outputs.token }}
        run: gh api /rate_limit | jq

      - name: "Add 'has: port to stable' label"
        if: steps.backport.outputs.created_pull_numbers != ''
        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
        with:
          # Not using the app on purpose to avoid triggering another workflow run after adding this label.
          script: |
            await github.rest.issues.addLabels({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.payload.pull_request.number,
              labels: [ '8.has: port to stable' ]
            })

      - name: "Add 'has: failed backport' label"
        if: steps.backport.outputs.was_successful == 'false'
        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
        with:
          # Not using the app on purpose to avoid triggering another workflow run after adding this label.
          script: |
            await github.rest.issues.addLabels({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.payload.pull_request.number,
              labels: [ '8.has: failed backport' ]
            })