# This workflow automatically adds the appropriate reviewers to a pull request.
#
# The workflow directly reuses logic in the BaseTools/Scripts/GetMaintainer.py script
# to determine the appropriate reviewers, so it matches what a user would see running
# the script locally.
#
# Copyright (c) Microsoft Corporation.
# SPDX-License-Identifier: BSD-2-Clause-Patent

name: Add Pull Request Reviewers

on:
  pull_request_target:
    branches:
      - master
    types: [opened, ready_for_review, reopened, synchronize]

env:
  GET_MAINTAINER_REL_PATH: "BaseTools/Scripts/GetMaintainer.py"

jobs:
  auto-request-review:
    name: Add Pull Request Reviewers
    # Do not run on draft PRs and only run on PRs in the tianocore organization
    if: ${{ github.event.pull_request.draft == false && github.repository_owner == 'tianocore' }}
    runs-on: ubuntu-latest

    permissions:
      contents: read
      issues: write
      pull-requests: write

    steps:
      # Reduce checkout time with sparse-checkout
      #   - .github: Contains the scripts to interact with Github and add reviewers
      #   - BaseTools/Scripts: Contains the GetMaintainer.py script
      #   - Maintainers.txt: Contains the list of maintainers for the repository
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 1
          sparse-checkout: |
            .github
            BaseTools/Scripts
            Maintainers.txt

      - name: Setup Python
        uses: actions/setup-python@v5
        with:
          python-version: '3.x'
          cache: 'pip'
          cache-dependency-path: '.github/scripts/requirements.txt'

      - name: Install PIP Modules
        run: pip install -r .github/scripts/requirements.txt --upgrade

      - name: Add Reviewers to Pull Request
        shell: python
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          ORG_NAME: ${{ github.repository_owner }}
          PR_NUMBER: ${{ github.event.number}}
          REPO_NAME: ${{ github.event.pull_request.base.repo.name }}
          TARGET_BRANCH: ${{ github.event.pull_request.base.ref }}
          WORKSPACE_PATH: ${{ github.workspace }}
        run: |
            import git
            import os
            import sys

            sys.path.append(os.path.join(os.environ["WORKSPACE_PATH"], ".github"))
            from scripts import GitHub

            WORKSPACE_PATH = os.environ["WORKSPACE_PATH"]
            GET_MAINTAINER_LOCAL_PATH = os.path.join(
                WORKSPACE_PATH, os.environ["GET_MAINTAINER_REL_PATH"]
            )

            # Step 1: Get the GitHub created PR commit SHA (contains all changes in a single commit)
            pr_commit_sha = GitHub.get_pr_sha(
                os.environ["GH_TOKEN"],
                os.environ["ORG_NAME"],
                os.environ["REPO_NAME"],
                int(os.environ["PR_NUMBER"]),
            )
            if not pr_commit_sha:
                sys.exit(1)

            print(
                f"::notice title=PR Commit SHA::Looking at files in consolidated PR commit: {pr_commit_sha}"
            )

            # Step 2: Fetch only the PR commit to get the files changed in the PR
            git.Repo(WORKSPACE_PATH).remotes.origin.fetch(pr_commit_sha, depth=1)

            # Step 3: Get the list of reviewers for the PR
            reviewers = GitHub.get_reviewers_for_range(
                WORKSPACE_PATH, GET_MAINTAINER_LOCAL_PATH, pr_commit_sha, pr_commit_sha
            )
            if not reviewers:
                print("::notice title=No New Reviewers Found!::No reviewers found for this PR.")
                sys.exit(0)

            print(
                f"::notice title=Preliminary Reviewer List::Total reviewer candidates for "
                f"PR {os.environ['PR_NUMBER']}: {', '.join(reviewers)}"
            )

            # Step 4: Add the reviewers to the PR
            #         Note the final requested reviewer list in the workflow run for reference
            new_reviewers = GitHub.add_reviewers_to_pr(
                os.environ["GH_TOKEN"],
                os.environ["ORG_NAME"],
                os.environ["REPO_NAME"],
                int(os.environ["PR_NUMBER"]),
                reviewers,
            )
            if new_reviewers:
                print(
                    f"::notice title=New Reviewers Added::New reviewers requested for PR "
                    f"{os.environ['PR_NUMBER']}: {', '.join(new_reviewers)}"
                )
            else:
                print(
                    "::notice title=No New Reviewers Added::No reviewers were found that "
                    "should be newly requested."
                )