pr-import.yml

# Import Subrepo PR Workflow
# --------------------------
# This workflow imports an open PR from a sub-repository into the monorepo.
# It is intended for maintainers to migrate pending pull requests from
# the subrepos, to help developers onboard to the monorepo sooner.
#
# Trigger: Manually via `workflow_dispatch` with the following inputs:
#   - subrepo-prefix:     Path within the monorepo where the subrepo lives (e.g., "projects/rocblas")
#   - subrepo-pr-number:  PR number in the subrepo to import
#   - subrepo-repo:       Full subrepo or fork name (e.g., "ROCm/rocBLAS" or "user/rocBLAS-fork")
#   - subrepo-upstream:   Canonical subrepo repo name (e.g., "ROCm/rocBLAS")
#
# Steps:
#   1. Validate that the caller has 'admin' or 'maintain' permission on the monorepo
#   2. Generate a GitHub App token for authenticated API access
#   3. Checkout only the necessary parts of the monorepo (sparse checkout)
#   4. Fetch PR metadata from the subrepo using GitHub CLI
#   5. Create a new branch and import the PR using `git subtree pull`
#   6. Create a corresponding draft PR in the monorepo with metadata preserved
#
# Notes:
# - This workflow requires GitHub App credentials (APP_ID and APP_PRIVATE_KEY)
# - The resulting monorepo PR is a draft and includes attribution to the original author

name: Import Subrepo PR

on:
  workflow_dispatch:
    inputs:
      subrepo-prefix:
        description: "Monorepo path prefix (e.g., projects/rocblas)"
        required: true
      subrepo-pr-number:
        description: "Subrepo PR number to import"
        required: true
      subrepo-repo:
        description: "Full name of subrepo repo or fork (e.g., ROCm/rocBLAS or user/rocBLAS-fork)"
        required: true
      subrepo-upstream:
        description: "Canonical subrepo repo (e.g., ROCm/rocBLAS)"
        required: true
      monorepo-target-branch:
        description: "Target branch in the monorepo (default: develop)"
        required: false
        default: "develop"

jobs:
  import:
    runs-on: ubuntu-24.04
    steps:
      - name: Validate maintainer permissions
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          echo "Actor is: ${{ github.actor }}"
          PERMISSION=$(gh api \
            repos/${{ github.repository }}/collaborators/${{ github.actor }}/permission \
            --jq .permission)
          if [[ "$PERMISSION" != "admin" && "$PERMISSION" != "maintain" ]]; then
            echo "❌ User ${{ github.actor }} is not authorized to run this workflow"
            exit 1
          fi

      - name: Generate a token
        id: generate-token
        uses: actions/create-github-app-token@a8d616148505b5069dccd32f177bb87d7f39123b # v2.1.1
        with:
          app-id: ${{ secrets.APP_ID }}
          private-key: ${{ secrets.APP_PRIVATE_KEY }}
          owner: ${{ github.repository_owner }}

      - name: Checkout code
        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
        with:
          sparse-checkout: |
            .github
            ${{ github.event.inputs.subrepo-prefix }}
          sparse-checkout-cone-mode: true
          token: ${{ steps.generate-token.outputs.token }}
          fetch-depth: 0  #for subtree operations

      - name: Set up Git user
        run: |
          git config user.name "assistant-librarian[bot]"
          git config user.email "assistant-librarian[bot]@users.noreply.github.com"

      - name: Fetch subrepo PR info using gh
        id: prdata
        env:
          GH_TOKEN: ${{ steps.generate-token.outputs.token }}
        run: |
          PR_JSON=$(gh pr view ${{ github.event.inputs.subrepo-pr-number }} \
            --repo ${{ github.event.inputs.subrepo-upstream }} \
            --json title,body,headRefName,headRepository,isDraft \
            --jq '{title: .title, body: .body, head_ref: .headRefName, head_repo: .headRepository.cloneUrl, is_draft: .isDraft}')

          echo "$PR_JSON" > pr.json

          # properly escape backticks in title
          TITLE=$(jq -r .title pr.json | sed 's/`/\\`/g')
          echo "title=$TITLE" >> $GITHUB_OUTPUT

          {
            echo 'body<<EOF'
            jq -r .body pr.json
            echo 'EOF'
          } >> $GITHUB_OUTPUT

          echo "head_ref=$(jq -r .head_ref pr.json)" >> $GITHUB_OUTPUT
          echo "head_repo=$(jq -r .head_repo pr.json)" >> $GITHUB_OUTPUT
          echo "is_draft=$(jq -r .is_draft pr.json)" >> $GITHUB_OUTPUT

      - name: Create new branch for import
        id: import-branch
        run: |
          git fetch origin ${{ github.event.inputs.monorepo-target-branch }}
          git checkout ${{ github.event.inputs.monorepo-target-branch }}
          SANITIZED_BASE=$(echo "${{ github.event.inputs.monorepo-target-branch }}" | sed 's|/|_|g')
          SANITIZED_REPO=$(echo "${{ github.event.inputs.subrepo-repo }}" | sed 's|/|_|g')
          SANITIZED_REF=$(echo "${{ steps.prdata.outputs.head_ref }}" | sed 's|/|_|g')
          IMPORT_BRANCH="import/${SANITIZED_BASE}/${SANITIZED_REPO}/${SANITIZED_REF}"
          echo "import_branch=$IMPORT_BRANCH" >> $GITHUB_OUTPUT
          git checkout -b "$IMPORT_BRANCH"

      - name: Split subrepo prefix from main branch
        run: |
          git subtree pull --prefix=${{ github.event.inputs.subrepo-prefix }} https://github.com/${{ github.event.inputs.subrepo-repo }} ${{ steps.prdata.outputs.head_ref }}
          git push origin ${{ steps.import-branch.outputs.import_branch }}

      - name: Create monorepo PR
        env:
          GH_TOKEN: ${{ steps.generate-token.outputs.token }}
        run: |
          IMPORT_BRANCH="import/${{ github.event.inputs.subrepo-prefix }}/pr-${{ github.event.inputs.subrepo-pr-number }}"
          PR_TITLE="${{ steps.prdata.outputs.title }}"
          UPSTREAM_REPO="${{ github.event.inputs.subrepo-upstream }}"
          SUBREPO_REPO="${{ github.event.inputs.subrepo-repo }}"
          SUBREPO_PR_NUMBER="${{ github.event.inputs.subrepo-pr-number }}"
          SUBREPO_URL="https://github.com/$UPSTREAM_REPO/pull/$SUBREPO_PR_NUMBER"
          AUTHOR=$(gh pr view "$SUBREPO_PR_NUMBER" --repo "$UPSTREAM_REPO" --json author --jq .author.login)

          echo "${{ steps.prdata.outputs.body }}" > pr_body.txt
          {
            echo ""
            echo "---"
            echo "🔁 Imported from [$UPSTREAM_REPO#$SUBREPO_PR_NUMBER]($SUBREPO_URL)"
            echo "🧑‍💻 Originally authored by @$AUTHOR"
          } >> pr_body.txt

          DRAFT_FLAG=""
          if [[ "${{ steps.prdata.outputs.is_draft }}" == "true" ]]; then
            DRAFT_FLAG="--draft"
          fi

          gh pr create \
            --base "${{ github.event.inputs.monorepo-target-branch }}" \
            --head "${{ steps.import-branch.outputs.import_branch }}" \
            --title "$PR_TITLE" \
            --label "imported pr" \
            $DRAFT_FLAG \
            --body-file pr_body.txt