PR_summary.yml

name: Post PR summary comment

on:
  pull_request:

jobs:
  build:
    name: "post-or-update-summary-comment"
    runs-on: ubuntu-latest

    steps:
    - name: Checkout code
      uses: actions/checkout@v4
      with:
        fetch-depth: 0

    - name: Set up Python
      uses: actions/setup-python@v5
      with:
        python-version: 3.12

    - name: Install dependencies
      run: |
        python -m pip install --upgrade pip
        sudo apt-get install -y jq
        # If you have additional dependencies, install them here

    - name: Get changed files
      run: |
        git fetch origin ${{ github.base_ref }}  # fetch the base branch
        git diff --name-only origin/${{ github.base_ref }}... > changed_files.txt  # get the list of changed files

    - name: Compute transitive imports
      run: |
        # the checkout dance, to avoid a detached head
        git checkout master
        git checkout -
        currentHash="$(git rev-parse HEAD)"

        # Compute the counts for the HEAD of the PR
        python ./scripts/count-trans-deps.py "Mathlib/" > head.json

        # Checkout the merge base
        git checkout "$(git merge-base master ${{ github.sha }})"

        # Compute the counts for the merge base
        python ./scripts/count-trans-deps.py "Mathlib/" > base.json

        # switch back to the current branch: the `declarations_diff` script should be here
        git checkout "${currentHash}"
    - name: Post or update the summary comment
      env:
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        BRANCH_NAME: ${{ github.head_ref }}
      run: |
        PR="${{ github.event.pull_request.number }}"
        title="### PR summary"

        graphAndHighPercentReports=$(python ./scripts/import-graph-report.py base.json head.json changed_files.txt)

        ## Import count comment
        importCount=$(
          printf '%s\n' "${graphAndHighPercentReports}" | sed '/^Import changes exceeding/Q'
          ./scripts/import_trans_difference.sh
        )

        ## High percentage imports
        high_percentages=$(
          printf '%s\n' "${graphAndHighPercentReports}" | sed -n '/^Import changes exceeding/,$p'
        )
        # if there are files with large increase in transitive imports, then we add the `large-import` label
        if [ -n "${high_percentages}" ]
        then
          high_percentages=$'\n\n'"${high_percentages}"
          gh pr edit "${PR}" --add-label large-import
        else # otherwise, we remove the label
          gh pr edit "${PR}" --remove-label large-import
        fi

        if [ "$(printf '%s' "${importCount}" | wc -l)" -gt 12 ]
        then
          importCount="$(printf '<details><summary>\n\n%s\n\n</summary>\n\n%s\n\n</details>\n' "#### Import changes for modified files" "${importCount}")"
        else
          importCount="$(printf '#### Import changes for modified files\n\n%s\n' "${importCount}")"
        fi

        ## Declarations' diff comment
        declDiff=$(./scripts/declarations_diff.sh)
        if [ "$(printf '%s' "${declDiff}" | wc -l)" -gt 15 ]
        then
          declDiff="$(printf '<details><summary>\n\n%s\n\n</summary>\n\n%s\n\n</details>\n' "#### Declarations diff" "${declDiff}")"
        else
          declDiff="$(printf '#### Declarations diff\n\n%s\n' "${declDiff}")"
        fi
        git checkout "${BRANCH_NAME}"
        currentHash="$(git rev-parse HEAD)"
        hashURL="https://github.com/${{ github.repository }}/pull/${{ github.event.pull_request.number }}/commits/${currentHash}"

        ## Technical debt changes
        techDebtVar="$(./scripts/technical-debt-metrics.sh pr_summary)"

        message="$(printf '%s [%s](%s)%s\n\n%s\n\n---\n\n%s\n\n---\n\n%s\n' "${title}" "$(git rev-parse --short HEAD)" "${hashURL}" "${high_percentages}" "${importCount}" "${declDiff}" "${techDebtVar}")"

        ./scripts/update_PR_comment.sh "${message}" "${title}" "${PR}"