# Rejects PR if requirements files are inconsistent.
#
# This will produce a failing check for any PR that does not produce a
# clean run of `make compile-requirements` on Linux.

name: Consistent Python dependencies

on:
  pull_request:
  merge_group:

defaults:
  run:
    shell: bash # strict bash

jobs:
  check-requirements:
    name: Compile requirements
    runs-on: ubuntu-24.04

    steps:
      # Always checkout the code because we don't always have a PR url.
      - uses: actions/checkout@v6

      # Only run remaining steps if there are changes to requirements/**
      # We do this instead of using path based short-circuiting.
      # see https://stackoverflow.com/questions/77996177/how-can-i-handle-a-required-check-that-isnt-always-triggered
      # for some more details.
      - name: "Decide whether to short-circuit"
        run: |
          if [[ "${{ github.event_name }}" == "pull_request" ]]; then
            BASE_SHA="${{ github.event.pull_request.base.sha }}"
          else
            BASE_SHA="${{ github.event.merge_group.base_sha }}"
          fi

          # Fetch the base sha so we can compare to it. It's not checked out by
          # default.
          git fetch origin "$BASE_SHA"

          # The ^"? is because git may quote weird file paths
          if git diff --name-only "$BASE_SHA" | grep -P '^"?((requirements/)|(scripts/.*?/requirements/))'; then
            echo "RELEVANT=true" >> "$GITHUB_ENV"
          fi

      - uses: actions/setup-python@v6
        if: ${{ env.RELEVANT == 'true' }}
        with:
          python-version: '3.11'

      - name: "Recompile requirements"
        if: ${{ env.RELEVANT == 'true' }}
        run: |
          make compile-requirements

      - name: Fail if compiling requirements caused changes
        if: ${{ env.RELEVANT == 'true' }}
        run: |
          SUMMARY_HELP=$(cat <<'EOMARKDOWN'
          # Inconsistent Python dependencies

          It appears that the Python dependencies in this PR are inconsistent: A re-run of
          `make compile-requirements` produced changes. This might mean that your PR would
          fail to deploy properly in production, or could have inconsistent behavior for
          developers.

          Please see the requirements README for information on how to resolve this:
          https://github.com/openedx/openedx-platform/blob/master/requirements/README.rst#inconsistent-dependencies
          EOMARKDOWN
          )

          make_summary () {
              echo "$SUMMARY_HELP"
              echo
              echo "----"
              echo
              echo "Diff follows:"
              echo
              echo '```'
              git diff || true
              echo '```'
          }

          git diff --quiet --exit-code || {
              # Job Summaries are cool, but echo to the job log as well, because
              # that's where the PR checks will actually link to.
              make_summary | tee -a $GITHUB_STEP_SUMMARY
              exit 1
          }