name: 'Evals: PR Guidance'

on:
  pull_request:
    paths:
      - 'packages/core/src/**/*.ts'
      - '!**/*.test.ts'
      - '!**/*.test.tsx'

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

jobs:
  provide-guidance:
    name: 'Model Steering Guidance'
    runs-on: 'ubuntu-latest'
    if: "github.repository == 'google-gemini/gemini-cli'"
    steps:
      - name: 'Checkout'
        uses: 'actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955' # ratchet:actions/checkout@v4
        with:
          fetch-depth: 0

      - name: 'Set up Node.js'
        uses: 'actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020' # ratchet:actions/setup-node@v4.4.0
        with:
          node-version-file: '.nvmrc'
          cache: 'npm'

      - name: 'Detect Steering Changes'
        id: 'detect'
        run: |
          STEERING_DETECTED=$(node scripts/changed_prompt.js --steering-only)
          echo "STEERING_DETECTED=$STEERING_DETECTED" >> "$GITHUB_OUTPUT"

      - name: 'Analyze PR Content'
        if: "steps.detect.outputs.STEERING_DETECTED == 'true'"
        id: 'analysis'
        env:
          GH_TOKEN: '${{ secrets.GITHUB_TOKEN }}'
        run: |
          # Check for behavioral eval changes
          EVAL_CHANGES=$(git diff --name-only origin/${{ github.base_ref }}...HEAD | grep "^evals/" || true)
          if [ -z "$EVAL_CHANGES" ]; then
            echo "MISSING_EVALS=true" >> "$GITHUB_OUTPUT"
          fi

          # Check if user is a maintainer (has write/admin access)
          USER_PERMISSION=$(gh api repos/${{ github.repository }}/collaborators/${{ github.actor }}/permission --jq '.permission')
          if [[ "$USER_PERMISSION" == "admin" || "$USER_PERMISSION" == "write" ]]; then
            echo "IS_MAINTAINER=true" >> "$GITHUB_OUTPUT"
          fi

      - name: 'Post Guidance Comment'
        if: "steps.detect.outputs.STEERING_DETECTED == 'true'"
        uses: 'thollander/actions-comment-pull-request@65f9e5c9a1f2cd378bd74b2e057c9736982a8e74' # ratchet:thollander/actions-comment-pull-request@v3
        with:
          comment-tag: 'eval-guidance-bot'
          message: |
            ### 🧠 Model Steering Guidance

            This PR modifies files that affect the model's behavior (prompts, tools, or instructions).

            ${{ steps.analysis.outputs.MISSING_EVALS == 'true' && '- ⚠️ **Consider adding Evals:** No behavioral evaluations (`evals/*.eval.ts`) were added or updated in this PR. Consider adding a test case to verify the new behavior and prevent regressions.' || '' }}
            ${{ steps.analysis.outputs.IS_MAINTAINER == 'true' && '- 🚀 **Maintainer Reminder:** Please ensure that these changes do not regress results on benchmark evals before merging.' || '' }}

            ---
            *This is an automated guidance message triggered by steering logic signatures.*