Add automated PR reviewer rotation system

- Add GitHub Action workflow for automatic reviewer assignment
- Create Python script that reads reviewers from MAINTAINERS.md
- Implement 3-week sprint-based rotation cycle
- Preserve existing reviewer assignments (manual/GitHub auto)
- Add configuration for start date and rotation cycle

Author: gursewak1997

.github/auto-review-config.yml

@@ -0,0 +1,6 @@
+# Auto-reviewer configuration
+# Start date for the rotation cycle (YYYY-MM-DD format)
+start_date: "2025-08-04"
+
+# Rotation cycle in weeks
+rotation_cycle_weeks: 3

.github/scripts/assign_reviewer.py

@@ -0,0 +1,184 @@
+#!/usr/bin/env python3
+"""
+Auto-reviewer assignment script for GitHub PRs.
+Rotates through a list of reviewers based on a weekly cycle.
+Automatically reads reviewers from MAINTAINERS.md
+"""
+
+import os
+import sys
+import yaml
+import subprocess
+import re
+from datetime import datetime
+from typing import List, Optional
+
+
+def load_config(config_path: str) -> dict:
+    """Load the reviewer configuration from YAML file."""
+    try:
+        with open(config_path, 'r') as f:
+            return yaml.safe_load(f)
+    except FileNotFoundError:
+        print(f"Error: Configuration file {config_path} not found")
+        sys.exit(1)
+    except yaml.YAMLError as e:
+        print(f"Error parsing YAML configuration: {e}")
+        sys.exit(1)
+
+
+def extract_reviewers_from_maintainers() -> List[str]:
+    """Extract GitHub usernames from MAINTAINERS.md file."""
+    maintainers_path = 'MAINTAINERS.md'
+    reviewers = []
+    
+    try:
+        with open(maintainers_path, 'r') as f:
+            content = f.read()
+        
+        # Look for GitHub usernames in the format [username](https://github.com/...)
+        # This regex matches the GitHub ID column in the maintainers table
+        pattern = r'\[([^\]]+)\]\(https://github\.com/[^)]+\)'
+        matches = re.findall(pattern, content)
+        
+        if matches:
+            reviewers = matches
+            print(f"Found {len(reviewers)} reviewers from MAINTAINERS.md: {', '.join(reviewers)}")
+        else:
+            print("Warning: No GitHub usernames found in MAINTAINERS.md")
+            
+    except FileNotFoundError:
+        print(f"Error: MAINTAINERS.md file not found")
+        sys.exit(1)
+    except Exception as e:
+        print(f"Error reading MAINTAINERS.md: {e}")
+        sys.exit(1)
+    
+    return reviewers
+
+
+def get_current_sprint_info(config: dict) -> dict:
+    """Calculate current sprint information."""
+    start_date_str = config.get('start_date')
+    rotation_cycle_weeks = config.get('rotation_cycle_weeks', 3)
+    
+    if not start_date_str:
+        return {"sprint_number": 1, "week_in_sprint": 1}
+    
+    try:
+        start_date = datetime.strptime(start_date_str, "%Y-%m-%d")
+        current_date = datetime.now()
+        weeks_since_start = (current_date - start_date).days / 7
+        
+        sprint_number = int(weeks_since_start // rotation_cycle_weeks) + 1
+        week_in_sprint = int(weeks_since_start % rotation_cycle_weeks) + 1
+        
+        return {
+            "sprint_number": sprint_number,
+            "week_in_sprint": week_in_sprint,
+            "total_weeks": int(weeks_since_start)
+        }
+    except ValueError:
+        return {"sprint_number": 1, "week_in_sprint": 1}
+
+
+def calculate_current_reviewer(config: dict, reviewers: List[str]) -> Optional[str]:
+    """Calculate the current reviewer based on the rotation schedule."""
+    start_date_str = config.get('start_date')
+    rotation_cycle_weeks = config.get('rotation_cycle_weeks', 3)
+    
+    if not start_date_str or not reviewers:
+        print("Error: Missing start_date or no reviewers found")
+        return None
+    
+    try:
+        start_date = datetime.strptime(start_date_str, "%Y-%m-%d")
+    except ValueError:
+        print(f"Error: Invalid start_date format: {start_date_str}")
+        return None
+    
+    current_date = datetime.now()
+    weeks_since_start = (current_date - start_date).days / 7
+    
+    # Calculate which week in the rotation cycle we're in
+    week_in_cycle = int(weeks_since_start) % rotation_cycle_weeks
+    
+    # Map week to reviewer (assuming one reviewer per week)
+    reviewer_index = week_in_cycle % len(reviewers)
+    
+    return reviewers[reviewer_index]
+
+
+def get_existing_reviewers(pr_number: str) -> List[str]:
+    """Get list of reviewers already assigned to the PR."""
+    try:
+        result = subprocess.run(
+            ['gh', 'pr', 'view', pr_number, '--json', 'reviewRequests', '--jq', '.reviewRequests[].login'],
+            capture_output=True, text=True, check=True
+        )
+        return result.stdout.strip().split('\n') if result.stdout.strip() else []
+    except subprocess.CalledProcessError:
+        print(f"Warning: Could not fetch existing reviewers for PR {pr_number}")
+        return []
+
+
+def assign_reviewer(pr_number: str, reviewer: str) -> bool:
+    """Assign a reviewer to the PR using GitHub CLI."""
+    try:
+        subprocess.run(
+            ['gh', 'pr', 'edit', pr_number, '--add-reviewer', reviewer],
+            check=True, capture_output=True
+        )
+        print(f"Successfully assigned reviewer {reviewer} to PR {pr_number}")
+        return True
+    except subprocess.CalledProcessError as e:
+        print(f"Error assigning reviewer {reviewer} to PR {pr_number}: {e}")
+        return False
+
+
+def main():
+    """Main function to handle reviewer assignment."""
+    # Get PR number from environment variable
+    pr_number = os.environ.get('PR_NUMBER')
+    if not pr_number:
+        print("Error: PR_NUMBER environment variable not set")
+        sys.exit(1)
+    
+    # Load configuration (for start_date and rotation_cycle_weeks)
+    config_path = '.github/auto-review-config.yml'
+    config = load_config(config_path)
+    
+    # Extract reviewers from MAINTAINERS.md
+    reviewers = extract_reviewers_from_maintainers()
+    if not reviewers:
+        print("Error: No reviewers found in MAINTAINERS.md")
+        sys.exit(1)
+    
+    # Get sprint information
+    sprint_info = get_current_sprint_info(config)
+    print(f"Current sprint: {sprint_info['sprint_number']}, week: {sprint_info['week_in_sprint']}")
+    
+    # Calculate current reviewer
+    current_reviewer = calculate_current_reviewer(config, reviewers)
+    if not current_reviewer:
+        print("Error: Could not calculate current reviewer")
+        sys.exit(1)
+    
+    print(f"Assigned reviewer for this week: {current_reviewer}")
+    
+    # Get existing reviewers
+    existing_reviewers = get_existing_reviewers(pr_number)
+    
+    # Check if current reviewer is already assigned
+    if current_reviewer in existing_reviewers:
+        print(f"Reviewer {current_reviewer} is already assigned to PR {pr_number}")
+        return
+    
+    # Assign the current reviewer
+    success = assign_reviewer(pr_number, current_reviewer)
+    if not success:
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()

.github/workflows/auto-review.yml

@@ -0,0 +1,33 @@
+name: Auto Assign Reviewer
+
+on:
+  pull_request:
+    types: [opened, ready_for_review]
+
+jobs:
+  assign-reviewer:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        
+      - name: Setup Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.11'
+          
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install pyyaml
+          
+      - name: Authenticate with GitHub
+        run: |
+          echo "${{ secrets.GITHUB_TOKEN }}" | gh auth login --with-token
+          
+      - name: Assign reviewer
+        env:
+          PR_NUMBER: ${{ github.event.pull_request.number }}
+        run: |
+          python .github/scripts/assign_reviewer.py