import pandas as pd

def assign_badges(csv_file):
    """
    Assigns badges based on quiz performance, speed, and consistency.
    
    Expected CSV columns:
    - Name
    - AverageScore (0–100)
    - TimeTaken (in minutes)
    - Consistency (0–1 scale)

    Returns:
        str: Badge assignment summary.
    """
    try:
        df = pd.read_csv(csv_file)

        # Validate columns
        expected_cols = {"Name", "AverageScore", "TimeTaken", "Consistency"}
        if not expected_cols.issubset(df.columns):
            return "❌ CSV must contain: Name, AverageScore, TimeTaken, Consistency"

        result = "🏅 Badge Assignment Summary:\n\n"
        for index, row in df.iterrows():
            name = row["Name"]
            score = row["AverageScore"]
            time_taken = row["TimeTaken"]
            consistency = row["Consistency"]

            # Rule-based badge logic
            if score >= 85 and consistency >= 0.9 and time_taken <= 20:
                badge = "🥇 Gold"
            elif score >= 70 and consistency >= 0.7 and time_taken <= 30:
                badge = "🥈 Silver"
            elif score >= 50:
                badge = "🥉 Bronze"
            else:
                badge = "❌ No Badge"

            result += f"{name}: {badge}\n"

        return result

    except Exception as e:
        return f"Error assigning badges: {str(e)}"