# src/intent.py

def detect_intent(text: str) -> str:
    """
    Fast rule-based intent detection.
    Returns one of: "code", "math", "civics", "exam_prep", "general".
    """
    if not text:
        return "general"
    t = text.lower()

    # Code-related keywords
    code_keys = ["python", "code", "error", "function", "class", "script", "import", "stack trace", "traceback", "bug"]
    if any(k in t for k in code_keys):
        return "code"

    # Math keywords
    math_keys = ["solve", "equation", "calculate", "simplify", "factor", "integrate", "differentiate", "sum", "prove", "find x", "x +"]
    if any(k in t for k in math_keys):
        return "math"

    # Civics / SST keywords (class 10)
    civics_keys = ["civics", "democracy", "constitution", "rights", "ncert", "class 10", "class 10th", "social studies", "sst"]
    if any(k in t for k in civics_keys):
        return "civics"

    # Exam prep keywords
    exam_keys = ["important questions", "exam", "board", "revision", "prepare", "question paper", "important", "mcq", "short answer"]
    if any(k in t for k in exam_keys):
        return "exam_prep"

    # Default
    return "general"