"""
NeoSyn - query_engine.py

This module processes natural language queries to determine user intent:
- Whether to generate synthetic data
- Whether to summarize data
- Whether to plot distributions

Author: Saivivek Katkuri
Date: June 2025
"""

import re

def parse_query(query: str) -> dict:
    """
    Parses the user query and extracts intent, table, column, and sample size.

    Args:
        query (str): User's natural language query.

    Returns:
        dict: Dictionary with intent, table, column (if any), and num_samples.
    """
    intent = None
    table = None
    column = None
    num_samples = 10  # Default samples

    # Lowercase for easy matching
    q = query.lower()

    # Determine intent
    if "generate" in q or "synthetic" in q:
        intent = "generate"
    elif "summarize" in q or "summary" in q:
        intent = "summarize"
    elif "plot" in q or "distribution" in q or "chart" in q:
        intent = "plot"
    else:
        intent = "unknown"

    # Extract table name from query (simple match for demo)
    for t in ["sales", "customers", "products", "transactions"]:
        if t in q:
            table = t
            break

    # Extract column name (optional, e.g., "plot price distribution")
    match = re.search(r"(plot|distribution|of)\s+(\w+)", q)
    if match:
        column = match.group(2)

    # Extract number of samples if mentioned (e.g., "generate 500 samples")
    match_samples = re.search(r"(\d+)\s+(samples|records|rows)", q)
    if match_samples:
        num_samples = int(match_samples.group(1))

    return {
        "intent": intent,
        "table": table,
        "column": column,
        "num_samples": num_samples
    }