from sqlalchemy import create_engine
import pandas as pd

# Database connection
engine = create_engine("mysql+pymysql://root:Kfsh&rc9788@localhost/car2db01022025")

try:
    # Load car_generation table
    car_generation_query = "SELECT * FROM car_generation;"
    car_generation_df = pd.read_sql(car_generation_query, engine)

    # Load car_serie table
    car_serie_query = "SELECT * FROM car_serie;"
    car_serie_df = pd.read_sql(car_serie_query, engine)

    # Perform a LEFT JOIN to keep all car series and merge with car generations
    merged_df = pd.merge(car_serie_df, car_generation_df, on="id_car_generation", how="left")

    # Select and rename the relevant columns
    final_df = merged_df.rename(columns={
        "id_car_serie": "id_car_serie",
        "id_car_model_x": "id_car_model",  # Ensure correct column selection
        "name_y": "generation_name",  # Car generation name
        "name_x": "serie_name",  # Car series name
        "year_begin": "year_begin",
        "year_end": "year_end"
    })[["id_car_serie", "id_car_model", "generation_name", "serie_name", "year_begin", "year_end"]]

    # Save the filtered data to a JSON file
    final_df.to_json("merged_car_data.json", orient="records", indent=4)
    print("Filtered merged data saved to 'merged_car_data.json'.")

except Exception as e:
    print("Error:", e)