import pickle
import pandas as pd

categorical = ['PULocationID', 'DOLocationID']

def read_data(filename):
    df = pd.read_parquet(filename)
    df['duration'] = df.tpep_dropoff_datetime - df.tpep_pickup_datetime
    df['duration'] = df.duration.dt.total_seconds() / 60
    df = df[(df.duration >= 1) & (df.duration <= 60)].copy()
    df[categorical] = df[categorical].fillna(-1).astype('int').astype('str')
    return df

def run(year: int, month: int):
    with open('model.bin', 'rb') as f_in:
        dv, model = pickle.load(f_in)

    url = f"https://d37ci6vzurychx.cloudfront.net/trip-data/yellow_tripdata_{year:04d}-{month:02d}.parquet"
    df = read_data(url)

    dicts = df[categorical].to_dict(orient='records')
    X_val = dv.transform(dicts)
    y_pred = model.predict(X_val)

    df['ride_id'] = f'{year:04d}/{month:02d}_' + df.index.astype('str')
    df_result = pd.DataFrame({'ride_id': df['ride_id'], 'predicted_duration': y_pred})

    output_file = f'output_{year:04d}_{month:02d}.parquet'
    df_result.to_parquet(output_file, engine='pyarrow', index=False)
    
    return output_file, y_pred.mean()