from flask import current_app, url_for
import os
import pandas as pd

def prepare_data(df):
    df["timestamp"] = pd.to_datetime(df["timestamp"])
    df["last_action"] = pd.to_datetime(df["last_action"])
    df["prev_timestamp"] = df.groupby("user_id")["timestamp"].shift(1)
    df["was_active"] = (df["timestamp"] - df["last_action"]) <= pd.Timedelta(seconds=60)
    df["was_active"] = df["was_active"].fillna(False)
    df['hour'] = df['timestamp'].dt.hour
    return df

def mk_plotdir(output_filename):
    plots_dir = os.path.join(current_app.root_path, "static", "plots")
    os.makedirs(plots_dir, exist_ok=True)

    output_path = os.path.join(plots_dir, output_filename)
    
    plot_url = url_for('static', filename=f'plots/{output_filename}', _external=True)

    return {'output_path': output_path, 'plot_url': plot_url}