import os
import pandas as pd
import matplotlib
matplotlib.use("Agg")  # Prevents GUI-related issues in Flask

import matplotlib.pyplot as plt
import seaborn as sns


def load_data(file_path: str) -> pd.DataFrame:
    """Loads the scraped data from a CSV file into a Pandas DataFrame."""
    if not os.path.exists(file_path):
        raise FileNotFoundError(f"File {file_path} not found.")

    df = pd.read_csv(file_path)
    df["timestamp"] = pd.to_datetime(df["timestamp"], errors="coerce")
    df["last_action"] = pd.to_datetime(df["last_action"], errors="coerce")

    return df

def generate_statistics(df: pd.DataFrame):
    """Generates activity statistics grouped by hour."""
    df["hour"] = df["timestamp"].dt.hour
    return df.groupby("hour").size()

def plot_activity_distribution(df: pd.DataFrame, output_path="activity_distribution.png"):
    """Plots user activity distribution and saves the figure."""

    # Ensure the directory exists
    static_dir = os.path.join("app", "static", "plots")
    output_path = os.path.join(static_dir, output_path)
    os.makedirs(static_dir, exist_ok=True)

    # Convert timestamp column to datetime (if not already)
    if not pd.api.types.is_datetime64_any_dtype(df["timestamp"]):
        df["timestamp"] = pd.to_datetime(df["timestamp"], errors="coerce")

    df["hour"] = df["timestamp"].dt.hour
    activity_counts = df.groupby("hour").size().reset_index(name="count")

    # Use non-GUI backend for Matplotlib
    plt.figure(figsize=(10, 5))

    # Fix Seaborn Warning: Assign `hue` explicitly
    sns.barplot(x="hour", y="count", data=activity_counts, hue="hour", palette="Blues", legend=False)

    plt.xlabel("Hour of the Day")
    plt.ylabel("Activity Count")
    plt.title("User Activity Distribution")
    plt.xticks(range(0, 24))

    # Save the plot file safely
    plt.savefig(output_path, bbox_inches="tight")
    plt.close()

    # Verify the file exists after saving
    if not os.path.exists(output_path):
        raise FileNotFoundError(f"Plot could not be saved to {output_path}")

    return output_path