modules/visualizer.py

# modules/visualizer.py
import pandas as pd
import matplotlib.pyplot as plt
from datetime import datetime
import os
import logging

def load_status_log(log_file="server_status_log.csv"):
    """Load server status log from CSV file"""
    if not os.path.exists(log_file):
        raise FileNotFoundError(f"Log file not found: {log_file}")
    
    try:
        df = pd.read_csv(log_file, parse_dates=["timestamp"])
        return df
    except Exception as e:
        logging.error(f"Error loading log file: {e}")
        raise

def plot_uptime_trend(df, output_file="server_uptime_trend.png"):
    """Plot server uptime trend over time"""
    try:
        # Sort by timestamp
        df = df.sort_values("timestamp")
        
        # Convert status to boolean
        df["status_bool"] = df["status"].map({"UP": 1, "DOWN": 0})
        
        plt.figure(figsize=(12, 4))
        plt.plot(df["timestamp"], df["status_bool"], drawstyle='steps-post', 
                marker='o', linestyle='-', markersize=3, color='#1f77b4')
        
        plt.title("Server Uptime Trend", fontsize=14, pad=20)
        plt.xlabel("Time", fontsize=12)
        plt.ylabel("Status", fontsize=12)
        plt.yticks([0, 1], ["DOWN", "UP"])
        plt.grid(True, linestyle='--', alpha=0.5)
        plt.tight_layout()
        plt.savefig(output_file)
        plt.close()
        
        print(f"📈 Chart saved to: {output_file}")
        logging.info(f"Uptime trend chart saved to: {output_file}")
        return output_file
    except Exception as e:
        logging.error(f"Error plotting uptime trend: {e}")
        raise

def plot_uptime_summary(df, output_file="server_uptime_summary.png"):
    """Plot server uptime summary as pie chart"""
    try:
        # Calculate uptime percentage
        total = len(df)
        up = df[df["status"] == "UP"].shape[0]
        down = df[df["status"] == "DOWN"].shape[0]
        
        if total == 0:
            raise ValueError("No data in log file")
        
        uptime_pct = (up / total) * 100
        downtime_pct = (down / total) * 100
        
        labels = [f'UP ({uptime_pct:.1f}%)', f'DOWN ({downtime_pct:.1f}%)']
        sizes = [up, down]
        colors = ['#28a745', '#dc3545']
        
        plt.figure(figsize=(6, 6))
        wedges, texts, autotexts = plt.pie(sizes, labels=labels, autopct='%1.1f%%', 
                                          startangle=140, colors=colors)
        
        # Make percentage text white and bold
        for autotext in autotexts:
            autotext.set_color('white')
            autotext.set_fontweight('bold')
        
        plt.title("Server Uptime Summary", fontsize=14, pad=20)
        plt.axis('equal')
        plt.tight_layout()
        plt.savefig(output_file)
        plt.close()
        
        print(f"📊 Summary chart saved to: {output_file}")
        logging.info(f"Uptime summary chart saved to: {output_file}")
        return output_file
    except Exception as e:
        logging.error(f"Error plotting uptime summary: {e}")
        raise

def get_uptime_stats(df):
    """Get uptime statistics"""
    try:
        total = len(df)
        up = df[df["status"] == "UP"].shape[0]
        down = df[df["status"] == "DOWN"].shape[0]
        
        if total == 0:
            return {"total_checks": 0, "uptime_pct": 0, "downtime_pct": 0}
        
        uptime_pct = (up / total) * 100
        downtime_pct = (down / total) * 100
        
        return {
            "total_checks": total,
            "up_checks": up,
            "down_checks": down,
            "uptime_pct": round(uptime_pct, 2),
            "downtime_pct": round(downtime_pct, 2)
        }
    except Exception as e:
        logging.error(f"Error calculating uptime stats: {e}")
        raise