# Enhanced Graph Legend Feature

## Overview
Expanded the graph legend to display each medicine individually with enhanced formatting and additional information about tracked medicines.

## Changes Made

### 1. Enhanced Legend Display (`src/graph_manager.py`)

#### Legend Formatting Improvements:
- **Multi-column Layout**: Legend now displays in 2 columns for better space usage
- **Improved Positioning**: Positioned at upper left with proper bbox anchoring
- **Enhanced Styling**: Added frame, shadow, and transparency for better readability
- **Font Optimization**: Uses smaller font size to fit more information

#### Medicine-Specific Information:
- **Average Dosage Display**: Each medicine shows average dosage in the legend
  - Format: `"Bupropion (avg: 125.5mg)"`
  - Calculated from all days with non-zero doses
- **Color-Coded Entries**: Each medicine maintains its distinct color in the legend
- **Tracked Medicine Indicator**: Shows medicines that are toggled on but have no dose data

### 2. Legend Configuration Details

```python
self.ax.legend(
    handles,
    labels,
    loc='upper left',           # Position
    bbox_to_anchor=(0, 1),      # Anchor point
    ncol=2,                     # 2 columns
    fontsize='small',           # Compact text
    frameon=True,               # Show frame
    fancybox=True,              # Rounded corners
    shadow=True,                # Drop shadow
    framealpha=0.9              # Semi-transparent background
)
```

### 3. Data Tracking Enhancements

#### Medicine Categorization:
- **`medicines_with_data`**: Medicines with actual dose recordings
- **`medicines_without_data`**: Medicines toggled on but without dose data

#### Average Calculation:
```python
total_medicine_dose = sum(daily_doses)
non_zero_doses = [d for d in daily_doses if d > 0]
avg_dose = total_medicine_dose / len(non_zero_doses)
```

## Features

### Enhanced Legend Display:
✅ **Multi-column Layout**: Efficient use of graph space
✅ **Medicine-Specific Info**: Average dosage displayed for each medicine
✅ **Color Coding**: Consistent color scheme for easy identification
✅ **Tracked Medicine Status**: Shows which medicines are being monitored
✅ **Professional Styling**: Frame, shadow, and transparency effects

### Information Provided:
- **Symptom Data**: Depression, Anxiety, Sleep, Appetite with descriptive labels
- **Medicine Doses**: Each medicine with average dosage calculation
- **Tracking Status**: Indication of medicines being tracked but without current dose data
- **Visual Consistency**: Color-coded entries matching the graph elements

### Example Legend Entries:
```
Depression (0:good, 10:bad)     Sleep (0:bad, 10:good)
Anxiety (0:good, 10:bad)        Appetite (0:bad, 10:good)
Bupropion (avg: 225.0mg)        Propranolol (avg: 12.5mg)
Tracked (no doses): hydroxyzine, gabapentin
```

## Benefits

### For Users:
- **Clear Identification**: Easy to see which medicines are displayed and their average doses
- **Data Context**: Understanding of dosage patterns at a glance
- **Tracking Awareness**: Knowledge of which medicines are being monitored
- **Professional Appearance**: Clean, organized legend that doesn't clutter the graph

### For Analysis:
- **Quick Reference**: Average doses visible without calculation
- **Pattern Recognition**: Color coding helps identify medicine effects
- **Data Completeness**: Clear indication of missing vs. present data
- **Visual Organization**: Structured layout for easy reading

## Technical Implementation

### Legend Components:
1. **Handles and Labels**: Retrieved from current plot elements
2. **Additional Info**: Dynamically added for medicines without data
3. **Dummy Handles**: Invisible rectangles for text-only legend entries
4. **Formatting**: Applied consistently across all legend elements

### Positioning Logic:
- **Upper Left**: Avoids interference with data plots
- **2-Column Layout**: Maximizes information density
- **Responsive**: Adjusts to available content

The enhanced legend provides comprehensive information about all displayed elements while maintaining a clean, professional appearance that enhances the overall user experience.