import gradio as gr
import joblib
import numpy as np
import matplotlib.pyplot as plt

# Load the model - Make sure 'dynamic_pricing_model.pkl' is in the same directory
# or provide the full path to your model file.
try:
    model = joblib.load("dynamic_pricing_model.pkl")
except FileNotFoundError:
    print("Error: 'dynamic_pricing_model.pkl' not found. Please ensure the model file is in the correct directory.")
    print("For demonstration purposes, a dummy model will be used.")
    # Create a dummy model for demonstration if the actual model is not found
    class DummyModel:
        def predict(self, X):
            # Simple dummy prediction logic
            demand, stock, expiry, perishable = X[0]
            base_price = 100.0
            price = base_price + (demand * 0.5) - (stock * 0.2)
            if perishable and expiry > 0:
                price -= (10 - min(expiry, 10)) * 2 # Price drops as expiry nears
            return [max(10, price)] # Ensure price is not too low
    model = DummyModel()


# Prediction and chart generation
def predict_price_and_plot(forecasted_demand, stock, expiry_days, is_perishable):
    # Ensure inputs are numerical and handle potential edge cases for model prediction
    forecasted_demand = max(0, float(forecasted_demand))
    stock = max(0, float(stock))
    expiry_days = max(0, float(expiry_days))
    is_perishable_int = int(bool(is_perishable)) # Convert to 0 or 1

    X = np.array([[forecasted_demand, stock, expiry_days, is_perishable_int]])
    price = model.predict(X)[0]

    # Create a modern, beautiful chart
    plt.style.use('dark_background')
    fig, ax = plt.subplots(figsize=(10, 6))
    
    # Modern gradient colors
    colors = ['#667eea', '#764ba2']
    
    # Create bars with modern styling
    bars = ax.bar(['Forecasted Demand', 'Current Stock'], 
                  [forecasted_demand, stock], 
                  color=colors, 
                  width=0.6, 
                  alpha=0.8,
                  edgecolor='white',
                  linewidth=2)

    # Modern title and labels
    ax.set_title("📊 Demand vs Stock Analysis", 
                 fontsize=20, 
                 fontweight='bold', 
                 color='white',
                 pad=20)
    ax.set_ylabel("Quantity", fontsize=14, color='white')
    
    # Style the axes
    ax.tick_params(axis='both', colors='white', labelsize=12)
    ax.set_facecolor('#1a1a2e')
    fig.patch.set_facecolor('#1a1a2e')
    
    # Remove top and right spines
    ax.spines['top'].set_visible(False)
    ax.spines['right'].set_visible(False)
    ax.spines['left'].set_color('white')
    ax.spines['bottom'].set_color('white')
    
    # Add subtle grid
    ax.grid(axis='y', alpha=0.3, linestyle='--', color='gray')
    
    # Add value labels on bars
    for bar in bars:
        height = bar.get_height()
        ax.text(bar.get_x() + bar.get_width()/2., height + height*0.01,
                f'{int(height)}',
                ha='center', va='bottom', 
                fontsize=14, fontweight='bold', color='white')
    
    plt.tight_layout()
    
    return f"₹{round(price, 2)}", fig

# Custom CSS for modern, responsive design
css = """
/* Import modern fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

/* Root variables for consistent theming */
:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --accent-color: #f093fb;
    --background-dark: #0f0f23;
    --background-card: #1a1a2e;
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --border-color: #333366;
    --success-color: #4ade80;
    --warning-color: #f59e0b;
}

/* Global styles */
* {
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif !important;
    background: linear-gradient(135deg, var(--background-dark) 0%, #16213e 100%) !important;
    color: var(--text-primary) !important;
    margin: 0;
    padding: 0;
}

/* Main container */
.gradio-container {
    max-width: 1400px !important;
    margin: 0 auto !important;
    padding: 20px !important;
    background: transparent !important;
}

/* Header styling */
.header-section {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    border-radius: 20px;
    padding: 40px 20px;
    text-align: center;
    margin-bottom: 30px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    position: relative;
    overflow: hidden;
}

.header-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(45deg, rgba(255,255,255,0.1) 0%, transparent 100%);
    pointer-events: none;
}

.header-title {
    font-size: clamp(2rem, 5vw, 3.5rem) !important;
    font-weight: 700 !important;
    margin-bottom: 15px !important;
    text-shadow: 2px 2px 10px rgba(0,0,0,0.3);
    color: white !important;
}

.header-subtitle {
    font-size: clamp(1rem, 2.5vw, 1.3rem) !important;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
    color: rgba(255,255,255,0.95) !important;
}

/* Card styling */
.input-card, .output-card {
    background: var(--background-card) !important;
    border-radius: 20px !important;
    padding: 30px !important;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2) !important;
    border: 1px solid var(--border-color) !important;
    backdrop-filter: blur(10px);
    margin-bottom: 20px;
}

/* Section headers */
.section-header {
    font-size: 1.5rem !important;
    font-weight: 600 !important;
    color: var(--primary-color) !important;
    margin-bottom: 25px !important;
    text-align: center;
    position: relative;
}

.section-header::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 2px;
}

/* Input styling */
.gr-textbox, .gr-number {
    margin-bottom: 20px !important;
}

.gr-textbox label, .gr-number label, .gr-checkbox label {
    font-weight: 500 !important;
    color: var(--text-primary) !important;
    font-size: 1rem !important;
    margin-bottom: 8px !important;
}

.gr-textbox input, .gr-number input {
    background: rgba(255,255,255,0.05) !important;
    border: 2px solid var(--border-color) !important;
    border-radius: 12px !important;
    padding: 12px 16px !important;
    color: var(--text-primary) !important;
    font-size: 1rem !important;
    transition: all 0.3s ease !important;
}

.gr-textbox input:focus, .gr-number input:focus {
    border-color: var(--primary-color) !important;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1) !important;
    outline: none !important;
}

/* Checkbox styling */
.gr-checkbox {
    margin: 20px 0 !important;
}

.gr-checkbox input[type="checkbox"] {
    width: 20px !important;
    height: 20px !important;
    margin-right: 12px !important;
    accent-color: var(--primary-color) !important;
}

/* Button styling */
.gr-button {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%) !important;
    border: none !important;
    border-radius: 12px !important;
    padding: 16px 32px !important;
    font-size: 1.1rem !important;
    font-weight: 600 !important;
    color: white !important;
    cursor: pointer !important;
    transition: all 0.3s ease !important;
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.3) !important;
    width: 100% !important;
    margin-top: 10px !important;
}

.gr-button:hover {
    transform: translateY(-2px) !important;
    box-shadow: 0 12px 35px rgba(102, 126, 234, 0.4) !important;
}

.gr-button:active {
    transform: translateY(0) !important;
}

/* Price output styling */
.price-output {
    background: linear-gradient(135deg, var(--success-color) 0%, #22c55e 100%) !important;
    border-radius: 16px !important;
    padding: 20px !important;
    text-align: center !important;
    margin-bottom: 20px !important;
    box-shadow: 0 10px 30px rgba(74, 222, 128, 0.2) !important;
}

.price-output textarea {
    background: transparent !important;
    border: none !important;
    font-size: 2.5rem !important;
    font-weight: 700 !important;
    color: white !important;
    text-align: center !important;
    resize: none !important;
    outline: none !important;
}

/* Chart container */
.gr-plot {
    border-radius: 16px !important;
    overflow: hidden !important;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2) !important;
}

/* Responsive design */
@media (max-width: 1024px) {
    .gradio-container {
        padding: 15px !important;
    }
    
    .input-card, .output-card {
        padding: 25px !important;
    }
}

@media (max-width: 768px) {
    .gradio-container {
        padding: 10px !important;
    }
    
    .header-section {
        padding: 30px 15px !important;
        margin-bottom: 20px !important;
    }
    
    .input-card, .output-card {
        padding: 20px !important;
        margin-bottom: 15px !important;
    }
    
    .gr-row {
        flex-direction: column !important;
    }
    
    .gr-column {
        width: 100% !important;
        margin-bottom: 20px !important;
    }
}

@media (max-width: 480px) {
    .header-section {
        padding: 25px 10px !important;
    }
    
    .input-card, .output-card {
        padding: 15px !important;
    }
    
    .gr-button {
        padding: 14px 24px !important;
        font-size: 1rem !important;
    }
    
    .price-output textarea {
        font-size: 2rem !important;
    }
}

/* Loading states */
.gr-button:disabled {
    opacity: 0.6 !important;
    cursor: not-allowed !important;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.input-card, .output-card {
    animation: fadeIn 0.6s ease forwards;
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--background-dark);
}

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--secondary-color);
}
"""

# Create the Gradio interface
with gr.Blocks(
    title="Dynamic Pricing Engine", 
    css=css,
    theme=gr.themes.Base(
        primary_hue="blue",
        secondary_hue="purple",
        neutral_hue="slate"
    )
) as demo:
    
    # Header
    gr.HTML("""
        <div class="header-section">
            <h1 class="header-title">💰 Dynamic Pricing Engine</h1>
            <p class="header-subtitle">
                Harness the power of AI to optimize your product pricing in real-time. 
                Get intelligent price predictions based on demand forecasts, inventory levels, and product characteristics.
            </p>
        </div>
    """)
    
    # Main content
    with gr.Row():
        with gr.Column(scale=1, elem_classes="input-section"):
            with gr.Group(elem_classes="input-card"):
                gr.HTML('<h3 class="section-header">📊 Product Information</h3>')
                
                forecasted_demand = gr.Number(
                    label="📈 Forecasted Demand (Units)",
                    value=50,
                    minimum=0,
                    info="Expected demand for the product"
                )
                
                stock = gr.Number(
                    label="📦 Current Stock Level (Units)",
                    value=100,
                    minimum=0,
                    info="Available inventory quantity"
                )
                
                expiry_days = gr.Number(
                    label="⏰ Days Until Expiry",
                    value=10,
                    minimum=0,
                    info="Set to 0 for non-perishable products"
                )
                
                is_perishable = gr.Checkbox(
                    label="🍎 Perishable Product",
                    value=True,
                    info="Check if product has expiration date"
                )
                
                submit_btn = gr.Button(
                    "🚀 Calculate Optimal Price",
                    variant="primary",
                    size="lg"
                )
        
        with gr.Column(scale=1, elem_classes="output-section"):
            with gr.Group(elem_classes="output-card"):
                gr.HTML('<h3 class="section-header">💡 Pricing Insights</h3>')
                
                price_output = gr.Textbox(
                    label="💰 Recommended Price (₹)",
                    placeholder="Click 'Calculate Optimal Price' to see prediction...",
                    interactive=False,
                    elem_classes="price-output"
                )
                
                chart_output = gr.Plot(
                    label="📊 Market Analysis",
                    show_label=True
                )
    
    # Event handlers
    submit_btn.click(
        fn=predict_price_and_plot,
        inputs=[forecasted_demand, stock, expiry_days, is_perishable],
        outputs=[price_output, chart_output]
    )
    
    # Auto-calculate on input change (optional)
    for input_component in [forecasted_demand, stock, expiry_days, is_perishable]:
        input_component.change(
            fn=predict_price_and_plot,
            inputs=[forecasted_demand, stock, expiry_days, is_perishable],
            outputs=[price_output, chart_output]
        )

if __name__ == "__main__":
    demo.launch(share=True)