import gradio as gr
import pandas as pd
import numpy as np
import pickle
import os
from comprehensive_recommendation_system import ComprehensiveRecommendationSystem
import warnings

warnings.filterwarnings('ignore')


rec_system = None

def load_recommendation_system():
    """Load the trained recommendation system"""
    global rec_system
    
    if rec_system is None:
        print("Loading comprehensive recommendation system...")
        rec_system = ComprehensiveRecommendationSystem()
        
        
        rec_system.load_data("u.data", "u.item")
        
        
        if os.path.exists("comprehensive_recommendation_model.pkl"):
            print("Loading pre-trained model...")
            rec_system.load_model("comprehensive_recommendation_model.pkl")
        else:
            print("Training models...")
            rec_system.train_all_models()
            rec_system.save_model("comprehensive_recommendation_model.pkl")
        
        print("Recommendation system loaded successfully!")
    
    return rec_system

def get_available_users():
    """Get list of available users"""
    if rec_system is None:
        return []
    return sorted(rec_system.ratings['user_id'].unique().tolist())

def get_user_stats():
    """Get user statistics"""
    if rec_system is None:
        return "System not loaded"
    
    total_users = rec_system.ratings['user_id'].nunique()
    total_movies = rec_system.movies['movie_id'].nunique()
    total_ratings = len(rec_system.ratings)
    avg_rating = rec_system.ratings['rating'].mean()
    
    return f"""
**Dataset Statistics:**
- **Users:** {total_users:,}
- **Movies:** {total_movies:,}
- **Ratings:** {total_ratings:,}
- **Average Rating:** {avg_rating:.2f}/5.0
- **Sparsity:** 93.70%
"""

def get_user_info(user_id):
    """Get detailed information about a user"""
    if rec_system is None:
        return "System not loaded"
    
    if user_id is None:
        return "Please select a user"
    
    user_ratings = rec_system.ratings[rec_system.ratings['user_id'] == user_id]
    
    if len(user_ratings) == 0:
        return f"User {user_id} not found in dataset"
    
    # Get user's rating statistics
    avg_rating = user_ratings['rating'].mean()
    num_ratings = len(user_ratings)
    rating_range = f"{user_ratings['rating'].min()} - {user_ratings['rating'].max()}"
    
    # Get rating distribution
    rating_dist = user_ratings['rating'].value_counts().sort_index()
    
    # Get user's top-rated movies
    top_movies = user_ratings.merge(
        rec_system.movies[['movie_id', 'title']], 
        on='movie_id'
    ).sort_values('rating', ascending=False).head(10)
    
    info = f"""
## 👤 User {user_id} Profile

### 📊 Rating Statistics
- **Total Ratings:** {num_ratings:,}
- **Average Rating:** {avg_rating:.2f}/5.0
- **Rating Range:** {rating_range}

### 📈 Rating Distribution
"""
    
    for rating, count in rating_dist.items():
        percentage = (count / num_ratings) * 100
        info += f"- **{rating} stars:** {count} ratings ({percentage:.1f}%)\n"
    
    info += f"""
### 🎬 Top 10 Rated Movies
"""
    
    for i, (_, movie) in enumerate(top_movies.iterrows(), 1):
        stars = "⭐" * int(movie['rating'])
        info += f"{i:2d}. {movie['title']} {stars} ({movie['rating']})\n"
    
    return info

def recommend_movies(user_id, num_recommendations, method):
    """Generate movie recommendations"""
    if rec_system is None:
        return "Error: Recommendation system not loaded"
    
    if user_id is None:
        return "Please select a user"
    
    try:
       
        recommendations = rec_system.recommend_movies(
            user_id=int(user_id), 
            N=int(num_recommendations), 
            method=method
        )
        
        if len(recommendations) == 0:
            return "No recommendations available for this user"
        
       
        method_names = {
            "user_based": "👥 User-based Collaborative Filtering",
            "item_based": "🎬 Item-based Collaborative Filtering", 
            "svd": "📊 SVD Matrix Factorization",
            "neural": "🧠 Neural Embeddings",
            "ensemble": "🎯 Ensemble Method"
        }
        
        result = f"## 🎬 Top {len(recommendations)} Movie Recommendations\n\n"
        result += f"**Method:** {method_names.get(method, method.upper())}\n"
        result += f"**User:** {user_id}\n\n"
        
        for i, (_, rec) in enumerate(recommendations.iterrows(), 1):
            rating_emoji = "⭐" * int(round(rec['predicted_rating']))
            result += f"**{i:2d}.** {rec['title']}\n"
            result += f"     {rating_emoji} Predicted Rating: {rec['predicted_rating']:.3f}\n\n"
        
        return result
        
    except Exception as e:
        return f"❌ Error generating recommendations: {str(e)}"

def compare_all_methods(user_id, num_recommendations):
    """Compare all recommendation methods"""
    if rec_system is None:
        return "Error: Recommendation system not loaded"
    
    if user_id is None:
        return "Please select a user"
    
    methods = ["user_based", "item_based", "svd", "neural", "ensemble"]
    results = {}
    
    try:
        for method in methods:
            recommendations = rec_system.recommend_movies(
                user_id=int(user_id), 
                N=int(num_recommendations), 
                method=method
            )
            results[method] = recommendations
        
        
        result = f"## ⚖️ Method Comparison for User {user_id}\n\n"
        result += f"**Number of recommendations:** {num_recommendations}\n\n"
        
        method_names = {
            "user_based": "👥 User-based CF",
            "item_based": "🎬 Item-based CF", 
            "svd": "📊 SVD",
            "neural": "🧠 Neural",
            "ensemble": "🎯 Ensemble"
        }
        
        for method, recs in results.items():
            result += f"### {method_names[method]}\n"
            if len(recs) == 0:
                result += "No recommendations available\n\n"
            else:
                for i, (_, rec) in enumerate(recs.iterrows(), 1):
                    rating_emoji = "⭐" * int(round(rec['predicted_rating']))
                    result += f"{i:2d}. {rec['title']} {rating_emoji} ({rec['predicted_rating']:.3f})\n"
                result += "\n"
        
        return result
        
    except Exception as e:
        return f"❌ Error comparing methods: {str(e)}"

def evaluate_system_performance():
    """Evaluate the recommendation system performance"""
    if rec_system is None:
        return "Error: Recommendation system not loaded"
    
    try:
        
        all_users = rec_system.ratings['user_id'].unique()
        test_users = np.random.choice(all_users, min(15, len(all_users)), replace=False)
        
        methods = ["user_based", "item_based", "svd", "neural", "ensemble"]
        results = {}
        
        for method in methods:
            eval_results = rec_system.evaluate_model(test_users, method=method, N=10)
            results[method] = eval_results
        
        
        result = "## 📊 System Performance Evaluation\n\n"
        result += f"**Evaluated on:** {len(test_users)} users\n"
        result += f"**Recommendations per user:** 10\n\n"
        
        result += "| Method | Precision@10 | Recall@10 | NDCG@10 |\n"
        result += "|--------|--------------|-----------|----------|\n"
        
        for method, eval_results in results.items():
            method_emoji = {"user_based": "👥", "item_based": "🎬", "svd": "📊", "neural": "🧠", "ensemble": "🎯"}
            emoji = method_emoji.get(method, "📈")
            result += f"| {emoji} {method:12} | {eval_results['precision']:.4f} | {eval_results['recall']:.4f} | {eval_results['ndcg']:.4f} |\n"
        
        
        best_method = max(results.keys(), key=lambda x: results[x]['ndcg'])
        best_emoji = {"user_based": "👥", "item_based": "🎬", "svd": "📊", "neural": "🧠", "ensemble": "🎯"}.get(best_method, "📈")
        
        result += f"\n### 🏆 Best Performing Method\n"
        result += f"**{best_emoji} {best_method.upper()}** with NDCG@10: {results[best_method]['ndcg']:.4f}\n\n"
        
        result += "### 📈 Metric Explanations\n"
        result += "- **Precision@10:** Fraction of recommended items that are relevant\n"
        result += "- **Recall@10:** Fraction of relevant items that are recommended\n"
        result += "- **NDCG@10:** Normalized Discounted Cumulative Gain (ranking quality)\n"
        
        return result
        
    except Exception as e:
        return f"❌ Error evaluating system: {str(e)}"

def get_method_explanations():
    """Get detailed explanations of each recommendation method"""
    return """
## 🔬 Recommendation Methods Explained

### 👥 User-based Collaborative Filtering
**How it works:** Finds users with similar rating patterns and recommends movies they liked.

**Strengths:**
- Intuitive approach that mimics human behavior
- Good for finding diverse recommendations
- Effective when user base is large

**Best for:** Users who want to discover new genres and diverse content

---

### 🎬 Item-based Collaborative Filtering  
**How it works:** Finds movies with similar rating patterns and recommends items similar to those a user has liked.

**Strengths:**
- More stable than user-based approach
- Computationally efficient
- Good for popular items

**Best for:** Users who want recommendations similar to movies they already like

---

### 📊 SVD Matrix Factorization
**How it works:** Decomposes the user-item matrix into latent factors representing user preferences and item characteristics.

**Strengths:**
- Handles sparsity well
- Captures implicit relationships
- Computationally efficient

**Best for:** Balanced performance with good generalization

---

### 🧠 Neural Embeddings
**How it works:** Uses deep learning to learn complex non-linear relationships between users and items.

**Strengths:**
- Can capture complex patterns
- Flexible architecture
- Good for non-linear relationships

**Best for:** Advanced pattern recognition and complex user behaviors

---

### 🎯 Ensemble Method
**How it works:** Combines predictions from all four approaches by averaging their recommendation scores.

**Strengths:**
- Reduces individual method biases
- More robust predictions
- Better coverage of different patterns

**Best for:** Optimal overall performance and reliability
"""

def create_interface():
    """Create the enhanced Gradio interface"""
    
   
    load_recommendation_system()
    
    with gr.Blocks(
        title="🎬 Comprehensive Movie Recommendation System",
        theme=gr.themes.Soft(
            primary_hue="blue",
            secondary_hue="purple",
            neutral_hue="slate"
        ),
        css="""
        .main-header {
            text-align: center;
            background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            font-size: 2.5em;
            font-weight: bold;
            margin-bottom: 20px;
        }
        .method-card {
            border: 2px solid #333333;
            border-radius: 12px;
            padding: 20px;
            margin: 15px 0;
            background: linear-gradient(135deg, #1a1a1a 0%, #2d2d2d 100%);
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
            color: white;
        }
        .stats-card {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            padding: 20px;
            border-radius: 12px;
            margin: 10px 0;
        }
        .footer-text {
            color: white !important;
        }
        .footer-text h2, .footer-text h3 {
            color: white !important;
        }
        .footer-text p, .footer-text li {
            color: #e0e0e0 !important;
        }
        """
    ) as app:
        
        
        gr.Markdown(
            """
            # 🎬 Comprehensive Movie Recommendation System
            
            **Advanced ML Approaches for Personalized Recommendations**
            
            This system implements multiple state-of-the-art recommendation approaches including collaborative filtering, 
            matrix factorization, and neural embeddings using the MovieLens 100K dataset.
            """,
            elem_classes="main-header"
        )
        
        # Stats overview
        with gr.Row():
            with gr.Column():
                stats_display = gr.Markdown(
                    get_user_stats(),
                    elem_classes="stats-card"
                )
        
        # Main tabs
        with gr.Tabs():
            
            # Recommendation Tab
            with gr.Tab("🎯 Get Recommendations", id="recommendations"):
                gr.Markdown("### Generate personalized movie recommendations using different ML approaches")
                
                with gr.Row():
                    with gr.Column(scale=1):
                        user_dropdown = gr.Dropdown(
                            choices=get_available_users(),
                            label="👤 Select User ID",
                            value=get_available_users()[0] if get_available_users() else None,
                            info="Choose from 943 available users"
                        )
                        
                        num_recommendations = gr.Slider(
                            minimum=5,
                            maximum=20,
                            value=10,
                            step=1,
                            label="📊 Number of Recommendations",
                            info="How many movies to recommend"
                        )
                        
                        method_dropdown = gr.Dropdown(
                            choices=[
                                ("🎯 Ensemble Method (Recommended)", "ensemble"),
                                ("👥 User-based Collaborative Filtering", "user_based"),
                                ("🎬 Item-based Collaborative Filtering", "item_based"),
                                ("📊 SVD Matrix Factorization", "svd"),
                                ("🧠 Neural Embeddings", "neural")
                            ],
                            value="ensemble",
                            label="🔬 Recommendation Method",
                            info="Choose the ML approach for recommendations"
                        )
                        
                        recommend_btn = gr.Button("🚀 Get Recommendations", variant="primary", size="lg")
                    
                    with gr.Column(scale=2):
                        recommendations_output = gr.Markdown(
                            "👆 Select a user and method to get personalized movie recommendations...",
                            label="🎬 Recommendations"
                        )
                
                recommend_btn.click(
                    fn=recommend_movies,
                    inputs=[user_dropdown, num_recommendations, method_dropdown],
                    outputs=recommendations_output
                )
            
            # User Analysis Tab
            with gr.Tab("👤 User Analysis", id="analysis"):
                gr.Markdown("### Analyze user preferences, rating patterns, and movie tastes")
                
                with gr.Row():
                    with gr.Column(scale=1):
                        user_analysis_dropdown = gr.Dropdown(
                            choices=get_available_users(),
                            label="👤 Select User ID",
                            value=get_available_users()[0] if get_available_users() else None,
                            info="Choose a user to analyze"
                        )
                        
                        analyze_user_btn = gr.Button("🔍 Analyze User", variant="primary", size="lg")
                    
                    with gr.Column(scale=2):
                        user_info_output = gr.Markdown(
                            "👆 Select a user to analyze their preferences and rating patterns...",
                            label="📊 User Profile"
                        )
                
                analyze_user_btn.click(
                    fn=get_user_info,
                    inputs=[user_analysis_dropdown],
                    outputs=user_info_output
                )
            
            # Method Comparison Tab
            with gr.Tab("⚖️ Compare Methods", id="comparison"):
                gr.Markdown("### Compare all recommendation methods side-by-side for a user")
                
                with gr.Row():
                    with gr.Column(scale=1):
                        compare_user_dropdown = gr.Dropdown(
                            choices=get_available_users(),
                            label="👤 Select User ID",
                            value=get_available_users()[0] if get_available_users() else None,
                            info="Choose a user to compare methods for"
                        )
                        
                        compare_num_recs = gr.Slider(
                            minimum=5,
                            maximum=15,
                            value=10,
                            step=1,
                            label="📊 Number of Recommendations",
                            info="How many recommendations per method"
                        )
                        
                        compare_btn = gr.Button("⚖️ Compare All Methods", variant="primary", size="lg")
                    
                    with gr.Column(scale=2):
                        comparison_output = gr.Markdown(
                            "👆 Select a user to compare all recommendation methods...",
                            label="📈 Method Comparison"
                        )
                
                compare_btn.click(
                    fn=compare_all_methods,
                    inputs=[compare_user_dropdown, compare_num_recs],
                    outputs=comparison_output
                )
            
        
            with gr.Tab("📊 System Evaluation", id="evaluation"):
                gr.Markdown("### Evaluate system performance with comprehensive metrics")
                
                with gr.Row():
                    with gr.Column(scale=1):
                        evaluate_btn = gr.Button("📊 Evaluate System Performance", variant="primary", size="lg")
                    
                    with gr.Column(scale=2):
                        evaluation_output = gr.Markdown(
                            "👆 Click 'Evaluate System Performance' to see detailed metrics...",
                            label="📈 Performance Results"
                        )
                
                evaluate_btn.click(
                    fn=evaluate_system_performance,
                    inputs=[],
                    outputs=evaluation_output
                )
            
            # Method Explanations Tab
            with gr.Tab("🔬 Method Explanations", id="explanations"):
                gr.Markdown("### Learn about each recommendation method and when to use them")
                
                explanations_output = gr.Markdown(
                    get_method_explanations(),
                    label="📚 Method Details"
                )
        
        
        gr.Markdown(
            """
            ---
            ## 🚀 About This System
            
            This comprehensive recommendation system demonstrates multiple state-of-the-art approaches:
            
            - **👥 Collaborative Filtering**: Both user-based and item-based methods
            - **📊 Matrix Factorization**: SVD for dimensionality reduction  
            - **🧠 Neural Networks**: Deep learning embeddings for complex patterns
            - **🎯 Ensemble Methods**: Combining multiple approaches for optimal performance
            
            ### 📈 Evaluation Metrics
            - **Precision@K**: Fraction of recommended items that are relevant
            - **Recall@K**: Fraction of relevant items that are recommended  
            - **NDCG@K**: Normalized Discounted Cumulative Gain for ranking quality
            
            ### 🎓 Educational Value
            Perfect for learning about recommendation systems, machine learning approaches, 
            and interactive web application development.
            """,
            elem_classes="method-card footer-text"
        )
    
    return app


if __name__ == "__main__":
    app = create_interface()
    app.launch(
        server_name="0.0.0.0",
        server_port=7860,
        share=True,
        show_error=True
    )