"""
SEA Prep Pro - AI-Powered Tutor 🇹🇹
FULLY FREE VERSION - No API Keys Required!
"""
import gradio as gr
import sqlite3
import json
import os
import re
import random
import math
import threading
from datetime import datetime

# ==================== FREE AI TUTOR ====================
class FreeAITutor:
    """Free AI tutor using rule-based generation"""
    
    def __init__(self):
        self.math_templates = {
            "Fractions": [
                "Simplify the fraction {num}/{den}.",
                "Add {a}/{b} + {c}/{d}.",
                "Subtract {a}/{b} - {c}/{d}.",
                "What is {num}/{den} of {whole}?",
                "Convert {decimal} to a fraction."
            ],
            "Geometry": [
                "Find the area of a rectangle with length {l}cm and width {w}cm.",
                "Calculate the perimeter of a square with side {s}cm.",
                "Find the area of a triangle with base {b}cm and height {h}cm.",
                "Calculate the circumference of a circle with radius {r}cm (use π=3.14).",
                "Find the volume of a cube with side {s}cm."
            ]
        }
        
        self.english_templates = {
            "Grammar": [
                "Correct the sentence: '{sentence}'",
                "Choose the correct word: '{sentence}'"
            ],
            "Vocabulary": [
                "What is a synonym for '{word}'?",
                "What is the antonym of '{word}'?"
            ]
        }
    
    def generate_math_question(self, topic, difficulty):
        """Generate math question"""
        templates = self.math_templates.get(topic, ["Practice {topic}."])
        template = random.choice(templates)
        
        # Generate values based on difficulty
        max_val = {1: 10, 2: 20, 3: 50, 4: 100, 5: 200}[difficulty]
        
        values = {
            'num': random.randint(1, max_val),
            'den': random.randint(2, max_val),
            'a': random.randint(1, max_val),
            'b': random.randint(2, max_val),
            'c': random.randint(1, max_val),
            'd': random.randint(2, max_val),
            'whole': random.randint(10, 100),
            'decimal': round(random.uniform(0.1, 0.9), 2),
            'l': random.randint(5, 20),
            'w': random.randint(3, 15),
            's': random.randint(4, 12),
            'r': random.randint(2, 10),
            'h': random.randint(3, 12),
            'b': random.randint(4, 16),
            'topic': topic
        }
        
        question = template.format(**values)
        answer = self._calculate_answer(question, values)
        
        return question, answer
    
    def _calculate_answer(self, question, values):
        """Calculate answer for math question"""
        try:
            if "Simplify the fraction" in question:
                num, den = values['num'], values['den']
                gcd = math.gcd(num, den)
                return f"{num//gcd}/{den//gcd}"
            
            elif "area of a rectangle" in question:
                return f"{values['l'] * values['w']} cm²"
            
            elif "perimeter of a square" in question:
                return f"{4 * values['s']} cm"
            
            elif "area of a triangle" in question:
                return f"{0.5 * values['b'] * values['h']} cm²"
            
            elif "circumference of a circle" in question:
                return f"{2 * 3.14 * values['r']:.2f} cm"
            
            elif "volume of a cube" in question:
                return f"{values['s'] ** 3} cm³"
            
            elif "Add" in question and "/" in question:
                a, b, c, d = values['a'], values['b'], values['c'], values['d']
                lcm = b * d // math.gcd(b, d)
                num = a * (lcm // b) + c * (lcm // d)
                gcd = math.gcd(num, lcm)
                return f"{num//gcd}/{lcm//gcd}"
            
            else:
                return "Calculate step by step"
                
        except Exception:
            return "Practice this concept"
    
    def evaluate_answer(self, student_answer, correct_answer):
        """Evaluate student's answer"""
        student = str(student_answer).strip().lower()
        correct = str(correct_answer).strip().lower()
        
        if student == correct:
            return {"correct": True, "score": 1.0, "feedback": "✅ Correct! Well done!"}
        
        # Partial credit for showing work
        if len(student) > 10:
            return {"correct": False, "score": 0.5, "feedback": "⚠️ Good attempt. Keep practicing!"}
        
        return {"correct": False, "score": 0.0, "feedback": "❌ Incorrect. Try again!"}

# ==================== DATABASE ====================
class ThreadLocal(threading.local):
    def __init__(self):
        self.connections = {}

thread_local = ThreadLocal()

def get_db_connection(db_name="questions"):
    """Get database connection"""
    if not hasattr(thread_local, 'connections'):
        thread_local.connections = {}
    
    if db_name not in thread_local.connections:
        conn = sqlite3.connect(f"/tmp/{db_name}.db", check_same_thread=False)
        thread_local.connections[db_name] = conn
    
    return thread_local.connections[db_name]

def init_databases():
    """Initialize databases"""
    # Questions DB
    conn = get_db_connection("questions")
    cur = conn.cursor()
    cur.execute('''
        CREATE TABLE IF NOT EXISTS questions (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            subject TEXT,
            topic TEXT,
            question_text TEXT,
            difficulty INTEGER,
            correct_answer TEXT,
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
        )
    ''')
    
    # Student DB
    conn = get_db_connection("students")
    cur = conn.cursor()
    cur.execute('''
        CREATE TABLE IF NOT EXISTS student_progress (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            student_id TEXT,
            question_id INTEGER,
            student_answer TEXT,
            correct BOOLEAN,
            score REAL,
            timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP
        )
    ''')
    
    cur.execute('''
        CREATE TABLE IF NOT EXISTS student_stats (
            student_id TEXT PRIMARY KEY,
            total_questions INTEGER DEFAULT 0,
            correct_answers INTEGER DEFAULT 0,
            total_score REAL DEFAULT 0,
            level INTEGER DEFAULT 1
        )
    ''')
    
    conn.commit()

# ==================== MAIN APP ====================
class SEAITutor:
    def __init__(self):
        self.ai = FreeAITutor()
        init_databases()
        print("🚀 SEA Prep Pro - Free AI Tutor Started!")
        
        self.subjects = {
            "Mathematics": {
                "topics": ["Fractions", "Geometry", "Algebra", "Word Problems", "Percentages"],
                "icon": "📐"
            },
            "English": {
                "topics": ["Grammar", "Vocabulary", "Comprehension", "Writing"],
                "icon": "📚"
            }
        }
        
        self.difficulty_levels = {
            1: "Beginner", 2: "Easy", 3: "Medium", 4: "Hard", 5: "Expert"
        }
        
        self.student_id = "student_001"
    
    def generate_question(self, subject, topic, difficulty):
        """Generate a new question"""
        if subject == "Mathematics":
            question, answer = self.ai.generate_math_question(topic, difficulty)
        else:
            question = f"Practice {topic} in {subject}. Write your answer below."
            answer = "Sample answer for practice."
        
        # Store in DB
        conn = get_db_connection("questions")
        cur = conn.cursor()
        cur.execute('''
            INSERT INTO questions (subject, topic, question_text, difficulty, correct_answer)
            VALUES (?, ?, ?, ?, ?)
        ''', (subject, topic, question, difficulty, answer))
        
        question_id = cur.lastrowid
        conn.commit()
        
        return {
            "id": question_id,
            "text": question,
            "subject": subject,
            "topic": topic,
            "difficulty": self.difficulty_levels.get(difficulty, "Medium")
        }
    
    def submit_answer(self, question_id, student_answer):
        """Submit and evaluate answer"""
        # Get question
        conn = get_db_connection("questions")
        cur = conn.cursor()
        cur.execute('SELECT correct_answer FROM questions WHERE id = ?', (question_id,))
        row = cur.fetchone()
        
        if not row:
            return {"feedback": "Question not found.", "score": 0}
        
        correct_answer = row[0]
        evaluation = self.ai.evaluate_answer(student_answer, correct_answer)
        
        # Record progress
        conn = get_db_connection("students")
        cur = conn.cursor()
        cur.execute('''
            INSERT INTO student_progress (student_id, question_id, student_answer, correct, score)
            VALUES (?, ?, ?, ?, ?)
        ''', (self.student_id, question_id, student_answer, evaluation["correct"], evaluation["score"]))
        
        # Update stats
        cur.execute('''
            INSERT OR REPLACE INTO student_stats (student_id, total_questions, correct_answers, total_score)
            VALUES (?, 
                COALESCE((SELECT total_questions FROM student_stats WHERE student_id = ?), 0) + 1,
                COALESCE((SELECT correct_answers FROM student_stats WHERE student_id = ?), 0) + ?,
                COALESCE((SELECT total_score FROM student_stats WHERE student_id = ?), 0) + ?
            )
        ''', (self.student_id, self.student_id, self.student_id, 
              1 if evaluation["correct"] else 0, self.student_id, evaluation["score"]))
        
        conn.commit()
        
        return evaluation
    
    def get_stats(self):
        """Get student statistics"""
        conn = get_db_connection("students")
        cur = conn.cursor()
        cur.execute('''
            SELECT total_questions, correct_answers, total_score, level 
            FROM student_stats WHERE student_id = ?
        ''', (self.student_id,))
        
        row = cur.fetchone()
        if not row:
            return {"total_questions": 0, "correct_answers": 0, "accuracy": 0, "level": 1}
        
        total, correct, score, level = row
        accuracy = (correct / total * 100) if total > 0 else 0
        
        return {
            "total_questions": total,
            "correct_answers": correct,
            "accuracy": round(accuracy, 1),
            "total_score": round(score, 1),
            "level": level
        }

# Initialize
tutor = SEAITutor()

# ==================== GRADIO UI ====================
def create_ui():
    with gr.Blocks(
        title="SEA Prep Pro - Free AI Tutor 🇹🇹",
        theme=gr.themes.Soft(primary_hue="blue", secondary_hue="purple")
    ) as demo:
        
        # Header
        gr.Markdown("""
        # 🤖 SEA Prep Pro - Free AI Tutor 🇹🇹
        ### 100% Free • No API Keys • Trinidad & Tobago SEA Exam Preparation
        """)
        
        with gr.Tabs():
            with gr.TabItem("🎯 Practice"):
                with gr.Row():
                    with gr.Column(scale=1):
                        subject = gr.Dropdown(
                            choices=["Mathematics", "English"],
                            value="Mathematics",
                            label="Subject"
                        )
                        topic = gr.Dropdown(
                            choices=tutor.subjects["Mathematics"]["topics"],
                            value="Fractions",
                            label="Topic"
                        )
                        difficulty = gr.Slider(
                            1, 5, value=3, step=1,
                            label="Difficulty Level"
                        )
                        
                        generate_btn = gr.Button("✨ Generate Question", variant="primary")
                        
                        gr.Markdown("---")
                        stats = gr.JSON(label="📊 Your Stats")
                        refresh_btn = gr.Button("🔄 Refresh Stats")
                    
                    with gr.Column(scale=2):
                        question_display = gr.Markdown("### Your question will appear here")
                        answer_input = gr.Textbox(label="Your Answer", lines=3)
                        
                        with gr.Row():
                            submit_btn = gr.Button("✅ Submit Answer", variant="primary")
                            clear_btn = gr.Button("🗑️ Clear")
                        
                        feedback = gr.Markdown("### 💬 Feedback")
            
            with gr.TabItem("📈 Progress"):
                gr.Markdown("### Your Learning Journey")
                progress_stats = gr.JSON()
                gr.Markdown("### 🎯 Tips for Success")
                gr.Markdown("""
                - Practice regularly
                - Review your mistakes
                - Ask for help when needed
                - Stay consistent
                """)
            
            with gr.TabItem("ℹ️ About"):
                gr.Markdown("""
                ## About SEA Prep Pro
                
                **SEA Prep Pro** is a completely free AI-powered tutoring system for Trinidad and Tobago students.
                
                ### Features:
                - ✅ 100% Free - No payments ever
                - 🔒 No API Keys Required
                - 🤖 Smart Question Generation
                - 📊 Progress Tracking
                - 🇹🇹 Trinidad & Tobago Focus
                
                ### Subjects:
                - **Mathematics**: Fractions, Geometry, Algebra
                - **English**: Grammar, Vocabulary, Comprehension
                
                ### How to Use:
                1. Select a subject and topic
                2. Choose difficulty level
                3. Generate questions
                4. Submit answers
                5. Track your progress
                
                **Made with ❤️ for Trinidad and Tobago students**
                """)
        
        # State
        current_q = gr.State()
        
        # Functions
        def update_topics(subject):
            topics = tutor.subjects.get(subject, {}).get("topics", [])
            return gr.Dropdown.update(choices=topics, value=topics[0] if topics else "")
        
        def generate(subject, topic, difficulty):
            q = tutor.generate_question(subject, topic, difficulty)
            display = f"""
            **Subject:** {q['subject']}  
            **Topic:** {q['topic']}  
            **Difficulty:** {q['difficulty']}  
            
            ---
            
            **Question:**
            {q['text']}
            """
            return display, q, ""
        
        def submit(answer, question):
            if not question:
                return "Please generate a question first!", question
            
            result = tutor.submit_answer(question["id"], answer)
            return f"**{result['feedback']}**  \n**Score:** {result['score']:.1%}", question
        
        def get_stats_func():
            return tutor.get_stats()
        
        def clear():
            return "", ""
        
        # Event handlers
        subject.change(update_topics, subject, topic)
        generate_btn.click(generate, [subject, topic, difficulty], [question_display, current_q, feedback])
        submit_btn.click(submit, [answer_input, current_q], [feedback, current_q])
        refresh_btn.click(get_stats_func, outputs=stats)
        clear_btn.click(clear, outputs=[answer_input, feedback])
        
        # Initialize
        demo.load(get_stats_func, outputs=stats)
    
    return demo

# Launch
if __name__ == "__main__":
    app = create_ui()
    app.launch(debug=True)