/**
 * Educational Tutor Bot JavaScript - Modern Design
 * Author: RSK World (https://rskworld.in)
 * Founded by: Molla Samser
 * Designer & Tester: Rima Khatun
 * Contact: info@rskworld.com, +91 93305 39277
 * Year: 2026
 */

// Demo state
let messageCount = 0;
let tokensUsed = 0;
let responsesCount = 0;
let sessionStartTime = Date.now();

// Initialize the application
document.addEventListener('DOMContentLoaded', function() {
    console.log('Educational Tutor Bot - © 2026 RSK World');
    console.log('Founded by Molla Samser | Designer & Tester: Rima Khatun');
    
    // Focus on message input
    const chatInput = document.getElementById('chatInput');
    if (chatInput) {
        chatInput.focus();
    }
    
    // Start session timer
    updateSessionTimer();
    
    // Initialize scroll progress
    initScrollProgress();
    
    // Initialize back to top button
    initBackToTop();
});

// Scroll Progress Bar
function initScrollProgress() {
    window.addEventListener('scroll', () => {
        const scrollProgress = document.getElementById('scrollProgress');
        if (scrollProgress) {
            const scrollTop = window.pageYOffset;
            const docHeight = document.documentElement.scrollHeight - window.innerHeight;
            const scrollPercent = (scrollTop / docHeight) * 100;
            scrollProgress.style.width = scrollPercent + '%';
        }
    });
}

// Back to Top Button
function initBackToTop() {
    const backToTopBtn = document.getElementById('backToTop');
    
    if (backToTopBtn) {
        window.addEventListener('scroll', () => {
            if (window.pageYOffset > 300) {
                backToTopBtn.classList.add('visible');
            } else {
                backToTopBtn.classList.remove('visible');
            }
        });
        
        backToTopBtn.addEventListener('click', () => {
            window.scrollTo({
                top: 0,
                behavior: 'smooth'
            });
        });
    }
}

function addMessage(text, isUser = false, metadata = {}) {
    const messagesDiv = document.getElementById('chatMessages');
    if (!messagesDiv) return;
    
    const messageDiv = document.createElement('div');
    messageDiv.className = `message ${isUser ? 'user' : 'bot'}`;
    
    const now = new Date();
    const timeStr = now.toLocaleTimeString();
    
    let metaHTML = '';
    if (metadata.model) {
        metaHTML += `<span class="meta-badge">Model: ${metadata.model}</span>`;
    }
    if (metadata.tokens) {
        metaHTML += `<span class="meta-badge">Tokens: ${metadata.tokens}</span>`;
    }
    if (metadata.type) {
        metaHTML += `<span class="meta-badge">Type: ${metadata.type}</span>`;
    }
    
    messageDiv.innerHTML = `
        <div class="message-content">
            ${text}
            <div class="message-meta">
                ${timeStr}
                ${metaHTML ? ' • ' + metaHTML : ''}
            </div>
        </div>
    `;
    
    messagesDiv.appendChild(messageDiv);
    messagesDiv.scrollTop = messagesDiv.scrollHeight;
    
    if (isUser) {
        messageCount++;
        updateStats();
    }
}

function detectMessageType(message) {
    // Detect message type based on keywords
    const messagePatterns = {
        code: /(?:python|function|code|programming|debug|algorithm|fibonacci|calculate|algebra|math)/i,
        explain: /(?:explain|what is|define|how does|tell me about|photosynthesis|concept)/i,
        creative: /(?:story|creative|write|narrative|quiz|practice)/i,
        math: /(?:solve|calculate|math|equation|x²|problem|value)/i,
        summarize: /(?:summarize|summary|key features|main points|overview)/i,
        compare: /(?:compare|difference|versus|vs|between|which is better)/i
    };
    
    if (messagePatterns.code.test(message)) {
        return 'code';
    } else if (messagePatterns.explain.test(message)) {
        return 'explain';
    } else if (messagePatterns.creative.test(message)) {
        return 'creative';
    } else if (messagePatterns.math.test(message)) {
        return 'math';
    } else if (messagePatterns.summarize.test(message)) {
        return 'summarize';
    } else if (messagePatterns.compare.test(message)) {
        return 'compare';
    }
    return 'default';
}

async function generateBotResponse(message) {
    const messageType = detectMessageType(message);
    
    try {
        // Send message to backend
        const response = await fetch('/chat', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
            },
            body: JSON.stringify({
                message: message,
                subject: 'General',
                difficulty: 'Intermediate',
                language: 'en'
            })
        });
        
        const data = await response.json();
        
        if (data.response) {
            const tokens = data.tokens_used || Math.floor(data.response.length / 4); // Estimate tokens
            tokensUsed += tokens;
            responsesCount++;
            updateStats();
            
            let metadata = {
                model: 'GPT-3.5 Turbo',
                tokens: tokens,
                type: messageType.charAt(0).toUpperCase() + messageType.slice(1)
            };
            
            return { response: data.response, metadata };
        } else {
            // Fallback response
            return {
                response: "I'm here to help you learn! Please ask me any educational question, and I'll do my best to assist you.",
                metadata: { model: 'GPT-3.5 Turbo', tokens: 25, type: 'Default' }
            };
        }
    } catch (error) {
        console.error('Error getting bot response:', error);
        // Fallback response
        return {
            response: "I apologize, but I'm experiencing technical difficulties. Please try again later.",
            metadata: { model: 'GPT-3.5 Turbo', tokens: 15, type: 'Error' }
        };
    }
}

function sendMessage() {
    const input = document.getElementById('chatInput');
    const message = input.value.trim();
    
    if (!message) return;
    
    addMessage(message, true);
    input.value = '';
    
    const sendButton = document.getElementById('sendButton');
    if (sendButton) {
        sendButton.disabled = true;
    }
    
    const loading = document.getElementById('loading');
    if (loading) {
        loading.classList.add('show');
    }
    
    // Get bot response
    generateBotResponse(message).then(({ response, metadata }) => {
        addMessage(response, false, metadata);
        
        if (loading) {
            loading.classList.remove('show');
        }
        if (sendButton) {
            sendButton.disabled = false;
        }
    }).catch(error => {
        console.error('Error:', error);
        addMessage('Sorry, I encountered an error. Please try again.', false);
        
        if (loading) {
            loading.classList.remove('show');
        }
        if (sendButton) {
            sendButton.disabled = false;
        }
    });
}

function sendQuickMessage(message) {
    const chatInput = document.getElementById('chatInput');
    if (chatInput) {
        chatInput.value = message;
        sendMessage();
    }
}

function handleKeyPress(event) {
    if (event.key === 'Enter') {
        sendMessage();
    }
}

function clearChat() {
    if (confirm('Are you sure you want to clear the chat?')) {
        messageCount = 0;
        tokensUsed = 0;
        responsesCount = 0;
        sessionStartTime = Date.now();
        
        const chatMessages = document.getElementById('chatMessages');
        if (chatMessages) {
            chatMessages.innerHTML = `
                <div class="message bot">
                    <div class="message-content">
                        <strong>Chat cleared!</strong><br><br>
                        I'm your Educational Tutor Bot, ready to help you learn. Type your message below or use the quick actions to get started!
                        <div class="message-meta">
                            <span class="meta-badge">Status: Ready</span>
                            <span class="meta-badge">Model: GPT-3.5 Turbo</span>
                        </div>
                    </div>
                </div>
            `;
        }
        
        updateStats();
    }
}

function updateStats() {
    const messageCountEl = document.getElementById('messageCount');
    const tokensUsedEl = document.getElementById('tokensUsed');
    const responsesCountEl = document.getElementById('responsesCount');
    const sessionTimeEl = document.getElementById('sessionTime');
    
    if (messageCountEl) {
        messageCountEl.textContent = messageCount;
    }
    if (tokensUsedEl) {
        tokensUsedEl.textContent = tokensUsed;
    }
    if (responsesCountEl) {
        responsesCountEl.textContent = responsesCount;
    }
    if (sessionTimeEl) {
        const sessionMinutes = Math.floor((Date.now() - sessionStartTime) / 60000);
        sessionTimeEl.textContent = sessionMinutes + 'm';
    }
}

function updateSessionTimer() {
    setInterval(() => {
        const sessionMinutes = Math.floor((Date.now() - sessionStartTime) / 60000);
        const sessionTimeEl = document.getElementById('sessionTime');
        if (sessionTimeEl) {
            sessionTimeEl.textContent = sessionMinutes + 'm';
        }
    }, 60000); // Update every minute
}

// Console branding
console.log('%c Educational Tutor Bot ', 'background: #667eea; color: white; font-size: 16px; font-weight: bold;');
console.log('%c © 2026 RSK World - All rights reserved ', 'background: #764ba2; color: white; font-size: 12px;');
console.log('%c Founded by Molla Samser | Designer & Tester: Rima Khatun ', 'background: #ffc107; color: black; font-size: 11px;');
console.log('%c Contact: info@rskworld.com | +91 93305 39277 ', 'background: #dc3545; color: white; font-size: 11px;');