// Shared JavaScript across all pages
class ChatApp {
    constructor() {
        this.apiKey = localStorage.getItem('openai-api-key') || '';
        this.messages = [];
        this.init();
    }

    init() {
        this.bindEvents();
        this.loadApiKey();
        this.updateApiKeyDisplay();
    }

    bindEvents() {
        document.getElementById('send-button').addEventListener('click', () => this.sendMessage());
        document.getElementById('message-input').addEventListener('keypress', (e) => {
            if (e.key === 'Enter') this.sendMessage();
        });
        document.getElementById('save-api-key').addEventListener('click', () => this.saveApiKey());
    }

    loadApiKey() {
        const savedKey = localStorage.getItem('openai-api-key');
        if (savedKey) {
            this.apiKey = savedKey;
            document.getElementById('api-key-input').value = savedKey;
        }
    }

    saveApiKey() {
        const keyInput = document.getElementById('api-key-input');
        if (keyInput.value.trim()) {
            this.apiKey = keyInput.value.trim();
            localStorage.setItem('openai-api-key', this.apiKey);
            this.updateApiKeyDisplay();
            this.showNotification('API key saved successfully!', 'success');
        } else {
            this.showNotification('Please enter a valid API key', 'error');
        }
    }

    updateApiKeyDisplay() {
        const keyInput = document.getElementById('api-key-input');
        if (this.apiKey) {
            keyInput.placeholder = 'API key saved';
        } else {
            keyInput.placeholder = 'Enter your OpenAI API key';
        }
    }

    async sendMessage() {
        const input = document.getElementById('message-input');
        const message = input.value.trim();
        
        if (!message) return;
        
        if (!this.apiKey) {
            this.showNotification('Please enter your OpenAI API key first', 'error');
            return;
        }
        
        // Add user message to UI
        this.addMessage(message, 'user');
        input.value = '';
        
        // Show typing indicator
        const typingIndicator = this.addTypingIndicator();
        
        try {
            const response = await this.callOpenAI(message);
            // Remove typing indicator
            typingIndicator.remove();
            // Add assistant response
            this.addMessage(response, 'assistant');
        } catch (error) {
            // Remove typing indicator
            typingIndicator.remove();
            this.addMessage('Sorry, I encountered an error. Please try again.', 'assistant');
            console.error('Error:', error);
        }
    }

    addMessage(content, sender) {
        const messagesContainer = document.getElementById('messages');
        const messageDiv = document.createElement('div');
        messageDiv.className = `message ${sender}-message rounded-lg p-4 max-w-[80%] ${sender === 'user' ? 'ml-auto' : ''}`;
        
        if (sender === 'user') {
            messageDiv.innerHTML = `
                <div class="font-bold text-blue-200 mb-1">You</div>
                <div>${content}</div>
            `;
        } else {
            messageDiv.innerHTML = `
                <div class="font-bold text-blue-400 mb-1">Assistant</div>
                <div>${content}</div>
            `;
        }
        
        messagesContainer.appendChild(messageDiv);
        messagesContainer.scrollTop = messagesContainer.scrollHeight;
        
        return messageDiv;
    }

    addTypingIndicator() {
        const messagesContainer = document.getElementById('messages');
        const typingDiv = document.createElement('div');
        typingDiv.className = 'message assistant-message rounded-lg p-4';
        typingDiv.innerHTML = `
            <div class="font-bold text-blue-400 mb-1">Assistant</div>
            <div class="flex space-x-1">
                <div class="w-2 h-2 bg-blue-400 rounded-full animate-bounce"></div>
                <div class="w-2 h-2 bg-blue-400 rounded-full animate-bounce" style="animation-delay: 0.2s"></div>
                <div class="w-2 h-2 bg-blue-400 rounded-full animate-bounce" style="animation-delay: 0.4s"></div>
            </div>
        `;
        messagesContainer.appendChild(typingDiv);
        messagesContainer.scrollTop = messagesContainer.scrollHeight;
        return typingDiv;
    }

    async callOpenAI(message) {
        const response = await fetch('https://api.openai.com/v1/chat/completions', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': `Bearer ${this.apiKey}`
            },
            body: JSON.stringify({
                model: 'gpt-3.5-turbo',
                messages: [
                    { role: 'system', content: 'You are a helpful assistant.' },
                    { role: 'user', content: message }
                ],
                temperature: 0.7
            })
        });

        if (!response.ok) {
            if (response.status === 401) {
                throw new Error('Invalid API key. Please check your API key and try again.');
            } else if (response.status === 429) {
                throw new Error('Rate limit exceeded. Please wait before sending another request.');
            } else {
                throw new Error(`API request failed with status ${response.status}`);
            }
        }

        const data = await response.json();
        return data.choices[0].message.content;
    }

    showNotification(message, type) {
        // Remove existing notifications
        const existing = document.querySelector('.notification');
        if (existing) existing.remove();
        
        const notification = document.createElement('div');
        notification.className = `notification fixed top-4 right-4 px-6 py-4 rounded-lg shadow-lg z-50 ${
            type === 'success' ? 'bg-green-600' : 'bg-red-600'
        } text-white`;
        notification.textContent = message;
        
        document.body.appendChild(notification);
        
        setTimeout(() => {
            notification.remove();
        }, 3000);
    }
}

// Initialize the app when DOM is loaded
document.addEventListener('DOMContentLoaded', () => {
    window.chatApp = new ChatApp();
});