class ChatInterface {
    constructor() {
        this.messagesContainer = document.getElementById('chatMessages');
        this.messageInput = document.getElementById('messageInput');
        this.sendButton = document.getElementById('sendButton');
        this.typingIndicator = document.getElementById('typingIndicator');
        this.quickReplies = document.getElementById('quickReplies');

        this.isTyping = false;
        this.conversationStarted = false;

        this.init();
    }

    init() {
        this.setupEventListeners();
        this.startConversation();
        this.adjustTextareaHeight();
    }

    setupEventListeners() {
        // Send button click
        this.sendButton.addEventListener('click', () => this.sendMessage());

        // Enter key to send (Shift+Enter for new line)
        this.messageInput.addEventListener('keydown', (e) => {
            if (e.key === 'Enter' && !e.shiftKey) {
                e.preventDefault();
                this.sendMessage();
            }
        });

        // Auto-resize textarea
        this.messageInput.addEventListener('input', () => this.adjustTextareaHeight());

        // Quick reply clicks
        this.quickReplies.addEventListener('click', (e) => {
            if (e.target.classList.contains('quick-reply')) {
                this.sendQuickReply(e.target.textContent);
            }
        });
    }

    adjustTextareaHeight() {
        this.messageInput.style.height = 'auto';
        this.messageInput.style.height = Math.min(this.messageInput.scrollHeight, 100) + 'px';
    }

    async startConversation() {
        await this.delay(2000);

        const welcomeMessage = "Hello! 👋 I'm your AI assistant calling on behalf of a client who is interested in making a reservation to visit your apartment. Could you please tell me which apartment you'd like to schedule a viewing for?";

        await this.addBotMessage(welcomeMessage);

        await this.delay(2000);

        this.showQuickReplies([
            "Apartment A - 2BR/1BA",
            "Apartment B - 3BR/2BA",
            "Apartment C - 1BR/1BA",
            "I have multiple units"
        ]);

        this.conversationStarted = true;
    }

    async sendMessage() {
        const message = this.messageInput.value.trim();
        if (!message || this.isTyping) return;

        this.addUserMessage(message);
        this.messageInput.value = '';
        this.adjustTextareaHeight();
        this.hideQuickReplies();

        // Simulate AI processing
        await this.showTyping();

        const response = await this.generateResponse(message);
        await this.addBotMessage(response.message);

        await this.delay(2000);

        if (response.quickReplies) {
            this.showQuickReplies(response.quickReplies);
        }
    }

    async sendQuickReply(reply) {
        this.addUserMessage(reply);
        this.hideQuickReplies();

        await this.showTyping();

        const response = await this.generateResponse(reply);
        await this.addBotMessage(response.message);

        await this.delay(2000);

        if (response.quickReplies) {
            this.showQuickReplies(response.quickReplies);
        }
    }

    async generateResponse(userMessage) {
        try {
            const response = await fetch('/chat', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json',
                },
                body: JSON.stringify({
                    message: userMessage,
                    conversation_history: this.getConversationHistory()
                })
            });

            if (!response.ok) {
                throw new Error(`HTTP error! status: ${response.status}`);
            }

            const data = await response.json();

            return {
                message: data.message,
                quickReplies: data.quick_replies || []
            };

        } catch (error) {
            console.error('Error calling chat API:', error);

            // Fallback response if API fails
            return {
                message: "I apologize, but I'm having trouble connecting right now. Could you please try again in a moment?",
                quickReplies: ["Try again", "Contact support"]
            };
        }
    }

    getConversationHistory() {
        const messages = this.messagesContainer.querySelectorAll('.message');
        const history = [];

        messages.forEach(messageEl => {
            const isBot = messageEl.classList.contains('message-bot');
            const content = messageEl.querySelector('.message-content').textContent;

            history.push({
                role: isBot ? 'assistant' : 'user',
                content: content
            });
        });

        return history;
    }

    addUserMessage(message) {
        const messageElement = this.createMessageElement('user', message);
        this.messagesContainer.appendChild(messageElement);
        this.scrollToBottom();
    }

    async addBotMessage(message) {
        const messageElement = this.createMessageElement('bot', message);
        this.messagesContainer.appendChild(messageElement);
        this.scrollToBottom();
        this.hideTyping();
    }

    createMessageElement(sender, content) {
        const messageDiv = document.createElement('div');
        messageDiv.className = `message message-${sender}`;

        const avatar = document.createElement('div');
        avatar.className = `avatar avatar-${sender}`;
        avatar.innerHTML = sender === 'bot' ? '<i class="fas fa-robot"></i>' : '<i class="fas fa-user"></i>';

        const contentDiv = document.createElement('div');
        contentDiv.className = 'message-content';
        contentDiv.textContent = content;

        messageDiv.appendChild(avatar);
        messageDiv.appendChild(contentDiv);

        return messageDiv;
    }

    async showTyping() {
        this.isTyping = true;
        this.sendButton.disabled = true;
        this.typingIndicator.style.display = 'flex';
        this.scrollToBottom();
    }

    hideTyping() {
        this.isTyping = false;
        this.sendButton.disabled = false;
        this.typingIndicator.style.display = 'none';
    }

    showQuickReplies(replies) {
        this.quickReplies.innerHTML = '';
        replies.forEach(reply => {
            const button = document.createElement('button');
            button.className = 'quick-reply';
            button.textContent = reply;
            this.quickReplies.appendChild(button);
        });
        this.quickReplies.style.display = 'flex';
    }

    hideQuickReplies() {
        this.quickReplies.style.display = 'none';
    }

    scrollToBottom() {
        setTimeout(() => {
            this.messagesContainer.scrollTop = this.messagesContainer.scrollHeight;
        }, 100);
    }

    delay(ms) {
        return new Promise(resolve => setTimeout(resolve, ms));
    }
}

// Initialize the chat interface when the page loads
document.addEventListener('DOMContentLoaded', () => {
    new ChatInterface();
});

// Add some smooth animations and interactions
document.addEventListener('DOMContentLoaded', () => {
    // Add hover effects to messages
    document.addEventListener('mouseover', (e) => {
        if (e.target.closest('.message')) {
            e.target.closest('.message').style.transform = 'translateY(-1px)';
        }
    });

    document.addEventListener('mouseout', (e) => {
        if (e.target.closest('.message')) {
            e.target.closest('.message').style.transform = 'translateY(0)';
        }
    });

    // Add some visual feedback for the send button
    const sendButton = document.getElementById('sendButton');
    sendButton.addEventListener('mousedown', () => {
        sendButton.style.transform = 'scale(0.95)';
    });

    sendButton.addEventListener('mouseup', () => {
        sendButton.style.transform = 'scale(1)';
    });
});