document.addEventListener("DOMContentLoaded", () => {
    const chatHistory = document.getElementById("chat-history");
    const messageInput = document.getElementById("message-input");
    const sendBtn = document.getElementById("send-btn");
    const clearBtn = document.getElementById("clear-btn");
    const typingIndicator = document.getElementById("typing-indicator");

    // Auto-resize textarea
    messageInput.addEventListener("input", function() {
        this.style.height = "auto";
        this.style.height = (this.scrollHeight < 150 ? this.scrollHeight : 150) + "px";
    });

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

    sendBtn.addEventListener("click", sendMessage);

    clearBtn.addEventListener("click", async () => {
        if(confirm("Sohbet geçmişini silmek istediğinize emin misiniz?")) {
            chatHistory.innerHTML = `
                <div class="message bot-message">
                    <div class="message-content">
                        Merhaba! Sana nasıl yardımcı olabilirim?
                    </div>
                </div>
            `;
            // Call backend to clear memory
            try {
                await fetch("/chat/default", { method: "DELETE" });
            } catch (err) {
                console.error("Failed to clear backend chat history", err);
            }
        }
    });

    function addMessage(content, sender) {
        const msgDiv = document.createElement("div");
        msgDiv.className = `message ${sender}-message`;
        
        const contentDiv = document.createElement("div");
        contentDiv.className = "message-content";
        
        // Use marked to parse markdown if it's the bot, else just text
        if (sender === "bot") {
            contentDiv.innerHTML = marked.parse(content);
        } else {
            contentDiv.textContent = content;
        }

        msgDiv.appendChild(contentDiv);
        chatHistory.appendChild(msgDiv);
        
        // Scroll to bottom
        setTimeout(() => {
            chatHistory.scrollTop = chatHistory.scrollHeight;
        }, 50);
    }

    async function sendMessage() {
        const text = messageInput.value.trim();
        if (!text) return;

        // Reset input
        messageInput.value = "";
        messageInput.style.height = "auto";
        
        // Add user message to UI
        addMessage(text, "user");
        
        // Show typing indicator
        typingIndicator.style.display = "flex";
        chatHistory.appendChild(typingIndicator);
        chatHistory.scrollTop = chatHistory.scrollHeight;

        try {
            const response = await fetch("/chat", {
                method: "POST",
                headers: {
                    "Content-Type": "application/json"
                },
                body: JSON.stringify({ message: text, session_id: "default" })
            });

            if (!response.ok) {
                throw new Error("Sunucu hatası oluştu.");
            }

            const data = await response.json();
            
            // Hide typing indicator
            typingIndicator.style.display = "none";
            
            // Add bot response
            addMessage(data.response, "bot");
            
        } catch (error) {
            typingIndicator.style.display = "none";
            addMessage("Üzgünüm, bir hata oluştu: " + error.message, "bot");
        }
    }
});