import tkinter as tk
from tkinter import scrolledtext, messagebox
import json
import os
from datetime import datetime

class ChatApplication:
    def __init__(self, root):
        self.root = root
        self.root.title("Chat Interface")
        self.root.geometry("600x500")
        self.root.configure(bg="#f0f0f0")
        
        self.message_history = []
        self.history_file = "chat_history.json"
        
        self.load_chat_history()
        self.create_widgets()
        
    def create_widgets(self):
        # Main frame
        main_frame = tk.Frame(self.root, bg="#f0f0f0")
        main_frame.pack(fill=tk.BOTH, expand=True, padx=10, pady=10)
        
        # Chat display area
        self.chat_display = scrolledtext.ScrolledText(
            main_frame,
            wrap=tk.WORD,
            width=60,
            height=20,
            font=("Arial", 10),
            state=tk.DISABLED
        )
        self.chat_display.pack(fill=tk.BOTH, expand=True, pady=(0, 10))
        
        # Input frame
        input_frame = tk.Frame(main_frame, bg="#f0f0f0")
        input_frame.pack(fill=tk.X)
        
        # User input field
        self.user_input = tk.Entry(
            input_frame,
            font=("Arial", 12),
            relief=tk.FLAT,
            bg="white"
        )
        self.user_input.pack(side=tk.LEFT, fill=tk.X, expand=True, padx=(0, 5))
        self.user_input.bind("<Return>", self.send_message)
        
        # Send button
        send_button = tk.Button(
            input_frame,
            text="Send",
            command=self.send_message,
            bg="#4CAF50",
            fg="white",
            font=("Arial", 10, "bold"),
            relief=tk.FLAT,
            padx=20
        )
        send_button.pack(side=tk.RIGHT)
        
        # Load existing messages
        self.display_messages()
        
        # Focus on input field
        self.user_input.focus_set()
        
    def send_message(self, event=None):
        message = self.user_input.get().strip()
        if not message:
            return
            
        timestamp = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
        message_data = {
            "timestamp": timestamp,
            "message": message,
            "sender": "user"
        }
        
        self.message_history.append(message_data)
        self.display_message(message_data)
        self.user_input.delete(0, tk.END)
        
        # Simulate bot response (in real app, this would be your AI/chat logic)
        self.simulate_bot_response(message)
        
        self.save_chat_history()
        
    def simulate_bot_response(self, user_message):
        # Simple response simulation - replace with actual AI/chat logic
        responses = {
            "hello": "Hello! How can I help you today?",
            "hi": "Hi there! What can I do for you?",
            "help": "I'm here to help! What do you need assistance with?",
            "bye": "Goodbye! Have a great day!"
        }
        
        response = responses.get(user_message.lower(), 
                               f"I received your message: '{user_message}'. How can I assist you further?")
        
        timestamp = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
        response_data = {
            "timestamp": timestamp,
            "message": response,
            "sender": "bot"
        }
        
        self.message_history.append(response_data)
        self.display_message(response_data)
        self.save_chat_history()
        
    def display_message(self, message_data):
        self.chat_display.config(state=tk.NORMAL)
        
        # Configure tags for different senders
        self.chat_display.tag_configure("user", foreground="blue", justify="right")
        self.chat_display.tag_configure("bot", foreground="green", justify="left")
        self.chat_display.tag_configure("timestamp", foreground="gray", font=("Arial", 8))
        
        # Insert message with appropriate formatting
        if message_data["sender"] == "user":
            self.chat_display.insert(tk.END, f"{message_data['timestamp']}\n", "timestamp")
            self.chat_display.insert(tk.END, f"You: {message_data['message']}\n\n", "user")
        else:
            self.chat_display.insert(tk.END, f"{message_data['timestamp']}\n", "timestamp")
            self.chat_display.insert(tk.END, f"Bot: {message_data['message']}\n\n", "bot")
            
        self.chat_display.config(state=tk.DISABLED)
        self.chat_display.see(tk.END)
        
    def display_messages(self):
        self.chat_display.config(state=tk.NORMAL)
        self.chat_display.delete(1.0, tk.END)
        
        for message in self.message_history:
            if message["sender"] == "user":
                self.chat_display.insert(tk.END, f"{message['timestamp']}\n", "timestamp")
                self.chat_display.insert(tk.END, f"You: {message['message']}\n\n", "user")
            else:
                self.chat_display.insert(tk.END, f"{message['timestamp']}\n", "timestamp")
                self.chat_display.insert(tk.END, f"Bot: {message['message']}\n\n", "bot")
                
        self.chat_display.config(state=tk.DISABLED)
        self.chat_display.see(tk.END)
        
    def load_chat_history(self):
        try:
            if os.path.exists(self.history_file):
                with open(self.history_file, 'r') as f:
                    self.message_history = json.load(f)
        except (FileNotFoundError, json.JSONDecodeError):
            self.message_history = []
            
    def save_chat_history(self):
        try:
            with open(self.history_file, 'w') as f:
                json.dump(self.message_history, f, indent=2)
        except Exception as e:
            messagebox.showerror("Error", f"Failed to save chat history: {str(e)}")

def main():
    root = tk.Tk()
    app = ChatApplication(root)
    root.mainloop()

if __name__ == "__main__":
    main()