import gradio as gr
import openai
from openai import OpenAI
import os
from typing import List, Tuple

# Initialize OpenAI with environment variable
# Set OPENAI_API_KEY in Hugging Face secrets
client = OpenAI(api_key=os.getenv("OPENAI_API_KEY"))

# Global session state
chat_history = []

def respond_to_message(message: str, history: List[List[str]]) -> Tuple[str, List[List[str]]]:
    """Handle user message and return response with updated history"""
    if not message.strip():
        return "", history
    
    # Add user message to history
    history.append([message, ""])
    
    # Add to global chat history for sidebar
    global chat_history
    chat_history.append(message)
    
    try:
        # Prepare messages for OpenAI API
        messages = [{"role": "system", "content": "You are a helpful assistant."}]
        
        # Add conversation history
        for user_msg, assistant_msg in history[:-1]:  # Exclude the current message
            if user_msg and assistant_msg:
                messages.append({"role": "user", "content": user_msg})
                messages.append({"role": "assistant", "content": assistant_msg})
        
        # Add current user message
        messages.append({"role": "user", "content": message})
        
        # Get response from OpenAI
        response = client.chat.completions.create(
            model="gpt-3.5-turbo",  # You can change to gpt-4 if available
            messages=messages,
            max_tokens=1000,
            temperature=0.7
        )
        
        assistant_response = response.choices[0].message.content
        
        # Update the last message in history with assistant response
        history[-1][1] = assistant_response
        
        return "", history
        
    except Exception as e:
        error_message = f"Error: {str(e)}"
        history[-1][1] = error_message
        return "", history

def clear_chat() -> Tuple[str, List[List[str]]]:
    """Clear the current chat history"""
    global chat_history
    chat_history = []
    return "", []

def get_chat_history() -> List[str]:
    """Get chat history for sidebar"""
    return chat_history

# Custom CSS for ChatGPT-like styling
custom_css = """
.gradio-container {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: white !important;
    min-height: 100vh;
}

.chat-layout {
    display: flex;
    height: 100vh;
    max-width: 100%;
    margin: 0 auto;
    background: white;
}

.sidebar {
    width: 280px;
    background: #f7f7f8;
    color: #374151;
    padding: 0;
    display: flex;
    flex-direction: column;
    border-right: 1px solid #e5e7eb;
    overflow-y: auto;
}

.sidebar-header {
    padding: 16px;
    border-bottom: 1px solid #e5e7eb;
    background: white;
}

.history-list {
    flex: 1;
    padding: 8px;
    background: #f7f7f8;
    overflow-y: auto;
}

.history-item {
    background: transparent !important;
    color: #374151 !important;
    border: none !important;
    border-radius: 6px !important;
    padding: 8px 12px !important;
    font-size: 13px !important;
    cursor: pointer !important;
    transition: background-color 0.2s !important;
    width: 100% !important;
    text-align: left !important;
    margin-bottom: 4px !important;
    box-shadow: none !important;
    line-height: 1.4 !important;
    word-wrap: break-word !important;
    white-space: normal !important;
}

.history-item:hover {
    background: #e5e7eb !important;
}

.history-item.active {
    background: #e5e7eb !important;
}

.main-chat {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: white;
    min-height: 0;
}

.chat-header {
    padding: 12px 24px;
    border-bottom: 1px solid #e5e7eb;
    color: #374151;
    font-size: 16px;
    font-weight: 600;
    background: white;
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 0;
    background: white;
    min-height: 0;
}

.chatbot {
    background: transparent !important;
    border: none !important;
    box-shadow: none !important;
    padding: 0 !important;
    height: 100% !important;
}

.chatbot .message {
    margin: 0 !important;
    padding: 16px 0 !important;
    border-radius: 0 !important;
    border-bottom: 1px solid #e5e7eb !important;
}

.chatbot .user-message {
    background: white !important;
    color: #374151 !important;
    margin: 0 !important;
    padding: 16px 24px !important;
}

.chatbot .bot-message {
    background: #f9fafb !important;
    color: #374151 !important;
    margin: 0 !important;
    padding: 16px 24px !important;
}

.chat-input-container {
    padding: 16px 24px;
    border-top: 1px solid #e5e7eb;
    background: white;
    position: sticky;
    bottom: 0;
}

.chat-input {
    background: white !important;
    border: 1px solid #d1d5db !important;
    color: #374151 !important;
    border-radius: 8px !important;
    padding: 12px 16px !important;
    font-size: 16px !important;
    resize: none !important;
    min-height: 48px !important;
}

.chat-input:focus {
    border-color: #3b82f6 !important;
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.2) !important;
}

.send-button {
    background: #3b82f6 !important;
    color: white !important;
    border: none !important;
    border-radius: 6px !important;
    padding: 8px 16px !important;
    font-size: 14px !important;
    font-weight: 500 !important;
    cursor: pointer !important;
    transition: background-color 0.2s !important;
    height: 36px !important;
}

.send-button:hover {
    background: #2563eb !important;
}

.clear-button {
    background: #6b7280 !important;
    color: white !important;
    border: none !important;
    border-radius: 6px !important;
    padding: 8px 16px !important;
    font-size: 14px !important;
    cursor: pointer !important;
    transition: background-color 0.2s !important;
    height: 36px !important;
}

.clear-button:hover {
    background: #4b5563 !important;
}

@media (max-width: 768px) {
    .chat-layout {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        height: auto;
        max-height: 200px;
    }
    
    .main-chat {
        flex: 1;
    }
}
"""

# Create the Gradio interface
with gr.Blocks(css=custom_css, title="ChatGPT Clone") as demo:
    
    with gr.Row(elem_classes="chat-layout"):
        # Left sidebar with chat history
        with gr.Column(elem_classes="sidebar"):
            # Sidebar header
            with gr.Row(elem_classes="sidebar-header"):
                gr.Markdown("### 💬 Chat History")
            
            # Chat history list
            with gr.Column(elem_classes="history-list"):
                chat_history_display = gr.Textbox(
                    value="",
                    label="",
                    elem_classes="history-item",
                    show_label=False,
                    interactive=False,
                    lines=25
                )
        
        # Main chat area
        with gr.Column(elem_classes="main-chat"):
            # Chat header
            with gr.Row(elem_classes="chat-header"):
                gr.Markdown("### AI Assistant")
            
            # Chat messages
            chatbot = gr.Chatbot(
                elem_classes="chatbot",
                height=500,
                show_label=False,
                container=True,
                bubble_full_width=True
            )
            
            # Chat input area
            with gr.Row(elem_classes="chat-input-container"):
                with gr.Column(scale=4):
                    user_input = gr.Textbox(
                        placeholder="Type your message here...",
                        show_label=False,
                        lines=2,
                        max_lines=4,
                        elem_classes="chat-input"
                    )
                with gr.Column(scale=1):
                    send_btn = gr.Button("Send", elem_classes="send-button")
                    clear_btn = gr.Button("Clear", elem_classes="clear-button")
    
    # Event handlers
    def handle_send(message, history):
        result = respond_to_message(message, history)
        # Update chat history display as list items
        if chat_history:
            history_text = ""
            for i, msg in enumerate(chat_history):
                history_text += f"• {msg}\n"
        else:
            history_text = "No chat history yet"
        return result[0], result[1], history_text
    
    def handle_clear():
        result = clear_chat()
        return result[0], result[1], "No chat history yet"
    
    # Connect events
    send_btn.click(
        fn=handle_send,
        inputs=[user_input, chatbot],
        outputs=[user_input, chatbot, chat_history_display]
    )
    
    user_input.submit(
        fn=handle_send,
        inputs=[user_input, chatbot],
        outputs=[user_input, chatbot, chat_history_display]
    )
    
    clear_btn.click(
        fn=handle_clear,
        outputs=[user_input, chatbot, chat_history_display]
    )

# Launch the app for Hugging Face
demo.launch()