app.py

from gradio import ChatMessage
from langchain_mcp_adapters.client import MultiServerMCPClient
from langchain.agents import create_agent
from langgraph.checkpoint.memory import InMemorySaver
from langchain_core.tools import tool
import pandas as pd
from youtube_search import YoutubeSearch
import gradio as gr
import asyncio
import re
import uuid
import json
from pathlib import Path

from dtc_display import DTCDisplay
from tools import search_youtube_video, decode_vin, hex_to_decimal, calculate_obd_value, combine_bytes
from prompts import system_prompt
from hackathon_detail import create_hackathon_detail_tab
from demo_video import create_demo_video_tab
from mcp_server_detail import create_mcp_server_tab

# from langchain_anthropic import ChatAnthropic
# model = ChatAnthropic(model="claude-haiku-4-5-20251001", temperature=0, streaming=True)  # streaming=True is required for token streaming

from langchain_nebius import ChatNebius
model = ChatNebius(
    model="Qwen/Qwen3-Coder-480B-A35B-Instruct",
    # model = "Qwen/Qwen3-235B-A22B-Instruct-2507",
    # model="meta-llama/Llama-3.3-70B-Instruct",  # Choose from available models
    # model="deepseek-ai/DeepSeek-R1-0528",  # Choose from available models
    temperature=0,
    top_p=0.95,
    streaming=True,
)
# Global variables
agent = None
mcp_error = None
checkpointer = None
historic_data = None 
dtc_component = None

async def setup_agent():
    global agent, mcp_error, checkpointer
    try:
        client = MultiServerMCPClient(  
            {
                "diagnostic": {
                    "transport": "streamable_http",
                    # "url": "http://192.168.10.69/mcp", # Actual physical dongle MCP server
                    "url": "https://castlebbs-elm327-simulator.hf.space/gradio_api/mcp/",  # Simulator MCP server on gradio
                    "timeout": 20.0,  # Increased timeout for multiple calls
                }
            }
        )
        
        tools = await client.get_tools() 
        print("Available MCP tools:", [tool.name for tool in tools])
        
        # Add YouTube search tool to the tools list
        all_tools = list(tools) + [search_youtube_video, decode_vin, hex_to_decimal, calculate_obd_value, combine_bytes]
        
        # Create the checkpointer
        checkpointer = InMemorySaver()
        
        # Create the agent with the retrieved tools
        agent = create_agent(
            model=model,
            system_prompt=system_prompt,
            tools=all_tools,
            checkpointer=checkpointer,
        )
        
        print("✅ MCP server connected successfully")
        return agent
    except Exception as e:
        mcp_error = str(e)
        print(f"⚠️ Warning: Could not connect to MCP server: {e}")
        print("The app will start but MCP tools will not be available.")
        return None

# Try to setup agent, but don't fail if it doesn't work
try:
    agent = asyncio.run(setup_agent())
except Exception as e:
    print(f"Failed to initialize agent: {e}")

async def interact_with_langchain_agent(user_prompt, messages, session_id, historic_data_state, vin_data_state, dtc_data_state):
    global agent, mcp_error
    
    # Skip if input is empty or only whitespace
    if not user_prompt or not user_prompt.strip():
        yield messages, historic_data_state, vin_data_state, dtc_data_state
        return
    
    print("> ", user_prompt)
    messages.append(ChatMessage(role="user", content=user_prompt))
    yield messages, historic_data_state, vin_data_state, dtc_data_state

    # Check if agent is available
    if agent is None:
        error_msg = f"❌ MCP server is not available. {mcp_error or 'Connection failed.'}\n\nPlease ensure MCP server is reachable and try again."
        messages.append(ChatMessage(role="assistant", content=error_msg))
        yield messages, historic_data_state, vin_data_state, dtc_data_state
        return
    # print("Agent is available, processing the request...")

    try:
        assistant_response = ""  # Collect assistant's full response
        current_message_index = None  # Track which message we're streaming to
        tool_call_tracker = {}  # Track tool calls: {tool_call_id: message_index}
        tool_args_accumulator = {}  # NEW: Accumulate streaming tool arguments
        current_tool_call_id = None  # Track the active tool call being streamed
        dtc_extracted = False  # Track if we've already extracted DTC data

        # Stream with messages mode for token-by-token streaming
        async for message_chunk, metadata in agent.astream(
            {"messages": [{"role": "user", "content": user_prompt}]},
            {"configurable": {"thread_id": session_id}},
            stream_mode="messages"
        ):
            node = metadata.get("langgraph_node", "unknown")
            # print(f"Token from node {node}: {message_chunk}")

            # Only process chunks from the model node (AI responses)
            if node == "model":
                # Check if this is the last chunk in a tool call sequence
                is_last_chunk = hasattr(message_chunk, "response_metadata") and message_chunk.response_metadata.get("finish_reason") == "tool_calls"

                # Check if this is a tool call or text content
                if hasattr(message_chunk, "tool_call_chunks") and message_chunk.tool_call_chunks:
                    # Handle tool call chunks
                    for tool_chunk in message_chunk.tool_call_chunks:
                        tool_call_id = tool_chunk.get("id")
                        tool_name = tool_chunk.get("name")
                        tool_args = tool_chunk.get("args")

                        # Determine active ID using pending key for chunks without ID
                        if not tool_call_id:
                            # No ID yet, use default key
                            active_id = "pending_tool_0"
                        else:
                            # We have an ID now - this is a new tool call
                            active_id = tool_call_id

                            # If this is a brand new tool call with a name, reset for fresh start
                            if tool_name and tool_call_id not in tool_call_tracker:
                                # Clear any stale pending data
                                if "pending_tool_0" in tool_args_accumulator:
                                    del tool_args_accumulator["pending_tool_0"]
                                # Initialize fresh accumulator for this tool call
                                tool_args_accumulator[tool_call_id] = ""
                                current_tool_call_id = tool_call_id

                            # Migrate any pending args to the real ID
                            elif "pending_tool_0" in tool_args_accumulator:
                                if tool_call_id not in tool_args_accumulator:
                                    tool_args_accumulator[tool_call_id] = ""
                                tool_args_accumulator[tool_call_id] = tool_args_accumulator["pending_tool_0"] + tool_args_accumulator.get(tool_call_id, "")
                                del tool_args_accumulator["pending_tool_0"]
                                current_tool_call_id = tool_call_id

                        # Initialize accumulator if needed
                        if active_id not in tool_args_accumulator:
                            tool_args_accumulator[active_id] = ""

                        # Accumulate arguments
                        if tool_args:
                            tool_args_accumulator[active_id] += tool_args

                        # Create message when we first see a tool call with name and ID
                        if tool_call_id and tool_name:
                            # Check if this is a reused ID (same ID appearing again)
                            if tool_call_id in tool_call_tracker:
                                # This ID was used before - check if previous call is complete
                                prev_msg_idx = tool_call_tracker[tool_call_id]
                                if prev_msg_idx < len(messages) and messages[prev_msg_idx].content:
                                    # Previous call has results, this is a NEW call with reused ID
                                    # Reset the accumulator and create a new message
                                    tool_args_accumulator[tool_call_id] = ""
                                    messages.append(ChatMessage(
                                        role="assistant",
                                        content="",
                                        metadata={"title": f"⚙️ Calling {tool_name}...", "tool_id": tool_call_id, "tool_name": tool_name},
                                    ))
                                    tool_call_tracker[tool_call_id] = len(messages) - 1
                                    yield messages, historic_data_state, vin_data_state, dtc_data_state
                            else:
                                # Truly new tool call ID
                                messages.append(ChatMessage(
                                    role="assistant",
                                    content="",
                                    metadata={"title": f"⚙️ Calling {tool_name}...", "tool_id": tool_call_id, "tool_name": tool_name},
                                ))
                                tool_call_tracker[tool_call_id] = len(messages) - 1
                                yield messages, historic_data_state, vin_data_state, dtc_data_state

                        # Update the message as args stream in OR on the last chunk
                        # Check both active_id and current_tool_call_id in case pending args exist
                        target_id = active_id if active_id in tool_call_tracker else current_tool_call_id

                        if target_id and target_id in tool_call_tracker:
                            # Try to get args from either active_id or pending
                            accumulated_args = tool_args_accumulator.get(active_id, "") or tool_args_accumulator.get("pending_tool_0", "")
                            if accumulated_args:
                                try:
                                    # Try to parse accumulated args
                                    args_dict = json.loads(accumulated_args)

                                    # Get the first parameter value (works for any parameter name)
                                    param_value = "..."
                                    if args_dict:
                                        # Get the first non-empty value from the dict
                                        param_value = next((str(v) for v in args_dict.values() if v), "...")

                                    # Update the message title with the actual parameter value
                                    msg_index = tool_call_tracker[target_id]
                                    tool_name = messages[msg_index].metadata.get("tool_name", "")
                                    messages[msg_index].metadata["title"] = f"⚙️ Calling {tool_name}: <b>{param_value}</b>"
                                    yield messages, historic_data_state, vin_data_state, dtc_data_state
                                except json.JSONDecodeError:
                                    # Args still streaming, don't update yet
                                    pass

                    # Force update on the last chunk to ensure we catch the final args
                    if is_last_chunk and current_tool_call_id and current_tool_call_id in tool_call_tracker:
                        # Check both the tool ID accumulator and pending
                        accumulated_args = tool_args_accumulator.get(current_tool_call_id, "") or tool_args_accumulator.get("pending_tool_0", "")
                        if accumulated_args:
                            try:
                                args_dict = json.loads(accumulated_args)
                                param_value = "..."
                                if args_dict:
                                    param_value = next((str(v) for v in args_dict.values() if v), "...")

                                msg_index = tool_call_tracker[current_tool_call_id]
                                tool_name = messages[msg_index].metadata.get("tool_name", "")
                                messages[msg_index].metadata["title"] = f"⚙️ Calling {tool_name}: <b>{param_value}</b>"
                                yield messages, historic_data_state, vin_data_state, dtc_data_state
                            except json.JSONDecodeError:
                                pass

                elif hasattr(message_chunk, "content") and message_chunk.content:
                    # Handle text streaming token by token
                    text_content = message_chunk.content

                    if isinstance(text_content, str) and text_content:
                        # Accumulate the full response for DTC extraction
                        if current_message_index is None:
                            assistant_response = text_content
                        else:
                            assistant_response += text_content
                        
                        # Check for complete DTC data block and extract it (only once)
                        if not dtc_extracted:
                            dtc_match = re.search(r'<DTC_DATA>\s*(\[.*?\])\s*</DTC_DATA>', 
                                                 assistant_response, re.DOTALL)
                            
                            if dtc_match:
                                try:
                                    # Extract and parse the DTC JSON
                                    dtc_json = json.loads(dtc_match.group(1))
                                    dtc_data_state = dtc_json
                                    dtc_extracted = True  # Mark as extracted
                                    print(f"✅ Extracted DTC data from LLM response: {dtc_json}")
                                except json.JSONDecodeError as e:
                                    print(f"⚠️ Could not parse DTC data from LLM response: {e}")
                        
                        # Remove the DTC_DATA block from display text (only from accumulated response)
                        display_response = re.sub(r'<DTC_DATA>.*?</DTC_DATA>', '', 
                                                 assistant_response, flags=re.DOTALL)
                        
                        # Stream the token (calculate what to add by comparing with previous content)
                        if current_message_index is None:
                            # Start a new assistant message with clean content
                            messages.append(ChatMessage(role="assistant", content=display_response))
                            current_message_index = len(messages) - 1
                        else:
                            # Update the message with the clean accumulated content
                            messages[current_message_index].content = display_response

                        yield messages, historic_data_state, vin_data_state, dtc_data_state

                    elif isinstance(text_content, list):
                        # Handle content blocks
                        for block in text_content:
                            if isinstance(block, dict) and block.get("type") == "text":
                                text = block.get("text", "")
                                if text:
                                    # Accumulate the full response for DTC extraction
                                    assistant_response += text
                                    
                                    # Check for complete DTC data block and extract it (only once)
                                    if not dtc_extracted:
                                        dtc_match = re.search(r'<DTC_DATA>\s*(\[.*?\])\s*</DTC_DATA>', 
                                                             assistant_response, re.DOTALL)
                                        
                                        if dtc_match:
                                            try:
                                                # Extract and parse the DTC JSON
                                                dtc_json = json.loads(dtc_match.group(1))
                                                dtc_data_state = dtc_json
                                                dtc_extracted = True  # Mark as extracted
                                                print(f"✅ Extracted DTC data from LLM response: {dtc_json}")
                                            except json.JSONDecodeError as e:
                                                print(f"⚠️ Could not parse DTC data from LLM response: {e}")
                                    
                                    # Remove the DTC_DATA block from display (only from accumulated response)
                                    display_response = re.sub(r'<DTC_DATA>.*?</DTC_DATA>', '', 
                                                             assistant_response, flags=re.DOTALL)
                                    
                                    if current_message_index is None:
                                        messages.append(ChatMessage(role="assistant", content=display_response))
                                        current_message_index = len(messages) - 1
                                    else:
                                        messages[current_message_index].content = display_response
                                    yield messages, historic_data_state, vin_data_state, dtc_data_state

            elif node == "tools":
                # Reset current message index when we move to tool execution
                current_message_index = None

                # Handle tool outputs
                if hasattr(message_chunk, "content"):
                    tool_output = message_chunk.content
                    tool_call_id = message_chunk.tool_call_id if hasattr(message_chunk, "tool_call_id") else None

                    # Decode escaped newlines for proper display
                    if isinstance(tool_output, str):
                        tool_output = tool_output.replace('\\n', '\n')

                        # Replace "?" with "NO DATA"
                        if tool_output.strip() == "?":
                            tool_output = "NO DATA"

                    # Update the corresponding tool call message
                    if tool_call_id and tool_call_id in tool_call_tracker:
                        msg_index = tool_call_tracker[tool_call_id]
                        
                        # Check if this is historic data tool
                        tool_metadata = messages[msg_index].metadata or {}
                        tool_name = tool_metadata.get("tool_name", "")
                        
                        # Check if toolname ends with "get_elm327_history"
                        if tool_name.endswith("get_elm327_history") and isinstance(tool_output, str):
                            try:
                                # Parse the JSON data
                                historic_data_state = json.loads(tool_output)
                                print(f"Captured historic data:  {historic_data_state}")
                            except json.JSONDecodeError:
                                print(f"Could not parse historic data as JSON")
                        # Check if this is VIN decode tool
                        if tool_name == "decode_vin" and isinstance(tool_output, str):
                            # Store the VIN decode output
                            vin_data_state = tool_output
                            print(f"Captured VIN data: {vin_data_state}")
                        messages[msg_index].content = f"{tool_output}\n"
                    else:
                        # Fallback: add as new message
                        messages.append(ChatMessage(
                            role="assistant",
                            content=f"{tool_output}\n",
                        ))

                    yield messages, historic_data_state, vin_data_state, dtc_data_state
    except ExceptionGroup as eg:
        # Handle Python 3.11+ ExceptionGroup from TaskGroup
        error_details = []
        for e in eg.exceptions:
            error_details.append(f"  - {type(e).__name__}: {str(e)}")
        error_message = f"❌ Multiple errors occurred:\n" + "\n".join(error_details[:3])  # Show first 3
        if len(eg.exceptions) > 3:
            error_message += f"\n  ... and {len(eg.exceptions) - 3} more"
        error_message += "\n\n💡 This usually means the elm327 device is unreachable or timing out."
        messages.append(ChatMessage(role="assistant", content=error_message))
        yield messages, historic_data_state, vin_data_state, dtc_data_state
    except Exception as e:
        error_message = f"❌ Error: {type(e).__name__}: {str(e)}\n\n💡 Make sure MCP server is online and responding."
        messages.append(ChatMessage(role="assistant", content=error_message))
        print(f"Error during agent interaction: {e}")
        yield messages, historic_data_state, vin_data_state, dtc_data_state

def clear_history():
    global checkpointer
    # Clear the checkpointer memory if it exists
    if checkpointer is not None:
        # InMemorySaver stores data in checkpointer.storage dict
        checkpointer.storage.clear()
        print("✅ Checkpointer memory cleared")
    
    # Return empty states for chatbot, historic_data, vin_data, dtc_data, plot, and vin_dataframe
    empty_vin_df = pd.DataFrame({
        'Property': ["NO DATA"],
        'Value': ['']
    })
    
    return [], None, None, None, None, empty_vin_df, []

def update_vin_dataframe(vin_data_state):
    """Update the VIN dataframe from the state data."""
    if not vin_data_state:
        # Return empty dataframe with default structure
        return pd.DataFrame({
                    'Property': [ "NO DATA" ],
                    'Value': [ '' ]
                })

    # Parse the VIN data (it comes as a formatted string from the tool)
    # Extract property-value pairs from the string
    df_data = {
        'Property': [
            'Make',
            'Model',
            'Model Year',
            'Vehicle Type',
            'Body Class',
            'Manufacturer Name',
            'Plant City',
            'Plant State',
            'Plant Country',
            'Trim',
            'Engine Number of Cylinders',
            'Displacement (L)',
            'Engine Model',
            'Fuel Type - Primary',
            'Fuel Type - Secondary',
            'Electrification Level',
            'Transmission Style',
            'Drive Type',
            'Number of Doors',
            'Number of Seats',
            'Gross Vehicle Weight Rating From',
            'Error Code',
            'Error Text'
        ],
        'Value': [''] * 23
    }

    # Parse the VIN data string and populate values
    for line in vin_data_state.split('\n'):
        if ':' in line:
            key, value = line.split(':', 1)
            key = key.strip()
            value = value.strip()
            if key in df_data['Property']:
                idx = df_data['Property'].index(key)
                df_data['Value'][idx] = value

    return pd.DataFrame(df_data)

#method to create a plot
def create_plot(data):
    
    if data is None or len(data) == 0:
        # print("No historic data to plot.")
        return None
        
    print("Creating plot with data:", data)
    
    # Create DataFrame from actual historic data
    df = pd.DataFrame(data)
    
    # Create long format DataFrame with all three metrics
    df_combined = pd.DataFrame({
        'time': list(df['time']) + list(df['time']) + list(df['time']),
        'value': list(df['rpm']) + list(df['speed']) + list(df['coolant_temp']),
        'metric': ['RPM'] * len(df) + ['Speed'] * len(df) + ['Coolant Temp'] * len(df)
    })

    # plot = gr.LinePlot(
    #     value=df_combined,
    #     x="time",
    #     y="value",
    #     color="metric",
    #     x_title="Time (ms)",
    #     y_title="Value",
    #     title="Vehicle Telemetry",
    #     colors_in_legend=["RPM", "Speed", "Coolant Temp"],
    #     color_map={"RPM": "red", "Speed": "blue", "Coolant Temp": "green"}
    # )
    # return plot
    return df_combined

def update_dtc(dtc_data):
    if dtc_data is None or len(dtc_data) == 0:
        # print("No DTC data to update.")
        return []

    print("Updating DTC component with data:", dtc_data)
    return dtc_data

# Gradio UI setup
with gr.Blocks() as demo:
    input = None
    chatbot = None
    submit_btn = None
    clear_btn = None
    examples = None
    plot_output = None
    vin_dataframe = None

    # Create a unique session ID for each user session
    session_id = gr.State(lambda: str(uuid.uuid4()))
    historic_data_state = gr.State(None)  # State to hold historic data
    dtc_data_state = gr.State(None)  # State to hold DTC data
    vin_data_state = gr.State(None)  # State to hold VIN decode data

    with gr.Row(equal_height=True, elem_classes="vertical-center"):
        gr.Image("mechanic_s.png", height=60, width=60,  show_label=False, container=False, buttons=[""], scale=0, min_width=0, elem_classes="logo-image")
        with gr.Column(scale=10, elem_classes="big-title"):
            gr.Markdown("## Vehicle Diagnostic Assistant 🚗 🛠️")
    with gr.Row( elem_classes="ask-me"):
        gr.Markdown("AI agent that connects to your car via an embedded MCP server to provide real-time diagnostics and insights.")

    with gr.Tabs():
        with gr.Tab("Main Dashboard"):
            with gr.Row():
                with gr.Column(scale=6, min_width=600):
                    with gr.Row():
                        chatbot = gr.Chatbot(

                            label="Diagnostic Agent",
                            avatar_images=(
                                None,
                                "mechanic_s.png",
                            ),
                            height=400,
                            group_consecutive_messages=False,
                            buttons=[""],
                        )

                    with gr.Row():

                        input = gr.Textbox(
                            lines=1,
                            label="Ask a question",
                            placeholder="e.g., Can you check for any faults? What's the engine RPM?",
                            show_label=True,
                            buttons=[""],
                        )
                    with gr.Row():

                        submit_btn = gr.Button("Run", size="lg", variant="primary", elem_classes="button_color")
                        clear_btn = gr.Button("Clear History", size="lg", variant="secondary")

                    # Example questions
                    gr.Examples(
                        examples=[
                            ["Can you see if there are any faults using OBD-II?"],
                            ["What's the vehicle VIN?"],
                            ["Check the engine RPM and speed"],
                            ["Read the temperature sensor"],
                            ["Get system information"],
                            ["Get the last 10 historic data"],
                        ],
                        inputs=input

                    )

                with gr.Column(scale=4, min_width=400, elem_classes="scroll-column"):
                    with gr.Column(min_width=400): # Added extra Column for scroll
                        with gr.Row():
                            with gr.Column():
                                gr.Markdown("### 📊 Historic Vehicle Data", elem_classes="section-title")
                                plot_output = gr.LinePlot(
                                    value=None,
                                    x="time",
                                    y="value",
                                    color="metric",
                                    x_title="Time (ms)",
                                    y_title="Value",
                                    title="Vehicle Telemetry",
                                    colors_in_legend=["RPM", "Speed", "Coolant Temp"],
                                    color_map={"RPM": "red", "Speed": "blue", "Coolant Temp": "green"},
                                    label="Vehicle Telemetry"
                                )
                        with gr.Row():
                            with gr.Column():
                                dtc_component = DTCDisplay(
                                    label="Diagnostic Trouble Codes",
                                    value=[],
                                    scale=1
                                )
                        with gr.Row():
                            with gr.Column():
                                gr.Markdown("### 🚘 Vehicle Information (VIN Decoded)", elem_classes="section-title")
                                vin_dataframe = gr.DataFrame(
                                    value=pd.DataFrame({
                                        'Property': [ "NO DATA" ],
                                        'Value': [ '' ]
                                    }),
                                    headers=["Property", "Value"],
                                    datatype=["str", "str"],
                                    column_count=2,
                                    interactive=False,
                                    column_widths=["30%", "60%"],
                                    max_height="100%",
                                    wrap=True
                                )

        with gr.Tab("Demo Video"):
            create_demo_video_tab()

        with gr.Tab("Hackathon project detail"):
            create_hackathon_detail_tab()

        with gr.Tab("MCP Server on embedded device"):
            create_mcp_server_tab()

    # Event handlers (must be outside the Row context but can reference components)
    input.submit(
        interact_with_langchain_agent,
        [input, chatbot, session_id, historic_data_state, vin_data_state, dtc_data_state],
        [chatbot, historic_data_state, vin_data_state, dtc_data_state],
        trigger_mode="always_last"
    ).then(
        lambda:"", None, input
    ).then(
        create_plot, historic_data_state, plot_output
    ).then(
        update_vin_dataframe, vin_data_state, vin_dataframe
    ).then(
           update_dtc, dtc_data_state, dtc_component)

    submit_btn.click(
        interact_with_langchain_agent,
        [input, chatbot, session_id, historic_data_state, vin_data_state, dtc_data_state],
        [chatbot, historic_data_state, vin_data_state, dtc_data_state],
        trigger_mode="always_last"
    ).then(
        lambda:"", None, input
    ).then(
        create_plot, historic_data_state, plot_output
    ).then(
        update_vin_dataframe, vin_data_state, vin_dataframe
    ).then(
           update_dtc, dtc_data_state, dtc_component)

    clear_btn.click(clear_history, None, [chatbot, historic_data_state, vin_data_state, dtc_data_state, plot_output, vin_dataframe, dtc_component])

gr.set_static_paths(paths=[Path.cwd().absolute()/"assets"])
demo.launch(css_paths=["styles.css"])