app.py

import re
import time
import chainlit as cl
import pandas as pd
import httpx
import asyncio
from typing import Dict, List, Any, Optional, Callable
from dataclasses import dataclass, field
import os
import uuid
from datetime import datetime, timedelta


API_BASE_URL = os.getenv("API_BASE_URL")


@dataclass
class ConversationState:
    """Data class to hold conversation state"""
    session_id: Optional[str] = None
    specs_advantages: Dict[str, Any] = field(default_factory=dict)
    solution_packages: List[str] = field(default_factory=list)
    raw_documents: Optional[Dict[str, Any]] = None
    outputs: Optional[Dict[str, Any]] = None
    selected_model: str = "Gemini 2.0 Flash"
    product_model_search: bool = False
    method: str = "dense"  # "dense", "sparse", "hybrid"
    is_enhance_query: bool = False  # New field for query enhancement toggle
    # New fields for delayed cleanup - now using asyncio
    pending_cleanup: bool = False
    cleanup_task: Optional[asyncio.Task] = None
    last_activity: datetime = field(default_factory=datetime.now)
    
    def reset(self):
        """Reset state to initial values"""
        self.session_id = None
        self.specs_advantages = {}
        self.solution_packages = []
        self.raw_documents = None
        self.outputs = None
        self.selected_model = "Gemini 2.0 Flash"
        self.product_model_search = False
        self.method = "dense"
        self.is_enhance_query = False
        # Reset cleanup fields but don't touch tasks
        self.pending_cleanup = False
        self.last_activity = datetime.now()

    def cancel_cleanup_task(self):
        """Cancel pending cleanup task if exists"""
        if self.cleanup_task and not self.cleanup_task.done():
            self.cleanup_task.cancel()
            self.cleanup_task = None
            print(f"🚫 Cancelled cleanup task for session: {self.session_id}")


class StateManager:
    """Manages conversation state operations with per-session isolation and delayed cleanup"""
    
    # CLASS-LEVEL session storage for isolation between different browser sessions
    _session_states: Dict[str, ConversationState] = {}
    _lock = asyncio.Lock()  # Async lock for consistency
    
    @staticmethod
    async def get_or_create_session_state(session_id: str) -> ConversationState:
        """Get existing session state or create new one"""
        async with StateManager._lock:
            if session_id not in StateManager._session_states:
                state = ConversationState()
                state.session_id = session_id
                StateManager._session_states[session_id] = state
                print(f"🆕 Created new session state for: {session_id}")
            else:
                state = StateManager._session_states[session_id]
                print(f"🔄 Retrieved existing session state for: {session_id}")
                
                # CRITICAL: If session was pending cleanup, cancel it because user is active again
                if state.pending_cleanup:
                    state.cancel_cleanup_task()
                    state.pending_cleanup = False
                    print(f"♻️ User activity detected! Cancelled pending cleanup for: {session_id}")
            
            # Update activity timestamp
            state.last_activity = datetime.now()
            return state
    
    @staticmethod
    async def schedule_delayed_cleanup(session_id: str, delay_seconds: int = 3600):
        """Schedule delayed cleanup for a session using asyncio (default 1 hour for disconnect tolerance)"""
        async with StateManager._lock:
            if session_id not in StateManager._session_states:
                print(f"⚠️ Cannot schedule cleanup for non-existent session: {session_id}")
                return
                
            state = StateManager._session_states[session_id]
            
            # Cancel existing task if any
            state.cancel_cleanup_task()
            
            # Mark as pending cleanup
            state.pending_cleanup = True
            
            # Schedule new cleanup using asyncio
            async def delayed_cleanup():
                try:
                    await asyncio.sleep(delay_seconds)
                    print(f"⏰ Executing delayed cleanup for session: {session_id}")
                    await StateManager._perform_actual_cleanup(session_id)
                except asyncio.CancelledError:
                    print(f"🚫 Cleanup task cancelled for session: {session_id}")
                    raise
                except Exception as e:
                    print(f"❌ Error in delayed cleanup for {session_id}: {e}")
            
            state.cleanup_task = asyncio.create_task(delayed_cleanup())
            
            print(f"⏱️ Scheduled cleanup in {delay_seconds}s for session: {session_id} (likely disconnect)")
    
    @staticmethod
    async def _perform_actual_cleanup(session_id: str):
        """Perform the actual cleanup after delay"""
        async with StateManager._lock:
            if session_id not in StateManager._session_states:
                print(f"⚠️ Session already cleaned or doesn't exist: {session_id}")
                return
                
            state = StateManager._session_states[session_id]
            
            # Double-check if session is still pending cleanup (user might have sent message)
            if not state.pending_cleanup:
                print(f"🚫 Cleanup cancelled - user activity detected for: {session_id}")
                return
            
            # Perform API cleanup using httpx
            try:
                if API_BASE_URL:
                    payload = {
                        "reset_cache": True, 
                        "reset_model": False, 
                        "session_id": session_id
                    }
                    async with httpx.AsyncClient(timeout=30.0) as client:
                        response = await client.post(f"{API_BASE_URL}/clear_memory", json=payload)
                        print(f"Clear memory response for {session_id}: {response.status_code}")
            except Exception as e:
                print(f"Warning: clear_memory failed for {session_id}: {e}")
            
            # Remove from memory
            del StateManager._session_states[session_id]
            print(f"🗑️ Successfully cleaned up session: {session_id}")
    
    @staticmethod
    async def cleanup_session_immediate(session_id: str):
        """Immediate cleanup (for testing or forced cleanup)"""
        async with StateManager._lock:
            if session_id in StateManager._session_states:
                state = StateManager._session_states[session_id]
                state.cancel_cleanup_task()
                await StateManager._perform_actual_cleanup(session_id)
    
    @staticmethod
    async def clear_chat_state(state: ConversationState):
        """Clear all conversation history and reset state via API (but keep session alive)"""
        if state.session_id is not None and API_BASE_URL:
            try:
                payload = {
                    "reset_cache": True, 
                    "reset_model": False, 
                    "session_id": state.session_id
                }
                async with httpx.AsyncClient(timeout=30.0) as client:
                    response = await client.post(f"{API_BASE_URL}/clear_memory", json=payload)
                    print(f"Clear memory response: {response.status_code}")
            except Exception as e:
                print(f"Warning: clear_memory failed: {e}")
        
        # Reset state but keep session_id and don't trigger cleanup
        session_id = state.session_id
        state.reset()
        state.session_id = session_id
    
    @staticmethod
    async def change_model(state: ConversationState, model_name: str):
        """Change the selected model"""
        state.selected_model = model_name
        state.last_activity = datetime.now()
    
    @staticmethod
    async def toggle_product_model_search(state: ConversationState):
        """Toggle product model search mode"""
        state.product_model_search = not state.product_model_search
        state.last_activity = datetime.now()
    
    @staticmethod
    async def toggle_enhance_query(state: ConversationState):
        """Toggle query enhancement mode"""
        state.is_enhance_query = not state.is_enhance_query
        state.last_activity = datetime.now()
    
    @staticmethod
    async def cycle_search_method(state: ConversationState):
        """Cycle search method: dense -> sparse -> hybrid -> dense"""
        if state.method == "dense":
            state.method = "sparse"
        elif state.method == "sparse":
            state.method = "hybrid"
        else:
            state.method = "dense"
        state.last_activity = datetime.now()
    
    @staticmethod
    async def get_session_status() -> Dict[str, Dict[str, Any]]:
        """Get status of all sessions (for debugging)"""
        async with StateManager._lock:
            status = {}
            for session_id, state in StateManager._session_states.items():
                status[session_id] = {
                    "pending_cleanup": state.pending_cleanup,
                    "has_task": state.cleanup_task is not None and not state.cleanup_task.done(),
                    "last_activity": state.last_activity.isoformat(),
                    "selected_model": state.selected_model,
                    "product_model_search": state.product_model_search,
                    "method": state.method,
                    "is_enhance_query": state.is_enhance_query
                }
            return status


class ChatService:
    """Handles chat-related operations with async HTTP calls"""
    
    @staticmethod
    async def respond_to_chat(
        state: ConversationState, 
        message: str, 
        image_path: Optional[str] = None
    ) -> str:
        """Handle chat responses with image support using async HTTP"""
        print(f"🔄 === DEBUG STATE ===\nChat request with model: {state.selected_model}, Product Model Search: {state.product_model_search}, Method: {state.method}, Session ID: {state.session_id}")
        
        # Update activity timestamp - this is KEY to prevent cleanup during active use
        state.last_activity = datetime.now()
                
        if not API_BASE_URL:
            return "Error: API_BASE_URL not configured"
        
        if not state.session_id:
            return "Error: Session ID not initialized"
        
        # Call API using httpx for async HTTP
        try:
            async with httpx.AsyncClient(timeout=600.0) as client:
                if image_path:
                    # For image uploads, use form-data format as expected by API
                    with open(image_path, 'rb') as f:
                        files = {"image": f.read()}
                    
                    data = {
                        "message": message,
                        "product_model_search": str(state.product_model_search).lower(),
                        "method": state.method,
                        "session_id": state.session_id,
                        "llm_model": state.selected_model,
                        "debug": "Normal",
                        "is_enhance_query": str(state.is_enhance_query).lower()
                    }
                    
                    # Use multipart form data for image upload
                    files_dict = {"image": ("image.jpg", files["image"], "image/jpeg")}
                    resp = await client.post(
                        f"{API_BASE_URL}/chat_with_image", 
                        files=files_dict, 
                        data=data
                    )
                else:
                    # For text messages, use form-data format as expected by API
                    data = {
                        "message": message,
                        "session_id": state.session_id,
                        "debug": "Normal",
                        "product_model_search": str(state.product_model_search).lower(),
                        "method": state.method,
                        "llm_model": state.selected_model,
                        "is_enhance_query": str(state.is_enhance_query).lower()
                    }
                    resp = await client.post(
                        f"{API_BASE_URL}/chat",
                        data=data  # Form data format
                    )

            if resp.status_code == 200:
                j = resp.json()
                response = j.get("response", "")
                specs_advantages = j.get("specs_advantages")
                solution_packages = j.get("solution_packages")
                raw_documents = j.get("raw_documents")  # This might be None from API
                outputs = j.get("outputs")
            else:
                print(f"API Error: {resp.status_code} - {resp.text}")
                response = f"Error: API status {resp.status_code}"
                specs_advantages, solution_packages, raw_documents, outputs = None, None, None, None
        except Exception as e:
            print(f"Exception calling API: {e}")
            response = f"Error calling API: {e}"
            specs_advantages, solution_packages, raw_documents, outputs = None, None, None, None


        # Update state
        if specs_advantages is not None:
            state.specs_advantages = specs_advantages
        if solution_packages is not None:
            state.solution_packages = solution_packages
        if raw_documents is not None:
            state.raw_documents = raw_documents
        if outputs is not None:
            state.outputs = outputs

        # Filter products based on query
        if state.specs_advantages is not None:
            await ChatService.get_specific_product_from_query(message, state)

        # NEW: Format response with 2-column grid for products
        formatted_response = ChatService.format_product_grid(response)

        return formatted_response

    @staticmethod
    def format_product_grid(response_text: str) -> str:
        """Format product listings into 2-column grid while keeping other content intact"""
        # Pattern to match: *   **[Name](url)**\n\n    ![alt](img_url)
        pattern = r'\*\s+\*\*\[(.*?)\]\((.*?)\)\*\*\s*\n\s*!\[(.*?)\]\((.*?)\)'
        
        matches = list(re.finditer(pattern, response_text))
        
        if not matches:
            # No product listings found, return original
            return response_text
        
        # Find boundaries of product section
        first_match_start = matches[0].start()
        last_match_end = matches[-1].end()
        
        # Split into: intro + products + rest
        intro_text = response_text[:first_match_start].strip()
        rest_text = response_text[last_match_end:].strip()
        
        # Extract all products
        products = []
        for match in matches:
            products.append({
                'name': match.group(1),
                'url': match.group(2),
                'alt': match.group(3),
                'img': match.group(4)
            })
        
        # Build 2-column markdown table
        grid_content = "\n\n"
        
        for i in range(0, len(products), 2):
            p1 = products[i]
            
            if i + 1 < len(products):
                p2 = products[i + 1]
                # Two columns
                grid_content += f"| **[{p1['name']}]({p1['url']})** | **[{p2['name']}]({p2['url']})** |\n"
                grid_content += f"|:---:|:---:|\n"
                grid_content += f"| ![{p1['alt']}]({p1['img']}) | ![{p2['alt']}]({p2['img']}) |\n\n"
            else:
                # Single column for last odd product
                grid_content += f"| **[{p1['name']}]({p1['url']})** |\n"
                grid_content += f"|:---:|\n"
                grid_content += f"| ![{p1['alt']}]({p1['img']}) |\n\n"
        
        # Reconstruct full response
        return intro_text + grid_content + rest_text

    @staticmethod
    async def get_specific_product_from_query(query, state):
        """Filter specs_advantages based on models found in query"""
        specs_map = state.specs_advantages or {}
        product_model_list = []
        
        for prod_id, data in specs_map.items():
            model = data.get("model", None) 
            if model is not None:
                product_model_list.append(model)
        
        found_models = []
        for model in product_model_list:
            pattern = re.escape(model)
            if re.search(pattern, query, re.IGNORECASE):
                found_models.append(model)
        
        new_specs_advantages = {}
        if found_models != []: 
            for prod_id, data in specs_map.items():
                if data.get("model", None) in found_models:
                    new_specs_advantages[prod_id] = data
        
            state.specs_advantages = new_specs_advantages


class DisplayService:
    """Handles display-related operations with async HTTP calls"""
    
    @staticmethod
    async def show_specs(state: ConversationState) -> str:
        """Generate specifications table"""
        specs_map = state.specs_advantages
        columns = ["Thông số"]
        raw_data = []

        if not specs_map:
            return "📄 **Thông số kỹ thuật**\n\nKhông có thông số kỹ thuật nào."

        print(specs_map)
        for prod_id, data in specs_map.items():
            spec = data.get("specification")
            if spec is None or spec == "" or spec == "None":
                spec = "Hiện tại trong dữ liệu chưa có thông tin về thông số kĩ thuật của sản phẩm này!"
            model = data.get("model", "")
            url = data.get("url", "")

            # Handle both products and solution packages
            if url:
                # full_name = f"**[{data['name']} {model}]({url})**"
                full_name = f"**[{data['name']}]({url})**"
            else:
                # full_name = f"**{data['name']} {model}**"
                full_name = f"**{data['name']}**"

            if full_name not in columns:
                columns.append(full_name)

            if spec:
                # Check if this is a solution package (contains markdown table)
                if "### 📦" in spec:
                    # For solution packages, parse the markdown table properly
                    lines = spec.split('\n')
                    in_table = False
                    headers = []

                    for line in lines:
                        line = line.strip()
                        if '|' in line and '---' not in line and line.startswith('|') and line.endswith('|'):
                            cells = [cell.strip()
                                     for cell in line.split('|')[1:-1]]

                            if not in_table:
                                # This is the header row
                                headers = cells
                                in_table = True
                                continue

                            # This is a data row
                            if len(cells) >= len(headers):
                                for i, header in enumerate(headers):
                                    if i < len(cells):
                                        param_name = header
                                        param_value = cells[i]

                                        existing_row = None
                                        for row in raw_data:
                                            if row["Thông số"] == param_name:
                                                existing_row = row
                                                break

                                        if existing_row:
                                            existing_row[full_name] = param_value
                                        else:
                                            new_row = {"Thông số": param_name}
                                            for col in columns[1:]:
                                                new_row[col] = ""
                                            new_row[full_name] = param_value
                                            raw_data.append(new_row)
                        elif in_table and (not line or not line.startswith('|')):
                            in_table = False
                else:
                    # For products, parse specification items
                    items = re.split(r';|\n', spec)
                    for item in items:
                        if ":" in item:
                            key, value = item.split(':', 1)
                            spec_key = key.strip().capitalize()
                            if spec_key == "Vậtl iệu":
                                spec_key = "Vật liệu"

                            if "|" in spec_key:
                                spec_key = spec_key.strip().replace("|", "").capitalize()

                            existing_row = None
                            for row in raw_data:
                                if row["Thông số"] == spec_key:
                                    existing_row = row
                                    break

                            if existing_row:
                                existing_row[full_name] = value.strip() if value else ""
                            else:
                                new_row = {"Thông số": spec_key}
                                for col in columns[1:]:
                                    new_row[col] = ""
                                new_row[full_name] = value.strip() if value else ""
                                raw_data.append(new_row)

        if raw_data:
            df = pd.DataFrame(raw_data, columns=columns)
            df = df.fillna("").replace("None", "").replace("nan", "")
        else:
            df = pd.DataFrame(
                [["Không có thông số kỹ thuật", "", ""]], columns=columns)

        markdown_table = df.to_markdown(index=False)
        return f"📄 **Thông số kỹ thuật**\n\n{markdown_table}"
    
    @staticmethod
    async def show_advantages(state: ConversationState) -> str:
        """Generate advantages as bullet list instead of table"""
        specs_map = state.specs_advantages

        if not specs_map:
            return "💡 **Ưu điểm nổi trội**\n\nKhông có ưu điểm nào."

        content = "💡 **Ưu điểm nổi trội**\n\n"
        
        for prod_id, data in specs_map.items():
            # adv = data.get("advantages", "Hiện tại trong dữ liệu chưa có thông tin về ưu điểm nổi trội của sản phẩm này!")
            adv = data.get("advantages")
            if adv is None or adv == "" or adv == "None":
                adv = "Hiện tại trong dữ liệu chưa có thông tin về ưu điểm nổi trội của sản phẩm này!"
            model = data.get("model", "")
            url = data.get("url", "")

            # Handle both products and solution packages
            if url:
                full_name = f"**[{data['name']}]({url})**"
            else:
                full_name = f"**{data['name']}**"

            content += f"### {full_name}\n"
            
            # Split by newlines and create bullet points
            advantages_list = [line.strip() for line in adv.split('\n') if line.strip()]
            for advantage in advantages_list:
                content += f"- {advantage}\n"
            content += "\n"

        return content
    
    @staticmethod
    async def show_solution_packages(state: ConversationState) -> str:
        """Show solution packages in a structured format"""
        packages = state.solution_packages

        if not packages or packages == []:
            return "📦 **Gói sản phẩm**\n\nKhông có gói sản phẩm nào"

        markdown_table = "\n\n".join(packages)
        return markdown_table

    @staticmethod
    async def show_all_products_table(state: ConversationState):
        """Show all products table using async HTTP"""
        outputs = state.outputs or {}

        if not outputs:
            return "Không có dữ liệu sản phẩm"
        
        try:
            # Updated to match API format - send outputs in request body
            payload = {"outputs": outputs}
            async with httpx.AsyncClient(timeout=60.0) as client:
                resp = await client.post(f"{API_BASE_URL}/products_by_category", json=payload)

            if resp.status_code == 200:
                data = resp.json()
                return data.get("markdown_table", "Không có dữ liệu sản phẩm")
            else:
                print(f"All products API error: {resp.status_code} - {resp.text}")
                return "Không có dữ liệu sản phẩm"
        except Exception as e:
            print(f"Exception in show_all_products_table: {e}")
            return f"Error: {e}"


class UIService:
    """Handles UI-related operations"""
    
    @staticmethod
    def create_action_buttons(state: ConversationState):
        """Create persistent action buttons"""
        search_status = "🔍 Tìm theo mã sản phẩm (Đang tắt)" if not state.product_model_search else "🔍 Tìm theo mã sản phẩm (Đang bật)"
        method_labels = {
            "dense": "🔎 Tìm kiếm: Dense",
            "sparse": "🔎 Tìm kiếm: Sparse (BM25)",
            "hybrid": "🔎 Tìm kiếm: Hybrid"
        }
        method_status = method_labels.get(state.method, "🔎 Tìm kiếm: Dense")
        enhance_status = "🧠 Tăng cường truy vấn (Đang tắt)" if not state.is_enhance_query else "🧠 Tăng cường truy vấn (Đang bật)"
        
        return [
            cl.Action(name="show_specs", value="specs", label="📄 Thông số kỹ thuật", payload={"action": "specs"}),
            cl.Action(name="show_advantages", value="advantages", label="💡 Ưu điểm nổi trội", payload={"action": "advantages"}),
            cl.Action(name="show_packages", value="packages", label="📦 Gói sản phẩm", payload={"action": "packages"}),
            cl.Action(name="show_all_products", value="all_products", label="🛒 Tất cả sản phẩm", payload={"action": "all_products"}),
            cl.Action(name="toggle_product_search", value="toggle_search", label=search_status, payload={"action": "toggle_search"}),
            cl.Action(name="change_search_method", value="change_method", label="🔎 Đổi phương thức tìm kiếm", payload={"action": "change_method"}),
            cl.Action(name="toggle_enhance_query", value="toggle_enhance", label=enhance_status, payload={"action": "toggle_enhance"}),
            cl.Action(name="change_model", value="model", label="🔄 Đổi model", payload={"action": "model"}),
        ]

    @staticmethod
    def create_start_buttons(state: ConversationState):
        """Create start buttons"""
        search_status = "🔍 Tìm theo mã sản phẩm (Đang tắt)" if not state.product_model_search else "🔍 Tìm theo mã sản phẩm (Đang bật)"
        method_labels = {
            "dense": "🔎 Tìm kiếm: Dense",
            "sparse": "🔎 Tìm kiếm: Sparse (BM25)",
            "hybrid": "🔎 Tìm kiếm: Hybrid"
        }
        method_status = method_labels.get(state.method, "🔎 Tìm kiếm: Dense")
        enhance_status = "🧠 Tăng cường truy vấn (Đang tắt)" if not state.is_enhance_query else "🧠 Tăng cường truy vấn (Đang bật)"
        
        return [
            cl.Action(name="toggle_product_search", value="toggle_search", label=search_status, payload={"action": "toggle_search"}),
            cl.Action(name="change_search_method", value="change_method", label="🔎 Đổi phương thức tìm kiếm", payload={"action": "change_method"}),
            cl.Action(name="toggle_enhance_query", value="toggle_enhance", label=enhance_status, payload={"action": "toggle_enhance"}),
            cl.Action(name="change_model", value="model", label="🔄 Đổi model", payload={"action": "model"}),
        ]
    
    @staticmethod
    async def send_message_with_buttons(content: str, state: ConversationState, actions=None, author="assistant"):
        """Send message with optional action buttons and author"""
        if actions is None:
            actions = UIService.create_action_buttons(state)
        await cl.Message(
            content=content, 
            actions=actions,
            author=author
        ).send()
    
    @staticmethod
    async def create_typing_animation():
        """Create typing animation effect (legacy method - kept for compatibility)"""
        msg = cl.Message(content="", author="assistant")
        await msg.send()
        
        # Typing animation frames
        typing_frames = ["⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"]
        
        for i in range(27):  # Show animation for ~2 seconds
            frame = typing_frames[i % len(typing_frames)]
            msg.content = f"{frame} Đang suy nghĩ..."
            await msg.update()
            await asyncio.sleep(0.25)
        
        return msg


async def run_typing_animation(msg: cl.Message):
    """Run typing animation until cancelled"""
    typing_frames = ["⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"]
    frame_index = 0
    
    try:
        while True:  # Run indefinitely until cancelled
            frame = typing_frames[frame_index % len(typing_frames)]
            msg.content = f"{frame} Đang suy nghĩ..."
            await msg.update()
            await asyncio.sleep(0.25)
            frame_index += 1
            
    except asyncio.CancelledError:
        # Animation was cancelled, this is expected
        print("🎬 Animation cancelled - API response received")
        raise


# HELPER FUNCTIONS: Session management with proper async error handling
async def ensure_session_state() -> Optional[ConversationState]:
    """Ensure session state exists, create if not"""
    try:
        session_id = cl.user_session.get("session_id")
        
        if not session_id:
            print(f"Lỗi: Không lấy được session id ở ensure_session_state")
            return None
        
        return await StateManager.get_or_create_session_state(session_id)
        
    except Exception as e:
        print(f"⚠️ Error ensuring session state: {e}")
        return None


async def get_current_session_state() -> Optional[ConversationState]:
    """Get current session state using Chainlit's session system"""
    try:
        # Use Chainlit's user session to get unique session ID
        chainlit_session_id = cl.user_session.get("session_id")
        
        if chainlit_session_id:
            return await StateManager.get_or_create_session_state(chainlit_session_id)
        else:
            print("⚠️ No Chainlit session ID found")
            return None
    except Exception as e:
        print(f"⚠️ Error getting session state: {e}")
        return None


@cl.on_chat_start
async def on_chat_start():
    """Initialize the chat session"""
    session_id = cl.user_session.get("session_id")
    if not session_id:
        session_id = str(uuid.uuid4())
        cl.user_session.set("session_id", session_id)
        print(f"🆕 Generated new session_id: {session_id}")
    else:
        print(f"🔄 Reusing existing session_id: {session_id}")
        
    app_state = await StateManager.get_or_create_session_state(session_id)

    await cl.Message(
        content=f"🛍️ **RangDong Sales Agent** (Session: {session_id[:8]}...)\n\n"
                   f"Xin chào! Tôi có thể giúp bạn tìm kiếm và tư vấn sản phẩm RangDong. Hãy thử các câu hỏi mẫu:\n\n"
                   f"- Tìm sản phẩm bình giữ nhiệt dung tích dưới 2 lít\n"
                   f"- Tìm sản phẩm ổ cắm thông minh\n"
                   f"- Tư vấn cho tôi đèn học chống cận cho con gái của tôi học lớp 6",
        author="assistant"
    ).send()

    actions = UIService.create_start_buttons(app_state)
    await cl.Message(
        content="Sử dụng nút bên dưới để cấu hình:", 
        actions=actions,
        author="assistant"
    ).send()


@cl.on_chat_end
async def on_chat_end():
    """Handle chat session end with delayed cleanup mechanism using asyncio"""
    try:
        session_id = cl.user_session.get("session_id")
        print(f"📤 on_chat_end triggered for session {session_id}")
        
        if session_id:
            # Schedule delayed cleanup instead of immediate cleanup
            # Use shorter delay (30s) since this is likely just a temporary disconnect
            await StateManager.schedule_delayed_cleanup(session_id, delay_seconds=3600)
            print(f"⏳ Scheduled delayed cleanup for session {session_id} (1h delay for disconnect tolerance)")
        else:
            print("⚠️ No session_id found in on_chat_end")
    except Exception as e:
        print(f"⚠️ Error during on_chat_end: {e}")


# ACTION CALLBACKS - All use ensure_session_state() for better reliability
@cl.action_callback("show_specs")
async def on_show_specs(action):
    """Handle show specifications action"""
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    specs_content = await DisplayService.show_specs(app_state)
    await UIService.send_message_with_buttons(specs_content, app_state, author="assistant")


@cl.action_callback("show_advantages")
async def on_show_advantages(action):
    """Handle show advantages action"""
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    adv_content = await DisplayService.show_advantages(app_state)
    await UIService.send_message_with_buttons(adv_content, app_state, author="assistant")


@cl.action_callback("show_packages")
async def on_show_packages(action):
    """Handle show packages action"""
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    pkg_content = await DisplayService.show_solution_packages(app_state)
    await UIService.send_message_with_buttons(pkg_content, app_state, author="assistant")

@cl.action_callback("show_all_products")
async def on_show_all_products(action):
    """Handle show all products action"""
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    all_products_content = await DisplayService.show_all_products_table(app_state)
    await UIService.send_message_with_buttons(all_products_content, app_state, author="assistant")

@cl.action_callback("toggle_product_search")
async def on_toggle_product_search(action):
    """Handle toggle product model search action"""
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    await StateManager.toggle_product_model_search(app_state)
    
    status_message = (
        "✅ **Đã bật tìm kiếm theo mã sản phẩm**\n\n"
        "Khi bạn nhắc đến mã/model cụ thể trong câu hỏi, hệ thống sẽ tìm kiếm chính xác theo mã đó."
        if app_state.product_model_search 
        else "✅ **Đã tắt tìm kiếm theo mã sản phẩm**\n\n"
        "Hệ thống sẽ tìm kiếm sản phẩm theo cách thông thường."
    )
    
    await UIService.send_message_with_buttons(status_message, app_state, author="assistant")


@cl.action_callback("toggle_enhance_query")
async def on_toggle_enhance_query(action):
    """Handle toggle enhance query action"""
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    await StateManager.toggle_enhance_query(app_state)
    
    status_message = (
        "✅ **Đã bật tăng cường truy vấn**\n\n"
        "Hệ thống sẽ tự động cải thiện và mở rộng câu hỏi của bạn để tìm kiếm chính xác hơn."
        if app_state.is_enhance_query 
        else "✅ **Đã tắt tăng cường truy vấn**\n\n"
        "Hệ thống sẽ sử dụng câu hỏi gốc của bạn mà không cải thiện."
    )
    
    await UIService.send_message_with_buttons(status_message, app_state, author="assistant")


@cl.action_callback("change_search_method")
async def on_change_search_method(action):
    """Handle change search method action"""
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    method_actions = [
        cl.Action(name="select_method_dense", value="dense", label="🔎 Dense (Mặc định)", payload={"method": "dense"}),
        cl.Action(name="select_method_sparse", value="sparse", label="🔎 Sparse (BM25)", payload={"method": "sparse"}),
        cl.Action(name="select_method_hybrid", value="hybrid", label="🔎 Hybrid", payload={"method": "hybrid"}),
        cl.Action(name="back_to_main", value="back", label="🔙 Quay lại", payload={"action": "back"})
    ]
    
    current_method_labels = {
        "dense": "Dense",
        "sparse": "Sparse (BM25)",
        "hybrid": "Hybrid"
    }
    current = current_method_labels.get(app_state.method, "Dense")
    
    await cl.Message(
        content=f"**Model hiện tại**: {app_state.selected_model}\n**Tìm kiếm theo mã**: {'Đang bật' if app_state.product_model_search else 'Đang tắt'}\n**Phương thức tìm kiếm**: {current}\n**Tăng cường truy vấn**: {'Đang bật' if app_state.is_enhance_query else 'Đang tắt'}\n\nChọn phương thức tìm kiếm mới:",
        actions=method_actions,
        author="assistant"
    ).send()


@cl.action_callback("select_method_dense")
async def on_select_method_dense(action):
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    app_state.method = "dense"
    app_state.last_activity = datetime.now()
    await UIService.send_message_with_buttons("✅ Đã chuyển sang **Dense Search**\n\nHệ thống sẽ sử dụng tìm kiếm semantic vector thông thường.", app_state, author="assistant")


@cl.action_callback("select_method_sparse")
async def on_select_method_sparse(action):
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    app_state.method = "sparse"
    app_state.last_activity = datetime.now()
    await UIService.send_message_with_buttons("✅ Đã chuyển sang **Sparse Search (BM25)**\n\nHệ thống sẽ sử dụng tìm kiếm từ khóa BM25.", app_state, author="assistant")


@cl.action_callback("select_method_hybrid")
async def on_select_method_hybrid(action):
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    app_state.method = "hybrid"
    app_state.last_activity = datetime.now()
    await UIService.send_message_with_buttons("✅ Đã chuyển sang **Hybrid Search**\n\nHệ thống sẽ kết hợp cả Dense và Sparse vector.", app_state, author="assistant")


@cl.action_callback("change_model")
async def on_change_model(action):
    """Handle model change action"""
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    models = ["Gemini 2.0 Flash", "Gemini 2.5 Flash Lite", "Gemini 2.0 Flash Lite"]
    
    model_actions = [
        cl.Action(name=f"select_model_{i}", value=model, label=model, payload={"model": model})
        for i, model in enumerate(models)
    ]
    
    model_actions.append(
        cl.Action(name="back_to_main", value="back", label="🔙 Quay lại", payload={"action": "back"})
    )
    
    await cl.Message(
        content=f"**Model hiện tại**: {app_state.selected_model}\n**Tìm kiếm theo mã**: {'Đang bật' if app_state.product_model_search else 'Đang tắt'}\n**Phương thức tìm kiếm**: {app_state.method}\n**Tăng cường truy vấn**: {'Đang bật' if app_state.is_enhance_query else 'Đang tắt'}\n\nChọn model mới:",
        actions=model_actions,
        author="assistant"
    ).send()


@cl.action_callback("back_to_main")
async def on_back_to_main(action):
    """Handle back to main menu action"""
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    actions = UIService.create_action_buttons(app_state)
    await cl.Message(
        content="📋 **Menu chính**\n\nSử dụng các nút bên dưới để:", 
        actions=actions,
        author="assistant"
    ).send()


@cl.action_callback("select_model_0")
async def on_select_model_0(action):
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    await StateManager.change_model(app_state, "Gemini 2.0 Flash")
    await UIService.send_message_with_buttons("✅ Đã chuyển sang **Gemini 2.0 Flash**", app_state, author="assistant")


@cl.action_callback("select_model_1")
async def on_select_model_1(action):
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    await StateManager.change_model(app_state, "Gemini 2.5 Flash Lite")
    await UIService.send_message_with_buttons("✅ Đã chuyển sang **Gemini 2.5 Flash Lite**", app_state, author="assistant")


@cl.action_callback("select_model_2")
async def on_select_model_2(action):
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
        
    await StateManager.change_model(app_state, "Gemini 2.0 Flash Lite")
    await UIService.send_message_with_buttons("✅ Đã chuyển sang **Gemini 2.0 Flash Lite**", app_state, author="assistant")


# DEBUG ENDPOINTS (optional - for monitoring session status)
@cl.action_callback("debug_sessions")
async def on_debug_sessions(action):
    """Debug action to show session status (can be added to debug builds)"""
    try:
        status = await StateManager.get_session_status()
        debug_content = "🔍 **Debug: Session Status**\n\n"
        
        if not status:
            debug_content += "No active sessions."
        else:
            for session_id, info in status.items():
                debug_content += f"**Session: {session_id[:8]}...**\n"
                debug_content += f"- Pending cleanup: {info['pending_cleanup']}\n"
                debug_content += f"- Has task: {info['has_task']}\n"
                debug_content += f"- Last activity: {info['last_activity']}\n"
                debug_content += f"- Model: {info['selected_model']}\n"
                debug_content += f"- Product search: {info['product_model_search']}\n"
                debug_content += f"- Method: {info.get('method', 'dense')}\n\n"
        
        await cl.Message(content=debug_content, author="assistant").send()
    except Exception as e:
        await cl.Message(content=f"Debug error: {e}", author="assistant").send()


@cl.on_message
async def main(message: cl.Message):
    """Main message handler with concurrent animation and API call"""
    app_state = await ensure_session_state()
    if app_state is None:
        await cl.Message(content="Error: Session state not found", author="assistant").send()
        return
    
    # Handle images if present
    image_path = None
    if message.elements:
        for element in message.elements:
            if isinstance(element, cl.Image):
                image_path = element.path
                break
    
    # Create initial message for animation
    msg = cl.Message(content="", author="assistant")
    await msg.send()
    
    # Create concurrent tasks for animation and API call
    animation_task = asyncio.create_task(run_typing_animation(msg))
    api_task = asyncio.create_task(ChatService.respond_to_chat(app_state, message.content, image_path))
    
    try:
        # Wait for API response (this will complete first usually)
        response = await api_task
        
        # Cancel animation task since we have the response
        animation_task.cancel()
        
        # Wait a bit for graceful animation cancellation
        try:
            await asyncio.wait_for(animation_task, timeout=0.1)
        except (asyncio.CancelledError, asyncio.TimeoutError):
            pass
        
    except Exception as e:
        # If API fails, cancel animation and show error
        animation_task.cancel()
        try:
            await asyncio.wait_for(animation_task, timeout=0.1)
        except (asyncio.CancelledError, asyncio.TimeoutError):
            pass
        response = f"Error: {e}"
    
    # Update message with final response and buttons
    msg.content = response
    msg.actions = UIService.create_action_buttons(app_state)
    await msg.update()