from fastapi import FastAPI, Request, HTTPException, WebSocket, WebSocketDisconnect
from fastapi.templating import Jinja2Templates
from fastapi.staticfiles import StaticFiles
from fastapi.responses import HTMLResponse
from pydantic import BaseModel
from typing import List, Optional
import uvicorn
import torch
from scripts.model import Net
from scripts.training.train import train, start_comparison_training
from pathlib import Path
from fastapi import BackgroundTasks
import warnings
import asyncio
import json
import numpy as np

warnings.filterwarnings("ignore", category=UserWarning, module="torchvision.transforms")

app = FastAPI()

# Mount static files with a name parameter
app.mount("/static", StaticFiles(directory="static"), name="static")
templates = Jinja2Templates(directory="templates")

# Model configurations
class TrainingConfig(BaseModel):
    block1: int
    block2: int
    block3: int
    optimizer: str
    batch_size: int
    epochs: int = 1

class ComparisonConfig(BaseModel):
    model1: TrainingConfig
    model2: TrainingConfig

def get_available_models():
    models_dir = Path("scripts/training/models")
    if not models_dir.exists():
        models_dir.mkdir(exist_ok=True, parents=True)
    return [f.stem for f in models_dir.glob("*.pth")]

# Add a global variable to store training task
training_task = None

@app.get("/", response_class=HTMLResponse)
async def home(request: Request):
    return templates.TemplateResponse("index.html", {"request": request})

@app.get("/train", response_class=HTMLResponse)
async def train_page(request: Request):
    return templates.TemplateResponse("train.html", {"request": request})

@app.get("/inference", response_class=HTMLResponse)
async def inference_page(request: Request):
    available_models = get_available_models()
    return templates.TemplateResponse(
        "inference.html", 
        {
            "request": request,
            "available_models": available_models
        }
    )

@app.post("/train")
async def train_model(config: TrainingConfig, background_tasks: BackgroundTasks):
    try:
        # Create model instance with the configuration
        model = Net(
            kernels=[config.block1, config.block2, config.block3]
        )
        
        # Store training configuration
        training_config = {
            "optimizer": config.optimizer,
            "batch_size": config.batch_size
        }
        
        return {"status": "success", "message": "Training configuration received"}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.websocket("/ws/train")
async def websocket_endpoint(websocket: WebSocket):
    await websocket.accept()
    try:
        print("WebSocket connection accepted for single model training")
        config_data = await websocket.receive_json()
        print(f"Received config data: {config_data}")
        
        model = Net(
            kernels=[
                config_data['block1'],
                config_data['block2'],
                config_data['block3']
            ]
        )
        
        # Create TrainingConfig object for single model using **kwargs
        config = TrainingConfig(**{
            'block1': config_data['block1'],
            'block2': config_data['block2'],
            'block3': config_data['block3'],
            'optimizer': config_data['optimizer'],
            'batch_size': config_data['batch_size'],
            'epochs': config_data['epochs']
        })
        
        print(f"Starting training with config: {config_data}")
        
        try:
            await train(model, config, websocket, model_type="single")
        except Exception as e:
            print(f"Training error: {str(e)}")
            await websocket.send_json({
                "type": "training_error",
                "data": {
                    "message": f"Training failed: {str(e)}"
                }
            })
            
    except WebSocketDisconnect:
        print("WebSocket disconnected")
    except Exception as e:
        print(f"WebSocket error: {str(e)}")
        await websocket.send_json({
            "type": "training_error",
            "data": {
                "message": f"WebSocket error: {str(e)}"
            }
        })
    finally:
        print("WebSocket connection closed")

@app.websocket("/ws/compare")
async def websocket_endpoint(websocket: WebSocket):
    print("\n=== New WebSocket Connection ===")
    print("New WebSocket connection attempt")
    try:
        await websocket.accept()
        print("WebSocket connection accepted")
        
        print("Waiting for initial message...")
        data = await websocket.receive_json()
        print(f"Received initial message: {data}")
        
        if 'action' not in data:
            print("Error: Missing 'action' in message")
            await websocket.send_json({
                'status': 'error',
                'message': 'Missing action in request'
            })
            return
            
        if data['action'] == 'start_training':
            if 'parameters' not in data:
                print("Error: Missing 'parameters' in message")
                await websocket.send_json({
                    'status': 'error',
                    'message': 'Missing parameters in request'
                })
                return
                
            print("Starting training task")
            try:
                training_task = asyncio.create_task(start_comparison_training(
                    websocket,
                    data['parameters']
                ))
                print("Training task created, awaiting completion...")
                await training_task
                print("Training task completed")
            except Exception as e:
                print(f"Error during training task: {str(e)}")
                await websocket.send_json({
                    'status': 'error',
                    'message': f'Training error: {str(e)}'
                })
        else:
            print(f"Unknown action received: {data['action']}")
            
    except WebSocketDisconnect:
        print("WebSocket disconnected")
    except json.JSONDecodeError as e:
        print(f"JSON decode error: {str(e)}")
    except Exception as e:
        print(f"Unexpected error in websocket handler: {str(e)}")
    finally:
        print("=== WebSocket Connection Closed ===\n")

# @app.post("/api/train_single")
# async def train_single_model(config: TrainingConfig):
#     try:
#         model = Net(kernels=config.kernels)
#         # Start training without passing the websocket
#         await train(model, config)
#         return {"status": "success"}
#     except Exception as e:
#         # Log the error for debugging
#         print(f"Error during training: {str(e)}")
#         # Return a JSON response with the error message
#         raise HTTPException(status_code=500, detail=f"Error during training: {str(e)}")

@app.post("/api/train_compare")
async def train_compare_models(config: ComparisonConfig):
    try:
        # Train both models
        model1 = Net(kernels=config.model1.kernels)
        model2 = Net(kernels=config.model2.kernels)
        
        results1 = train(model1, config.model1)
        results2 = train(model2, config.model2)
        
        return {
            "status": "success",
            "model1_results": results1,
            "model2_results": results2
        }
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

def parse_model_filename(filename):
    """Extract configuration from model filename"""
    # Example filename: single_arch_32_64_128_opt_adam_batch_64_20240322_123456.pth
    try:
        parts = filename.split('_')
        # Find architecture values
        arch_index = parts.index('arch')
        block1 = int(parts[arch_index + 1])
        block2 = int(parts[arch_index + 2])
        block3 = int(parts[arch_index + 3])
        
        # Find optimizer
        opt_index = parts.index('opt')
        optimizer = parts[opt_index + 1]
        
        # Find batch size
        batch_index = parts.index('batch')
        batch_size = int(parts[batch_index + 1])
        
        return {
            'block1': block1,
            'block2': block2,
            'block3': block3,
            'optimizer': optimizer,
            'batch_size': batch_size
        }
    except Exception as e:
        print(f"Error parsing model filename: {e}")
        return None

@app.post("/api/inference")
async def perform_inference(data: dict):
    try:
        model_name = data.get("model_name")
        if not model_name:
            raise HTTPException(status_code=400, detail="No model selected")
            
        model_path = Path("scripts/training/models") / f"{model_name}.pth"
        if not model_path.exists():
            raise HTTPException(status_code=404, detail=f"Model not found: {model_path}")
        
        # Parse model configuration from filename
        config = parse_model_filename(model_name)
        if not config:
            raise HTTPException(status_code=500, detail="Could not parse model configuration")
            
        # Create model with the correct configuration
        model = Net(
            kernels=[
                config['block1'],
                config['block2'],
                config['block3']
            ]
        )
        
        # Load model weights
        model.load_state_dict(torch.load(str(model_path), map_location=torch.device('cpu'), weights_only=True))
        model.eval()
        
        # Process image data and get prediction
        image_data = data.get("image")
        if not image_data:
            raise HTTPException(status_code=400, detail="No image data provided")
            
        # Convert base64 image to tensor and process
        try:
            # Remove the data URL prefix
            image_data = image_data.split(',')[1]
            import base64
            import io
            from PIL import Image
            import torchvision.transforms as transforms
            
            # Decode base64 to image
            image_bytes = base64.b64decode(image_data)
            image = Image.open(io.BytesIO(image_bytes)).convert('L')  # Convert to grayscale
            
            # Resize using PIL directly with LANCZOS
            image = image.resize((28, 28), Image.LANCZOS)
            
            # Invert the image (subtract from 255 to invert grayscale)
            image = Image.fromarray(255 - np.array(image))
            
            # Preprocess image
            transform = transforms.Compose([
                transforms.ToTensor(),
                transforms.Normalize((0.1307,), (0.3081,))
            ])
            
            # Convert to tensor and add batch dimension
            image_tensor = transform(image).unsqueeze(0)
            
            # Get prediction
            with torch.no_grad():
                output = model(image_tensor)
                prediction = output.argmax(dim=1).item()
            
            # Add configuration info to response
            return {
                "prediction": prediction,
                "model_config": {
                    "architecture": f"{config['block1']}-{config['block2']}-{config['block3']}",
                    "optimizer": config['optimizer'],
                    "batch_size": config['batch_size']
                }
            }
            
        except Exception as e:
            raise HTTPException(status_code=500, detail=f"Error processing image: {str(e)}")
            
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.get("/train/single", response_class=HTMLResponse)
async def train_single_page(request: Request):
    return templates.TemplateResponse("train_single.html", {"request": request})

@app.get("/train/compare", response_class=HTMLResponse)
async def train_compare_page(request: Request):
    return templates.TemplateResponse("train_compare.html", {"request": request})

if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=8000)