# backend/routes/custom_strategies.py
"""
Custom Strategy API Routes
Handles strategy upload, backtesting, hyperopt, and deployment
"""

from fastapi import APIRouter, UploadFile, File, HTTPException, Header
from fastapi.responses import JSONResponse
from typing import Optional
from datetime import datetime
import logging

from ..integrations.freqtrade_integration import FreqtradeBacktester

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/api/yuki/strategies/custom", tags=["custom_strategies"])

# Initialize backtester (in production: inject via dependency)
backtester = FreqtradeBacktester(base_config={})


@router.post("/upload")
async def upload_strategy(
    file: UploadFile = File(...),
    description: Optional[str] = None
):
    """
    Upload custom strategy file (Freqtrade format)
    
    Supports:
    - Freqtrade IStrategy subclass
    - Custom Python agent
    
    Returns:
        strategy_id for use in other endpoints
    """
    
    try:
        content = await file.read()
        strategy_code = content.decode('utf-8')
        
        # 1. Validate syntax
        is_valid, error = backtester.validate_strategy_syntax(strategy_code)
        if not is_valid:
            raise HTTPException(status_code=400, detail=error)
        
        # 2. Check for Freqtrade methods
        is_freqtrade, missing = backtester.validate_freqtrade_interface(strategy_code)
        
        # 3. Store in database (TODO)
        strategy_id = f"strat_{datetime.now().timestamp()}".replace(".", "_")
        
        logger.info(f"Strategy uploaded: {strategy_id} from {file.filename}")
        
        return {
            "status": "success",
            "strategy_id": strategy_id,
            "filename": file.filename,
            "is_freqtrade_format": is_freqtrade,
            "description": description,
            "uploaded_at": datetime.now().isoformat()
        }
        
    except UnicodeDecodeError:
        raise HTTPException(status_code=400, detail="File must be valid UTF-8")
    except Exception as e:
        logger.error(f"Upload error: {e}")
        raise HTTPException(status_code=500, detail=str(e))


@router.post("/backtest/{strategy_id}")
async def backtest_strategy(
    strategy_id: str,
    timerange: str = "20230101-20240101",
    stake_amount: float = 100,
    pair: str = "SOL/USDC",
    timeframe: str = "5m"
):
    """
    Backtest uploaded strategy on historical data
    
    Args:
        strategy_id: Strategy identifier from upload
        timerange: Format "YYYYMMDD-YYYYMMDD"
        stake_amount: Initial capital per trade in USDC
        pair: Trading pair
        timeframe: Candle timeframe
    
    Returns:
        Backtest results with metrics
    """
    
    try:
        # TODO: Retrieve strategy code from database
        strategy_code = """
# Placeholder strategy
from freqtrade.strategy import IStrategy
import pandas as pd

class PlaceholderStrategy(IStrategy):
    stoploss = -0.05
    timeframe = "5m"
    
    def populate_indicators(self, dataframe: pd.DataFrame, metadata: dict) -> pd.DataFrame:
        return dataframe
    
    def populate_entry_trend(self, dataframe: pd.DataFrame, metadata: dict) -> pd.DataFrame:
        dataframe.loc[dataframe.index > 0, 'enter_long'] = 1
        return dataframe
    
    def populate_exit_trend(self, dataframe: pd.DataFrame, metadata: dict) -> pd.DataFrame:
        dataframe.loc[dataframe.index > 5, 'exit_long'] = 1
        return dataframe
"""
        
        result = backtester.backtest_strategy(
            strategy_code=strategy_code,
            strategy_id=strategy_id,
            timerange=timerange,
            stake_amount=stake_amount,
            pair=pair,
            timeframe=timeframe
        )
        
        return result
        
    except Exception as e:
        logger.error(f"Backtest error: {e}")
        raise HTTPException(status_code=500, detail=str(e))


@router.post("/hyperopt/{strategy_id}")
async def hyperopt_strategy(
    strategy_id: str,
    n_epochs: int = 100,
    timerange: str = "20230101-20240101",
    loss_function: str = "SharpeHyperOptLoss"
):
    """
    Run hyperparameter optimization on strategy
    
    Finds best parameters to maximize specified loss function
    
    Returns:
        Best parameters found + top 3 results
    """
    
    try:
        # TODO: Retrieve strategy code from database
        strategy_code = "# Strategy code here"
        
        result = backtester.hyperopt_strategy(
            strategy_code=strategy_code,
            strategy_id=strategy_id,
            n_epochs=n_epochs,
            timerange=timerange,
            loss_function=loss_function
        )
        
        return result
        
    except Exception as e:
        logger.error(f"Hyperopt error: {e}")
        raise HTTPException(status_code=500, detail=str(e))


@router.post("/deploy/{strategy_id}")
async def deploy_strategy(
    strategy_id: str,
    mode: str = "paper",  # paper | live
    initial_balance: float = 1000,
    max_open_trades: int = 3
):
    """
    Deploy strategy to live or paper trading
    
    Returns:
        Deployment status and connection details
    """
    
    try:
        # TODO: Actual deployment logic
        
        return {
            "status": "success",
            "strategy_id": strategy_id,
            "mode": mode,
            "initial_balance": initial_balance,
            "max_open_trades": max_open_trades,
            "deployed_at": datetime.now().isoformat(),
            "websocket_url": "wss://yuki.api/ws/strategy/signals"
        }
        
    except Exception as e:
        logger.error(f"Deploy error: {e}")
        raise HTTPException(status_code=500, detail=str(e))


@router.get("/{strategy_id}")
async def get_strategy(strategy_id: str):
    """Get strategy metadata and status"""
    
    try:
        result = backtester.get_strategy_info(strategy_id)
        return result
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))


@router.get("")
async def list_strategies():
    """List all uploaded strategies"""
    
    try:
        result = backtester.list_strategies()
        return result
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))