import logging
import time
from typing import Dict, Any, List, Optional
import requests
import hmac
import hashlib
from urllib.parse import urlencode, quote_plus

from .exchange_interface import ExchangeInterface

logger = logging.getLogger(__name__)


# https://github.com/mexcdevelop/mexc-api-postman/blob/main/MEXC%20V3.postman_collection.json
# MEXC V3.postman_collection.json

class MEXCInterface(ExchangeInterface):
    """MEXC Exchange API Interface"""
    
    def __init__(self, api_key: str = "", api_secret: str = "", test_mode: bool = True, trading_mode: str = 'simulation'):
        """Initialize MEXC exchange interface.
        
        Args:
            api_key: MEXC API key
            api_secret: MEXC API secret
            test_mode: If True, use test/sandbox environment (Note: MEXC doesn't have a true sandbox)
            trading_mode: 'simulation', 'testnet', or 'live'. Determines API endpoints used.
        """
        super().__init__(api_key, api_secret, test_mode)
        
        self.trading_mode = trading_mode # Store the trading mode

        # MEXC API Base URLs
        self.base_url = "https://api.mexc.com" # Live API URL
        if self.trading_mode == 'testnet':
            # Note: MEXC does not have a separate testnet for spot trading.
            # We use the live API for 'testnet' mode and rely on 'simulation' for true dry-runs.
            logger.warning("MEXC does not have a separate testnet for spot trading. Using live API for 'testnet' mode.")
        
        self.api_version = "api/v3"
        self.recv_window = 5000  # 5 seconds window for request validity

        # Session for HTTP requests
        self.session = requests.Session()

        logger.info(f"MEXCInterface initialized in {self.trading_mode} mode. Ensure correct API endpoints are being used.")
        
    def connect(self) -> bool:
        """Test connection to MEXC API by fetching account info."""
        if not self.api_key or not self.api_secret:
            logger.error("MEXC API key or secret not set. Cannot connect.")
            return False
        
        # Test connection by making a small, authenticated request
        try:
            account_info = self.get_account_info()
            if account_info:
                logger.info("Successfully connected to MEXC API and retrieved account info.")
                return True
            else:
                logger.error("Failed to connect to MEXC API: Could not retrieve account info.")
                return False
        except Exception as e:
            logger.error(f"Exception during MEXC API connection test: {e}")
            return False
    
    def _format_spot_symbol(self, symbol: str) -> str:
        """Formats a symbol to MEXC spot API standard and converts USDT to USDC for execution."""
        if '/' in symbol:
            base, quote = symbol.split('/')
            # Convert USDT to USDC for MEXC execution (MEXC API only supports USDC pairs)
            if quote.upper() == 'USDT':
                quote = 'USDC'
            return f"{base.upper()}{quote.upper()}"
        else:
            # Convert USDT to USDC for symbols like ETHUSDT -> ETHUSDC
            if symbol.upper().endswith('USDT'):
                symbol = symbol.upper().replace('USDT', 'USDC')
            return symbol.upper()

    def _format_futures_symbol(self, symbol: str) -> str:
        """Formats a symbol to MEXC futures API standard (e.g., 'ETH/USDT' -> 'ETH_USDT')."""
        # This method is included for completeness but should not be used for spot trading
        return symbol.replace('/', '_').upper()

    def _generate_signature(self, params: Dict[str, Any]) -> str:
        """Generate signature for private API calls using MEXC's parameter ordering"""
        # MEXC uses specific parameter ordering for signature generation
        # Based on working Postman collection: symbol, side, type, quantity, price, timestamp, recvWindow, then others
        
        # Remove signature if present
        clean_params = {k: v for k, v in params.items() if k != 'signature'}
        
        # MEXC parameter order (from working Postman collection)
        mexc_order = ['symbol', 'side', 'type', 'quantity', 'price', 'timestamp', 'recvWindow']
        
        ordered_params = []
        
        # Add parameters in MEXC's expected order
        for param_name in mexc_order:
            if param_name in clean_params:
                ordered_params.append(f"{param_name}={clean_params[param_name]}")
                del clean_params[param_name]
        
        # Add any remaining parameters in alphabetical order
        for key in sorted(clean_params.keys()):
            ordered_params.append(f"{key}={clean_params[key]}")
        
        # Create query string
        query_string = '&'.join(ordered_params)
        
        logger.debug(f"MEXC signature query string: {query_string}")
        
        # Generate HMAC SHA256 signature
        signature = hmac.new(
            self.api_secret.encode('utf-8'),
            query_string.encode('utf-8'),
            hashlib.sha256
        ).hexdigest()
        
        logger.debug(f"MEXC signature: {signature}")
        return signature
    
    def _send_public_request(self, method: str, endpoint: str, params: Optional[Dict[str, Any]] = None) -> Any:
        """Send a public API request to MEXC."""
        if params is None:
            params = {}

        url = f"{self.base_url}/{self.api_version}/{endpoint}"

        headers = {'Accept': 'application/json'}

        try:
            response = requests.request(method, url, params=params, headers=headers, timeout=10)
            response.raise_for_status()  # Raise HTTPError for bad responses (4xx or 5xx)
            return response.json()
        except requests.exceptions.HTTPError as http_err:
            logger.error(f"HTTP error in public request to {endpoint}: {response.status_code} {response.reason}")
            logger.error(f"Response content: {response.text}")
            return {}
        except requests.exceptions.ConnectionError as conn_err:
            logger.error(f"Connection error in public request to {endpoint}: {conn_err}")
            return {}
        except requests.exceptions.Timeout as timeout_err:
            logger.error(f"Timeout error in public request to {endpoint}: {timeout_err}")
            return {}
        except Exception as e:
            logger.error(f"Error in public request to {endpoint}: {e}")
            return {}

    def _send_private_request(self, method: str, endpoint: str, params: Optional[Dict[str, Any]] = None) -> Optional[Dict[str, Any]]:
        """Send a private request to the exchange with proper signature and MEXC error handling"""
        if params is None:
            params = {}
        
        timestamp = str(int(time.time() * 1000))
        
        # Add timestamp and recvWindow to params for signature and request
        params['timestamp'] = timestamp
        params['recvWindow'] = str(self.recv_window)
        
        # Generate signature with all parameters
        signature = self._generate_signature(params)
        params['signature'] = signature
        
        headers = {
            "X-MEXC-APIKEY": self.api_key
        }
        
        # For spot API, use the correct endpoint format
        if not endpoint.startswith('api/v3/'):
            endpoint = f"api/v3/{endpoint}"
        url = f"{self.base_url}/{endpoint}"
        
        try:
            if method.upper() == "GET":
                response = self.session.get(url, headers=headers, params=params, timeout=10)
            elif method.upper() == "POST":
                # For POST requests, MEXC expects parameters as query parameters, not form data
                # Based on Postman collection: Content-Type header is disabled
                response = self.session.post(url, headers=headers, params=params, timeout=10)
            elif method.upper() == "DELETE":
                response = self.session.delete(url, headers=headers, params=params, timeout=10)
            else:
                logger.error(f"Unsupported method: {method}")
                return None
            
            logger.debug(f"Request URL: {response.url}")
            logger.debug(f"Response status: {response.status_code}")
            
            if response.status_code == 200:
                return response.json()
            else:
                # Parse error response for specific error codes
                try:
                    error_data = response.json()
                    error_code = error_data.get('code')
                    error_msg = error_data.get('msg', 'Unknown error')
                    
                    # Handle specific MEXC error codes
                    if error_code == 30005:  # Oversold
                        logger.warning(f"MEXC Oversold detected (Code 30005) for {endpoint}. This indicates risk control measures are active.")
                        logger.warning(f"Possible causes: Market manipulation detection, abnormal trading patterns, or position limits.")
                        logger.warning(f"Action: Waiting before retry and reducing position size if needed.")
                        
                        # For oversold errors, we should not retry immediately
                        # Return a special error structure that the trading executor can handle
                        return {
                            'error': 'oversold',
                            'code': 30005,
                            'message': error_msg,
                            'retry_after': 60  # Suggest waiting 60 seconds
                        }
                    elif error_code == 30001:  # Transaction direction not allowed
                        logger.error(f"MEXC: Transaction direction not allowed for {endpoint}")
                        return {
                            'error': 'direction_not_allowed',
                            'code': 30001,
                            'message': error_msg
                        }
                    elif error_code == 30004:  # Insufficient position
                        logger.error(f"MEXC: Insufficient position for {endpoint}")
                        return {
                            'error': 'insufficient_position',
                            'code': 30004,
                            'message': error_msg
                        }
                    else:
                        logger.error(f"MEXC API error: Code: {error_code}, Message: {error_msg}")
                        return {
                            'error': 'api_error',
                            'code': error_code,
                            'message': error_msg
                        }
                except:
                    # Fallback if response is not JSON
                    logger.error(f"API error: Status Code: {response.status_code}, Response: {response.text}")
                    return None
                
        except requests.exceptions.HTTPError as http_err:
            logger.error(f"HTTP error for {endpoint}: Status Code: {response.status_code}, Response: {response.text}")
            logger.error(f"HTTP error details: {http_err}")
            return None
        except Exception as e:
            logger.error(f"Request error for {endpoint}: {e}")
            return None
    
    def get_account_info(self) -> Dict[str, Any]:
        """Get account information"""
        endpoint = "account"
        result = self._send_private_request("GET", endpoint, {})
        return result if result is not None else {}
    
    def get_balance(self, asset: str) -> float:
        """Get available balance for a specific asset."""
        account_info = self.get_account_info()
        if account_info and 'balances' in account_info:
            for balance in account_info['balances']:
                if balance.get('asset') == asset.upper():
                    return float(balance.get('free', 0.0))
        logger.warning(f"Could not retrieve free balance for {asset}")
        return 0.0
    
    def get_ticker(self, symbol: str) -> Optional[Dict[str, Any]]:
        """Get ticker information for a symbol."""
        formatted_symbol = self._format_spot_symbol(symbol)
        endpoint = "ticker/24hr"
        params = {'symbol': formatted_symbol}
        
        response = self._send_public_request('GET', endpoint, params)
                
        if response:
            # MEXC ticker returns a dictionary if single symbol, list if all symbols
            if isinstance(response, dict):
                ticker_data = response
            elif isinstance(response, list) and len(response) > 0:
                # If the response is a list, try to find the specific symbol
                found_ticker = None
                for item in response:
                    if isinstance(item, dict) and item.get('symbol') == formatted_symbol:
                        found_ticker = item
                        break
                if found_ticker:
                    ticker_data = found_ticker
                else:
                    logger.error(f"Ticker data for {formatted_symbol} not found in response list.")
                    return None
            else:
                logger.error(f"Unexpected ticker response format: {response}")
                return None

            # Extract relevant info and format for universal use
            last_price = float(ticker_data.get('lastPrice', 0))
            bid_price = float(ticker_data.get('bidPrice', 0))
            ask_price = float(ticker_data.get('askPrice', 0))
            volume = float(ticker_data.get('volume', 0)) # Base asset volume

            # Determine price change and percent change
            price_change = float(ticker_data.get('priceChange', 0))
            price_change_percent = float(ticker_data.get('priceChangePercent', 0))

            logger.info(f"MEXC: Got ticker from {endpoint} for {symbol}: ${last_price:.2f}")
            
            return {
                'symbol': formatted_symbol,
                'last': last_price,
                'bid': bid_price,
                'ask': ask_price,
                'volume': volume,
                'high': float(ticker_data.get('highPrice', 0)),
                'low': float(ticker_data.get('lowPrice', 0)),
                'change': price_change_percent, # This is usually priceChangePercent
                'exchange': 'MEXC',
                'raw_data': ticker_data
            }
        logger.error(f"Failed to get ticker for {symbol}")
        return None
    
    def get_api_symbols(self) -> List[str]:
        """Get list of symbols supported for API trading"""
        try:
            endpoint = "selfSymbols"
            result = self._send_private_request("GET", endpoint, {})
            if result and 'data' in result:
                return result['data']
            elif isinstance(result, list):
                return result
            else:
                logger.warning(f"Unexpected response format for API symbols: {result}")
                return []
        except Exception as e:
            logger.error(f"Error getting API symbols: {e}")
            return []

    def is_symbol_supported(self, symbol: str) -> bool:
        """Check if a symbol is supported for API trading"""
        formatted_symbol = self._format_spot_symbol(symbol)
        supported_symbols = self.get_api_symbols()
        return formatted_symbol in supported_symbols
    
    def place_order(self, symbol: str, side: str, order_type: str, quantity: float, price: Optional[float] = None) -> Dict[str, Any]:
        """Place a new order on MEXC."""
        try:
            logger.info(f"MEXC: place_order called with symbol={symbol}, side={side}, order_type={order_type}, quantity={quantity}, price={price}")
            
            formatted_symbol = self._format_spot_symbol(symbol)
            logger.info(f"MEXC: Formatted symbol: {symbol} -> {formatted_symbol}")
            
            # Check if symbol is supported for API trading
            if not self.is_symbol_supported(symbol):
                supported_symbols = self.get_api_symbols()
                logger.error(f"Symbol {formatted_symbol} is not supported for API trading")
                logger.info(f"Supported symbols include: {supported_symbols[:10]}...")  # Show first 10
                return {}
            
            # Round quantity to MEXC precision requirements and ensure minimum order value
            # MEXC ETHUSDC requires precision based on baseAssetPrecision (5 decimals for ETH)
            original_quantity = quantity
            if 'ETH' in formatted_symbol:
                quantity = round(quantity, 5)  # MEXC ETHUSDC precision: 5 decimals
                # Ensure minimum order value (typically $10+ for MEXC)
                if price and quantity * price < 10.0:
                    quantity = round(10.0 / price, 5)  # Adjust to minimum $10 order
            elif 'BTC' in formatted_symbol:
                quantity = round(quantity, 6)  # MEXC BTCUSDC precision: 6 decimals
                if price and quantity * price < 10.0:
                    quantity = round(10.0 / price, 6)  # Adjust to minimum $10 order  
            else:
                quantity = round(quantity, 5)  # Default precision for MEXC
                if price and quantity * price < 10.0:
                    quantity = round(10.0 / price, 5)  # Adjust to minimum $10 order
            
            if quantity != original_quantity:
                logger.info(f"MEXC: Adjusted quantity: {original_quantity} -> {quantity}")
            
            # MEXC doesn't support MARKET orders for many pairs - use LIMIT orders instead
            if order_type.upper() == 'MARKET':
                # Convert market order to limit order with aggressive pricing for immediate execution
                if price is None:
                    ticker = self.get_ticker(symbol)
                    if ticker and 'last' in ticker:
                        current_price = float(ticker['last'])
                        # For buy orders, use slightly above market to ensure immediate execution
                        # For sell orders, use slightly below market to ensure immediate execution
                        if side.upper() == 'BUY':
                            price = current_price * 1.002  # 0.2% premium for immediate buy execution
                        else:
                            price = current_price * 0.998  # 0.2% discount for immediate sell execution
                    else:
                        logger.error("Cannot get current price for market order conversion")
                        return {}
                
                # Convert to limit order with immediate execution pricing
                order_type = 'LIMIT'
                logger.info(f"MEXC: Converting MARKET to aggressive LIMIT order at ${price:.2f} for immediate execution")

            # Prepare order parameters
            params = {
                'symbol': formatted_symbol,
                'side': side.upper(),
                'type': order_type.upper(),
                'quantity': str(quantity) # Quantity must be a string
            }
            
            if price is not None:
                # Format price to remove unnecessary decimal places (e.g., 2900.0 -> 2900)
                params['price'] = str(int(price)) if price == int(price) else str(price)

            logger.info(f"MEXC: Placing {side.upper()} {order_type.upper()} order for {quantity} {formatted_symbol} at price {price}")
            logger.info(f"MEXC: Order parameters: {params}")
            
            # Use the standard private request method which handles timestamp and signature
            endpoint = "order"
            result = self._send_private_request("POST", endpoint, params)
            
            if result:
                # Check if result contains error information
                if isinstance(result, dict) and 'error' in result:
                    error_type = result.get('error')
                    error_code = result.get('code')
                    error_msg = result.get('message', 'Unknown error')
                    logger.error(f"MEXC: Order failed with error {error_code}: {error_msg}")
                    return result  # Return error result for handling by trading executor
                else:
                    logger.info(f"MEXC: Order placed successfully: {result}")
                    return result
            else:
                logger.error(f"MEXC: Failed to place order - _send_private_request returned None/empty result")
                logger.error(f"MEXC: Failed order details - symbol: {formatted_symbol}, side: {side}, type: {order_type}, quantity: {quantity}, price: {price}")
                return {}
                
        except Exception as e:
            logger.error(f"MEXC: Exception in place_order: {e}")
            logger.error(f"MEXC: Exception details - symbol: {symbol}, side: {side}, type: {order_type}, quantity: {quantity}, price: {price}")
            import traceback
            logger.error(f"MEXC: Full traceback: {traceback.format_exc()}")
            return {}

    def cancel_order(self, symbol: str, order_id: str) -> Dict[str, Any]:
        """Cancel an existing order on MEXC."""
        formatted_symbol = self._format_spot_symbol(symbol)
        endpoint = "order"
        params = {
            'symbol': formatted_symbol,
            'orderId': order_id
        }
        logger.info(f"MEXC: Cancelling order {order_id} for {formatted_symbol}")
        try:
            # MEXC API endpoint for cancelling orders is /api/v3/order (DELETE)
            cancel_result = self._send_private_request('DELETE', endpoint, params)
            if cancel_result:
                logger.info(f"MEXC: Order cancelled successfully: {cancel_result}")
                return cancel_result
            else:
                logger.error(f"MEXC: Error cancelling order: {cancel_result}")
                return {}
        except Exception as e:
            logger.error(f"MEXC: Exception cancelling order: {e}")
            return {}
    
    def get_order_status(self, symbol: str, order_id: str) -> Dict[str, Any]:
        """Get the status of an order on MEXC."""
        formatted_symbol = self._format_spot_symbol(symbol)
        endpoint = "order"
        params = {
            'symbol': formatted_symbol,
            'orderId': order_id
        }
        logger.info(f"MEXC: Getting status for order {order_id} for {formatted_symbol}")
        try:
            # MEXC API endpoint for order status is /api/v3/order (GET)
            status_result = self._send_private_request('GET', endpoint, params)
            if status_result:
                logger.info(f"MEXC: Order status retrieved: {status_result}")
                return status_result
            else:
                logger.error(f"MEXC: Error getting order status: {status_result}")
                return {}
        except Exception as e:
            logger.error(f"MEXC: Exception getting order status: {e}")
            return {}

    def get_open_orders(self, symbol: Optional[str] = None) -> List[Dict[str, Any]]:
        """Get all open orders on MEXC for a symbol or all symbols."""
        endpoint = "openOrders"
        params = {}
        if symbol:
            params['symbol'] = self._format_spot_symbol(symbol)
        
        logger.info(f"MEXC: Getting open orders for {symbol if symbol else 'all symbols'}")
        try:
            # MEXC API endpoint for open orders is /api/v3/openOrders (GET)
            open_orders = self._send_private_request('GET', endpoint, params)
            if open_orders and isinstance(open_orders, list):
                logger.info(f"MEXC: Retrieved {len(open_orders)} open orders.")
                return open_orders
            else:
                logger.error(f"MEXC: Error getting open orders: {open_orders}")
                return []
        except Exception as e:
            logger.error(f"MEXC: Exception getting open orders: {e}")
            return []

    def get_my_trades(self, symbol: str, limit: int = 100) -> List[Dict[str, Any]]:
        """Get trade history for a specific symbol."""
        formatted_symbol = self._format_spot_symbol(symbol)
        endpoint = "myTrades"
        params = {'symbol': formatted_symbol, 'limit': limit}

        logger.info(f"MEXC: Getting trade history for {formatted_symbol} (limit: {limit})")
        try:
            # MEXC API endpoint for trade history is /api/v3/myTrades (GET)
            trade_history = self._send_private_request('GET', endpoint, params)
            if trade_history and isinstance(trade_history, list):
                logger.info(f"MEXC: Retrieved {len(trade_history)} trade records.")
                return trade_history
            else:
                logger.error(f"MEXC: Error getting trade history: {trade_history}")
                return []
        except Exception as e:
            logger.error(f"MEXC: Exception getting trade history: {e}")
            return []

    def get_server_time(self) -> int:
        """Get current MEXC server time in milliseconds."""
        endpoint = "time"
        response = self._send_public_request('GET', endpoint)
        if response and 'serverTime' in response:
            return int(response['serverTime'])
        logger.error("Failed to get MEXC server time.")
        return int(time.time() * 1000) # Fallback to local time

    def get_all_balances(self) -> Dict[str, Dict[str, float]]:
        """Get all asset balances from MEXC account."""
        account_info = self.get_account_info()
        balances = {}
        if account_info and 'balances' in account_info:
            for balance in account_info['balances']:
                asset = balance.get('asset')
                free = float(balance.get('free'))
                locked = float(balance.get('locked'))
                if asset:
                    balances[asset.upper()] = {'free': free, 'locked': locked, 'total': free + locked}
        return balances

    def get_trading_fees(self) -> Dict[str, Any]:
        """Get current trading fee rates from MEXC API"""
        endpoint = "account/commission"
        response = self._send_private_request('GET', endpoint)
        if response and 'data' in response:
            fees_data = response['data']
            return {
                'maker': float(fees_data.get('makerCommission', 0.0)),
                'taker': float(fees_data.get('takerCommission', 0.0)),
                'default': float(fees_data.get('defaultCommission', 0.0))
            }
        logger.error("Failed to get trading fees from MEXC API.")
        return {}
    
    def get_symbol_trading_fees(self, symbol: str) -> Dict[str, Any]:
        """Get trading fee rates for a specific symbol from MEXC API"""
        formatted_symbol = self._format_spot_symbol(symbol)
        endpoint = "account/commission"
        params = {'symbol': formatted_symbol}
        response = self._send_private_request('GET', endpoint, params)
        if response and 'data' in response:
            fees_data = response['data']
            return {
                'maker': float(fees_data.get('makerCommission', 0.0)),
                'taker': float(fees_data.get('takerCommission', 0.0)),
                'default': float(fees_data.get('defaultCommission', 0.0))
            }
        logger.error(f"Failed to get trading fees for {symbol} from MEXC API.")
        return {}