//! Configuration structures

use serde::{Deserialize, Serialize};
use rust_decimal::Decimal;
use std::collections::HashMap;

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RiskConfig {
    pub max_position_size: Decimal,
    pub max_daily_loss: Decimal,
    pub var_confidence_level: f64,
    pub var_time_horizon: u32,
    pub var_config: VarConfig,
    pub circuit_breaker: CircuitBreakerConfig,
    pub position_limits: PositionLimitsConfig,
    pub asset_classification: AssetClassificationConfig,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct VarConfig {
    pub confidence_level: f64,
    pub time_horizon_days: u32,
    pub lookback_period_days: u32,
    pub calculation_method: String,
    pub max_var_limit: f64,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct KellyConfig {
    pub kelly_fraction: f64,
    pub max_kelly_leverage: f64,
    pub min_kelly_leverage: f64,
    pub confidence_threshold: f64,
    pub lookback_periods: usize,
    pub default_position_fraction: f64,
    pub enabled: bool,
    pub fractional_kelly: f64,
    pub min_kelly_fraction: f64,
    pub max_kelly_fraction: f64,
}

impl Default for KellyConfig {
    fn default() -> Self {
        Self {
            kelly_fraction: 0.25,
            max_kelly_leverage: 2.0,
            min_kelly_leverage: 0.1,
            confidence_threshold: 0.95,
            lookback_periods: 252,
            default_position_fraction: 0.02,
            enabled: true,
            fractional_kelly: 0.5,
            min_kelly_fraction: 0.01,
            max_kelly_fraction: 0.5,
        }
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CircuitBreakerConfig {
    pub enabled: bool,
    pub price_move_threshold: f64,
    pub halt_duration_seconds: u64,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PositionLimitsConfig {
    pub global_limit: f64,
    pub max_leverage: f64,
    pub max_var_limit: f64,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BacktestingDatabaseConfig {
    pub url: String,
    pub max_connections: u32,
    pub query_timeout: std::time::Duration,
    pub enable_query_logging: bool,
}

/// Broker configuration for order routing and execution
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BrokerConfig {
    /// Broker routing rules based on symbol patterns and sizes
    pub routing_rules: Vec<BrokerRoutingRule>,
    /// Default broker when no rules match
    pub default_broker: String,
    /// Commission rates by broker
    pub commission_rates: HashMap<String, CommissionConfig>,
}

/// Rule for routing orders to specific brokers
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BrokerRoutingRule {
    /// Priority (higher numbers take precedence)
    pub priority: u32,
    /// Symbol pattern (regex)
    pub symbol_pattern: String,
    /// Minimum quantity for this rule
    pub min_quantity: Option<f64>,
    /// Maximum quantity for this rule
    pub max_quantity: Option<f64>,
    /// Target broker ID
    pub broker_id: String,
    /// Rule description for debugging
    pub description: String,
}

/// Commission configuration per broker
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CommissionConfig {
    /// Commission rate (basis points, e.g., 0.00007 = 0.7 bps)
    pub rate_bps: f64,
    /// Minimum commission per trade
    pub min_commission: f64,
}

impl Default for BrokerConfig {
    fn default() -> Self {
        let mut commission_rates = HashMap::new();

        commission_rates.insert(
            "ICMARKETS".to_string(),
            CommissionConfig {
                rate_bps: 0.00007, // 0.7 bps
                min_commission: 0.0,
            },
        );

        commission_rates.insert(
            "IBKR".to_string(),
            CommissionConfig {
                rate_bps: 0.00005, // 0.5 bps
                min_commission: 1.0,
            },
        );

        let routing_rules = vec![
            BrokerRoutingRule {
                priority: 100,
                symbol_pattern: r"^(BTC|ETH).*".to_string(),
                min_quantity: None,
                max_quantity: None,
                broker_id: "ICMARKETS".to_string(),
                description: "Route all crypto symbols to ICMarkets".to_string(),
            },
            BrokerRoutingRule {
                priority: 90,
                symbol_pattern: r".*USD$".to_string(),
                min_quantity: None,
                max_quantity: Some(1_000_000.0),
                broker_id: "ICMARKETS".to_string(),
                description: "Route smaller USD pairs to ICMarkets".to_string(),
            },
            BrokerRoutingRule {
                priority: 50,
                symbol_pattern: r".*".to_string(), // Catch-all
                min_quantity: None,
                max_quantity: None,
                broker_id: "IBKR".to_string(),
                description: "Default routing to IBKR".to_string(),
            },
        ];

        Self {
            routing_rules,
            default_broker: "IBKR".to_string(),
            commission_rates,
        }
    }
}

impl BrokerConfig {
    /// Select optimal broker based on symbol and quantity using routing rules
    pub fn select_broker(&self, symbol: &str, quantity: f64) -> String {
        let symbol_upper = symbol.to_uppercase();

        // Sort rules by priority (highest first)
        let mut applicable_rules: Vec<_> = self.routing_rules.iter()
            .filter(|rule| {
                // Check symbol pattern
                let symbol_matches = if let Ok(regex) = regex::Regex::new(&rule.symbol_pattern) {
                    regex.is_match(&symbol_upper)
                } else {
                    false
                };

                // Check quantity bounds
                let quantity_matches = {
                    let min_ok = rule.min_quantity.map_or(true, |min| quantity >= min);
                    let max_ok = rule.max_quantity.map_or(true, |max| quantity <= max);
                    min_ok && max_ok
                };

                symbol_matches && quantity_matches
            })
            .collect();

        applicable_rules.sort_by(|a, b| b.priority.cmp(&a.priority));

        if let Some(rule) = applicable_rules.first() {
            rule.broker_id.clone()
        } else {
            self.default_broker.clone()
        }
    }

    /// Calculate commission for a given broker and notional value
    pub fn calculate_commission(&self, broker_id: &str, notional: f64) -> f64 {
        if let Some(config) = self.commission_rates.get(broker_id) {
            (notional * config.rate_bps).max(config.min_commission)
        } else {
            // Default commission if broker not found
            notional * 0.0001 // 1 bps
        }
    }
}

/// Asset classification for risk management and volatility profiling
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Hash)]
pub enum AssetClass {
    /// Equity securities and stocks
    Equities,
    /// Bonds and fixed income securities
    FixedIncome,
    /// Physical and financial commodities
    Commodities,
    /// Foreign exchange and currencies
    Currencies,
    /// Alternative investments
    Alternatives,
    /// Derivative instruments
    Derivatives,
    /// Cash and cash equivalents
    Cash,
}

/// Volatility and risk profile for an asset class
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct VolatilityProfile {
    /// Annual volatility (0.0 to 1.0, e.g., 0.25 = 25%)
    pub annual_volatility: f64,
    /// Maximum position size as fraction of portfolio (0.0 to 1.0)
    pub max_position_fraction: f64,
    /// Volatility threshold for risk alerts (0.0 to 1.0)
    pub volatility_threshold: f64,
    /// Maximum daily loss threshold (0.0 to 1.0)
    pub daily_loss_threshold: f64,
}

/// Asset classification configuration with symbol mappings and volatility profiles
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AssetClassificationConfig {
    /// Explicit symbol to asset class mappings
    pub symbol_mappings: HashMap<String, AssetClass>,
    /// Volatility profiles for each asset class
    pub volatility_profiles: HashMap<AssetClass, VolatilityProfile>,
    /// Pattern-based classification rules (regex patterns)
    pub pattern_rules: Vec<PatternRule>,
}

/// Pattern-based rule for asset classification
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PatternRule {
    /// Regex pattern to match against symbol
    pub pattern: String,
    /// Asset class to assign if pattern matches
    pub asset_class: AssetClass,
    /// Priority (higher numbers take precedence)
    pub priority: u32,
}

impl Default for AssetClassificationConfig {
    fn default() -> Self {
        let mut symbol_mappings = HashMap::new();

        // Equity stocks
        for symbol in ["AAPL", "MSFT", "GOOGL", "AMZN", "META", "TSLA", "NVDA", "JPM", "JNJ", "V"] {
            symbol_mappings.insert(symbol.to_string(), AssetClass::Equities);
        }
        
        // Major cryptocurrencies
        for symbol in ["BTC", "ETH", "BTCUSD", "ETHUSD", "BTCUSDT", "ETHUSDT"] {
            symbol_mappings.insert(symbol.to_string(), AssetClass::Alternatives);
        }

        let mut volatility_profiles = HashMap::new();

        volatility_profiles.insert(AssetClass::Equities, VolatilityProfile {
            annual_volatility: 0.25,
            max_position_fraction: 0.20,
            volatility_threshold: 0.025,
            daily_loss_threshold: 0.03,
            
        });
        
        volatility_profiles.insert(AssetClass::Alternatives, VolatilityProfile {
            annual_volatility: 0.80,
            max_position_fraction: 0.08,
            volatility_threshold: 0.15,
            daily_loss_threshold: 0.05,
            
        });
        
        volatility_profiles.insert(AssetClass::Currencies, VolatilityProfile {
            annual_volatility: 0.15,
            max_position_fraction: 0.30,
            volatility_threshold: 0.02,
            daily_loss_threshold: 0.02,
            
        });
        
        volatility_profiles.insert(AssetClass::Cash, VolatilityProfile {
            annual_volatility: 0.01,
            max_position_fraction: 1.00,
            volatility_threshold: 0.001,
            daily_loss_threshold: 0.001,
            
        });
        
        volatility_profiles.insert(AssetClass::FixedIncome, VolatilityProfile {
            annual_volatility: 0.25,
            max_position_fraction: 0.15,
            volatility_threshold: 0.03,
            daily_loss_threshold: 0.025,
            
        });

        volatility_profiles.insert(AssetClass::Derivatives, VolatilityProfile {
            annual_volatility: 0.40,
            max_position_fraction: 0.10,
            volatility_threshold: 0.05,
            daily_loss_threshold: 0.04,
            
        });
        
        volatility_profiles.insert(AssetClass::Commodities, VolatilityProfile {
            annual_volatility: 0.30,
            max_position_fraction: 0.15,
            volatility_threshold: 0.04,
            daily_loss_threshold: 0.03,
            
        });

        let pattern_rules = vec![
            PatternRule {
                pattern: r"^(BTC|ETH).*".to_string(),
                asset_class: AssetClass::Alternatives,
                priority: 100,
            },
            PatternRule {
                pattern: r".*USD$".to_string(),
                asset_class: AssetClass::Currencies,
                priority: 80,
            },
            PatternRule {
                pattern: r".*JPY$".to_string(),
                asset_class: AssetClass::Currencies,
                priority: 90,
            },
            PatternRule {
                pattern: r"^[A-Z]{3,6}$".to_string(), // 3-6 letter symbols (likely equities)
                asset_class: AssetClass::Equities,
                priority: 50,
            },
        ];

        Self {
            symbol_mappings,
            volatility_profiles,
            pattern_rules,
        }
    }
}

impl AssetClassificationConfig {
    /// Classify a symbol based on explicit mappings and pattern rules
    pub fn classify_symbol(&self, symbol: &str) -> AssetClass {
        let symbol_upper = symbol.to_uppercase();

        // First check explicit mappings
        if let Some(asset_class) = self.symbol_mappings.get(&symbol_upper) {
            return asset_class.clone();
        }

        // Then check pattern rules (sorted by priority, highest first)
        let mut applicable_rules: Vec<_> = self.pattern_rules.iter()
            .filter(|rule| {
                if let Ok(regex) = regex::Regex::new(&rule.pattern) {
                    regex.is_match(&symbol_upper)
                } else {
                    false
                }
            })
            .collect();

        applicable_rules.sort_by(|a, b| b.priority.cmp(&a.priority));

        if let Some(rule) = applicable_rules.first() {
            rule.asset_class.clone()
        } else {
            AssetClass::Cash  // Default fallback for unknown symbols
        }
    }

    /// Get volatility profile for a symbol
    pub fn get_volatility_profile(&self, symbol: &str) -> VolatilityProfile {
        let asset_class = self.classify_symbol(symbol);
        self.volatility_profiles.get(&asset_class)
            .cloned()
            .unwrap_or_else(|| VolatilityProfile {
                annual_volatility: 0.20,
                max_position_fraction: 0.05,
                volatility_threshold: 0.02,
                daily_loss_threshold: 0.01,
                    
                })
    }

    /// Get daily volatility for a symbol
    pub fn get_daily_volatility(&self, symbol: &str) -> f64 {
        let profile = self.get_volatility_profile(symbol);
        profile.annual_volatility / 252.0_f64.sqrt()
    }

    /// Get risk configuration tuple (position_fraction, volatility_threshold, daily_loss_threshold)
    pub fn get_risk_config(&self, symbol: &str) -> (f64, f64, f64) {
        let profile = self.get_volatility_profile(symbol);
        (profile.max_position_fraction, profile.volatility_threshold, profile.daily_loss_threshold)
    }
    
    }