/**
 * Position Manager
 * 
 * Tracks active trades and manages automatic exits
 */

import { getDriftService } from '../drift/client'
import { closePosition } from '../drift/orders'
import { getPythPriceMonitor, PriceUpdate } from '../pyth/price-monitor'
import { getMergedConfig, TradingConfig } from '../../config/trading'

export interface ActiveTrade {
  id: string
  positionId: string // Transaction signature
  symbol: string
  direction: 'long' | 'short'
  
  // Entry details
  entryPrice: number
  entryTime: number
  positionSize: number
  leverage: number
  
  // Targets
  stopLossPrice: number
  tp1Price: number
  tp2Price: number
  emergencyStopPrice: number
  
  // State
  currentSize: number // Changes after TP1
  tp1Hit: boolean
  slMovedToBreakeven: boolean
  slMovedToProfit: boolean
  
  // P&L tracking
  realizedPnL: number
  unrealizedPnL: number
  peakPnL: number
  
  // Monitoring
  priceCheckCount: number
  lastPrice: number
  lastUpdateTime: number
}

export interface ExitResult {
  success: boolean
  reason: 'TP1' | 'TP2' | 'SL' | 'emergency' | 'manual' | 'error'
  closePrice?: number
  closedSize?: number
  realizedPnL?: number
  transactionSignature?: string
  error?: string
}

export class PositionManager {
  private activeTrades: Map<string, ActiveTrade> = new Map()
  private config: TradingConfig
  private isMonitoring: boolean = false

  constructor(config?: Partial<TradingConfig>) {
    this.config = getMergedConfig(config)
    console.log('✅ Position manager created')
  }

  /**
   * Add a new trade to monitor
   */
  async addTrade(trade: ActiveTrade): Promise<void> {
    console.log(`📊 Adding trade to monitor: ${trade.symbol} ${trade.direction}`)
    
    this.activeTrades.set(trade.id, trade)
    
    console.log(`✅ Trade added. Active trades: ${this.activeTrades.size}`)
    
    // Start monitoring if not already running
    if (!this.isMonitoring && this.activeTrades.size > 0) {
      await this.startMonitoring()
    }
  }

  /**
   * Remove a trade from monitoring
   */
  removeTrade(tradeId: string): void {
    const trade = this.activeTrades.get(tradeId)
    if (trade) {
      console.log(`🗑️ Removing trade: ${trade.symbol}`)
      this.activeTrades.delete(tradeId)
      
      // Stop monitoring if no more trades
      if (this.activeTrades.size === 0 && this.isMonitoring) {
        this.stopMonitoring()
      }
    }
  }

  /**
   * Get all active trades
   */
  getActiveTrades(): ActiveTrade[] {
    return Array.from(this.activeTrades.values())
  }

  /**
   * Get specific trade
   */
  getTrade(tradeId: string): ActiveTrade | null {
    return this.activeTrades.get(tradeId) || null
  }

  /**
   * Start price monitoring for all active trades
   */
  private async startMonitoring(): Promise<void> {
    if (this.isMonitoring) {
      return
    }

    // Get unique symbols from active trades
    const symbols = [...new Set(
      Array.from(this.activeTrades.values()).map(trade => trade.symbol)
    )]

    if (symbols.length === 0) {
      return
    }

    console.log('🚀 Starting price monitoring for:', symbols)

    const priceMonitor = getPythPriceMonitor()

    await priceMonitor.start({
      symbols,
      onPriceUpdate: async (update: PriceUpdate) => {
        await this.handlePriceUpdate(update)
      },
      onError: (error: Error) => {
        console.error('❌ Price monitor error:', error)
      },
    })

    this.isMonitoring = true
    console.log('✅ Position monitoring active')
  }

  /**
   * Stop price monitoring
   */
  private async stopMonitoring(): Promise<void> {
    if (!this.isMonitoring) {
      return
    }

    console.log('🛑 Stopping position monitoring...')

    const priceMonitor = getPythPriceMonitor()
    await priceMonitor.stop()

    this.isMonitoring = false
    console.log('✅ Position monitoring stopped')
  }

  /**
   * Handle price update for all relevant trades
   */
  private async handlePriceUpdate(update: PriceUpdate): Promise<void> {
    // Find all trades for this symbol
    const tradesForSymbol = Array.from(this.activeTrades.values())
      .filter(trade => trade.symbol === update.symbol)

    for (const trade of tradesForSymbol) {
      try {
        await this.checkTradeConditions(trade, update.price)
      } catch (error) {
        console.error(`❌ Error checking trade ${trade.id}:`, error)
      }
    }
  }

  /**
   * Check if any exit conditions are met for a trade
   */
  private async checkTradeConditions(
    trade: ActiveTrade,
    currentPrice: number
  ): Promise<void> {
    // Update trade data
    trade.lastPrice = currentPrice
    trade.lastUpdateTime = Date.now()
    trade.priceCheckCount++

    // Calculate P&L
    const profitPercent = this.calculateProfitPercent(
      trade.entryPrice,
      currentPrice,
      trade.direction
    )
    
    const accountPnL = profitPercent * trade.leverage
    trade.unrealizedPnL = (trade.currentSize * profitPercent) / 100

    // Track peak P&L
    if (trade.unrealizedPnL > trade.peakPnL) {
      trade.peakPnL = trade.unrealizedPnL
    }

    // Log status every 10 checks (~20 seconds)
    if (trade.priceCheckCount % 10 === 0) {
      console.log(
        `📊 ${trade.symbol} | ` +
        `Price: ${currentPrice.toFixed(4)} | ` +
        `P&L: ${profitPercent.toFixed(2)}% (${accountPnL.toFixed(1)}% acct) | ` +
        `Unrealized: $${trade.unrealizedPnL.toFixed(2)} | ` +
        `Peak: $${trade.peakPnL.toFixed(2)}`
      )
    }

    // Check exit conditions (in order of priority)

    // 1. Emergency stop (-2%)
    if (this.shouldEmergencyStop(currentPrice, trade)) {
      console.log(`🚨 EMERGENCY STOP: ${trade.symbol}`)
      await this.executeExit(trade, 100, 'emergency', currentPrice)
      return
    }

    // 2. Stop loss
    if (!trade.tp1Hit && this.shouldStopLoss(currentPrice, trade)) {
      console.log(`🔴 STOP LOSS: ${trade.symbol} at ${profitPercent.toFixed(2)}%`)
      await this.executeExit(trade, 100, 'SL', currentPrice)
      return
    }

    // 3. Take profit 1 (50%)
    if (!trade.tp1Hit && this.shouldTakeProfit1(currentPrice, trade)) {
      console.log(`🎉 TP1 HIT: ${trade.symbol} at ${profitPercent.toFixed(2)}%`)
      await this.executeExit(trade, 50, 'TP1', currentPrice)
      
      // Move SL to breakeven
      trade.tp1Hit = true
      trade.currentSize = trade.positionSize * 0.5
      trade.stopLossPrice = this.calculatePrice(
        trade.entryPrice,
        0.15, // +0.15% to cover fees
        trade.direction
      )
      trade.slMovedToBreakeven = true
      
      console.log(`🔒 SL moved to breakeven: ${trade.stopLossPrice.toFixed(4)}`)
      return
    }

    // 4. Profit lock trigger
    if (
      trade.tp1Hit &&
      !trade.slMovedToProfit &&
      profitPercent >= this.config.profitLockTriggerPercent
    ) {
      console.log(`🔐 Profit lock trigger: ${trade.symbol}`)
      
      trade.stopLossPrice = this.calculatePrice(
        trade.entryPrice,
        this.config.profitLockPercent,
        trade.direction
      )
      trade.slMovedToProfit = true
      
      console.log(`🎯 SL moved to +${this.config.profitLockPercent}%: ${trade.stopLossPrice.toFixed(4)}`)
    }

    // 5. Take profit 2 (remaining 50%)
    if (trade.tp1Hit && this.shouldTakeProfit2(currentPrice, trade)) {
      console.log(`🎊 TP2 HIT: ${trade.symbol} at ${profitPercent.toFixed(2)}%`)
      await this.executeExit(trade, 100, 'TP2', currentPrice)
      return
    }
  }

  /**
   * Execute exit (close position)
   */
  private async executeExit(
    trade: ActiveTrade,
    percentToClose: number,
    reason: ExitResult['reason'],
    currentPrice: number
  ): Promise<void> {
    try {
      console.log(`🔴 Executing ${reason} for ${trade.symbol} (${percentToClose}%)`)

      const result = await closePosition({
        symbol: trade.symbol,
        percentToClose,
        slippageTolerance: this.config.slippageTolerance,
      })

      if (!result.success) {
        console.error(`❌ Failed to close ${trade.symbol}:`, result.error)
        return
      }

      // Update trade state
      if (percentToClose >= 100) {
        // Full close - remove from monitoring
        trade.realizedPnL += result.realizedPnL || 0
        this.removeTrade(trade.id)
        
        console.log(`✅ Position closed | P&L: $${trade.realizedPnL.toFixed(2)} | Reason: ${reason}`)
      } else {
        // Partial close (TP1)
        trade.realizedPnL += result.realizedPnL || 0
        trade.currentSize -= result.closedSize || 0
        
        console.log(`✅ 50% closed | Realized: $${result.realizedPnL?.toFixed(2)} | Remaining: ${trade.currentSize}`)
      }

      // TODO: Save to database
      // TODO: Send notification

    } catch (error) {
      console.error(`❌ Error executing exit for ${trade.symbol}:`, error)
    }
  }

  /**
   * Decision helpers
   */
  private shouldEmergencyStop(price: number, trade: ActiveTrade): boolean {
    if (trade.direction === 'long') {
      return price <= trade.emergencyStopPrice
    } else {
      return price >= trade.emergencyStopPrice
    }
  }

  private shouldStopLoss(price: number, trade: ActiveTrade): boolean {
    if (trade.direction === 'long') {
      return price <= trade.stopLossPrice
    } else {
      return price >= trade.stopLossPrice
    }
  }

  private shouldTakeProfit1(price: number, trade: ActiveTrade): boolean {
    if (trade.direction === 'long') {
      return price >= trade.tp1Price
    } else {
      return price <= trade.tp1Price
    }
  }

  private shouldTakeProfit2(price: number, trade: ActiveTrade): boolean {
    if (trade.direction === 'long') {
      return price >= trade.tp2Price
    } else {
      return price <= trade.tp2Price
    }
  }

  /**
   * Calculate profit percentage
   */
  private calculateProfitPercent(
    entryPrice: number,
    currentPrice: number,
    direction: 'long' | 'short'
  ): number {
    if (direction === 'long') {
      return ((currentPrice - entryPrice) / entryPrice) * 100
    } else {
      return ((entryPrice - currentPrice) / entryPrice) * 100
    }
  }

  /**
   * Calculate price based on percentage
   */
  private calculatePrice(
    entryPrice: number,
    percent: number,
    direction: 'long' | 'short'
  ): number {
    if (direction === 'long') {
      return entryPrice * (1 + percent / 100)
    } else {
      return entryPrice * (1 - percent / 100)
    }
  }

  /**
   * Emergency close all positions
   */
  async closeAll(): Promise<void> {
    console.log('🚨 EMERGENCY: Closing all positions')

    const trades = Array.from(this.activeTrades.values())
    
    for (const trade of trades) {
      await this.executeExit(trade, 100, 'emergency', trade.lastPrice)
    }

    console.log('✅ All positions closed')
  }

  /**
   * Get monitoring status
   */
  getStatus(): {
    isMonitoring: boolean
    activeTradesCount: number
    symbols: string[]
  } {
    const symbols = [...new Set(
      Array.from(this.activeTrades.values()).map(t => t.symbol)
    )]

    return {
      isMonitoring: this.isMonitoring,
      activeTradesCount: this.activeTrades.size,
      symbols,
    }
  }
}

// Singleton instance
let positionManagerInstance: PositionManager | null = null

export function getPositionManager(): PositionManager {
  if (!positionManagerInstance) {
    positionManagerInstance = new PositionManager()
  }
  return positionManagerInstance
}