/**
 * Drift Order Execution
 * 
 * Handles opening and closing positions with market orders
 */

import { getDriftService } from './client'
import { getMarketConfig } from '../../config/trading'
import {
  MarketType,
  PositionDirection,
  OrderType,
  OrderParams,
} from '@drift-labs/sdk'

export interface OpenPositionParams {
  symbol: string // e.g., 'SOL-PERP'
  direction: 'long' | 'short'
  sizeUSD: number // USD notional size
  slippageTolerance: number // Percentage (e.g., 1.0 for 1%)
}

export interface OpenPositionResult {
  success: boolean
  transactionSignature?: string
  fillPrice?: number
  fillSize?: number
  slippage?: number
  error?: string
}

export interface ClosePositionParams {
  symbol: string
  percentToClose: number // 0-100
  slippageTolerance: number
}

export interface ClosePositionResult {
  success: boolean
  transactionSignature?: string
  closePrice?: number
  closedSize?: number
  realizedPnL?: number
  error?: string
}

/**
 * Open a position with a market order
 */
export async function openPosition(
  params: OpenPositionParams
): Promise<OpenPositionResult> {
  try {
    console.log('📊 Opening position:', params)
    
    const driftService = getDriftService()
    const marketConfig = getMarketConfig(params.symbol)
    const driftClient = driftService.getClient()
    
    // Get current oracle price
    const oraclePrice = await driftService.getOraclePrice(marketConfig.driftMarketIndex)
    console.log(`💰 Current ${params.symbol} price: $${oraclePrice.toFixed(4)}`)
    
    // Calculate position size in base asset
    const baseAssetSize = params.sizeUSD / oraclePrice
    
    // Validate minimum order size
    if (baseAssetSize < marketConfig.minOrderSize) {
      throw new Error(
        `Order size ${baseAssetSize.toFixed(4)} is below minimum ${marketConfig.minOrderSize}`
      )
    }
    
    // Calculate worst acceptable price (with slippage)
    const slippageMultiplier = params.direction === 'long'
      ? 1 + (params.slippageTolerance / 100)
      : 1 - (params.slippageTolerance / 100)
    const worstPrice = oraclePrice * slippageMultiplier
    
    console.log(`📝 Order details:`)
    console.log(`   Size: ${baseAssetSize.toFixed(4)} ${params.symbol.split('-')[0]}`)
    console.log(`   Notional: $${params.sizeUSD.toFixed(2)}`)
    console.log(`   Oracle price: $${oraclePrice.toFixed(4)}`)
    console.log(`   Worst price (${params.slippageTolerance}% slippage): $${worstPrice.toFixed(4)}`)
    
    // Prepare order parameters
    const orderParams: OrderParams = {
      orderType: OrderType.MARKET,
      marketIndex: marketConfig.driftMarketIndex,
      marketType: MarketType.PERP,
      direction: params.direction === 'long' 
        ? PositionDirection.LONG 
        : PositionDirection.SHORT,
      baseAssetAmount: BigInt(Math.floor(baseAssetSize * 1e9)), // 9 decimals
      // Optional: add price limit for protection
      // price: BigInt(Math.floor(worstPrice * 1e6)), // 6 decimals
    }
    
    // Place market order
    console.log('🚀 Placing market order...')
    const txSig = await driftClient.placeAndTakePerpOrder(orderParams)
    
    console.log(`✅ Order placed! Transaction: ${txSig}`)
    
    // Wait for confirmation
    await driftClient.txSender.confirmTransaction(txSig)
    console.log('✅ Transaction confirmed')
    
    // Get actual fill price from position
    const position = await driftService.getPosition(marketConfig.driftMarketIndex)
    
    if (!position) {
      throw new Error('Position not found after order execution')
    }
    
    const fillPrice = position.entryPrice
    const slippage = Math.abs((fillPrice - oraclePrice) / oraclePrice) * 100
    
    console.log(`💰 Fill details:`)
    console.log(`   Fill price: $${fillPrice.toFixed(4)}`)
    console.log(`   Slippage: ${slippage.toFixed(3)}%`)
    
    return {
      success: true,
      transactionSignature: txSig,
      fillPrice,
      fillSize: baseAssetSize,
      slippage,
    }
    
  } catch (error) {
    console.error('❌ Failed to open position:', error)
    return {
      success: false,
      error: error instanceof Error ? error.message : 'Unknown error',
    }
  }
}

/**
 * Close a position (partially or fully) with a market order
 */
export async function closePosition(
  params: ClosePositionParams
): Promise<ClosePositionResult> {
  try {
    console.log('📊 Closing position:', params)
    
    const driftService = getDriftService()
    const marketConfig = getMarketConfig(params.symbol)
    const driftClient = driftService.getClient()
    
    // Get current position
    const position = await driftService.getPosition(marketConfig.driftMarketIndex)
    
    if (!position || position.side === 'none') {
      throw new Error(`No active position for ${params.symbol}`)
    }
    
    // Calculate size to close
    const sizeToClose = position.size * (params.percentToClose / 100)
    
    console.log(`📝 Close order details:`)
    console.log(`   Current position: ${position.size.toFixed(4)} ${position.side}`)
    console.log(`   Closing: ${params.percentToClose}% (${sizeToClose.toFixed(4)})`)
    console.log(`   Entry price: $${position.entryPrice.toFixed(4)}`)
    console.log(`   Unrealized P&L: $${position.unrealizedPnL.toFixed(2)}`)
    
    // Get current oracle price
    const oraclePrice = await driftService.getOraclePrice(marketConfig.driftMarketIndex)
    console.log(`   Current price: $${oraclePrice.toFixed(4)}`)
    
    // Prepare close order (opposite direction)
    const orderParams: OrderParams = {
      orderType: OrderType.MARKET,
      marketIndex: marketConfig.driftMarketIndex,
      marketType: MarketType.PERP,
      direction: position.side === 'long' 
        ? PositionDirection.SHORT 
        : PositionDirection.LONG,
      baseAssetAmount: BigInt(Math.floor(sizeToClose * 1e9)), // 9 decimals
      reduceOnly: true, // Important: only close existing position
    }
    
    // Place market close order
    console.log('🚀 Placing market close order...')
    const txSig = await driftClient.placeAndTakePerpOrder(orderParams)
    
    console.log(`✅ Close order placed! Transaction: ${txSig}`)
    
    // Wait for confirmation
    await driftClient.txSender.confirmTransaction(txSig)
    console.log('✅ Transaction confirmed')
    
    // Calculate realized P&L
    const pnlPerUnit = oraclePrice - position.entryPrice
    const realizedPnL = pnlPerUnit * sizeToClose * (position.side === 'long' ? 1 : -1)
    
    console.log(`💰 Close details:`)
    console.log(`   Close price: $${oraclePrice.toFixed(4)}`)
    console.log(`   Realized P&L: $${realizedPnL.toFixed(2)}`)
    
    return {
      success: true,
      transactionSignature: txSig,
      closePrice: oraclePrice,
      closedSize: sizeToClose,
      realizedPnL,
    }
    
  } catch (error) {
    console.error('❌ Failed to close position:', error)
    return {
      success: false,
      error: error instanceof Error ? error.message : 'Unknown error',
    }
  }
}

/**
 * Close entire position for a market
 */
export async function closeEntirePosition(
  symbol: string,
  slippageTolerance: number = 1.0
): Promise<ClosePositionResult> {
  return closePosition({
    symbol,
    percentToClose: 100,
    slippageTolerance,
  })
}

/**
 * Emergency close all positions
 */
export async function emergencyCloseAll(): Promise<{
  success: boolean
  results: Array<{
    symbol: string
    result: ClosePositionResult
  }>
}> {
  console.log('🚨 EMERGENCY: Closing all positions')
  
  try {
    const driftService = getDriftService()
    const positions = await driftService.getAllPositions()
    
    if (positions.length === 0) {
      console.log('✅ No positions to close')
      return { success: true, results: [] }
    }
    
    const results = []
    
    for (const position of positions) {
      console.log(`🔴 Emergency closing ${position.symbol}...`)
      const result = await closeEntirePosition(position.symbol, 2.0) // Allow 2% slippage
      results.push({
        symbol: position.symbol,
        result,
      })
    }
    
    console.log('✅ Emergency close complete')
    
    return {
      success: true,
      results,
    }
    
  } catch (error) {
    console.error('❌ Emergency close failed:', error)
    return {
      success: false,
      results: [],
    }
  }
}