/**
 * Persistent File Logger - Survives Container Restarts
 * Critical for debugging database save failures and system issues
 */

import * as fs from 'fs'
import { logger } from '../utils/logger'
import * as path from 'path'

const LOG_DIR = '/app/logs'
const ERROR_LOG = path.join(LOG_DIR, 'errors.log')
const TRADE_LOG = path.join(LOG_DIR, 'trades.log')
const MAX_LOG_SIZE = 10 * 1024 * 1024 // 10MB per log file

// Ensure log directory exists
function ensureLogDir() {
  try {
    if (!fs.existsSync(LOG_DIR)) {
      fs.mkdirSync(LOG_DIR, { recursive: true })
    }
  } catch (error) {
    console.error('Failed to create log directory:', error)
  }
}

// Rotate log if too large
function rotateLogIfNeeded(logPath: string) {
  try {
    if (fs.existsSync(logPath)) {
      const stats = fs.statSync(logPath)
      if (stats.size > MAX_LOG_SIZE) {
        const timestamp = new Date().toISOString().replace(/[:.]/g, '-')
        const rotatedPath = `${logPath}.${timestamp}`
        fs.renameSync(logPath, rotatedPath)
        logger.log(`📦 Rotated log: ${rotatedPath}`)
      }
    }
  } catch (error) {
    console.error('Failed to rotate log:', error)
  }
}

// Format log entry
function formatLogEntry(level: string, message: string, details?: any): string {
  const timestamp = new Date().toISOString()
  const detailsStr = details ? `\n${JSON.stringify(details, null, 2)}` : ''
  return `[${timestamp}] ${level}: ${message}${detailsStr}\n`
}

// Append to log file
function appendToLog(logPath: string, entry: string) {
  try {
    ensureLogDir()
    rotateLogIfNeeded(logPath)
    fs.appendFileSync(logPath, entry, 'utf8')
  } catch (error) {
    console.error(`Failed to write to ${logPath}:`, error)
  }
}

/**
 * Log critical error (database failures, position issues)
 */
export function logCriticalError(message: string, details?: any) {
  const entry = formatLogEntry('CRITICAL', message, details)
  console.error('🔴 CRITICAL:', message, details || '')
  appendToLog(ERROR_LOG, entry)
}

/**
 * Log trade execution (success or failure)
 */
export function logTradeExecution(
  success: boolean,
  tradeDetails: {
    symbol: string
    direction: string
    entryPrice: number
    positionSize: number
    transactionSignature?: string
    error?: string
  }
) {
  const level = success ? 'SUCCESS' : 'FAILURE'
  const message = success
    ? `Trade opened: ${tradeDetails.symbol} ${tradeDetails.direction} @ $${tradeDetails.entryPrice}`
    : `Trade failed: ${tradeDetails.symbol} ${tradeDetails.direction} - ${tradeDetails.error}`
  
  const entry = formatLogEntry(level, message, tradeDetails)
  logger.log(success ? '✅' : '❌', message)
  appendToLog(TRADE_LOG, entry)
}

/**
 * Log database operation (create, update, query)
 */
export function logDatabaseOperation(
  operation: string,
  success: boolean,
  details: {
    table?: string
    recordId?: string
    error?: any
    retryAttempt?: number
  }
) {
  const level = success ? 'DB_SUCCESS' : 'DB_FAILURE'
  const message = success
    ? `${operation} succeeded: ${details.table || 'unknown'}`
    : `${operation} failed: ${details.error?.message || 'Unknown error'}`
  
  const entry = formatLogEntry(level, message, details)
  logger.log(success ? '💾' : '❌', message)
  appendToLog(ERROR_LOG, entry)
}

/**
 * Read recent error logs (for debugging)
 */
export function getRecentErrors(lines: number = 50): string[] {
  try {
    if (!fs.existsSync(ERROR_LOG)) {
      return []
    }
    
    const content = fs.readFileSync(ERROR_LOG, 'utf8')
    const allLines = content.split('\n').filter(line => line.trim())
    return allLines.slice(-lines)
  } catch (error) {
    console.error('Failed to read error log:', error)
    return []
  }
}

/**
 * Read recent trade logs
 */
export function getRecentTrades(lines: number = 50): string[] {
  try {
    if (!fs.existsSync(TRADE_LOG)) {
      return []
    }
    
    const content = fs.readFileSync(TRADE_LOG, 'utf8')
    const allLines = content.split('\n').filter(line => line.trim())
    return allLines.slice(-lines)
  } catch (error) {
    console.error('Failed to read trade log:', error)
    return []
  }
}