//
//  WidgetAPI+Electrum.swift
//  BlueWallet
//
//  Created by Marcos Rodriguez on 11/8/20.
//  Copyright © 2020 BlueWallet. All rights reserved.
//

import Foundation

struct APIError: LocalizedError {
  var errorDescription: String = "Failed to fetch Electrum data..."
}

extension WidgetAPI {
  
  static func fetchNextBlockFee(completion: @escaping ((MarketData?, Error?) -> Void), userElectrumSettings: UserDefaultsElectrumSettings = UserDefaultsGroup.getElectrumSettings()) {
         let settings = userElectrumSettings
         let portToUse = settings.sslPort ?? settings.port
         let isSSLSupported = settings.sslPort != nil

         DispatchQueue.global(qos: .background).async {
             let client = SwiftTCPClient()
             
             defer {
               print("Closing connection to \(String(describing: settings.host)):\(String(describing: portToUse)).")
                 client.close()
             }
           
           guard let host = settings.host, let portToUse = portToUse else { return }
           
           print("Attempting to connect to \(String(describing: settings.host)):\(portToUse) with SSL supported: \(isSSLSupported).")
      
             if client.connect(to: host, port: UInt32(portToUse), useSSL: isSSLSupported) {
               print("Successfully connected to \(String(describing: settings.host)):\(portToUse) with SSL:\(isSSLSupported).")
             } else {
               print("Failed to connect to \(String(describing: settings.host)):\(portToUse) with SSL:\(isSSLSupported).")
                 completion(nil, APIError())
                 return
             }
           
             let message = "{\"id\": 1, \"method\": \"blockchain.estimatefee\", \"params\": [1]}\n"
             guard let data = message.data(using: .utf8), client.send(data: data) else {
               print("Message sending failed to \(String(describing: settings.host)):\(portToUse) with SSL supported: \(isSSLSupported).")
                 completion(nil, APIError())
                 return
             }
           print("Message sent successfully to \(String(describing: settings.host)):\(portToUse) with SSL:\(isSSLSupported).")

             do {
                 let receivedData = try client.receive()
                 print("Data received. Parsing...")
                 guard let responseString = String(data: receivedData, encoding: .utf8),
                       let responseData = responseString.data(using: .utf8),
                       let json = try JSONSerialization.jsonObject(with: responseData, options: .allowFragments) as? [String: AnyObject],
                       let nextBlockResponseDouble = json["result"] as? Double else {
                   print("Failed to parse response from \(String(describing: settings.host)).")
                     completion(nil, APIError())
                     return
                 }
               
               print("Response: \(json)")

               print("Response from \(String(describing: settings.host)) parsed successfully.")
                 let marketData = MarketData(nextBlock: String(format: "%.0f", (nextBlockResponseDouble / 1024) * 100000000), sats: "0", price: "0", rate: 0)
                 completion(marketData, nil) // Successfully fetched data, return it
             } catch {
               print("Error receiving data from \(String(describing: settings.host)): \(error.localizedDescription)")
                 completion(nil, APIError())
             }
         }
     }
  
  static func fetchMarketData(currency: String, completion: @escaping ((MarketData?, Error?) -> Void)) {
    var marketDataEntry = MarketData(nextBlock: "...", sats: "...", price: "...", rate: 0)
    WidgetAPI.fetchPrice(currency: currency, completion: { (result, error) in
      if let result = result {
        marketDataEntry.rate = result.rateDouble
        marketDataEntry.price = result.formattedRate ?? "!"
      }
      WidgetAPI.fetchNextBlockFee { (marketData, error) in
        if let nextBlock = marketData?.nextBlock {
          marketDataEntry.nextBlock = nextBlock
        } else {
          marketDataEntry.nextBlock = "!"
        }
        if let rateDouble = result?.rateDouble {
          marketDataEntry.sats = numberFormatter.string(from:  NSNumber(value: Double(10 / rateDouble) * 10000000)) ?? "!"
        }
        completion(marketDataEntry, nil)
      }
    })
  }
  
}