//
//  PrimerRNHeadlessUniversalCheckoutKlarnaComponent.k.swift
//  primer-io-react-native
//
//  Created by Stefan Vrancianu on 01.04.2024.
//

import Foundation
import PrimerSDK
import UIKit
import React

// swiftlint:disable type_name
@objc(RNTPrimerHeadlessUniversalCheckoutKlarnaComponent)
class RNTPrimerHeadlessUniversalCheckoutKlarnaComponent: RCTEventEmitter {
  // swiftlint:enable type_name

  #if canImport(PrimerKlarnaSDK)
    private var klarnaManager: PrimerHeadlessUniversalCheckout.KlarnaManager =
      PrimerHeadlessUniversalCheckout.KlarnaManager()
  #endif
  var klarnaComponent: (any KlarnaComponent)?
  var clientToken: String?

  override class func requiresMainQueueSetup() -> Bool {
    return true
  }

  override init() {
    super.init()
  }

  override func supportedEvents() -> [String] {
    return PrimerHeadlessUniversalCheckoutComponentEvent.allCases.compactMap({ $0.stringValue })
  }

  // MARK: - API

  @objc
  public func configure(
    _ primerSessionIntent: String,
    resolver: @escaping RCTPromiseResolveBlock,
    rejecter: @escaping RCTPromiseRejectBlock
  ) {
    do {
      guard
        let sessionIntent: PrimerSessionIntent = PrimerSessionIntent(rawValue: primerSessionIntent)
      else {
        let err = RNTNativeError(
          errorId: "native-ios",
          errorDescription: "Invalid value for 'intent'.",
          recoverySuggestion: "'intent' can be 'CHECKOUT' or 'VAULT'.")
        throw err
      }
      #if canImport(PrimerKlarnaSDK)
        klarnaComponent = try klarnaManager.provideKlarnaComponent(with: sessionIntent)
        klarnaComponent?.stepDelegate = self
        klarnaComponent?.errorDelegate = self
        klarnaComponent?.validationDelegate = self
      #else
        let err = RNTNativeError(
          errorId: "native-ios",
          errorDescription: "PrimerKlarnaSDK missing",
          recoverySuggestion: "Check if PrimerKlarnaSDK is included in your Podfile")

        throw err
      #endif

      resolver(nil)
    } catch {
      rejecter(error.rnError["errorId"]!, error.rnError["description"], error)
    }
  }

  @objc
  public func cleanUp(
    _ resolver: RCTPromiseResolveBlock,
    rejecter: RCTPromiseRejectBlock
  ) {
    klarnaComponent = nil
    resolver(nil)
  }

  @objc
  public func start(
    _ resolver: RCTPromiseResolveBlock,
    rejecter: RCTPromiseRejectBlock
  ) {
    print("Start Klarna process")

    guard let klarnaComponent = self.klarnaComponent else {
      rejecter("UNINITIALIZED_ERROR", "Klarna component is uninitialized", nil)
      return
    }

    klarnaComponent.start()
    resolver(nil)
  }

  @objc
  public func submit(
    _ resolver: RCTPromiseResolveBlock,
    rejecter: RCTPromiseRejectBlock
  ) {
    guard let klarnaComponent = self.klarnaComponent else {
      rejecter("UNINITIALIZED_ERROR", "Klarna component is uninitialized", nil)
      return
    }

    klarnaComponent.submit()
    resolver(nil)
  }

  @objc
  public func onSetPaymentOptions(
    _ paymentOptions: NSDictionary,
    resolver: RCTPromiseResolveBlock,
    rejecter: RCTPromiseRejectBlock
  ) {
    guard let paymentCategoryDict = paymentOptions["paymentCategory"] as? NSDictionary else {
      rejecter("error", "paymentCategory is missing or not a dictionary", nil)
      return
    }

    guard let klarnaPaymentCategory = getDecodedKlarnaPaymentCategory(paymentCategoryDict) else {
      rejecter("error", "Failed to parse paymentCategory", nil)
      return
    }

    guard let klarnaComponent = self.klarnaComponent else {
      rejecter("UNINITIALIZED_ERROR", "Klarna component is uninitialized", nil)
      return
    }

    DispatchQueue.main.async {
      klarnaComponent.updateCollectedData(
        collectableData: KlarnaCollectableData.paymentCategory(
          klarnaPaymentCategory, clientToken: self.clientToken)
      )
    }

    resolver(nil)
  }

  @objc
  public func onFinalizePayment(
    _ resolver: RCTPromiseResolveBlock,
    rejecter: RCTPromiseRejectBlock
  ) {
    klarnaComponent?.updateCollectedData(collectableData: KlarnaCollectableData.finalizePayment)
    resolver(nil)
  }

  private func getDecodedKlarnaPaymentCategory(_ dictionary: NSDictionary) -> KlarnaPaymentCategory? {
    let transformedDictionary = transformKey(for: dictionary)
    guard
      let jsonData = try? JSONSerialization.data(withJSONObject: transformedDictionary, options: [])
    else { return nil }
    let paymentCategory = try? JSONDecoder().decode(KlarnaPaymentCategory.self, from: jsonData)
    return paymentCategory
  }

  private func transformKey(for dictionary: NSDictionary) -> [String: Any] {
    let transformedDictionary = dictionary.reduce(into: [String: Any]()) { (result, element) in
      // Check if the current key is "identifier" and change it to "id", otherwise keep the original key
      let key: String =
        (element.key as? String) == "identifier" ? "id" : (element.key as? String) ?? ""
      result[key] = element.value
    }

    return transformedDictionary
  }
}

extension RNTPrimerHeadlessUniversalCheckoutKlarnaComponent: PrimerHeadlessSteppableDelegate {
  func didReceiveStep(step: PrimerSDK.PrimerHeadlessStep) {
    guard let step = step as? KlarnaStep else { return }

    switch step {
    case .paymentSessionCreated(let clientToken, let categories):
      self.clientToken = clientToken
      let rnSessionCreated = try? step.toPaymentSessionCreatedRN(categories: categories)
        .toJsonObject()

      sendEvent(
        withName: PrimerHeadlessUniversalCheckoutComponentEvent.onStep.stringValue,
        body: rnSessionCreated
      )

    case .paymentSessionAuthorized(_, let checkoutData):
      let rnSessionAuthorized = try? step.toPaymentSessionAuthorizedRN(isFinalized: true)
        .toJsonObject()

      sendEvent(
        withName: PrimerHeadlessUniversalCheckoutComponentEvent.onStep.stringValue,
        body: rnSessionAuthorized
      )

      DispatchQueue.main.async {
        PrimerHeadlessUniversalCheckout.current.delegate?
          .primerHeadlessUniversalCheckoutDidCompleteCheckoutWithData(checkoutData)
      }

    case .paymentSessionFinalizationRequired:
      let rnSessionAuthorized = try? step.toPaymentSessionAuthorizedRN(isFinalized: false)
        .toJsonObject()

      sendEvent(
        withName: PrimerHeadlessUniversalCheckoutComponentEvent.onStep.stringValue,
        body: rnSessionAuthorized
      )

    case .paymentSessionFinalized(_, let checkoutData):
      let rnSessionFinalized = try? step.toPaymentSessionFinalizedRN().toJsonObject()

      sendEvent(
        withName: PrimerHeadlessUniversalCheckoutComponentEvent.onStep.stringValue,
        body: rnSessionFinalized
      )

      DispatchQueue.main.async {
        PrimerHeadlessUniversalCheckout.current.delegate?
          .primerHeadlessUniversalCheckoutDidCompleteCheckoutWithData(checkoutData)
      }

    case .viewLoaded(let view):
      DispatchQueue.main.async {
        RNTPrimerKlarnaPaymentViewManager.updatePrimerKlarnaPaymentView(view)
      }

      let rnPaymentViewLoaded = try? step.toPaymentViewLoadedRN().toJsonObject()

      sendEvent(
        withName: PrimerHeadlessUniversalCheckoutComponentEvent.onStep.stringValue,
        body: rnPaymentViewLoaded
      )

    default:
      break
    }

  }
}

// swiftlint:disable todo
extension RNTPrimerHeadlessUniversalCheckoutKlarnaComponent: PrimerHeadlessValidatableDelegate {
  func didUpdate(
    validationStatus: PrimerSDK.PrimerValidationStatus, for data: PrimerSDK.PrimerCollectableData?
  ) {
    guard let data = data as? KlarnaCollectableData else { return }

    let eventName: String
    switch validationStatus {
    case .valid:
      eventName = PrimerHeadlessUniversalCheckoutComponentEvent.onValid.stringValue
    case .validating:
      eventName = PrimerHeadlessUniversalCheckoutComponentEvent.onValidating.stringValue
    case .invalid(let errors):
      let rnErrors = errors.map { $0.toPrimerValidationErrorRN() }
      let serializedData = try? ["errors": rnErrors].toJsonObject()  // TODO TWS iOS: include 'data'

      self.sendEvent(
        withName: PrimerHeadlessUniversalCheckoutComponentEvent.onInvalid.stringValue,
        body: serializedData)
      return
    case .error(let error):
      let rnError = error.toPrimerErrorRN()
      let serializedData = try? ["errors": [rnError]].toJsonObject()  // TODO TWS iOS: include 'data'

      self.sendEvent(
        withName: PrimerHeadlessUniversalCheckoutComponentEvent.onValidationError.stringValue,
        body: serializedData)
      return
    }

    var serializedData: Any?
    switch data {
    case .paymentCategory(let category, _):
      let rnPaymentCategory = data.toKlarnaPaymentOptionsRN(category: category)
      serializedData = try? ["data": rnPaymentCategory].toJsonObject()
    case .finalizePayment:
      let rnFinalizePayment = data.toFinalizePaymentRN()
      serializedData = try? ["data": rnFinalizePayment].toJsonObject()
    }

    sendEvent(withName: eventName, body: serializedData)
  }
}
// swiftlint:enable todo

extension RNTPrimerHeadlessUniversalCheckoutKlarnaComponent: PrimerHeadlessErrorableDelegate {
  func didReceiveError(error: PrimerSDK.PrimerError) {
    let rnError = error.toPrimerErrorRN()
    let serializedData = try? ["errors": [rnError]].toJsonObject()

    self.sendEvent(
      withName: PrimerHeadlessUniversalCheckoutComponentEvent.onError.stringValue,
      body: serializedData)
  }
}