//
//  SwapControllerMain.swift
//  Wallet
//
//  Created by Saveliy Stavitsky on 3/1/21.
//  Copyright © 2021 AM. All rights reserved.
//

import UIKit
import WalletFoundation

//https://www.hackingwithswift.com/example-code/language/how-to-split-an-array-into-chunks
extension Array {
    func chunked(into size: Int) -> [[Element]] {
        return stride(from: 0, to: count, by: size).map {
            Array(self[$0 ..< Swift.min($0 + size, count)])
        }
    }
}

class SwapControllerMain: UIViewController {

    let service = Swap.Service.Pools()

    @IBOutlet private weak var tokenGiveView: CommonViewCard!
    @IBOutlet private weak var tokenGetStackView: UIStackView!
    @IBOutlet private weak var changeTokensButton: UIButton!
    @IBOutlet private weak var tokenGetView: CommonViewCard!

    @IBOutlet private weak var conversionRateStackView: UIStackView!
    @IBOutlet private weak var forwardConversionRate: UILabel!
    @IBOutlet private weak var backwardConversionRate: UILabel!

    @IBOutlet private weak var conversionFieldsStackView: UIStackView!
    @IBOutlet private weak var amount1TextField: CommonTextField!
    @IBOutlet private weak var amount2TextField: CommonTextField!

    @IBOutlet private weak var minimumTextField: CommonTextField!

    @IBOutlet private weak var routeContainerView: UIView!
    @IBOutlet private weak var routeStackView: UIStackView!
    @IBOutlet private weak var routeTokensStackView: UIStackView!

    @IBOutlet var swapButton: CommonButtonAction!

    override func viewDidLoad() {
        super.viewDidLoad()

        self.title = L10n.Swap.Main.title
        self.navigationItem.leftBarButtonItem = .pop(self)
        tabBarItem.title = L10n.Swap.Main.TabBar.title

        tokenGiveView.action = .cards(collection: nil)
        tokenGetView.action = .cards(collection: nil)

        for textField in [amount1TextField, amount2TextField, minimumTextField] {
            textField?.delegate = self
            textField?.keyboardType = .decimalPad
        }

        swapButton.isEnabled = false

        service.didUpdate = { [weak self] in
            self?.setupTokensViews()
        }
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        Accounts().isLocked = true
        service.tokenGive = nil
        service.tokenGet = nil
        setupTokensViews()
        service.fetch {
            Alert.error($0)
        }

        self.navigationController >>- {
            $0.navigationBar.isTranslucent = false
            $0.setNavigationBarHidden(false, animated: true)
        }
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        Accounts().isLocked = false
    }

    func setupTokensViews() {
        if service.showPreselectError {
            service.showPreselectError = false
            Popup.show(title: L10n.Swap.Main.PreselectToken.errorTitle,
                       text: L10n.Swap.Main.PreselectToken.errorText,
                       submit: L10n.Common.Button.understand)
        }

        tokenGiveView.action = .cards(
            tokens: service.tokensFrom,
            selected: service.tokenGive,
            empty: .menu(
                image: Asset.commonToken.image.tinted(with: Asset.deepWater.color),
                title: L10n.Swap.Main.TokenGive.titleCard), { [weak self] in
            self?.service.tokenGive = self?.service.tokensFrom.object(menu: $0)
            self?.amount1TextField.precision = self?.service.tokensFrom.object(menu: $0)?.precision
            self?.setupTokensViews()
        })

        tokenGetStackView.isHidden = service.tokenGive == nil
        tokenGetView.action = .cards(
            tokens: service.tokensTo,
            selected: service.tokenGet,
            empty: .menu(
                image: Asset.commonToken.image.tinted(with: Asset.deepWater.color),
                title: L10n.Swap.Main.TokenGet.titleCard), { [weak self] in
            self?.service.tokenGet = self?.service.tokensTo.object(menu: $0)
            self?.amount2TextField.precision = self?.service.tokensTo.object(menu: $0)?.precision
            self?.minimumTextField.precision = self?.service.tokensTo.object(menu: $0)?.precision
            self?.setupTokensViews()
        })

        changeTokensButton.isHidden = service.tokenGive == nil || service.tokenGet == nil
        minimumTextField.isHidden = service.amountSend.isEmpty || service.amountReceive.isEmpty
        conversionRateStackView.isHidden = tokenGetStackView.isHidden || service.tokenGet == nil
        conversionFieldsStackView.isHidden = conversionRateStackView.isHidden
        routeContainerView.isHidden = service.tokenGive == nil || service.tokenGet == nil
        routeStackView.isHidden = service.tokenGive == nil || service.tokenGet == nil

        guard let tokenGive = service.tokenGive, let tokenGet = service.tokenGet else {
            return
        }
        let processAmount = service.amountSend.toOptionalDecimal() != nil
            ? service.processRate(amount: service.amountSend.toDecimal()) / service.amountSend.toDecimal()
            : service.processRate(amount: 1.0)
        forwardConversionRate.lzText = "\(Decimal(1).toString(precision: tokenGive)) ≈ \(processAmount.toString(precision: tokenGet))"
        backwardConversionRate.lzText = "(\(Decimal(1).toString(precision: tokenGet)) ≈ \((1 / processAmount).toString(precision: tokenGive)))"

        let giveImage = UIImageView(token: tokenGive)
        giveImage.addHeightWidthConstraints(height: 24, width: 24)
        amount1TextField.accessoryView = giveImage
        amount1TextField.value = service.amountSend
        amount1TextField.error = service.amountSendError

        let getImage = UIImageView(token: tokenGet)
        getImage.addHeightWidthConstraints(height: 24, width: 24)
        amount2TextField.accessoryView = getImage
        amount2TextField.value = service.amountReceive
        amount2TextField.error = service.amountReceiveError

        minimumTextField.value = service.amountMinimum
//        minimumTextField.error = service.amountMinimumShowError ? L10n.Swap.Main.Minimum.error : nil

        routeTokensStackView.arrangedSubviews.forEach({ $0.removeFromSuperview() })

        for tokensChunk in service.route.chunked(into: (Int(UIScreen.main.bounds.width) - 32) / 85) {
            let stackViewLine = UIStackView(subviews: [], axis: .horizontal, distribution: .fill, alignment: .center, spacing: 0)
            for token in tokensChunk {
                let image = UIImageView(token: token)
                image.addHeightWidthConstraints(height: 32, width: 32)
                let label = UILabel()
                label.font = UIFont.font(style: .medium, size: 10)
                label.textColor = Asset.textCoal.color
                label.textAlignment = .center
                label.text = token.symbol
                label.addHeightWidthConstraints(height: 12, width: 65)
                let stack = UIStackView(subviews: [image, label], axis: .vertical, distribution: .fill, alignment: .center, spacing: 2)
                stackViewLine.addArrangedSubview(stack)

                let imageArrow = UIImageView(image: Asset.commonArrowRight.image)
                imageArrow.addHeightWidthConstraints(height: 20, width: 20)
                stackViewLine.addArrangedSubview(imageArrow)
            }
            routeTokensStackView.addArrangedSubview(stackViewLine)
        }
        (routeTokensStackView.arrangedSubviews.last as? UIStackView)?
            .arrangedSubviews.last?.removeFromSuperview()

        swapButton.isEnabled = !amount1TextField.value.isEmpty && !amount2TextField.value.isEmpty
            && service.amountSendError == nil && service.amountReceiveError == nil
            && service.amountSend.toDecimal() > 0 && service.amountReceive.toDecimal() > 0
//            && (service.amountMinimum ?? 0) > 0
    }
    
    @IBAction func changeTokensPressed(_ sender: Any) {
        if let tokenGive = service.tokenGive, let tokenGet = service.tokenGet {
            service.tokenGive = tokenGet
            amount1TextField.precision = tokenGet.precision

            service.tokenGet = tokenGive
            amount2TextField.precision = tokenGive.precision
            minimumTextField.precision = tokenGive.precision

            service.preselectTokenGive = nil

            setupTokensViews()
        }
    }

    @IBAction func swapPressed(_ sender: Any) {
        view.endEditing(true)
        guard let tokenGive = service.tokenGive, let tokenGet = service.tokenGet else {
            return
        }

        let amountSend = service.amountSend.toDecimal().toString(max: tokenGive)
        let amountReceive = service.amountReceive.toDecimal().toString(max: tokenGet)

        var views: [UIView] = [
            .label(
                text: L10n.Swap.Main.Confirmation.description
                    .attributed(style: .regular, size: 14, color: Asset.textCoal.color),
                numberOfLines: 0
            ),
            .field(
                title: L10n.Swap.Main.Confirmation.give,
                text: amountSend
            ),
            .field(
                title: L10n.Swap.Main.Confirmation.get,
                text: amountReceive
            )
        ]
        if let amountMinimum = service.amountMinimum.toOptionalDecimal() {
            views.append(
                .field(
                    title: L10n.Swap.Main.Confirmation.minimum,
                    titleStyle: "regular_16",
                    titleColor: Asset.textPebble.color,
                    text: amountMinimum.toString(max: tokenGet),
                    textStyle: "regular_16", textColor: Asset.textPebble.color
                )
            )
        }
        Popup.show(title: L10n.Common.Title.confirmation, views: views, submit: L10n.Common.Button.confirm, in: self) { ctrl in
            AccountViewAuthorize.showGetPrivateKey(in: self) { [weak self] in
                Loader.show(in: ctrl)
                self?.service.submit(privateKey: $0) { [weak self] (result) in
                    guard let self = self else { return }
                    Loader.hide(in: ctrl)
                    ctrl.dismiss(animated: true)
                    switch result {
                    case .success(let transactionId):
                        self.showSuccessfulPopup(amountSend: amountSend, amountReceive: amountReceive, transactionId: transactionId,
                        completion: {
                            self.clear()
                            self.service.tokenGet = self.service.getToken(tokenGet)
                            self.service.tokenGive = self.service.getToken(tokenGive)
                            self.service.fetch({ _ in })
                        })

                    case let .failure(error):
                        Alert.notify(error, pop: self)
                    }
                }
            }
        }
    }

    private func clear() {
        amount1TextField.value = .init()
        amount2TextField.value = .init()
        minimumTextField.value = .init()
        service.update(send: "")
        service.update(receive: "")
        service.update(minimum: "")
    }
}

extension SwapControllerMain: CommonTextFieldDelegate {

    func textField(_ textField: CommonTextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        let newString = (textField.value as NSString).replacingCharacters(in: range, with: string)
        switch textField {
        case amount1TextField:
            if let precision = service.tokenGive?.precision,
               newString.precision > precision {
                return false
            }
        case amount2TextField:
            if let precision = service.tokenGet?.precision,
               newString.precision > precision {
                return false
            }
        case minimumTextField:
            if let precision = service.tokenGet?.precision,
               newString.precision > precision {
                return false
            }
        default:
            break
        }
        return true
    }

    func textFieldDidChange(_ textField: CommonTextField) {
        switch textField {
        case amount1TextField:
            textField.value = textField.value.replacingOccurrences(of: ",", with: ".")
            let newPosition = textField.textField.endOfDocument
            textField.textField.selectedTextRange = textField.textField.textRange(from: newPosition, to: newPosition)
            service.update(send: textField.value)
        case amount2TextField:
            textField.value = textField.value.replacingOccurrences(of: ",", with: ".")
            let newPosition = textField.textField.endOfDocument
            textField.textField.selectedTextRange = textField.textField.textRange(from: newPosition, to: newPosition)
            service.update(receive: textField.value)
        case minimumTextField:
            textField.value = textField.value.replacingOccurrences(of: ",", with: ".")
            let newPosition = textField.textField.endOfDocument
            textField.textField.selectedTextRange = textField.textField.textRange(from: newPosition, to: newPosition)
            service.update(minimum: textField.value)
        default:
            break
        }
    }
}

extension SwapControllerMain {
    fileprivate func showSuccessfulPopup(amountSend: String,
                                         amountReceive: String,
                                         transactionId: String,
                                         completion: @escaping () -> Void) {
        let views: [UIView] = [
            .field(
                title: L10n.Swap.Main.Success.give,
                text: amountSend
            ),
            .field(
                title: L10n.Swap.Main.Success.get,
                text: amountReceive
            ),
            .field(
                title: L10n.Swap.Main.Success.id,
                text: transactionId,
                rightButtonAvailbale: true,
                rightButtonImage: Asset.commonCopy.image,
                rightButtonAction: {
                    Alert.copy(transactionId)
                }
            )
        ]

        Popup.show(title: L10n.Swap.Main.Success.title, views: views, submit: L10n.Common.Button.checkOnBloksIO, submitStyle: .outline, cancel: L10n.Common.Button.done, in: self, { ctrl in
            guard let checkTransactionUrl = URL(transactionId: transactionId) else { return }

            UIApplication.shared.open(checkTransactionUrl, options: [:], completionHandler: nil)
        }, {
            completion()
        })
    }
}