//
//  ExchangeCryptocashViewController.swift
//  PayCash
//
//  Created by Saveliy Stavitsky on 9/3/22.
//  Copyright © 2022 AM. All rights reserved.
//

import UIKit

final class ExchangeCryptocashViewController: UIViewController {
    
    typealias FetchCompletion = () -> Void

    private var tokenUSDT = Network.Model.Token(
        symbol: "USDT", precision: 4, amount: 100, contract: ""
    )

    private var tokenOut = Network.Model.Token(
        symbol: "USDCASH", precision: 5, amount: 100, contract: ApplicationEnvironment.shared().current.contract(.cash)
    )
    
    private var p2pTokenscollection = [Network.Model.Token]()
    private var walletP2pTokenscollection: [Network.Model.Token] {
        self.p2pTokenscollection.compactMap { Wallet.Service.Tokens.shared.balances.collection.first($0) }
    }
    
    private var selectedToken: Network.Model.Token? {
        didSet {
            self.amountTextField.isHidden = !self.selectedToken.isExist

            let messages = [
                L10n.ExchangeCryptocashViewController.Amount.error2,
                L10n.ExchangeCryptocashViewController.Amount.error3
            ]
            
            if messages.contains(where: { $0 == self.amountTextField.error }) {
                self.amountTextField.error = nil
            }
            
            self.view.endEditing(true)
            self.amountTextField.value = ""
            self.infoAmountsStackView.arrangedSubviews.forEach { $0.removeFromSuperview() }

            if let selectedToken = self.selectedToken {
                
                self.amountTextField.lzText = L10n.ExchangeCryptocashViewController.Amount.info
                + (p2pTokenscollection.first(selectedToken)?.certCoef ?? 0)
                    .toReadebleString(precisionMax: selectedToken.precision, symbol: selectedToken.symbol, group: true)
                
                let lImage = UIImageView(token: selectedToken)
                lImage.addHeightWidthConstraints(height: 24, width: 24)
                self.amountTextField.accessoryView = lImage
                self.amountTextField.precision = selectedToken.precision
                
                self.amountTextField.becomeFirstResponder()
            }
        }
    }

    private var deposits = [Deposit]()
    private func calcMLNKViaDeposits(amount: Decimal) -> Decimal {
        var tempAmount = amount * tokenUSDT.amount
        var tempMLNK = Decimal(0)
        for deposit in deposits {
            if tempAmount <= 0 {
                break
            }
            if deposit.usdt_in.amount.toDecimal() <= tempAmount {
                tempMLNK += deposit.mlnk_in.amount.toDecimal()
                tempAmount -= deposit.usdt_in.amount.toDecimal()
            } else {
                tempMLNK += tempAmount * (deposit.mlnk_in.amount.toDecimal() / deposit.usdt_in.amount.toDecimal())
                tempAmount -= tempAmount
            }
        }
        return tempMLNK
    }

    @IBOutlet private weak var tokeGiveView: CommonViewCard!
    @IBOutlet private weak var explanationStackView: UIStackView!
    @IBOutlet private weak var amountTextField: CommonTextField!
    @IBOutlet private weak var infoAmountsStackView: UIStackView!
    @IBOutlet private weak var warningView: CommonViewWarning!

    @IBOutlet var swapButton: CommonButtonAction!

    override func viewDidLoad() {
        super.viewDidLoad()

        self.title = L10n.ExchangeCryptocashViewController.title
        self.navigationItem.leftBarButtonItem = .pop(self)

        for textField in [self.amountTextField] {
            textField?.delegate = self
            textField?.keyboardType = .decimalPad
        }
        self.amountTextField.lzPlaceholder = L10n.ExchangeCryptocashViewController.Amount.placeholder
        self.amountTextField.lzTitle = L10n.ExchangeCryptocashViewController.Amount.title

        self.swapButton.isEnabled = false
        self.swapButton.isUserInteractionEnabled = false
        
        self.warningView.lzText = L10n.ExchangeCryptocashViewController.warning
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        Accounts().isLocked = true

        self.fetchData(animated)
    }

    private func fetchData(_ animated: Bool) {
        
        self.fetchSwap {
            self.fetchSwapBack(animated: animated) { [weak self] in
                self?.fetchDeposit(animated: animated)
            }
        }
    }
    
    private func fetchSwap(_ completion: @escaping FetchCompletion) {
        
        struct Income: Codable {
            let income: Network.Model.TokenSmall
        }

        Network.table.fetch(
            code: ApplicationEnvironment.shared().current.contract(.cash),
            table: "swap1",
            scope: ApplicationEnvironment.shared().current.contract(.cash),
            type: Income.self
        ) { [weak self] in
            if let token = $0.map({ $0.income }).first?.asToken {
                self?.tokenUSDT = token
            }
            
            completion()
        }
        
    }
    
    private func fetchSwapBack(animated: Bool, _ completion: @escaping FetchCompletion) {
        
        struct CashToken: Codable {
            private let cash: String

            var symbol: String { String(cash.split(separator: " ").last!) }
            var precision: Int { cash.amount.precision }
            var coef: Decimal { cash.amount.toDecimal() }

            func asNetworkToken() -> Network.Model.Token {
                .init(symbol: symbol,
                      precision: precision,
                      amount: 0,
                      contract: ApplicationEnvironment.shared().current.contract(.cash),
                      certCoef: coef,
                      certName: "")
            }
        }

        Network.table.fetch(
            code: ApplicationEnvironment.shared().current.contract(.cash),
            table: "swapback",
            scope: ApplicationEnvironment.shared().current.contract(.cash),
            type: CashToken.self) { [weak self] rows in
                guard let self = self else { return }
                self.p2pTokenscollection = rows.map({ $0.asNetworkToken() })
                if !self.p2pTokenscollection.isEmpty {
                    self.tokeGiveView.action = .cards(
                        tokens: self.walletP2pTokenscollection,
                        selected: self.selectedToken,
                        empty: .menu(
                            image: Asset.commonToken.image.tinted(with: Asset.deepWater.color),
                            title: L10n.ExchangeCryptocashViewController.Cryptocash.placeholder
                        ),
                        title: L10n.ExchangeCryptocashViewController.Cryptocash.placeholder, {
                            self.selectedToken = self.walletP2pTokenscollection.object(menu: $0)
                        }
                    )
                } else {
                    self.navigationController?.popViewController(animated: animated)
                }
                
                completion()
            }
        
    }
    
    private func fetchDeposit(animated: Bool) {
        
        Network.table.fetch(
            code: ApplicationEnvironment.shared().current.contract(.cash),
            table: "deposits",
            scope: ApplicationEnvironment.shared().current.contract(.cash),
            keyType: "i128",
            indexPosition: "2",
            type: Deposit.self
        ) { [weak self] deposits in
            self?.deposits = deposits
            if deposits.isEmpty {
                self?.navigationController?.popViewController(animated: animated)
            }
        }
        
    }

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

    @IBAction private func onAccountType(_ : AnyObject?) {
        guard let selectedToken = self.selectedToken,
                let coef = p2pTokenscollection.first(selectedToken)?.certCoef,
                amountTextField.value.toDecimal() / coef == (amountTextField.value.toDecimal() / coef).roundUp(to: 0),
                amountTextField.value.toDecimal() > 0 else {
            return
        }
        infoAmountsStackView.arrangedSubviews.forEach { $0.removeFromSuperview() }

        if let coef = p2pTokenscollection.first(selectedToken)?.certCoef {
            infoAmountsStackView.insertArrangedSubview(
                .field(
                    title: L10n.ExchangeCryptocashViewController.Get.title,
                    text: (tokenUSDT.amount * (amountTextField.value.toDecimal() / coef)).toString(max: tokenUSDT)
                ), at: 0)

            infoAmountsStackView.insertArrangedSubview(
                .field(
                    title: L10n.ExchangeCryptocashViewController.Return.title,
                    text: amountTextField.value.toDecimal().toString(max: selectedToken)
                ), at: 0)
        }
    }

    @IBAction func swapPressed(_ sender: Any) {
        view.endEditing(true)

        guard let selectedToken = self.selectedToken, let coef = p2pTokenscollection.first(selectedToken)?.certCoef else {
            return
        }

        let views: [UIView] = [
            .field(
                title: L10n.ExchangeCryptocashViewController.Popup1.title1,
                text: amountTextField.value.toDecimal().toString(max: selectedToken)
            ),
            .field(
                title: L10n.ExchangeCryptocashViewController.Popup1.title2,
                text: (tokenUSDT.amount * (amountTextField.value.toDecimal() / coef)).toString(max: tokenUSDT)
            )
        ]
        Popup.show(title: L10n.ExchangeCryptocashViewController.Popup1.title, views: views, submit: L10n.Common.Button.confirm, in: self) { ctrl in
            AccountViewAuthorize.showGetPrivateKey(in: self) { privateKey in
                Loader.show(in: ctrl)

                var actions = [(contract: String, action: Network.Model.Blockchain.Action, data: Codable)]()

                let returnToken = self.tokenUSDT
                if !Wallet.Service.Tokens.shared.balances.collection.contains(returnToken) {
                    actions.append(
                        (contract: returnToken.contract,
                        action: .open,
                        data: [
                            "owner": Accounts().current?.name ?? "",
                            "symbol": "\(returnToken.precision),\(returnToken.symbol)",
                            "ram_payer": Accounts().current?.name ?? ""
                        ])
                    )
                }

                actions.append(
                    (contract: selectedToken.contract,
                     action: .transfer,
                     data: [
                        "from": Accounts().current?.name ?? "",
                        "to": ApplicationEnvironment.shared().current.contract(.cash),
                        "quantity": "\(self.amountTextField.value.toDecimal().toString(precision: selectedToken))",
                        "memo": returnToken.symbol.lowercased()
                     ]))
                Network.Service.Blockchain.execute(actions: actions, privateKeys: [privateKey]) { (result) in
                    ctrl.dismiss(animated: true)

                    if case let .success(trxId) = result {
                        self.showCompletion(transactionId: trxId)
                        delayed(3) { Wallet.Service.Tokens.shared.balances.fetch() }
                    } else {
                        Alert.notify(result.error)
                    }
                }
            }
        }
    }

    private func showCompletion(transactionId: String) {
        guard let selectedToken = self.selectedToken, let coef = p2pTokenscollection.first(selectedToken)?.certCoef else {
            return
        }

        let views: [UIView] = [
            .field(
                title: L10n.ExchangeCryptocashViewController.Popup2.title1,
                text: amountTextField.value.toDecimal().toString(max: selectedToken)
            ),
            .field(
                title: L10n.ExchangeCryptocashViewController.Popup2.title2,
                text: (tokenUSDT.amount * (amountTextField.value.toDecimal() / coef)).toString(max: tokenUSDT)
            ),
            .field(
                title: L10n.Wallet.History.Details.id,
                text: transactionId,
                rightButtonAvailbale: true,
                rightButtonImage: Asset.commonCopy.image,
                rightButtonAction: {
                    Alert.copy(transactionId)
                }
            )
        ]
        Popup.show(title: L10n.ExchangeCryptocashViewController.Popup2.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)
        }, {
            self.navigationController?.popViewController(animated: true)
        })
    }

}

extension ExchangeCryptocashViewController: CommonTextFieldDelegate {

    func textFieldDidChange(_ textField: CommonTextField) {
        switch textField {

        case amountTextField:
            textField.value = textField.value.replacingOccurrences(of: ",", with: ".")
            let newPosition = textField.textField.endOfDocument
            textField.textField.selectedTextRange = textField.textField.textRange(from: newPosition, to: newPosition)

            infoAmountsStackView.arrangedSubviews.forEach { $0.removeFromSuperview() }
            if let selectedToken = self.selectedToken,
               let coef = p2pTokenscollection.first(selectedToken)?.certCoef,
               amountTextField.value.toDecimal() / coef == (amountTextField.value.toDecimal() / coef).roundUp(to: 0),
               amountTextField.value.toDecimal() > (selectedToken.symbol.uppercased() == "USDCASH" ? 9999 : 0),
               amountTextField.value.toDecimal() <= selectedToken.amount {
                swapButton.isEnabled = true
                swapButton.isUserInteractionEnabled = true

                infoAmountsStackView.insertArrangedSubview(
                    .field(
                        title: L10n.ExchangeCryptocashViewController.Get.title,
                        text: (tokenUSDT.amount * (amountTextField.value.toDecimal() / coef)).toString(max: tokenUSDT)
                    ), at: 0)

                infoAmountsStackView.insertArrangedSubview(
                    .field(
                        title: L10n.ExchangeCryptocashViewController.Return.title,
                        text: amountTextField.value.toDecimal().toString(max: selectedToken)
                    ), at: 0)
            } else {
                swapButton.isEnabled = false
                swapButton.isUserInteractionEnabled = false
                
                if (selectedToken?.amount ?? 0) < amountTextField.value.toDecimal() { 
                    amountTextField.error = L10n.ExchangeCryptocashViewController.Amount.error3
                } else if amountTextField.value.toDecimal() > 0 {
                    amountTextField.error = amountTextField.lzText
                } else {
                    amountTextField.error = nil
                }
            }

        default:
            break
        }
    }
}