//
//  PaymentsVC.swift
//  wallet
//
//  Created by Adriana Epure on 22.08.2022.
//  Copyright © 2022 Jason. All rights reserved.
//

import UIKit
import QRCodeScanner

class PaymentsVC: CustomViewController<PaymentsViewModel> {

    @IBOutlet weak var paymentElements: UIStackView!
    @IBOutlet weak var selectedListControl: UISegmentedControl!
    @IBOutlet weak var tableView: UITableView!
    @IBOutlet weak var paymentButtonsStack: UIStackView!
    @IBOutlet weak var localBalanceValue: UILabel!
    @IBOutlet weak var remoteBalanceValue: UILabel!
    @IBOutlet weak var walletBalanceValue: UILabel!
    @IBOutlet weak var estimateFeeValue: UILabel!
    
    @IBOutlet weak var feeStackView: UIStackView!
        //Send
    @IBOutlet weak var sendStackView: UIStackView!
    @IBOutlet weak var sendPaymentAddress: UITextView!
    @IBOutlet weak var payBtn: UIButton!
    @IBOutlet weak var paymentInfoStack: UIStackView!
    @IBOutlet weak var paymentInfoLbl: UILabel!
    @IBOutlet weak var memoLbl: UILabel!
    @IBOutlet weak var paymentInfoCreated: UILabel!
    @IBOutlet weak var paymentInfoExpiry: UILabel!
    @IBOutlet weak var cancelPayBtn: UIButton!
    
    
    //Receive
    @IBOutlet weak var receiveStackView: UIStackView!
    @IBOutlet weak var invoiceAmount: UITextField!
    @IBOutlet weak var invoiceComment: UITextField!
    @IBOutlet weak var amountStepper: UIStepper!
    @IBOutlet weak var receivePaymentAddress: UITextView!
    @IBOutlet weak var generateInvoiceBtn: UIButton!
    @IBOutlet weak var cancelReceiveBtn: UIButton!
    
    
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        viewModel.getInfo()
        title = "Payments"
        tableView.delegate = self
        tableView.dataSource = self
        selectedListControl.selectedSegmentIndex == 0 ? viewModel.listPayments() : viewModel.listInvoices()
    }
    override func viewModelDidLoad() {
        viewModel.invoices.observe = { [weak self] invoices in
            self?.tableView.reloadData()
        }
        viewModel.payments.observe = { [weak self] payments in
            self?.tableView.reloadData()
        }
        viewModel.channelBalance.observe = { [weak self] balance in
            self?.localBalanceValue.text = String(balance)
        }
        viewModel.walletBalance.observe = { [weak self] walletBalance in
            self?.walletBalanceValue.text = String(walletBalance.total)
        }
        viewModel.isLoading.observe = { [weak self] isLoading in
            self?.viewModel.updateBalance()
        }
        viewModel.paymentInfo.observe = { [weak self] paymentInfo in
            if let paymentInfo = paymentInfo{
                self?.paymentInfoStack.isHidden = false
                self?.payBtn.isHidden = false
                self?.paymentInfoLbl.text = String(paymentInfo.numSatoshis)
                self?.paymentInfoCreated.text = paymentInfo.timestamp.getAsDate().format(style: .medium)
                self?.paymentInfoExpiry.text = String(paymentInfo.timestamp.getAsDate().adding(seconds: Int(paymentInfo.expiry)).format(style: .medium))
                self?.memoLbl.text = String(paymentInfo.description_p)
            }else{
                self?.paymentInfoStack.isHidden = true
                self?.payBtn.isHidden = true
                self?.paymentInfoCreated.text = ""
                self?.paymentInfoLbl.text = ""
                self?.paymentInfoExpiry.text = ""
                self?.memoLbl.text = ""
            }
        }
        viewModel.load()
        
    }
    
//MARK: - Selection
    @IBAction func didChangeSelection(_ sender: Any) {
        selectedListControl.selectedSegmentIndex == 0 ? viewModel.listPayments() : viewModel.listInvoices()
        tableView.reloadData()
    }
    
    @IBAction func didPressCancel(_ sender: Any) {
        showHideViews(isSending: !sendStackView.isHidden, isFinished: true)
    }
    
//MARK: - Send
    @IBAction func didPressSend(_ sender: Any) {
        sendPaymentAddress.text = "Input Address ..."
        sendPaymentAddress.textColor = UIColor.lightGray
        sendPaymentAddress.delegate = self
        sendPaymentAddress.layer.borderColor = UIColor.lightGray.cgColor
        sendPaymentAddress.layer.borderWidth = 1
        showHideViews(isSending: true, isFinished: false)
    }
    
    @IBAction func didPressScan(_ sender: Any) {
        
            // Create an instance of QRCodeScanViewController
        let viewController = QRCodeScanViewController.create()
        
            // Set itself as delegate
        viewController.delegate = self
        
            // Present the view controller
        self.present(viewController, animated: true)
    }
    @IBAction func didPressPay(_ sender: Any) {
        
        self.selectedListControl.selectedSegmentIndex = 0
        self.selectedListControl.sendActions(for: .valueChanged)
        if let paymentAddress = sendPaymentAddress.text{
            debugPrint("Invoice ", paymentAddress)
            self.viewModel.payInvoice(invoice: paymentAddress) { response in
                self.showAlert(title: "Payment", errorMsg: "Payment Request Sent")
            } onFailure: { error in
                self.showAlert(title: "Payment", errorMsg: error.debugDescription)
            }

            self.showAlert(title: "Payment", errorMsg: "Payment Request Sent")
        }else{
            self.showAlert(title: "Payment", errorMsg: "Payment Request Failed")
        }
        showHideViews(isSending: true, isFinished: true)
    }
    
    
//MARK: - Receive
    @IBAction func didPressReceive(_ sender: Any) {
        invoiceComment.delegate = self
        invoiceAmount.delegate = self
        showHideViews(isSending: false, isFinished: false)

    }
    
    @IBAction func didUpdateStepper(_ sender: UIStepper) {
        invoiceAmount.text = String(String(format: "%.f", sender.value))
        estimateFeeValue.text =  String(String(format: "%.2f", sender.value/1000))
        generateInvoiceBtn.isHidden = false
    }
    @IBAction func didPressGenerateBtn(_ sender: Any) {
        
        self.selectedListControl.selectedSegmentIndex = 1
        self.selectedListControl.sendActions(for: .valueChanged)
        guard let amountText = invoiceAmount.text else{
            self.showAlert(title: "Invoice", errorMsg: "Empty Amount")
            return
        }
        
        debugPrint("✅", amountText)
        guard let amount:Int = Int(amountText) else{
            self.showAlert(title: "Invoice", errorMsg: "Invalid Amount")
            return
        }
        guard let balance:Int = viewModel.walletBalance.value?.total else {
            self.showAlert(title: "Invoice", errorMsg: "Invalid wallet balance")
            return
        }
       
        if(amount > balance){
            self.showAlert(title: "Invoice", errorMsg: "Insufficient funds")
        }else if amount == 0{
            self.showAlert(title: "Invoice", errorMsg: "No amount selected")
        }else{
            createInvoice(amount: amount, comment: invoiceComment.text ?? "")
        }
        showHideViews(isSending: false, isFinished: true)
       
    }
    func showHideViews(isSending: Bool, isFinished: Bool){
        sendStackView.isHidden = isFinished || (!isFinished && !isSending)
        receiveStackView.isHidden = isFinished || (!isFinished && isSending)
        feeStackView.isHidden = isFinished || (!isFinished && isSending)
        paymentButtonsStack.isHidden = !isFinished
        tableView.isHidden = !isFinished
        selectedListControl.isHidden = !isFinished
        generateInvoiceBtn.isHidden = true
        payBtn.isHidden = true
        if isFinished{
            invoiceComment.text = ""
            invoiceAmount.text = "0"
            estimateFeeValue.text = "0"
            sendPaymentAddress.text = ""
        }
    }
    
    
}
//MARK: - Create Invoice
extension PaymentsVC{
    func createInvoice(amount: Int, comment: String){
        self.showLoadingView()
        viewModel.createInvoice(amount: amount, comment: comment) { paymentRequest in
            self.showContentView()
            self.showAlert(title: "Invoice", address: paymentRequest)
        } onFailure: { error in
            self.showContentView()
            self.showAlert(title: "Invoice", errorMsg: error.debugDescription)
        }

    }
    
}
extension PaymentsVC: UITableViewDelegate, UITableViewDataSource{
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        let emptyLabel = UILabel(frame: CGRect(x: 0, y: 0, width: self.view.bounds.size.width, height: self.view.bounds.size.height))
        emptyLabel.text = ""
        emptyLabel.textAlignment = NSTextAlignment.center
        self.tableView.backgroundView = emptyLabel
        if selectedListControl.selectedSegmentIndex == 0{
            if let noOfPayments = viewModel.payments.value?.count{
                return noOfPayments
            }else{
                emptyLabel.text = "No Payments"
                self.tableView.separatorStyle = UITableViewCell.SeparatorStyle.none
                return 0
            }
        }else{
            if let noOfInvoices = viewModel.invoices.value?.count{
                return noOfInvoices
            }else{
                emptyLabel.text = "No Invoices"
                self.tableView.separatorStyle = UITableViewCell.SeparatorStyle.none
                return 0
            }
        }
        
        
        
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let reuseCellIdentifier = "cellIdentifier"
        var cell = tableView.dequeueReusableCell(withIdentifier: reuseCellIdentifier)
        if (!(cell != nil)) {
            
            cell = UITableViewCell(style: .subtitle, reuseIdentifier: reuseCellIdentifier)
        }
        cell?.textLabel?.numberOfLines = 0
        cell?.detailTextLabel?.numberOfLines = 0
        if selectedListControl.selectedSegmentIndex == 0{
            if let payment = viewModel.payments.value?[indexPath.row]{
                cell?.textLabel?.text = "Status: \(payment.status) \nAmount: \(payment.value) sat"
                cell?.detailTextLabel?.text = "\nDate: \(payment.creationDate.getAsDate()) \nFee:\(payment.feeSat) \nPayment hash:\n\(payment.paymentRequest.description)"
            }
        }else{
            if let invoice = viewModel.invoices.value?[indexPath.row]{
                cell?.textLabel?.text = "Status: \(invoice.state) \nAmount: \(invoice.value) sat"
                cell?.detailTextLabel?.text = "\nDate Created: \(invoice.creationDate.getAsDate()) \nMemo:\(invoice.memo) \nPayment request: \(invoice.paymentRequest)"
            }
        }
        
        
        return cell!
    }
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        if selectedListControl.selectedSegmentIndex == 0{
            if let payment = viewModel.payments.value?[indexPath.row]{
                UIPasteboard.general.string = payment.paymentRequest.description
            }
        }else{
            if let invoice = viewModel.invoices.value?[indexPath.row]{
                self.showAlert(title: "Invoice", address: invoice.paymentRequest)
            }
        }
    }
    
}

extension PaymentsVC: UITextFieldDelegate{
    /**
     * Called when 'return' key pressed. return NO to ignore.
     */
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        if !(invoiceAmount.text?.isEmpty ?? true){
            generateInvoiceBtn.isHidden = false
        }
        textField.resignFirstResponder()
        return true
    }
    
    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        if textField == invoiceAmount{
            let allowedCharacters = CharacterSet.decimalDigits
            let characterSet = CharacterSet(charactersIn: string)
            return allowedCharacters.isSuperset(of: characterSet)
        }
        return true
    }
    /**
     * Called when the user click on the view (outside the UITextField).
     */
    func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
        self.view.endEditing(true)
    }

}
extension PaymentsVC: UITextPasteDelegate {
    func textPasteConfigurationSupporting(_ textPasteConfigurationSupporting: UITextPasteConfigurationSupporting, shouldAnimatePasteOf attributedString: NSAttributedString, to textRange: UITextRange) -> Bool {
        return false
    }
}

extension PaymentsVC: UITextViewDelegate{
    func textViewDidBeginEditing(_ textView: UITextView) {
        if textView.textColor == UIColor.lightGray {
            textView.text = nil
            textView.textColor = UIColor.black
        }
    }
    func textViewDidEndEditing(_ textView: UITextView) {
        if textView.text.isEmpty {
            textView.text = "Input Address ..."
            textView.textColor = UIColor.lightGray
        }
    }
    func textViewDidChange(_ textView: UITextView) {
        
        if(textView.text == UIPasteboard.general.string){
        }
    }
    func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
        
            // Combine the textView text and the replacement text to
            // create the updated text string
        let currentText:String = textView.text
        let updatedText = (currentText as NSString).replacingCharacters(in: range, with: text)
        
            // If updated text view will be empty, add the placeholder
            // and set the cursor to the beginning of the text view
        if updatedText.isEmpty {
            
            textView.text = "Input Address ..."
            textView.textColor = UIColor.lightGray
            
            textView.selectedTextRange = textView.textRange(from: textView.beginningOfDocument, to: textView.beginningOfDocument)
        }
        
            // Else if the text view's placeholder is showing and the
            // length of the replacement string is greater than 0, set
            // the text color to black then set its text to the
            // replacement string
        else if textView.textColor == UIColor.lightGray && !text.isEmpty {
            textView.textColor = UIColor.black
            textView.text = text
        }else if text == "\n" {
            textView.resignFirstResponder()
            self.viewModel.getPaymentDetail(invoice: textView.text)
            return false
        }
        
            // For every other case, the text should change with the usual
            // behavior...
        else {
            return true
        }
        
            // ...otherwise return false since the updates have already
            // been made
        return false
    }
    func textViewDidChangeSelection(_ textView: UITextView) {
        if self.view.window != nil {
            if textView.textColor == UIColor.lightGray {
                textView.selectedTextRange = textView.textRange(from: textView.beginningOfDocument, to: textView.beginningOfDocument)
            }
        }
    }
}
extension PaymentsVC: QRCodeScanViewControllerDelegate{
        // MARK: QRCodeScanViewControllerDelegate
    
        /// Called when the camera scans a QR code
        /// - Parameters:
        ///   - viewController: View controller that scanned the QR code
        ///   - value: String encoded in the QR code
    func qrCodeScanViewController(_ viewController: QRCodeScanViewController, didScanQRCode value: String) {
        
            // Dismiss the view controller
        viewController.dismiss(animated: true) {
            self.sendPaymentAddress.text = value
            self.sendPaymentAddress.tintColor = UIColor.black
            self.viewModel.getPaymentDetail(invoice: value)
        }
    }
}