Enum to handle credit card issuers for iOS

CreditCardType.swift

//
//  CreditCardType.swift
//
//  Created by Rigoberto Sáenz Imbacuán (https://www.linkedin.com/in/rsaenzi/)
//  Copyright © 2019. All rights reserved.
//

enum CreditCardType: String, Codable {
    
    case visa               = "VISA"
    case visaElectron       = "VISA_ELECTRON"
    case mastercard         = "MASTERCARD"
    case maestro            = "MAESTRO"
    case americanExpress    = "AMERICAN_EXPRESS"
    case dinersClub         = "DINERS_CLUB"
    case discover           = "DISCOVER"
    case jcb                = "JCB"
}

extension CreditCardType {
    
    static var all: [CreditCardType] {
        return [
            .visa,
            .visaElectron,
            .mastercard,
            .maestro,
            .americanExpress,
            .dinersClub,
            .discover,
            .jcb
        ]
    }
    
    static func getCreditCardType(fromTypeName rawTypeName: String?) -> CreditCardType? {
        
        guard let typeNameToTest = rawTypeName else {
            return nil
        }
        
        if typeNameToTest.lowercased() == CreditCardType.visa.rawValue.lowercased() {
            return .visa
            
        } else if typeNameToTest.lowercased() == CreditCardType.visaElectron.rawValue.lowercased() {
            return .visaElectron

        } else if typeNameToTest.lowercased() == CreditCardType.mastercard.rawValue.lowercased() {
            return .mastercard
            
        } else if typeNameToTest.lowercased() == CreditCardType.maestro.rawValue.lowercased() {
            return .maestro
            
        } else if typeNameToTest.lowercased() == CreditCardType.americanExpress.rawValue.lowercased() {
            return .americanExpress
            
        } else if typeNameToTest.lowercased() == CreditCardType.dinersClub.rawValue.lowercased() {
            return .dinersClub
            
        } else if typeNameToTest.lowercased() == CreditCardType.discover.rawValue.lowercased() {
            return .discover
            
        } else if typeNameToTest.lowercased() == CreditCardType.jcb.rawValue.lowercased() {
            return .jcb
        }
        
        return nil
    }
    
    static func getCreditCardType(fromNumber rawCardNumber: String?) -> CreditCardType? {
        
        guard let rawValidCardNumber = rawCardNumber else {
            return nil
        }
        
        // Removes all non-digits
        let numberToTest = rawValidCardNumber.removeCharacters(from: CharacterSet.decimalDigits.inverted)
        
        if CreditCardType.visa.doesCardNumberBelongsToCreditCardType(numberToTest) {
            return .visa
            
        } else if CreditCardType.visaElectron.doesCardNumberBelongsToCreditCardType(numberToTest) {
            return .visaElectron
            
        } else if CreditCardType.mastercard.doesCardNumberBelongsToCreditCardType(numberToTest) {
            return .mastercard
            
        } else if CreditCardType.maestro.doesCardNumberBelongsToCreditCardType(numberToTest) {
            return .maestro
            
        } else if CreditCardType.americanExpress.doesCardNumberBelongsToCreditCardType(numberToTest) {
            return .americanExpress
            
        } else if CreditCardType.dinersClub.doesCardNumberBelongsToCreditCardType(numberToTest) {
            return .dinersClub
            
        } else if CreditCardType.discover.doesCardNumberBelongsToCreditCardType(numberToTest) {
            return .discover
            
        } else if CreditCardType.jcb.doesCardNumberBelongsToCreditCardType(numberToTest) {
            return .jcb
        }
        
        return nil
    }
}

extension CreditCardType {
    
    var icon: UIImage {
        switch self {
        case .visa:             return #imageLiteral(resourceName: "CardVisa")
        case .visaElectron:     return #imageLiteral(resourceName: "CardVisaElectron")
        case .mastercard:       return #imageLiteral(resourceName: "CardMastercard")
        case .maestro:          return #imageLiteral(resourceName: "CardMaestro")
        case .americanExpress:  return #imageLiteral(resourceName: "CardAmericanExpress")
        case .dinersClub:       return #imageLiteral(resourceName: "CardDinersClub")
        case .discover:         return #imageLiteral(resourceName: "CardDiscover")
        case .jcb:              return #imageLiteral(resourceName: "CardJCB")
        }
    }
    
    var regexPattern: String {
        switch self {
        case .visa:             return "^4[0-9]{12}(?:[0-9]{3})?$"
        case .visaElectron:     return "^(4026|417500|4508|4844|491(3|7))"
        case .mastercard:       return "^5[1-5][0-9]{14}$"
        case .maestro:          return "^(5018|5020|5038|6304|6759|676[1-3])"
        case .americanExpress:  return "^3[47][0-9]{13}$"
        case .dinersClub:       return "^3(?:0[0-5]|[68][0-9])[0-9]{11}$"
        case .discover:         return "^6(?:011|5[0-9]{2})[0-9]{12}$"
        case .jcb:              return "^(?:2131|1800|35\\d{3})\\d{11}$"
        }
    }
    
    var exampleValue: String {
        switch self {
        case .visa:             return "4111111111111111"
        case .visaElectron:     return "4026000000000002"
        case .mastercard:       return "5538383883833838"
        case .maestro:          return "501800000009"
        case .americanExpress:  return "347000000000000"
        case .dinersClub:       return "30099999999999"
        case .discover:         return "6550000000000000"
        case .jcb:              return "180000000000000"
        }
    }
    
    private func doesCardNumberBelongsToCreditCardType(_ cardNumber: String) -> Bool {
        
        do {
            let regex = try NSRegularExpression(pattern: regexPattern,
                                                options: .caseInsensitive)
            return regex.matches(in: cardNumber,
                                 options: [],
                                 range: NSMakeRange(0, cardNumber.count)).count > 0
        } catch {
            return false
        }
    }
}