//
//  AppSettingsModel.swift
//  Malinka
//
//  Created by Juraldinio on 12/16/22.
//  Copyright © 2022 NUT.Tech. All rights reserved.
//

import Foundation

struct AppSettingsModel: Decodable {
    
    static private var instance: AppSettingsModel?
    
    enum ExchangeType: Decodable {
        
        case uninmplemented(String)
        case form
        case url(String)
        
        // MARK: - Decodable
        
        private enum CodingKeys: String, CodingKey {
            case wbtn
            case wurl
        }
        
        init(from decoder: Decoder) throws {
            let container = try decoder.container(keyedBy: CodingKeys.self)
            
            let type = try container.decodeIfPresent(String.self, forKey: .wbtn)
            let url = try container.decodeIfPresent(String.self, forKey: .wurl)
            
            guard let type else {
                self = ExchangeType.form
                return
            }
            
            switch type {
            case "form": self = ExchangeType.form
            case "url":
                if let url {
                    self = ExchangeType.url(url)
                } else {
                    self = ExchangeType.form
                }
            default: self = ExchangeType.uninmplemented(type)
            }
        }
    }
    
    let isSwapActive: Bool
    let exchangeType: ExchangeType

    private enum CodingKeys: String, CodingKey {
        case isSwapActive = "is_swap_active"
    }
    
    private init() {
        self.isSwapActive = true
        self.exchangeType = .form
    }
    
    init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        self.isSwapActive = (try? container.decode(Bool.self, forKey: .isSwapActive)) ?? true
        self.exchangeType = try ExchangeType(from: decoder)
    }
    
    static func shared(with data: Data? = nil) -> Self {
        
        if let model = Self.instance { return model }
        
        if let data,
           let model = try? JSONDecoder().decode(AppSettingsModel.self, from: data) {
            Self.instance = model
            return model
        }
        
        let model = AppSettingsModel()
        Self.instance = model
        return model
            
    }
    
}