//
//  MessageFetcher.swift
//  tst
//
//  Created by Vitaly Takmazov on 10.12.2019.
//  Copyright © 2019 com.juick. All rights reserved.
//

import Foundation
import Combine

class MessageFetcher: ObservableObject {
    
    @Published var state: LoadableState<Root> = .loading
    
    init(url: String) {
        guard let apiUrl = URL(string: url) else {
            state = .fetched(.failure(.error("Malformed API URL.")))
            return
        }
        
        URLSession.shared.dataTask(with: apiUrl) { [weak self] (data, _, error) in
            if let error = error {
                self?.state = .fetched(.failure(.error(error.localizedDescription)))
                return
            }
            
            guard let data = data else {
                self?.state = .fetched(.failure(.error("Malformed response data")))
                return
            }
            let root = try! JSONDecoder().decode(Root.self, from: data)
            
            DispatchQueue.main.async { [weak self] in
                self?.state = .fetched(.success(root))
            }
        }.resume()
    }
}