//
//  AppDelegate.swift
//  ReviewsFeed
//
//  Created by Dmitrii Ivanov on 21/07/2020.
//  Copyright © 2020 ING. All rights reserved.
//

import Combine
import ReviewsUIKit
import SwiftUI
import UIKit

public class FeedViewController: UITableViewController {

    // MARK: Constants
    private let viewModel: ViewModel
    
    // MARK: Properties
    private var cancellables: Set<AnyCancellable> = []
    
    // MARK: Initialisers
    public init(configuration: Configuration = .init()) {
        self.viewModel = .init(configuration: configuration)

        super.init(style: .plain)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    // MARK: UIViewController
    public override func viewDidLoad() {
        super.viewDidLoad()
        
        tableView.register(
            UITableViewCell.self,
            forCellReuseIdentifier: .Cell.feedItem
        )

        bindViewModel()
        
        viewModel.fetch()
    }
    
    // MARK: UITableViewDataSource
    public override func tableView(
        _ tableView: UITableView,
        numberOfRowsInSection section: Int
    ) -> Int {
        viewModel.items.count
    }
    
    public override func tableView(
        _ tableView: UITableView,
        cellForRowAt indexPath: IndexPath
    ) -> UITableViewCell {
        guard let cell = tableView.dequeueReusableCell(withIdentifier: .Cell.feedItem) else {
            return .init()
        }

        cell.contentConfiguration = {
            if #available(iOS 16.0, *) {
                UIHostingConfiguration {
                    FeedItem(viewModel.items[indexPath.row])
                }
            } else {
                HostingConfiguration {
                    FeedItem(viewModel.items[indexPath.row])
                }
            }
        }()

        return cell
    }
    
    // MARK: UITableViewDelegate
    public override func tableView(
        _ tableView: UITableView,
        didSelectRowAt indexPath: IndexPath
    ) {
        let details = DetailsViewController(review: viewModel.items[indexPath.row])
        
        tableView.deselectRow(
            at: indexPath,
            animated: true
        )

        navigationController?.pushViewController(details, animated: true)
    }
    
}

// MARK: - Helpers
private extension FeedViewController {
    
    // MARK: Functions
    func bindViewModel() {
        viewModel.$loading
            .sink { loading in
                print("LOADING: \(loading)")
            }
            .store(in: &cancellables)
        
        viewModel.$loading
            .dropFirst()
            .filter { $0 == false }
            .receive(on: RunLoop.main)
            .sink { [weak self] _ in
                self?.tableView.reloadData()
            }
            .store(in: &cancellables)
    }
    
}

// MARK: - Configuration
extension FeedViewController {
    public struct Configuration {
        
        // MARK: Constants
        let appID: String
        let countryCode: String
        let session: URLSessionConfiguration
        
        // MARK: Initialisers
        public init(
            appID: String = "474495017",
            countryCode: String = "nl",
            session: URLSessionConfiguration = .ephemeral
        ) {
            self.appID = appID
            self.countryCode = countryCode
            self.session = session
        }
        
    }
}

// MARK: - String+Constants
private extension String {
    enum Cell {
        static let feedItem = "FeedItemCell"
    }
}