GitHawk/Classes/Systems/InboxZeroLoader.swift

//
//  InboxZeroLoader.swift
//  Freetime
//
//  Created by Ryan Nystrom on 8/25/18.
//  Copyright © 2018 Ryan Nystrom. All rights reserved.
//

import Foundation

final class InboxZeroLoader {

    private let url = URL(string: "http://githawk.com/holidays.json")!
    private let path: String = {
        let path = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
        return "\(path)/holidays.json"
    }()
    private typealias SerializedType = [String: [String: [String: String]]]
    private lazy var json: SerializedType = {
        return NSKeyedUnarchiver.unarchiveObject(withFile: path) as? SerializedType ?? [:]
    }()
    private let session: URLSession = {
        let config = URLSessionConfiguration.default
        config.requestCachePolicy = .reloadIgnoringLocalCacheData
        config.urlCache = nil
        return URLSession.init(configuration: config)
    }()

    func load(completion: @escaping (Bool) -> Void) {
        let path = self.path
        session.dataTask(with: url) { [weak self] (data, response, error) in
            if let data = data,
                let tmp = try? JSONSerialization.jsonObject(with: data, options: []) as? SerializedType,
                let json = tmp {
                DispatchQueue.main.async {
                    self?.json = json
                    completion(true)
                }
                NSKeyedArchiver.archiveRootObject(json, toFile: path)
            } else {
                DispatchQueue.main.async {
                    completion(false)
                }
            }
        }.resume()
    }

    private var fallback: (String, String) {
        return ("🎉", NSLocalizedString("Inbox zero!", comment: ""))
    }

    func message(date: Date = Date()) -> (emoji: String, message: String) {
        let components = Calendar.current.dateComponents([.day, .month], from: date)
        guard let day = components.day, let month = components.month else {
            return fallback
        }
        if let monthData = json["\(month)"],
            let data = monthData["\(day)"],
            let emoji = data["emoji"],
            let message = data["message"] {
            return (emoji, message)
        }
        return fallback
    }

}