//
//  Copyright RevenueCat Inc. All Rights Reserved.
//
//  Licensed under the MIT License (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//      https://opensource.org/licenses/MIT
//
//  SubscriberAttribute.swift
//
//  Created by Joshua Liebowitz on 7/1/21.
//

import Foundation

struct SubscriberAttribute {

    let setTime: Date
    let key: String
    let value: String
    var isSynced: Bool

    init(withKey key: String, value: String?, isSynced: Bool, setTime: Date) {
        self.key = key
        self.value = value ?? ""
        self.isSynced = isSynced
        self.setTime = setTime
    }

    init(withKey key: String, value: String?, dateProvider: DateProvider = DateProvider()) {
        self.init(withKey: key, value: value, isSynced: false, setTime: dateProvider.now())
    }

    init(attribute: ReservedSubscriberAttribute, value: String?, dateProvider: DateProvider = DateProvider()) {
        self.init(withKey: attribute.rawValue, value: value, dateProvider: dateProvider)
    }

}

extension SubscriberAttribute {

    init?(dictionary: [String: Any]) {
        guard let key = dictionary[Key.key.rawValue] as? String,
              let isSynced = (dictionary[Key.isSynced.rawValue] as? NSNumber)?.boolValue,
              let setTime = dictionary[Key.setTime.rawValue] as? Date else {
            return nil
        }

        let value = dictionary[Key.value.rawValue] as? String

        self.init(withKey: key, value: value, isSynced: isSynced, setTime: setTime)
    }

    func asDictionary() -> [String: NSObject] {
        return [Key.key.rawValue: self.key as NSString,
                Key.value.rawValue: self.value as NSString,
                Key.isSynced.rawValue: NSNumber(value: self.isSynced),
                Key.setTime.rawValue: self.setTime as NSDate]
    }

    func asBackendDictionary() -> [String: Any] {
        return [BackendKey.value.rawValue: self.value,
                BackendKey.timestamp.rawValue: self.setTime.millisecondsSince1970]
    }

}

extension SubscriberAttribute: Equatable {}

extension SubscriberAttribute: CustomStringConvertible {

    var description: String {
        return "[SubscriberAttribute] key: \(self.key) value: \(self.value) setTime: \(self.setTime)"
    }

}

extension SubscriberAttribute {

    typealias Dictionary = [String: SubscriberAttribute]

}

extension SubscriberAttribute {

    static func map(subscriberAttributes: SubscriberAttribute.Dictionary) -> [String: [String: Any]] {
        return subscriberAttributes.mapValues { $0.asBackendDictionary() }
    }
}

// MARK: - Private

extension SubscriberAttribute {

    private enum Key: String {

        case key
        case value
        case isSynced
        case setTime

    }

    private enum BackendKey: String {

        case value = "value"
        case timestamp = "updated_at_ms"

    }

}