//: Playground - noun: a place where people can play

import UIKit

struct JSON { }

struct ZewoMySQL {
    func execute(sqlStatement: String) {}
}

protocol ModelAdaptor {

    associatedtype ModelType

    func save   ( task: ModelType, onCompletion: (SuccessOrFail<ModelType>)->Void)
    // delete
    // fetch

}

enum SuccessOrFail<T> {
    case success(T)
    case failure(Error)
}

protocol Model {

    static var databaseAdaptor: ModelAdaptor? {get set}

    func save   (onComplete: (SuccessOrFail<Self>) -> Void)

}


struct Task: Model {

    static var databaseAdaptor: ModelAdaptor? = nil

    var id          : String? = nil
    var title       : String

}

extension Task {

    func save   (onComplete: (SuccessOrFail<Task>) -> Void) {
        Task.databaseAdaptor?.save(task: Task) { result in
            onComplete(result)
        }
    }

}

extension Task {

    init?(withJSON: JSON) {
        return nil
    }

    init(title: String) {
        self.title
    }
}

struct TaskAdaptor : ModelAdaptor {

    let mysql = ZewoMySQL()

    typealias ModelType = Task

    init(username: String, password: String, tableName: String) {
        self.tableName = tableName
    }

    let tableName: String = "tasks"

    func save( task: Task, onCompletion: (SuccessOrFail<Task>)->Void) {
        let statement = "INSERT INTO \(tableName) (title) VALUES \(task.title)"

        mysql.execute(sqlStatement: statement)


    }
}

Task.databaseAdaptor = TaskAdaptor(username: "root", password: "password", tableName: "tasks")

let task1 = Task(title: "Reticulate Splines")
task1.save {
    result in
}