JSON.swift

import Foundation

enum JSONValue
{
	case JSONObject([String: JSONValue])
	case JSONArray([JSONValue])
	case JSONString(String)
	case JSONNumber(NSNumber)
	case JSONBool(Bool)
	case JSONNull
	
	var object: [String: JSONValue]?
	{
		switch self
		{
			case .JSONObject(let value):
				return value
			default:
				return nil
		}
	}
	
	var array: [JSONValue]?
	{
		switch self
		{
			case .JSONArray(let value):
				return value
			default:
				return nil
		}
	}
	
	var string: String?
	{
		switch self
		{
			case .JSONString(let value):
				return value
			default:
				return nil
		}
	}
	
	var integer: Int?
	{
		switch self
		{
			case .JSONNumber(let value):
				return value.integerValue
			default:
				return nil
		}
	}
	
	var double: Double?
	{
		switch self
		{
			case .JSONNumber(let value):
				return value.doubleValue
			default:
				return nil
		}
	}
	
	var bool: Bool?
	{
		switch self
		{
			case .JSONBool(let value):
				return value
			case .JSONNumber(let value):
				return value.boolValue
			default:
				return nil
		}
	}
	
	subscript(index: Int) -> JSONValue?
	{
		get
		{
			switch self
			{
				case .JSONArray(let value):
					return value[index]
				default:
					return nil
			}
		}
	}
	
	subscript(key: String) -> JSONValue?
	{
		get
		{
			switch self
			{
				case .JSONObject(let value):
					return value[key]
				default:
					return nil
			}
		}
	}
	
	static func fromObject(object: AnyObject) -> JSONValue?
	{
		switch object
		{
			case let value as NSString:
				return JSONValue.JSONString(value)
			case let value as NSNumber:
				return JSONValue.JSONNumber(value)
			case let value as NSNull:
				return JSONValue.JSONNull
			case let value as NSDictionary:
				var jsonObject: [String: JSONValue] = [:]
				for (key: AnyObject, value: AnyObject) in value
				{
					if let key = key as? NSString
					{
						if let v = JSONValue.fromObject(v)
						{
							jsonObject[k] = value
						}
						else
						{
							return nil
						}
					}
				}
				return JSONValue.JSONObject(jsonObject)
			case let value as NSArray:
				var jsonArray: [JSONValue] = []
				for object in value
				{
					if let object = JSONValue.fromObject(object)
					{
						jsonArray.append(object)
					}
					else
					{
						return nil
					}
				}
				return JSONValue.JSONArray(jsonArray)
			default:
				return nil
		}
	}
}