Perfect-CURL

open class CURLRequest {
	// Init with a url and options array.
	public convenience init(_ url: String, options: [Option] = [])
	/// Init with url and one or more options.
	public convenience init(_ url: String, _ option1: Option, _ options: Option...)
	/// Init with array of options.
	public init(options: [Option] = [])
}

open class CURLRequest {
	public struct POSTField {
		/// Init with a name, value and optional mime-type.
		public init(name: String, value: String, mimeType: String? = nil)
		/// Init with a name, file path and optional mime-type.
		public init(name: String, filePath: String, mimeType: String? = nil)
	}
}

let json = try CURLRequest(url, .failOnError,
			               .postField(.init(name: "key1", value: "value1")),
			               .postField(.init(name: "key2", value: "value2")),
			               .postField(.init(name: "file1", filePath: testFile.path, mimeType: "text/plain")))
										.perform().bodyJSON

public extension CURLRequest {
	/// Execute the request synchronously. 
	/// Returns the response or throws an Error.
	func perform() throws -> CURLResponse
	/// Execute the request asynchronously.
	/// The parameter passed to the completion callback must be called to obtain the response or throw an Error.
	func perform(_ completion: @escaping (CURLResponse.Confirmation) -> ())
	/// Execute the request asynchronously. 
	/// Returns a Promise object which can be used to monitor the operation.
	func promise() -> Promise<CURLResponse>
}

let url = "https://httpbin.org/get?p1=v1&p2=v2"
let json: [String:Any] = try CURLRequest(url).perform().bodyJSON

let url = "https://httpbin.org/post"
CURLRequest(url).perform {
	confirmation in
	do {
		let response = try confirmation()
		let json: [String:Any] = response.bodyJSON
		
	} catch let error as CURLResponse.Error {
		print("Failed: response code \(error.response.responseCode)")
	} catch {
		print("Fatal error \(error)")
	}
}

let url = "https://httpbin.org/get?p1=v1&p2=v2"
if let json = try CURLRequest(url).promise().then { return try $0().bodyJSON }.wait() {
	...
}

public extension CURLRequest {
	/// Reset the request. Clears all options so that the object can be reused.
	/// New options can be provided.
	func reset(_ options: [Option] = [])
	/// Reset the request. Clears all options so that the object can be reused.
	/// New options can be provided.
	func reset(_ option: Option, _ options: Option...)
}

public extension CURLResponse {
	/// The response's raw content body bytes.
	public var bodyBytes: [UInt8]
	/// Get the response body converted from UTF-8.
	public var bodyString: String
	/// Get the response body decoded from JSON into a [String:Any] dictionary.
	/// Invalid/non-JSON body data will result in an empty dictionary being returned.
	public var bodyJSON: [String:Any]
  /// Get the response body decoded from JSON into a decodable structure
  /// Invalid/non-JSON body data will throw errors.
  public func bodyJSON<T: Decodable>(_ type: T.Type) throws -> T
}

public extension CURLResponse {
	/// Get an response info String value.
	func get(_ stringValue: Info.StringValue) -> String?
	/// Get an response info Int value.
	func get(_ intValue: Info.IntValue) -> Int?
	/// Get an response info Double value.
	func get(_ doubleValue: Info.DoubleValue) -> Double?
	/// Get a response header value. Returns the first found instance or nil.
	func get(_ header: Header.Name) -> String?
	/// Get a response header's values. Returns all found instances.
	func get(all header: Header.Name) -> [String]
}

// get the response code
let code = response.get(.responseCode)

// get the response code using the accessor
let code = response.responseCode

// get the "Last-Modified" header from the response
if let lastMod = response.get(.lastModified) {
	...
}

open class CURLResponse {
	/// An error thrown while retrieving a response.
	public struct Error: Swift.Error {
		/// The curl specific request response code.
		public let code: Int
		/// The string message for the curl response code.
		public let description: String
		/// The response object for this error.
		public let response: CURLResponse
	}
}