//
//  GeminiDataTask.swift
//  GeminiProtocol
//
//  Created by Shadowfacts on 7/14/20.
//

import Foundation
import Network

public class GeminiDataTask {
    public let request: GeminiRequest
    private let completion: (Result<GeminiResponse, Error>) -> Void
    
    private let connection: GeminiConnection
    
    public private(set) var completed: Bool = false
    
    public init(request: GeminiRequest, completion: @escaping (Result<GeminiResponse, Error>) -> Void) {
        self.request = request
        self.completion = completion
        self.connection = GeminiConnection(endpoint: .url(request.url))
        self.connection.delegate = self
        
    }
    
    public convenience init(url: URL, completion: @escaping (Result<GeminiResponse, Error>) -> Void) throws {
        self.init(request: try GeminiRequest(url: url), completion: completion)
    }
    
    deinit {
        self.cancel()
    }
    
    public func resume() {
        self.connection.startConnection()
    }
    
    public func cancel() {
        connection.cancelConnection()
    }
}

public extension GeminiDataTask {
    enum Error: Swift.Error {
        case noData
        case connectionError(NWError)
    }
}

extension GeminiDataTask: GeminiConnectionDelegate {
    public func connectionReady(_ connection: GeminiConnection) {
        connection.sendRequest(self.request)
    }
    
    public func connection(_ connection: GeminiConnection, receivedData data: Data?, header: GeminiResponseHeader) {
        guard !completed else {
            print("GeminiRequestTask(\(self)) has already completed, shouldn't be receiving any data")
            return
        }
        completed = true
        if let data = data {
            let response = GeminiResponse(header: header, body: data)
            self.completion(.success(response))
        } else {
            self.completion(.failure(.noData))
        }
    }
    
    public func connection(_ connection: GeminiConnection, handleError error: GeminiConnection.Error) {
        guard !completed else {
            print("GeminiRequestTask(\(self)) has already completed, shouldn't be receiving any data")
            return
        }
        completed = true
        self.completion(.failure(.connectionError(error)))
    }
    
    public func connectionCompleted(_ connection: GeminiConnection) {
    }
    
}