HttpClient

import Foundation
import SwiftHTTP

class HttpClient {
    enum METHOD: String {
        case GET        = "GET"
        case POST       = "POST"
        case UPLOAD     = "UPLOAD"
        case DOWNLOAD   = "DOWNLOAD"
        case DELETE     = "DELETE"
        case PUT        = "PUT"
    }
    enum ErrorCode: Int {
        case OK                         = 0
        case MissingAccessToken         = 1
        case InvalidAccessToken         = 2

        case InvalidEmailOrPassword     = 11
        case InvalidParams              = 12
        case FacebookUserNotRegistered  = 13
        case InvalidFacebookToken       = 14
        case UserWasStopped             = 15
//        case UserNotFound               = 15
        case UserTokenExpired           = 16

        case Failure                    = 0x8000000

        func toString() -> String {
            switch self {
            case .OK: return "OK"
            case .MissingAccessToken: return "MISSING_ACCESS_TOKEN"
            case .InvalidAccessToken: return "INVALID_ACCESS_TOKEN"

            case .InvalidEmailOrPassword: return "INVALID_EMAIL_OR_PASSWORD"
            case .InvalidParams: return "INVALID_PARAMS"
            case .FacebookUserNotRegistered: return "FACEBOOK_USER_NOT_REGISTERED"
            default: return "UNKNOWN_ERROR"
            }
        }
    }

    typealias Completion = (_ result: String?, _ errorCode: ErrorCode?) -> ()

    enum API: String {
        case Login                = "login"
        case Events               = "events"
        case Companies            = "companies"
        case Messages             = "messages"
        case MyPage               = "mypage"
        case Profile              = "profile"
        case AccessToken          = "access_token"
        case CheckIn              = "event/checkin"
        case Resume               = "resume"
        case EditResume           = "edit_resume"
        case MessageDetail        = "message_detail"
        case JobDetail            = "job_detail"
        case Account              = "account"
        case Total_Unread_Message = "total_unread_messages"
        case Schedule             = "schedule"
        case Interview            = "interview"
        case CompanyDetail        = "company_detail"
    }
    private let BaseURL = "https://example.com/"
    private let headers = [
        "Authorization": "Basic ZGlzY286RFNrczNQNktLdXZieGR1cA==",
        "Content-Type": "application/json"
    ]
    private var defaultParameters = [String: Any]()
    private let serializer = JSONParameterSerializer()

    static let shared = HttpClient()

    func addDefaultParameter(_ key: String, _ value: Any) {
        defaultParameters[key] = value
    }

    func request(method: METHOD, api: API, params: Dictionary<String, Any>? = nil, completion: Completion? = nil) {
        var requestParams = defaultParameters
        if let p = params {
            requestParams.merge(with: p)
        }
        LOG(#function, #line, "method: \(method) - params: \(requestParams)")
        switch method {
        case .GET:
            GET(api: api, params: requestParams, completion: completion)
        default:
            POST(api: api, params: requestParams, completion: completion)
        }
    }

    private func GET(api: API, params: Dictionary<String, Any>? = nil, completion: Completion? = nil) {
        do {
            let opt = try HTTP.GET(BaseURL + api.rawValue, parameters: params, headers: headers, requestSerializer: serializer)
            startQuery(query: opt, completion: completion)
        } catch _ {
            if let callback = completion {
                callback(nil, .Failure)
            }
        }
    }

    private func POST(api: API, params: Dictionary<String, Any>? = nil, completion: Completion? = nil) {
        do {
            let opt = try HTTP.POST(BaseURL + api.rawValue, parameters: params, headers: headers, requestSerializer: serializer)
            startQuery(query: opt, completion: completion)
        } catch _ {
            if let callback = completion {
                callback(nil, .Failure)
            }
        }
    }

    private func startQuery(query: HTTP, completion: Completion? = nil) {
        var attempted = false
        query.auth = { challenge in
            if let trust = challenge.protectionSpace.serverTrust , !attempted {
                attempted = true
                return URLCredential(trust: trust)
            }
            return nil
        }
        query.start { response in
            var result: String?
            var errorCode: ErrorCode?
            if let error = response.error {
                errorCode = ErrorCode(rawValue: error.code)
                if errorCode == nil {
                    errorCode = ErrorCode.Failure
                }
            } else {
                result = String(data: response.data, encoding: .utf8)
                errorCode = .OK
            }

            if let callback = completion {
                LOG(#function, #line, "errorCode: \(errorCode)")
                callback(result, errorCode)
            }
        }
    }
}