AutoCat/AutoCat/Utils/Api.swift

import Foundation
import RxSwift

class Api {
    private static func genError(_ msg: String, suggestion: String, code: Int = 0) -> Error {
        return NSError(domain: "", code: code, userInfo: [NSLocalizedDescriptionKey: msg, NSLocalizedRecoverySuggestionErrorKey: suggestion])
    }
    
    private static func createRequest<T>(api: String, method: String, body: [String: T]? = nil) -> URLRequest? where T: LosslessStringConvertible {
        guard var urlComponents = URLComponents(string: Constants.baseUrl + api) else { return nil }
        
        if let body = body, method.uppercased() == "GET" {
            urlComponents.queryItems = body.map { URLQueryItem(name: $0, value: String($1)) }
        }
        
        var request = URLRequest(url: urlComponents.url!)
        request.httpMethod = method
        request.addValue("application/json", forHTTPHeaderField: "Content-Type")
        request.addValue("application/json", forHTTPHeaderField: "Accept")
        request.addValue("Bearer " + Settings.shared.user.token, forHTTPHeaderField: "Authorization")
        
        if let body = body, method.uppercased() != "GET" {
            request.httpBody = try? JSONSerialization.data(withJSONObject: body, options: .prettyPrinted)
        }
        
        return request
    }
    
    private static func makeRequest<T, U>(api: String, method: String, body: [String: U]? = nil) -> Observable<T> where T: Decodable, U: LosslessStringConvertible {
        guard let request = self.createRequest(api: api, method: method, body: body) else {
            return Observable.error(self.genError("Error creating request", suggestion: ""))
        }
        
        return URLSession.shared.rx.data(request: request).map { data in
//            let str = String(data: data, encoding: .utf8)
//            print("================================")
//            print(str?.replacingOccurrences(of: "\\\"", with: "\""))
//            print("================================")
            let resp = try JSONDecoder().decode(Response<T>.self, from: data)
            if resp.success {
                return resp.data!
            } else {
                throw self.genError(resp.error!, suggestion: "")
            }
        }
    }
    
    public static func refreshFbToken() -> Observable<Void> {
        guard let token = Settings.shared.user.googleIdToken, let refreshToken = Settings.shared.user.googleRefreshToken, let jwt = JWT(string: token), jwt.expired else {
            return .just(())
        }
        
        let refreshUrlString = Constants.fbRefreshToken + "?key=" + Constants.fbApiKey
        
        let body = [
            "grantType": "refresh_token",
            "refreshToken": refreshToken
        ]
        
        if let url = URL(string: refreshUrlString) {
            var request = URLRequest(url: url)
            request.httpMethod = "POST"
            request.httpBody = try? JSONSerialization.data(withJSONObject: body, options: .prettyPrinted)
            request.addValue("application/json", forHTTPHeaderField: "Content-Type")
            request.addValue(Constants.fbClientVersion, forHTTPHeaderField: "X-Client-Version")
            request.addValue(Constants.vin01BUndleId, forHTTPHeaderField: "X-Ios-Bundle-Identifier")
            request.addValue(Constants.fbUserAgent, forHTTPHeaderField: "User-Agent")
            return URLSession.shared.rx.json(request: request).map { resp in
                guard let json = resp as? [String: Any] else { return }
                if let newToken = json["id_token"] as? String {
                    Settings.shared.user.googleIdToken = newToken
                    print("Token was successfully refresh to: \(newToken)")
                }
                if let newRefreshToken = json["refresh_token"] as? String {
                    Settings.shared.user.googleRefreshToken = newRefreshToken
                }
            }.catchError { error in
                print(error)
                return .just(())
            }
        } else {
            return .just(())
        }
    }
    
    public static func login(username: String, password: String) -> Observable<User> {
        let body = [
            "login": username,
            "password": password
        ]
        return self.makeRequest(api: "user/login", method: "POST", body: body)
    }
    
    public static func signup(username: String, password: String) -> Observable<User> {
        let body = [
            "login": username,
            "password": password
        ]
        return self.makeRequest(api: "user/signup", method: "POST", body: body)
    }
    
    public static func getVehicles(with filter: Filter) -> Observable<[Vehicle]> {
        let body = [
            "limit": "0", // Unlimited
            "query": filter.searchString
        ]
        return self.makeRequest(api: "vehicles", method: "GET", body: body)
    }
    
    public static func checkVehicle(by number: String, force: Bool = false) -> Observable<Vehicle> {
        return self.refreshFbToken().flatMap { () -> Observable<Vehicle> in
            var body = [
                "number": number,
                "forceUpdate": String(force)
            ]
            if let token = Settings.shared.user.googleIdToken {
                body["googleIdToken"] = token
            }
            return self.makeRequest(api: "vehicles/check", method: "POST", body: body).map { (vehicle: Vehicle) -> Vehicle in
                vehicle.addedDate = Date().timeIntervalSince1970*1000
                return vehicle
            }
        }
    }
}