import Foundation
import SwiftKeychainWrapper
import SwiftyJSON

class Session {
    var curUser: User?

    init() {
        if let accessToken = KeychainWrapper.standard.string(forKey: ACCESS_TOKEN) {
            EndpointManager.authenticatUser(accessToken: accessToken)
        }
    }

    func login(email: String, password: String, responseDelegate: ResponseDelegate) {
        let parameters: Dictionary<String, Any> = [
            "user[email]": email,
            "user[password]": password
        ]

        EndpointManager.sendRequest(with: parameters, request: .login) {
            [weak self] data in

            if let errors = data.dictionary?["errors"] {
                responseDelegate.onFail(error: Error(data: errors))
            } else if let user = data.dictionary?["user"] {
                self?.curUser = User(data: user)
                self?.persistUser(accessToken: data["user"]["access_token"].stringValue)
                responseDelegate.onSuccess()
            } else {
                responseDelegate.onFail(error: Error(data:
                    ["Unkown data received from api server"]))
            }
        }
    }

    func signup(name: String, email: String, password: String, responseDelegate: ResponseDelegate) {
        let parameters: Dictionary<String, Any> = [
            "user[name]": name,
            "user[email]": email,
            "user[password]": password
        ]

        EndpointManager.sendRequest(with: parameters, request: .signup) {
            [weak self] data in

            if let errors = data.dictionary?["errors"] {
                responseDelegate.onFail(error: Error(data: errors))
            } else if let user = data.dictionary?["user"] {
                self?.curUser = User(data: user)
                self?.persistUser(accessToken: data["user"]["access_token"].stringValue)
                responseDelegate.onSuccess()
            } else {
                responseDelegate.onFail(error: Error(data:
                    ["Unkown data received from api server"]))
            }
        }
    }

    func logOut() {
        removeUser()
    }

    func isLoggedIn() -> Bool {
        return KeychainWrapper.standard.hasValue(forKey: ACCESS_TOKEN)
    }

    func getUserData(getCached: Bool, responseDelegate: ResponseDelegate) {
        if !getCached || curUser == nil {
            EndpointManager.sendRequest(with: nil, request: .get_user) {
                [weak self] data in

                if let errors = data.dictionary?["errors"] {
                    responseDelegate.onFail(error: Error(data: errors))
                } else if let user = data.dictionary?["user"] {
                    self?.curUser = User(data: user)
                    responseDelegate.onSuccess()
                } else {
                    responseDelegate.onFail(error: Error(data: "Unkown data received from api server"))
                }
            }
        } else {
            responseDelegate.onSuccess()
        }
    }

    // Mark: - save user access_token to keychain
    private func persistUser(accessToken: String) {
        KeychainWrapper.standard.set(accessToken, forKey: ACCESS_TOKEN)
        EndpointManager.authenticatUser(accessToken: accessToken)
    }

    // Mark: - remove user access_token from keychain
    private func removeUser() {
        KeychainWrapper.standard.removeObject(forKey: ACCESS_TOKEN)
        EndpointManager.deauthenticatUser()
        curUser = nil
    }

}