eqn.ios/Sources/Earthquake Network/Models/EQNUser.m

//
//  EQNUser.m
//  Earthquake Network
//
//  Created by Luca Beretta on 20/09/18.
//  Copyright © 2018 Luca Beretta. All rights reserved.
//

#import "EQNUser.h"
#import "Costanti.h"
#import "ServerRequest.h"
#import "EQNAccelerometroManager.h"
#import "EQNGeneratoreURLServer.h"
#import "EQNUtility.h"
#import "EQNManager.h"

@interface EQNUser ()
@property (strong, nonatomic) NSString *currentFirebaseToken;
@property (nonatomic) BOOL registrationInProgress;
@end

@implementation EQNUser

#pragma mark - Singleton

+ (instancetype)defaultUser
{
    static EQNUser *sharedInstance = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        sharedInstance = [[self alloc] init];
    });
    return sharedInstance;
}

#pragma mark - Init

- (instancetype)init
{
    self = [super init];
    if (self) {
        self.registrationInProgress = NO;
        self.user_ID = EQNUserData.sharedData.userId;
        self.lastPosition = EQNUserData.sharedData.lastLocation;
        
        [self registerForLocationUpdates];
    }
    return self;
}

#pragma mark - Public

- (void)saveUserInfo
{
    [EQNUserData.sharedData saveFirebaseToken:self.currentFirebaseToken];
    [EQNUserData.sharedData saveUserId:self.user_ID];
    [EQNUserData.sharedData saveLastLocation:self.lastPosition];
}

- (void)removeUser
{
    self.currentFirebaseToken = nil;
    [EQNUserData.sharedData removeAllData];
}

#pragma mark - Public

- (void)retryUserRegistration
{
    [self registerUserIfNeededWithFirebaseToken:self.currentFirebaseToken];
}

- (void)registerUserIfNeededWithFirebaseToken:(NSString *)firebaseToken
{
    self.currentFirebaseToken = firebaseToken;
    NSString *previousFirebaseToken = EQNUserData.sharedData.firebaseToken;
    
    // dobbiamo effettuare la registrazione se:
    // - userId non disponibile (si tratta di prima registrazione)
    // - i due token di Firebase sono diversi (il token è stato aggiornato)
    
    if (!self.user_ID) {
        // prima registrazione dell'utente
        NSLog(@"[EQNUser] perform first registration");
        [self performServerRegistrationWithFirebaseToken:firebaseToken existingUserId:nil];
    } else if (![previousFirebaseToken isEqualToString:firebaseToken]) {
        // token cambiato, effettuiamo una nuova registrazione
        NSLog(@"[EQNUser] firebase token is changed, update registration");
        [self performServerRegistrationWithFirebaseToken:firebaseToken existingUserId:self.user_ID];
    } else {
        // non serve la registrazione, monitorniamo la posizione
        NSLog(@"[EQNUser] user already registered, start location update");
        [self registerForLocationUpdates];
    }
}

- (void)downloadOfferTimeRemainingWithCompletion:(_Nonnull timeRemainingCompletion)completionHandler
{
    NSURL *url = [EQNGeneratoreURLServer urlDownloadOfferTimeRemaining];
    [[ServerRequest defaultServerConnectionSingleton] inviaInformazioniAlServerWithURL:url richiesta:EQNTipoChiamataOfferTimeRemaining success:^(id result) {
        NSInteger timeRemaining = 0;
        if ([result isKindOfClass:[NSNumber class]]) {
            NSNumber *timeRemainingNumber = (NSNumber *)result;
            timeRemaining = [timeRemainingNumber integerValue];
        } else if ([result isKindOfClass:[NSString class]]) {
            NSString *timeRemainingString = (NSString *)result;
            timeRemaining = [timeRemainingString integerValue];
        }
        
        completionHandler(timeRemaining);
    } failure:^(NSError *error) {
        completionHandler(0);
    }];
}

#pragma mark - Network

- (void)performServerRegistrationWithFirebaseToken:(NSString *)token existingUserId:(NSString *)userId
{
    if (self.registrationInProgress) {
        NSLog(@"[EQNUser] Registration already in progress");
        return;
    }
    
    if (token == nil) {
        NSLog(@"[EQNUser] Firebase token is null, abort registration");
        self.registrationInProgress = NO;
        [[NSNotificationCenter defaultCenter] postNotificationName:EQNServerRegistrationDidFailNotification object:nil];
        return;
    }
    
    self.registrationInProgress = YES;
    NSURL *url = [EQNGeneratoreURLServer urlRegistrazioneFirebaseToken:token existingUserId:userId];
    [[ServerRequest defaultServerConnectionSingleton] inviaInformazioniAlServerWithURL:url richiesta:EQNTipoChiamataRegistrazione success:^(id result) {
        NSLog(@"[EQNUser] User registration completed");

        // store userId
        self.registrationInProgress = NO;
        self.user_ID = [self convertUserIdIntoString:result];
        [self saveUserInfo];
        
        // inviamo, se già disponibile, la posizione al server
        [self performServerSendLocation];
    } failure:^(NSError *errore) {
        NSLog(@"[EQNUser] Unable to perform user registration: %@", errore);
        self.registrationInProgress = NO;
        [[NSNotificationCenter defaultCenter] postNotificationName:EQNServerRegistrationDidFailNotification object:nil];
    }];
}

- (void)performServerSendLocation
{
    if (!self.user_ID) {
        NSLog(@"[EQNUser] User id not available");
        return;
    }
    
    NSURL *url = [EQNGeneratoreURLServer urlPosizione];
    [[ServerRequest defaultServerConnectionSingleton] inviaInformazioniAlServerWithURL:url richiesta:EQNTipoChiamataPosizione success:^(id result) {
        
        if ([result isKindOfClass:[NSString class]]) {
            NSString *stringResult = (NSString *)result;
            if ([stringResult isEqualToString:@"reg"]) {
                // l'utente non è stato trovato sul server, ri-eseguiamo la registrazione
                NSLog(@"[EQNUser] User not found, retry registration");
                [self retryUserRegistration];
            } else {
                NSLog(@"[EQNUser] Position saved on server");
            }
        }
                
        [self saveUserInfo];
    } failure:^(NSError *error) {
        NSLog(@"[EQNUser] Unable to save position. Error: %@", error.localizedDescription);
    }];
}

#pragma mark - Private

- (void)registerForLocationUpdates
{
    [[EQNAccelerometroManager sharedInstance] addObserver:(id)self
                                               forKeyPath:@"currentLocation"
                                                  options:NSKeyValueObservingOptionNew
                                                  context:nil];
    
    [[EQNAccelerometroManager sharedInstance] startUpdatingLocationBackground];
}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
    if ([keyPath isEqualToString:@"currentLocation"]) {
        NSLog(@"[EQNUser] currentLocation changed");
        // do some stuff
        if (self.lastPosition) {
            self.distanza = [self.lastPosition distanceFromLocation:[EQNAccelerometroManager sharedInstance].currentLocation];
        }
        self.lastPosition = [EQNAccelerometroManager sharedInstance].currentLocation;
        [self performServerSendLocation];
        
        if (![EQNManager defaultManager].isBackground) {
            [[EQNAccelerometroManager sharedInstance] stopUpdatingLocation];
        }
    }
}

#pragma mark - Helpers

/// user_id saved as a Number, but is used as a NSString
- (NSString *)convertUserIdIntoString:(id)userId
{
    if ([userId isKindOfClass:[NSString class]]) {
        return (NSString *)userId;
    } else if ([userId isKindOfClass:[NSNumber class]]) {
        NSNumber *userIdNumber = (NSNumber *)userId;
        return [userIdNumber stringValue];
    } else {
        return userId;
    }
}

@end