ELLanguageRunner.h

//
//  ELLanguageRunner.h
//  DiorHUB
//
//  Created by Milan Vít on 26.09.16.
//  Copyright (c) 2016 EYELEVEL. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface ELLanguageRunner : NSObject
- (instancetype)initWithTimeInterval:(NSTimeInterval)interval;
@end

ELLanguageRunner.m

//
//  ELLanguageRunner.m
//  DiorHUB
//
//  Created by Milan Vít on 26.09.16.
//  Copyright (c) 2016 EYELEVEL. All rights reserved.
//

#import <Foundation/Foundation.h>
#import <libextobjc/extobjc.h>
#import "ELLanguageRunner.h"
#import "ELLanguageRealm.h"
#import "ELSettingRealm.h"

@interface ELLanguageRunner ()
@property (assign, nonatomic) NSTimeInterval interval;
@end

@implementation ELLanguageRunner
#pragma mark - Init
- (instancetype)initWithTimeInterval:(NSTimeInterval)interval {
	self = [super init];
	
	if (self) {
		self.interval = interval;

		[self cycleWithRemainingLanguageCodes:nil];
	}

	return self;
}

- (void)cycleWithRemainingLanguageCodes:(NSArray<NSString *> *)languageCodes {
	if (languageCodes && languageCodes.count == 0) {
		// Naturally ending cycle
		return;
	}

	languageCodes = languageCodes ?: [ELLanguageRealm languageCodes];
	[ELSettingRealm setCurrentLanguage:languageCodes.firstObject];

	@weakify(self);
	dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t) (self.interval * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
		@strongify(self);
		[self cycleWithRemainingLanguageCodes:[languageCodes subarrayWithRange:NSMakeRange(1, languageCodes.count - 1)]];
	});

}
@end

ELLanguageRunnerManager.h

//
//  ELLanguageRunnerManager.h
//  DiorHUB
//
//  Created by Milan Vít on 26.09.16.
//  Copyright (c) 2016 EYELEVEL. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface ELLanguageRunnerManager : NSObject
+ (instancetype)sharedManager;

- (void)runWithTimeInterval:(NSTimeInterval)interval;
@end

ELLanguageRunnerManager.m

//
//  ELLanguageRunnerManager.m
//  DiorHUB
//
//  Created by Milan Vít on 26.09.16.
//  Copyright (c) 2016 EYELEVEL. All rights reserved.
//

#import "ELLanguageRunnerManager.h"
#import "ELLanguageRunner.h"

@interface ELLanguageRunnerManager ()
@property (strong, nonatomic) ELLanguageRunner *runner;
@end

@implementation ELLanguageRunnerManager
#pragma mark - Init
+ (instancetype)sharedManager {
	static ELLanguageRunnerManager *sharedManager = nil;
	static dispatch_once_t onceToken;

	dispatch_once(&onceToken, ^{
		sharedManager = [[self alloc] init];
	});

	return sharedManager;
}

#pragma mark - ELLanguageRunnerManager
- (void)runWithTimeInterval:(NSTimeInterval)interval {
	self.runner = nil;
	self.runner = [[ELLanguageRunner alloc] initWithTimeInterval:interval];
}
@end