/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/

#import "RCTI18nUtil.h"

#import <UIKit/UIKit.h>

@implementation RCTI18nUtil

+ (instancetype)sharedInstance
{
static RCTI18nUtil *sharedInstance;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedInstance = [self new];
[sharedInstance swapLeftAndRightInRTL:true];
});

return sharedInstance;
}

/**
* Check if the app is currently running on an RTL locale.
* This only happens when the app:
* - is forcing RTL layout, regardless of the active language (for development purpose)
* - allows RTL layout when using RTL locale
*/
- (BOOL)isRTL
{
if ([self isRTLForced]) {
return YES;
}
if ([self isRTLAllowed] && [self isApplicationPreferredLanguageRTL]) {
return YES;
}
return NO;
}

/**
* Should be used very early during app start up
* Before the bridge is initialized
* @return whether the app allows RTL layout, default is true
*/
- (BOOL)isRTLAllowed
{
NSNumber *value = [[NSUserDefaults standardUserDefaults] objectForKey:@"RCTI18nUtil_allowRTL"];
if (value == nil) {
return YES;
}
return [value boolValue];
}

- (void)allowRTL:(BOOL)rtlStatus
{
[[NSUserDefaults standardUserDefaults] setBool:rtlStatus forKey:@"RCTI18nUtil_allowRTL"];
[[NSUserDefaults standardUserDefaults] synchronize];
}

/**
* Could be used to test RTL layout with English
* Used for development and testing purpose
*/
- (BOOL)isRTLForced
{
BOOL rtlStatus = [[NSUserDefaults standardUserDefaults] boolForKey:@"RCTI18nUtil_forceRTL"];
return rtlStatus;
}

- (void)forceRTL:(BOOL)rtlStatus
{
[[NSUserDefaults standardUserDefaults] setBool:rtlStatus forKey:@"RCTI18nUtil_forceRTL"];
[[NSUserDefaults standardUserDefaults] synchronize];
}

- (BOOL)doLeftAndRightSwapInRTL
{
return [[NSUserDefaults standardUserDefaults] boolForKey:@"RCTI18nUtil_makeRTLFlipLeftAndRightStyles"];
}

- (void)swapLeftAndRightInRTL:(BOOL)value
{
[[NSUserDefaults standardUserDefaults] setBool:value forKey:@"RCTI18nUtil_makeRTLFlipLeftAndRightStyles"];
[[NSUserDefaults standardUserDefaults] synchronize];
}

// Check if the current device language is RTL
- (BOOL)isDevicePreferredLanguageRTL
{
NSLocaleLanguageDirection direction =
[NSLocale characterDirectionForLanguage:[[NSLocale preferredLanguages] objectAtIndex:0]];
return direction == NSLocaleLanguageDirectionRightToLeft;
}

// Check if the current application language is RTL
- (BOOL)isApplicationPreferredLanguageRTL
{
NSWritingDirection direction = [NSParagraphStyle defaultWritingDirectionForLanguage:nil];
return direction == NSWritingDirectionRightToLeft;
}

@end