#import "MGLVectorSource+MGLAdditions.h"

@implementation MGLVectorSource (MGLAdditions)

+ (NS_SET_OF(NSString *) *)mapboxStreetsLanguages {
    // https://www.mapbox.com/vector-tiles/mapbox-streets-v7/#overview
    static dispatch_once_t onceToken;
    static NS_SET_OF(NSString *) *mapboxStreetsLanguages;
    dispatch_once(&onceToken, ^{
        // https://www.mapbox.com/vector-tiles/mapbox-streets-v7/#overview
        mapboxStreetsLanguages = [NSSet setWithObjects:@"ar", @"de", @"en", @"es", @"fr", @"pt", @"ru", @"zh", @"zh-Hans", nil];
    });
    return mapboxStreetsLanguages;
}

+ (NSString *)preferredMapboxStreetsLanguage {
    NSArray<NSString *> *supportedLanguages = [MGLVectorSource mapboxStreetsLanguages].allObjects;
    NSArray<NSString *> *preferredLanguages = [NSBundle preferredLocalizationsFromArray:supportedLanguages
                                                                         forPreferences:[NSLocale preferredLanguages]];
    NSString *mostSpecificLanguage;
    for (NSString *language in preferredLanguages) {
        if (language.length > mostSpecificLanguage.length) {
            mostSpecificLanguage = language;
        }
    }
    return mostSpecificLanguage ?: @"en";
}

- (BOOL)isMapboxStreets {
    NSURL *url = self.configurationURL;
    if (![url.scheme isEqualToString:@"mapbox"]) {
        return NO;
    }
    NSArray *identifiers = [url.host componentsSeparatedByString:@","];
    return [identifiers containsObject:@"mapbox.mapbox-streets-v7"] || [identifiers containsObject:@"mapbox.mapbox-streets-v6"];
}

- (NS_DICTIONARY_OF(NSString *, NSString *) *)localizedKeysByKeyForPreferredLanguage:(nullable NSString *)preferredLanguage {
    if (!self.mapboxStreets) {
        return @{};
    }

    // Replace {name} and {name_*} with the matching localized name tag.
    NSString *localizedKey = preferredLanguage ? [NSString stringWithFormat:@"name_%@", preferredLanguage] : @"name";
    NSMutableDictionary *localizedKeysByKey = [NSMutableDictionary dictionaryWithObject:localizedKey forKey:@"name"];
    for (NSString *languageCode in [MGLVectorSource mapboxStreetsLanguages]) {
        NSString *key = [NSString stringWithFormat:@"name_%@", languageCode];
        localizedKeysByKey[key] = localizedKey;
    }
    return localizedKeysByKey;
}

@end