session-ios/Signal/src/util/PhoneNumberUtil.m

#import "PhoneNumberUtil.h"
#import "ContactsManager.h"
#import "Util.h"

@implementation PhoneNumberUtil

MacrosSingletonImplemention

- (instancetype)init {
    self = [super init];
    
    if (self) {
        _nbPhoneNumberUtil = [[NBPhoneNumberUtil alloc] init];
    }
    
    return self;
}

// country code -> country name
+ (NSString *)countryNameFromCountryCode:(NSString *)code {
    NSDictionary *countryCodeComponent = @{NSLocaleCountryCode: code};
    NSString *identifier = [NSLocale localeIdentifierFromComponents:countryCodeComponent];
    NSString *country = [NSLocale.currentLocale displayNameForKey:NSLocaleIdentifier
                                                              value:identifier];
    return country;
}

// country code -> calling code
+ (NSString *)callingCodeFromCountryCode:(NSString *)code {
    NSNumber *callingCode = [[[self sharedInstance] nbPhoneNumberUtil] getCountryCodeForRegion:code];
    return [NSString stringWithFormat:@"%@%@", COUNTRY_CODE_PREFIX, callingCode];
}

// search term -> country codes
+ (NSArray *)countryCodesForSearchTerm:(NSString *)searchTerm {
    
    NSArray *countryCodes = NSLocale.ISOCountryCodes;
    
    if (searchTerm) {
        countryCodes = [countryCodes filter:^int(NSString *code) {
            NSString *countryName = [self countryNameFromCountryCode:code];
            NSString *callingCode = [self callingCodeFromCountryCode:code];
            
            if ([ContactsManager name:countryName matchesQuery:searchTerm]) {
                return YES;
            }
            
            // We rely on the already internationalized string; as that is what
            // the user would see entered (i.e. with COUNTRY_CODE_PREFIX).

            if ([callingCode containsString:searchTerm]) {
                return YES;
            }
            return NO;
        }];
    }
    
    return [self sortedCountryCodesByName:countryCodes];
}

+(NSArray *)validCountryCallingPrefixes:(NSString *)string {
    NSArray *countryCodes = NSLocale.ISOCountryCodes;
    NSArray *matches = [countryCodes filter:^int(NSString *code) {
        NSString *callingCode = [self callingCodeFromCountryCode:code];
        
        return [string hasPrefix:callingCode];
    }];
    
    return [matches sortedArrayWithOptions:NSSortConcurrent usingComparator:^NSComparisonResult(NSString * obj1, NSString * obj2) {
        if (obj1 == nil) {
            return obj2 ? NSOrderedAscending : NSOrderedSame;
        }
        
        if (obj2 == nil) {
            return NSOrderedDescending;
        }
        
        NSInteger d = (NSInteger)[obj1 length] - (NSInteger)[obj2 length];
        return d ? ( d < 0  ? NSOrderedAscending : NSOrderedDescending) : NSOrderedSame;
    }];
}

+ (NSArray*)sortedCountryCodesByName:(NSArray*)countryCodesByISOCode{
    return [countryCodesByISOCode sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
        return [[self countryNameFromCountryCode:obj1] caseInsensitiveCompare:[self countryNameFromCountryCode:obj2]];
    }];
}

// normalizes a phone number, so parentheses and spaces are stripped
+ (NSString*) normalizePhoneNumber:(NSString *) number {
    return [[[self sharedInstance] nbPhoneNumberUtil]  normalizePhoneNumber:number];
}

// black  magic
+(NSUInteger) translateCursorPosition:(NSUInteger)offset
                                 from:(NSString*)source
                                   to:(NSString*)target
                    stickingRightward:(bool)preferHigh {
    require(source != nil);
    require(target != nil);
    require(offset <= source.length);
    
    NSUInteger n = source.length;
    NSUInteger m = target.length;
    
    int moves[n+1][m+1];
    {
        // Wagner-Fischer algorithm for computing edit distance, with a tweaks:
        // - Tracks best moves at each location, to allow reconstruction of edit path
        // - Does not allow substitutions
        // - Over-values digits relative to other characters, so they're "harder" to delete or insert
        const int DIGIT_VALUE = 10;
        NSUInteger scores[n+1][m+1];
        moves[0][0] = 0; // (match) move up and left
        scores[0][0] = 0;
        for (NSUInteger i = 1; i <= n; i++) {
            scores[i][0] = i;
            moves[i][0] = -1; // (deletion) move left
        }
        for (NSUInteger j = 1; j <= m; j++) {
            scores[0][j] = j;
            moves[0][j] = +1; // (insertion) move up
        }
        
        NSCharacterSet* digits = NSCharacterSet.decimalDigitCharacterSet;
        for (NSUInteger i = 1; i <= n; i++) {
            unichar c1 = [source characterAtIndex:i-1];
            bool isDigit1 = [digits characterIsMember:c1];
            for (NSUInteger j = 1; j <= m; j++) {
                unichar c2 = [target characterAtIndex:j-1];
                bool isDigit2 = [digits characterIsMember:c2];
                if (c1 == c2) {
                    scores[i][j] = scores[i-1][j-1];
                    moves[i][j] = 0; // move up-and-left
                } else {
                    NSUInteger del = scores[i-1][j] + (isDigit1 ? DIGIT_VALUE : 1);
                    NSUInteger ins = scores[i][j-1] + (isDigit2 ? DIGIT_VALUE : 1);
                    bool isDel = del < ins;
                    scores[i][j] = isDel ? del : ins;
                    moves[i][j] = isDel ? -1 : +1;
                }
            }
        }
    }
    
    // Backtrack to find desired corresponding offset
    for (NSUInteger i = n, j = m; ; i -= 1) {
        if (i == offset && preferHigh) return j; // early exit
        while (moves[i][j] == +1) j -= 1; // zip upward
        if (i == offset) return j; // late exit
        if (moves[i][j] == 0) j -= 1;
    }
}

@end