//
//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
//

#import "NBAsYouTypeFormatter.h"
#import "NBPhoneNumber.h"
#import "PhoneNumber.h"
#import "PhoneNumberUtil.h"

static NSString *const RPDefaultsKeyPhoneNumberString    = @"RPDefaultsKeyPhoneNumberString";
static NSString *const RPDefaultsKeyPhoneNumberCanonical = @"RPDefaultsKeyPhoneNumberCanonical";

@implementation PhoneNumber

+ (PhoneNumber *)phoneNumberFromText:(NSString *)text andRegion:(NSString *)regionCode {
    OWSAssert(text != nil);
    OWSAssert(regionCode != nil);

    PhoneNumberUtil *phoneUtil = [PhoneNumberUtil sharedUtil];

    NSError *parseError   = nil;
    NBPhoneNumber *number = [phoneUtil parse:text defaultRegion:regionCode error:&parseError];

    if (parseError) {
        return nil;
    }

    NSError *toE164Error;
    NSString *e164 = [phoneUtil format:number numberFormat:NBEPhoneNumberFormatE164 error:&toE164Error];
    if (toE164Error) {
        DDLogDebug(@"Issue while formatting number: %@", [toE164Error description]);
        return nil;
    }

    PhoneNumber *phoneNumber = [PhoneNumber new];
    phoneNumber->phoneNumber = number;
    phoneNumber->e164        = e164;
    return phoneNumber;
}

+ (PhoneNumber *)phoneNumberFromUserSpecifiedText:(NSString *)text {
    OWSAssert(text != nil);

    return [PhoneNumber phoneNumberFromText:text andRegion:[self defaultRegionCode]];
}

+ (NSString *)defaultRegionCode {
    NSString *defaultRegion;
#if TARGET_OS_IPHONE
    defaultRegion = [[PhoneNumberUtil sharedUtil].nbPhoneNumberUtil countryCodeByCarrier];

    if ([defaultRegion isEqualToString:@"ZZ"]) {
        defaultRegion = [[NSLocale currentLocale] objectForKey:NSLocaleCountryCode];
    }
#else
    defaultRegion = [[NSLocale currentLocale] objectForKey:NSLocaleCountryCode];
#endif
    return defaultRegion;
}

+ (PhoneNumber *)phoneNumberFromE164:(NSString *)text {
    OWSAssert(text != nil);
    OWSAssert([text hasPrefix:COUNTRY_CODE_PREFIX]);
    PhoneNumber *number = [PhoneNumber phoneNumberFromText:text andRegion:@"ZZ"];

    OWSAssert(number != nil);
    return number;
}

+ (NSString *)bestEffortFormatPartialUserSpecifiedTextToLookLikeAPhoneNumber:(NSString *)input {
    return [PhoneNumber bestEffortFormatPartialUserSpecifiedTextToLookLikeAPhoneNumber:input
                                                               withSpecifiedRegionCode:[self defaultRegionCode]];
}

+ (NSString *)bestEffortFormatPartialUserSpecifiedTextToLookLikeAPhoneNumber:(NSString *)input
                                              withSpecifiedCountryCodeString:(NSString *)countryCodeString {
    return [PhoneNumber
        bestEffortFormatPartialUserSpecifiedTextToLookLikeAPhoneNumber:input
                                               withSpecifiedRegionCode:
                                                   [PhoneNumber regionCodeFromCountryCodeString:countryCodeString]];
}

+ (NSString *)bestEffortFormatPartialUserSpecifiedTextToLookLikeAPhoneNumber:(NSString *)input
                                                     withSpecifiedRegionCode:(NSString *)regionCode {
    NBAsYouTypeFormatter *formatter = [[NBAsYouTypeFormatter alloc] initWithRegionCode:regionCode];

    NSString *result = input;
    for (NSUInteger i = 0; i < input.length; i++) {
        result = [formatter inputDigit:[input substringWithRange:NSMakeRange(i, 1)]];
    }
    return result;
}


+ (NSString *)regionCodeFromCountryCodeString:(NSString *)countryCodeString {
    NBPhoneNumberUtil *phoneUtil = [PhoneNumberUtil sharedUtil].nbPhoneNumberUtil;
    NSString *regionCode =
        [phoneUtil getRegionCodeForCountryCode:@([[countryCodeString substringFromIndex:1] integerValue])];
    return regionCode;
}


+ (PhoneNumber *)tryParsePhoneNumberFromText:(NSString *)text fromRegion:(NSString *)regionCode {
    OWSAssert(text != nil);
    OWSAssert(regionCode != nil);

    return [self phoneNumberFromText:text andRegion:regionCode];
}

+ (PhoneNumber *)tryParsePhoneNumberFromUserSpecifiedText:(NSString *)text {
    OWSAssert(text != nil);

    if ([text isEqualToString:@""]) {
        return nil;
    }
    NSString *sanitizedString = [self removeFormattingCharacters:text];

    return [self phoneNumberFromUserSpecifiedText:sanitizedString];
}

+ (NSArray<PhoneNumber *> *)tryParsePhoneNumbersFromsUserSpecifiedText:(NSString *)text
                                                     clientPhoneNumber:(NSString *)clientPhoneNumber
{
    OWSAssert(text != nil);

    text = [text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
    if ([text isEqualToString:@""]) {
        return nil;
    }
    
    NSString *sanitizedString = [self removeFormattingCharacters:text];
    OWSAssert(sanitizedString != nil);

    NSMutableArray *result = [NSMutableArray new];
    NSMutableSet *phoneNumberSet = [NSMutableSet new];
    void (^tryParsingWithCountryCode)(NSString *, NSString *) = ^(NSString *text,
                                                      NSString *countryCode) {
        PhoneNumber *phoneNumber = [PhoneNumber phoneNumberFromText:text
                                                          andRegion:countryCode];
        if (phoneNumber && [phoneNumber toE164] && ![phoneNumberSet containsObject:[phoneNumber toE164]]) {
            [result addObject:phoneNumber];
            [phoneNumberSet addObject:[phoneNumber toE164]];
        }
    };

    tryParsingWithCountryCode(sanitizedString, [self defaultRegionCode]);

    if ([sanitizedString hasPrefix:@"+"]) {
        // If the text starts with "+", don't try prepending
        // anything else.
        return result;
    }

    // Try just adding "+" and parsing it.
    tryParsingWithCountryCode([NSString stringWithFormat:@"+%@", sanitizedString], [self defaultRegionCode]);

    // Order matters; better results should appear first so prefer
    // matches with the same country code as this client's phone number.
    OWSAssert(clientPhoneNumber.length > 0);
    if (clientPhoneNumber.length > 0) {
        // Note that NBPhoneNumber uses "country code" to refer to what we call a
        // "calling code" (i.e. 44 in +44123123).  Within SSK we use "country code"
        // (and sometimes "region code") to refer to a country's ISO 2-letter code
        // (ISO 3166-1 alpha-2).
        NSNumber *callingCodeForLocalNumber = [[PhoneNumber phoneNumberFromE164:clientPhoneNumber] getCountryCode];
        if (callingCodeForLocalNumber != nil) {
            NSString *callingCodePrefix = [NSString stringWithFormat:@"+%@", callingCodeForLocalNumber];

            tryParsingWithCountryCode(
                [callingCodePrefix stringByAppendingString:sanitizedString], [self defaultRegionCode]);

            // Try to determine what the country code is for the local phone number
            // and also try parsing the phone number using that country code if it
            // differs from the device's region code.
            //
            // For example, a French person living in Italy might have an
            // Italian phone number but use French region/language for their
            // phone. They're likely to have both Italian and French contacts.
            NSString *localCountryCode =
                [PhoneNumberUtil.sharedUtil probableCountryCodeForCallingCode:callingCodePrefix];
            if (localCountryCode && ![localCountryCode isEqualToString:[self defaultRegionCode]]) {
                tryParsingWithCountryCode(
                    [callingCodePrefix stringByAppendingString:sanitizedString], localCountryCode);
            }
        }
    }
    
    return result;
}

+ (NSString *)removeFormattingCharacters:(NSString *)inputString {
    char outputString[inputString.length + 1];

    int outputLength = 0;
    for (NSUInteger i = 0; i < inputString.length; i++) {
        unichar c = [inputString characterAtIndex:i];
        if (c == '+' || (c >= '0' && c <= '9')) {
            outputString[outputLength++] = (char)c;
        }
    }

    outputString[outputLength] = 0;
    return [NSString stringWithUTF8String:(void *)outputString];
}

+ (PhoneNumber *)tryParsePhoneNumberFromE164:(NSString *)text {
    OWSAssert(text != nil);

    return [self phoneNumberFromE164:text];
}

- (NSURL *)toSystemDialerURL {
    NSString *link = [NSString stringWithFormat:@"telprompt://%@", e164];
    return [NSURL URLWithString:link];
}

- (NSString *)toE164 {
    return e164;
}

- (NSNumber *)getCountryCode {
    return phoneNumber.countryCode;
}

- (BOOL)isValid {
    return [[PhoneNumberUtil sharedUtil].nbPhoneNumberUtil isValidNumber:phoneNumber];
}

- (NSString *)localizedDescriptionForUser {
    NBPhoneNumberUtil *phoneUtil = [PhoneNumberUtil sharedUtil].nbPhoneNumberUtil;

    NSError *formatError = nil;
    NSString *pretty = [phoneUtil format:phoneNumber numberFormat:NBEPhoneNumberFormatINTERNATIONAL error:&formatError];

    if (formatError != nil)
        return e164;
    return pretty;
}

- (BOOL)resolvesInternationallyTo:(PhoneNumber *)otherPhoneNumber {
    return [self.toE164 isEqualToString:otherPhoneNumber.toE164];
}

- (NSString *)description {
    return e164;
}

- (void)encodeWithCoder:(NSCoder *)encoder {
    [encoder encodeObject:phoneNumber forKey:RPDefaultsKeyPhoneNumberString];
    [encoder encodeObject:e164 forKey:RPDefaultsKeyPhoneNumberCanonical];
}

- (id)initWithCoder:(NSCoder *)decoder {
    if ((self = [super init])) {
        phoneNumber = [decoder decodeObjectForKey:RPDefaultsKeyPhoneNumberString];
        e164        = [decoder decodeObjectForKey:RPDefaultsKeyPhoneNumberCanonical];
    }
    return self;
}

- (NSComparisonResult)compare:(PhoneNumber *)other
{
    return [self.toE164 compare:other.toE164];
}

@end