//  _____ _
// |_   _| |_  _ _ ___ ___ _ __  __ _
//   | | | ' \| '_/ -_) -_) '  \/ _` |_
//   |_| |_||_|_| \___\___|_|_|_\__,_(_)
//
// Threema iOS Client
// Copyright (c) 2013-2020 Threema GmbH
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License, version 3,
// as published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.

#import "PhoneNumberNormalizer.h"
#import "NBPhoneNumberUtil.h"
#import <CoreTelephony/CTTelephonyNetworkInfo.h>
#import <CoreTelephony/CTCarrier.h>
#import "NBMetadataHelper.h"

@interface PhoneNumberNormalizer ()

@property NBPhoneNumberUtil *phoneNumberUtil;

@end

@implementation PhoneNumberNormalizer

+ (PhoneNumberNormalizer*)sharedInstance {
    static PhoneNumberNormalizer *sharedInstance;
    static dispatch_once_t pred;
    dispatch_once(&pred, ^{
        sharedInstance = [[PhoneNumberNormalizer alloc] init];
        
        sharedInstance.phoneNumberUtil = [NBPhoneNumberUtil sharedInstance];
    });
    return sharedInstance;
}

- (NSString*)phoneNumberToE164:(NSString*)phoneNumber withDefaultRegion:(NSString*)defaultRegion prettyFormat:(NSString**)prettyFormat {
    
    NSError *error = nil;
    NBPhoneNumber *parsed = [_phoneNumberUtil parse:phoneNumber defaultRegion:defaultRegion error:&error];
    if (parsed == nil)
        return nil;
    
    NSString *e164WithPlus = [_phoneNumberUtil format:parsed numberFormat:NBEPhoneNumberFormatE164 error:&error];
    if (e164WithPlus == nil)
        return nil;
    
    NSString *result = [e164WithPlus stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"+"]];
    
    if (prettyFormat != nil)
        *prettyFormat = [_phoneNumberUtil format:parsed numberFormat:NBEPhoneNumberFormatINTERNATIONAL error:&error];
    
    return result;
}

- (NSString *)examplePhoneNumberForRegion:(NSString *)region {
    
    NSError *error = nil;
    
    NBPhoneNumber *exampleNumber = [_phoneNumberUtil getExampleNumber:region error:&error];
    if (exampleNumber == nil)
        return nil;
    
    return [_phoneNumberUtil format:exampleNumber numberFormat:NBEPhoneNumberFormatNATIONAL error:&error];
}

- (NSString *)exampleRegionalPhoneNumberForRegion:(NSString *)region {
    
    NSError *error = nil;
    
    NBPhoneNumber *exampleNumber = [_phoneNumberUtil getExampleNumber:region error:&error];
    if (exampleNumber == nil) {
        return nil;
    }
    
    NSString *number = [_phoneNumberUtil format:exampleNumber numberFormat:NBEPhoneNumberFormatINTERNATIONAL error:&error];

    return [self regionalPartForPhoneNumber:number];
}

- (NSString *)regionalPartForPhoneNumber:(NSString *)phoneNumber {
    NSString *region = [self regionForPhoneNumber:phoneNumber];
    if (region) {
        NSString *code = [NBMetadataHelper.CCode2CNMap objectForKey:region];
    
        NSRange codeRange = [phoneNumber rangeOfString:code];
        if (codeRange.location != NSNotFound) {
            return [phoneNumber substringFromIndex:codeRange.location + codeRange.length];
        }
    }
    
    return phoneNumber;
}

- (NSString *)regionForPhoneNumber:(NSString *)phoneNumber {
    NSError *error = nil;
    
    NSString *defaultRegion = [PhoneNumberNormalizer userRegion];
    NBPhoneNumber *parsed = [_phoneNumberUtil parse:phoneNumber defaultRegion:defaultRegion error:&error];
    if (parsed == nil) {
        return nil;
    }
    
    return [_phoneNumberUtil getRegionCodeForNumber:parsed];
}

+ (NSString*)userRegion {
    /* try CTCarrier first as it's probably more reliable (who knows what the user's country setting may be) */
    CTTelephonyNetworkInfo *netInfo = [[CTTelephonyNetworkInfo alloc] init];
    CTCarrier *carrier = [netInfo subscriberCellularProvider];
    if (carrier.isoCountryCode != nil)
        return [carrier.isoCountryCode uppercaseString];
    
    /* fall back to NSLocale */
    return [[NSLocale currentLocale] objectForKey:NSLocaleCountryCode];
}

@end