RestKit/Code/Support/RKDotNetDateFormatter.m

//
//  RKDotNetDateFormatter.m
//  RestKit
//
//  Created by Greg Combs on 9/8/11.
//  Copyright (c) 2011 RestKit. All rights reserved.
//

#import "RKDotNetDateFormatter.h"
#import "RestKit.h"

BOOL isValidRange(NSRange rangeOfMatch);
NSTimeInterval secondsFromMilliseconds(NSTimeInterval millisecs);
NSTimeInterval millisecondsFromSeconds(NSTimeInterval seconds);

@interface RKDotNetDateFormatter()
- (NSString *)millisecondsFromString:(NSString *)string;
@end

@implementation RKDotNetDateFormatter

+ (RKDotNetDateFormatter *)dotNetDateFormatter {
    return [RKDotNetDateFormatter dotNetDateFormatterWithTimeZone:nil];
}

+ (RKDotNetDateFormatter *)dotNetDateFormatterWithTimeZone:(NSTimeZone *)newTimeZone {
    RKDotNetDateFormatter *formatter = [[[RKDotNetDateFormatter alloc] init] autorelease];
    if (newTimeZone)
        formatter.timeZone = newTimeZone;
    return formatter;
}

- (NSDate *)dateFromString:(NSString *)string {
    NSString *milliseconds = [self millisecondsFromString:string];
    if (!milliseconds) {
        RKLogError(@"Attempted to interpret an invalid .NET date string: %@", string);
        return nil;
    }
    NSTimeInterval seconds = secondsFromMilliseconds([milliseconds doubleValue]);
    return [NSDate dateWithTimeIntervalSince1970:seconds];
}


- (NSString *)stringFromDate:(NSDate *)date {
    if (!date) {
        RKLogError(@"Attempted to represent an invalid date: %@", date);
        return nil;
    }
    NSTimeInterval milliseconds = millisecondsFromSeconds([date timeIntervalSince1970]);
    NSString *timeZoneOffset = [super stringFromDate:date];
    return [NSString stringWithFormat:@"/Date(%1.0lf%@)/", milliseconds, timeZoneOffset];
}


- (id)init {
    self = [super init];
    if (self) {
        self.locale = [[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"] autorelease];
        self.timeZone = [NSTimeZone timeZoneWithName:@"UTC"];
        [self setDateFormat:@"ZZ"]; // GMT offset, like "-0500"
        NSString *pattern = @"\\/Date\\((\\d+)((?:[\\+\\-]\\d+)?)\\)\\/"; // /Date(mSecs)/ or /Date(mSecs-0400)/
        dotNetExpression = [[NSRegularExpression alloc] initWithPattern:pattern options:NSRegularExpressionCaseInsensitive error:NULL];
    }
    return self;
}


- (void)dealloc {
    [dotNetExpression release];
    [super dealloc];
}


- (NSString *)millisecondsFromString:(NSString *)string {
    if (!string)
        return nil;
    NSTextCheckingResult *match = [dotNetExpression firstMatchInString:string options:NSMatchingCompleted range:NSMakeRange(0, [string length])];
    if (!match)
        return nil;
    NSRange millisecRange = [match rangeAtIndex:1];
    if (!isValidRange(millisecRange))
        return nil;
    //NSRange timeZoneRange = [match rangeAtIndex:2];
    NSString *milliseconds = [string substringWithRange:millisecRange];
    return milliseconds;
}
@end


BOOL isValidRange(NSRange rangeOfMatch) {
    return (!NSEqualRanges(rangeOfMatch, NSMakeRange(NSNotFound, 0)));
}


NSTimeInterval secondsFromMilliseconds(NSTimeInterval millisecs) {
    return millisecs / 1000.f;
}


NSTimeInterval millisecondsFromSeconds(NSTimeInterval seconds) {
    return seconds * 1000.f;
}