#import "DDCurrencyUnitConverter.h"
#import <dispatch/dispatch.h>
@interface DDCurrencyUnitConverterConnectionDelegate : NSObject {
@private
NSError *error;
NSMutableData *data;
NSStringEncoding encoding;
BOOL finished;
}
@property (nonatomic, getter=isFinished) BOOL finished;
@property (nonatomic, retain) NSError *error;
@property (nonatomic, readonly) NSString *string;
@end
@implementation DDCurrencyUnitConverterConnectionDelegate
@synthesize finished;
@synthesize error;
- (id)init {
self = [super init];
if (self) {
encoding = NSMacOSRomanStringEncoding;
[self setFinished:NO];
}
return self;
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSHTTPURLResponse *)response {
NSString *contentLength = [[response allHeaderFields] objectForKey:@"Content-Length"];
NSUInteger length = [contentLength intValue];
data = [[NSMutableData alloc] initWithLength:length];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)chunk {
[data appendData:chunk];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
[self setError:nil];
[self setFinished:YES];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)anError {
[self setError:anError];
[self setFinished:YES];
}
- (NSString *)string {
return [[[NSString alloc] initWithData:data encoding:encoding] autorelease];
}
- (void)dealloc {
[error release];
[data release];
[super dealloc];
}
@end
static NSString *_DDCurrencyNames[] = {
@"Euro",
@"Japanese Yen",
@"U.K. Pound Sterling",
@"U.S. Dollar",
@"Algerian Dinar",
@"Argentine Peso",
@"Australian Dollar",
@"Bahrain Dinar",
@"Botswana Pula",
@"Brazilian Real",
@"Brunei Dollar",
@"Canadian Dollar",
@"Chilean Peso",
@"Chinese Yuan",
@"Colombian Peso",
@"Czech Koruna",
@"Danish Krone",
@"Hungarian Forint",
@"Icelandic Krona",
@"Indian Rupee",
@"Indonesian Rupiah",
@"Iranian Rial",
@"Israeli New Sheqel",
@"Kazakhstani Tenge",
@"Korean Won",
@"Kuwaiti Dinar",
@"Libyan Dinar",
@"Malaysian Ringgit",
@"Mauritian Rupee",
@"Mexican Peso",
@"Nepalese Rupee",
@"New Zealand Dollar",
@"Norwegian Krone",
@"Rial Omani",
@"Pakistani Rupee",
@"Nuevo Sol",
@"Philippine Peso",
@"Polish Zloty",
@"Qatar Riyal",
@"Russian Ruble",
@"Saudi Arabian Riyal",
@"Singapore Dollar",
@"South African Rand",
@"Sri Lanka Rupee",
@"Swedish Krona",
@"Swiss Franc",
@"Thai Baht",
@"Trinidad And Tobago Dollar",
@"Tunisian Dinar",
@"U.A.E. Dirham",
@"Peso Uruguayo",
@"Bolivar Fuerte",
@"SDR"
};
static NSMutableDictionary *_DDCurrencyExchangeRates = nil;
static dispatch_queue_t updateQueue = nil;
@implementation DDUnitConverter (DDCurrencyUnitConverter)
+ (id) currencyUnitConverter {
return [[[DDCurrencyUnitConverter alloc] init] autorelease];
}
@end
@implementation DDCurrencyUnitConverter
+ (NSString *)nameOfCurrencyUnit:(DDCurrencyUnit)unit {
if (unit > DDCurrencyUnitSDR) { return nil; }
return _DDCurrencyNames[unit];
}
+ (NSError *) refreshExchangeRatesInBackground {
if ([NSThread currentThread] == [NSThread mainThread]) { return nil; }
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
NSURL * imfURL = [NSURL URLWithString:@"http://www.imf.org/external/np/fin/data/rms_five.aspx?tsvflag=Y"];
NSURLRequest *imfRequest = [NSURLRequest requestWithURL:imfURL];
DDCurrencyUnitConverterConnectionDelegate *tmpDelegate = [[DDCurrencyUnitConverterConnectionDelegate alloc] init];
NSURLConnection *imfConnection = [[NSURLConnection alloc] initWithRequest:imfRequest delegate:tmpDelegate];
while ([tmpDelegate isFinished] == NO) {
[[NSRunLoop currentRunLoop] runUntilDate:[NSDate date]];
}
[imfConnection release];
NSString *raw = [tmpDelegate string];
NSError *error = [tmpDelegate error];
if (error == nil) {
NSArray * rows = [raw componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]];
BOOL hasStartedCulling = NO;
short rowIndex = 0;
for (NSString * row in rows) {
if ([row length] == 0) { continue; }
if (hasStartedCulling == NO) {
if ([row hasPrefix:@"Currency"]) {
hasStartedCulling = YES;
}
} else {
if ([row hasPrefix:@"Currency"]) {
break;
} else {
NSArray * fields = [row componentsSeparatedByString:@"\t"];
NSString *currencyName = [fields objectAtIndex:0];
double conversionValue = 0.0f;
for (int i = 1; i < [fields count]; ++i) {
NSString * field = [fields objectAtIndex:i];
if ([field length] > 0) {
conversionValue = [field doubleValue];
break;
}
}
[_DDCurrencyExchangeRates setObject:[NSDecimalNumber numberWithDouble:conversionValue] forKey:currencyName];
rowIndex++;
}
}
}
}
[error retain];
[tmpDelegate release];
[pool drain];
return [error autorelease];
}
+ (void) initialize {
if (self == [DDCurrencyUnitConverter class]) {
updateQueue = dispatch_queue_create("com.davedelong.ddunitconverter", 0);
_DDCurrencyExchangeRates = [[NSMutableDictionary alloc] init];
dispatch_async(updateQueue, ^{
[self refreshExchangeRatesInBackground];
});
}
}
+ (NSDecimalNumber *) multiplierForUnit:(DDUnit)unit {
NSDecimalNumber * multiplier = [NSDecimalNumber one];
if (unit < DDCurrencyUnitSDR) {
NSString *name = _DDCurrencyNames[unit];
multiplier = [_DDCurrencyExchangeRates objectForKey:name];
if (multiplier == nil) {
NSLog(@"unknown currency: %@ (%lu)", name, unit);
multiplier = [NSDecimalNumber one];
}
}
return multiplier;
}
- (NSNumber *) convertNumber:(NSNumber *)number fromUnit:(DDUnit)from toUnit:(DDUnit)to {
dispatch_sync(updateQueue, ^{ });
return [super convertNumber:number fromUnit:from toUnit:to];
}
- (void) refreshExchangeRates {
[self refreshExchangeRatesWithCompletion:NULL];
}
- (void)refreshExchangeRatesWithCompletion:(void (^)(NSError *))completionHandler {
dispatch_queue_t currentQueue = dispatch_get_main_queue();
completionHandler = [completionHandler copy];
dispatch_async(updateQueue, ^{
NSError *error = [[self class] refreshExchangeRatesInBackground];
if (completionHandler != NULL) {
//wrap the completion handler in another block so we can capture the error
dispatch_block_t block = ^{
completionHandler(error);
};
dispatch_async(currentQueue, block);
}
});
[completionHandler release];
}
