#import "JSONHTTPClient.h"

#pragma mark - constants

NSString* const kHTTPMethodGET = @"GET";

NSString* const kHTTPMethodPOST = @"POST";

NSString* const kContentTypeAutomatic = @"jsonmodel/automatic";

NSString* const kContentTypeJSON = @"application/json";

NSString* const kContentTypeWWWEncoded = @"application/x-www-form-urlencoded";

#pragma mark - static variables

#ifdef __IPHONE_OS_VERSION_MAX_ALLOWED

static int defaultTextEncoding = NSUTF8StringEncoding;

static int defaultCachePolicy = NSURLRequestReloadIgnoringLocalCacheData;

#else

static long defaultTextEncoding = NSUTF8StringEncoding;

static long defaultCachePolicy = NSURLRequestReloadIgnoringLocalCacheData;

#endif

static int defaultTimeoutInSeconds = 60;

static BOOL doesControlIndicator = YES;

static NSMutableDictionary* requestHeaders = nil;

static NSString* requestContentType = nil;

#pragma mark - implementation

@implementation JSONHTTPClient

#pragma mark - initialization

+(void)initialize

{

static dispatch_once_t once;

dispatch_once(&once, ^{

requestHeaders = [NSMutableDictionary dictionary];

requestContentType = kContentTypeAutomatic;

});

}

#pragma mark - configuration methods

+(NSMutableDictionary*)requestHeaders

{

return requestHeaders;

}

+(void)setDefaultTextEncoding:(NSStringEncoding)encoding

{

defaultTextEncoding = encoding;

}

+(void)setCachingPolicy:(NSURLRequestCachePolicy)policy

{

defaultCachePolicy = policy;

}

+(void)setTimeoutInSeconds:(int)seconds

{

defaultTimeoutInSeconds = seconds;

}

+(void)setControlsNetworkIndicator:(BOOL)does

{

doesControlIndicator = does;

}

+(void)setRequestContentType:(NSString*)contentTypeString

{

requestContentType = contentTypeString;

}

#pragma mark - helper methods

+(NSString*)contentTypeForRequestString:(NSString*)requestString

{

//fetch the charset name from the default string encoding

NSString* contentType = requestContentType;

if ([contentType isEqualToString:kContentTypeAutomatic]) {

//check for "eventual" JSON array or dictionary

NSString* firstAndLastChar = [NSString stringWithFormat:@"%@%@",

[requestString substringToIndex:1],

[requestString substringFromIndex: requestString.length -1]

];

if ([firstAndLastChar isEqualToString:@"{}"] || [firstAndLastChar isEqualToString:@"[]"]) {

//guessing for a JSON request

contentType = kContentTypeJSON;

} else {

//fallback to www form encoded params

contentType = kContentTypeWWWEncoded;

}

}

//type is set, just add charset

NSString *charset = (NSString *)CFStringConvertEncodingToIANACharSetName(CFStringConvertNSStringEncodingToEncoding(NSUTF8StringEncoding));

return [NSString stringWithFormat:@"%@; charset=%@", contentType, charset];

}

+(NSString*)urlEncode:(id<NSObject>)value

{

//make sure param is a string

if ([value isKindOfClass:[NSNumber class]]) {

value = [(NSNumber*)value stringValue];

}

NSAssert([value isKindOfClass:[NSString class]], @"request parameters can be only of NSString or NSNumber classes. '%@' is of class %@.", value, [value class]);

return (NSString *)CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(

NULL,

(__bridge CFStringRef) value,

NULL,

(CFStringRef)@"!*'();:@&=+$,/?%#[]",

kCFStringEncodingUTF8));

}

#pragma mark - networking worker methods

+(NSData*)syncRequestDataFromURL:(NSURL*)url method:(NSString*)method requestBody:(NSString*)bodyString headers:(NSDictionary*)headers etag:(NSString**)etag error:(JSONModelError**)err

{

//turn on network indicator

if (doesControlIndicator) dispatch_async(dispatch_get_main_queue(), ^{[self setNetworkIndicatorVisible:YES];});

NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL: url

cachePolicy: defaultCachePolicy

timeoutInterval: defaultTimeoutInSeconds];

[request setHTTPMethod:method];

if ([requestContentType isEqualToString:kContentTypeAutomatic]) {

//automatic content type

if (bodyString) {

[request setValue: [self contentTypeForRequestString: bodyString] forHTTPHeaderField:@"Content-type"];

}

} else {

//user set content type

[request setValue: requestContentType forHTTPHeaderField:@"Content-type"];

}

//add all the custom headers defined

for (NSString* key in [requestHeaders allKeys]) {

[request setValue:requestHeaders[key] forHTTPHeaderField:key];

}

//add the custom headers

for (NSString* key in [headers allKeys]) {

[request setValue:headers[key] forHTTPHeaderField:key];

}

if (bodyString) {

//BODY params

NSData* bodyData = [bodyString dataUsingEncoding:defaultTextEncoding];

[request setHTTPBody: bodyData];

#ifdef __IPHONE_OS_VERSION_MAX_ALLOWED

[request setValue:[NSString stringWithFormat:@"%i", [bodyData length]] forHTTPHeaderField:@"Content-Length"];

#else

[request setValue:[NSString stringWithFormat:@"%ld", [bodyData length]] forHTTPHeaderField:@"Content-Length"];

#endif

}

//prepare output

NSHTTPURLResponse* response = nil;

//fire the request

NSData *responseData = [NSURLConnection sendSynchronousRequest: request

returningResponse: &response

error: err];

//convert an NSError to a JSONModelError

if (*err != nil) {

NSError* errObj = *err;

*err = [JSONModelError errorWithDomain:errObj.domain code:errObj.code userInfo:errObj.userInfo];

}

//turn off network indicator

if (doesControlIndicator) dispatch_async(dispatch_get_main_queue(), ^{[self setNetworkIndicatorVisible:NO];});

//if not OK status set the err to a JSONModelError instance

if (response.statusCode >= 300 || response.statusCode < 200) {

//create a new error

if (*err==nil) *err = [JSONModelError errorBadResponse];

}

//if there was an error, include the HTTP response and return

if (*err) {

//assign the response to the JSONModel instance

[*err setHttpResponse: [response copy]];

//empty respone, return nil instead

if ([responseData length]<1) {

return nil;

}

}

//return the data fetched from web

return responseData;

}

+(NSData*)syncRequestDataFromURL:(NSURL*)url method:(NSString*)method params:(NSDictionary*)params headers:(NSDictionary*)headers etag:(NSString**)etag error:(JSONModelError**)err

{

//create the request body

NSMutableString* paramsString = nil;

if (params) {

//build a simple url encoded param string

paramsString = [NSMutableString stringWithString:@""];

for (NSString* key in [[params allKeys] sortedArrayUsingSelector:@selector(compare:)]) {

[paramsString appendFormat:@"%@=%@&", key, [self urlEncode:params[key]] ];

}

if ([paramsString hasSuffix:@"&"]) {

paramsString = [[NSMutableString alloc] initWithString: [paramsString substringToIndex: paramsString.length-1]];

}

}

//set the request params

if ([method isEqualToString:kHTTPMethodGET] && params) {

//add GET params to the query string

url = [NSURL URLWithString:[NSString stringWithFormat: @"%@%@%@",

[url absoluteString],

[url query] ? @"&" : @"?",

paramsString

]];

}

//call the more general synq request method

return [self syncRequestDataFromURL: url

method: method

requestBody: [method isEqualToString:kHTTPMethodPOST]?paramsString:nil

headers: headers

etag: etag

error: err];

}

#pragma mark - Async network request

+(void)JSONFromURLWithString:(NSString*)urlString method:(NSString*)method params:(NSDictionary*)params orBodyString:(NSString*)bodyString completion:(JSONObjectBlock)completeBlock

{

[self JSONFromURLWithString:urlString

method:method

params:params

orBodyString:bodyString

headers:nil

completion:completeBlock];

}

+(void)JSONFromURLWithString:(NSString*)urlString method:(NSString*)method params:(NSDictionary*)params orBodyString:(NSString*)bodyString headers:(NSDictionary*)headers completion:(JSONObjectBlock)completeBlock

{

NSDictionary* customHeaders = headers;

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

NSDictionary* jsonObject = nil;

JSONModelError* error = nil;

NSData* responseData = nil;

NSString* etag = nil;

@try {

if (bodyString) {

responseData = [self syncRequestDataFromURL: [NSURL URLWithString:urlString]

method: method

requestBody: bodyString

headers: customHeaders

etag: &etag

error: &error];

} else {

responseData = [self syncRequestDataFromURL: [NSURL URLWithString:urlString]

method: method

params: params

headers: customHeaders

etag: &etag

error: &error];

}

}

@catch (NSException *exception) {

error = [JSONModelError errorBadResponse];

}

//step 3: if there's no response so far, return a basic error

if (!responseData && !jsonObject) {

//check for false response, but no network error

error = [JSONModelError errorBadResponse];

}

//step 4: if there's a response at this and no errors, convert to object

if (error==nil && jsonObject==nil) {

//convert to an object

jsonObject = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];

}

//step 4.5: cover an edge case in which meaningful content is return along an error HTTP status code

if (error && responseData && jsonObject==nil) {

//try to get the JSON object, while preserving the origianl error object

jsonObject = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:nil];

}

//step 5: invoke the complete block

dispatch_async(dispatch_get_main_queue(), ^{

if (completeBlock) {

completeBlock(jsonObject, error);

}

});

});

}

#pragma mark - request aliases

+(void)getJSONFromURLWithString:(NSString*)urlString completion:(JSONObjectBlock)completeBlock

{

[self JSONFromURLWithString:urlString method:kHTTPMethodGET

params:nil

orBodyString:nil completion:^(NSDictionary *json, JSONModelError* e) {

if (completeBlock) completeBlock(json, e);

}];

}

+(void)getJSONFromURLWithString:(NSString*)urlString params:(NSDictionary*)params completion:(JSONObjectBlock)completeBlock

{

[self JSONFromURLWithString:urlString method:kHTTPMethodGET

params:params

orBodyString:nil completion:^(NSDictionary *json, JSONModelError* e) {

if (completeBlock) completeBlock(json, e);

}];

}

+(void)postJSONFromURLWithString:(NSString*)urlString params:(NSDictionary*)params completion:(JSONObjectBlock)completeBlock

{

[self JSONFromURLWithString:urlString method:kHTTPMethodPOST

params:params

orBodyString:nil completion:^(NSDictionary *json, JSONModelError* e) {

if (completeBlock) completeBlock(json, e);

}];

}

+(void)postJSONFromURLWithString:(NSString*)urlString bodyString:(NSString*)bodyString completion:(JSONObjectBlock)completeBlock

{

[self JSONFromURLWithString:urlString method:kHTTPMethodPOST

params:nil

orBodyString:bodyString completion:^(NSDictionary *json, JSONModelError* e) {

if (completeBlock) completeBlock(json, e);

}];

}

+(void)postJSONFromURLWithString:(NSString*)urlString bodyData:(NSData*)bodyData completion:(JSONObjectBlock)completeBlock

{

[self JSONFromURLWithString:urlString method:kHTTPMethodPOST

params:nil

orBodyString:[[NSString alloc] initWithData:bodyData encoding:defaultTextEncoding]

completion:^(NSDictionary *json, JSONModelError* e) {

if (completeBlock) completeBlock(json, e);

}];

}

#pragma mark - iOS UI helper

+(void)setNetworkIndicatorVisible:(BOOL)isVisible

{

#ifdef __IPHONE_OS_VERSION_MAX_ALLOWED

[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:isVisible];

#endif

}