//
//  AcidCowFeedburnerParser.m
//  PicCast
//
//  Created by Matthew Handler on 4/15/11.
//  Copyright 2011 Earl Industries. All rights reserved.
//

#import "AcidCowFeedburnerParser.h"
#import "Topic.h"

@implementation AcidCowFeedburnerParser

@synthesize currentString, currentTopic, parseFormatter, xmlData, rssConnection, downloadAndParsePool;


- (void)downloadAndParse:(NSURL *)url {
    self.downloadAndParsePool = [[NSAutoreleasePool alloc] init];
    done = NO;
    self.parseFormatter = [[[NSDateFormatter alloc] init] autorelease];
    [parseFormatter setDateStyle:NSDateFormatterLongStyle];
    [parseFormatter setTimeStyle:NSDateFormatterNoStyle];
	[parseFormatter setDateFormat:@"EEE, d MMM yyyy HH:mm:ss Z"];
    // necessary because iTunes RSS feed is not localized, so if the device region has been set to other than US
    // the date formatter must be set to US locale in order to parse the dates
    [parseFormatter setLocale:[[[NSLocale alloc] initWithLocaleIdentifier:@"US"] autorelease]];
    self.xmlData = [NSMutableData data];
    //[[NSURLCache sharedURLCache] removeAllCachedResponses];
    NSURLRequest *theRequest = [NSURLRequest requestWithURL:url];
    // create the connection with the request and start loading the data
    rssConnection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
    [self performSelectorOnMainThread:@selector(downloadStarted) withObject:nil waitUntilDone:NO];
    if (rssConnection != nil) {
        do {
            [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
        } while (!done);
    }
    self.rssConnection = nil;
    self.parseFormatter = nil;
    self.currentTopic = nil;
    [downloadAndParsePool release];
    self.downloadAndParsePool = nil;
}

#pragma mark NSURLConnection Delegate methods

/*
 Disable caching so that each time we run this app we are starting with a clean slate. You may not want to do this in your application.
 */
//- (NSCachedURLResponse *)connection:(NSURLConnection *)connection willCacheResponse:(NSCachedURLResponse *)cachedResponse {
//    return nil;
//}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    done = YES;
    [self performSelectorOnMainThread:@selector(parseError:) withObject:error waitUntilDone:NO];
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [xmlData appendData:data];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
	NSLog(@"finishedLoading");
    [self performSelectorOnMainThread:@selector(downloadEnded) withObject:nil waitUntilDone:NO];
	[self convertXMLData];
	
    NSXMLParser *parser = [[NSXMLParser alloc] initWithData:xmlData];
    parser.delegate = self;
    self.currentString = [NSMutableString string];
    //NSTimeInterval start = [NSDate timeIntervalSinceReferenceDate];
    [parser parse];
    //NSTimeInterval duration = [NSDate timeIntervalSinceReferenceDate] - start;
    //[self performSelectorOnMainThread:@selector(addToParseDuration:) withObject:[NSNumber numberWithDouble:duration] waitUntilDone:NO];
    [self performSelectorOnMainThread:@selector(parseEnded) withObject:nil waitUntilDone:NO];
    [parser release];
    self.currentString = nil;
    self.xmlData = nil;
    // Set the condition which ends the run loop.
    done = YES; 
}

// needed to convert feedburners xml into utf-8 because the iphone parser breaks on windows-1251
- (void)convertXMLData {
	NSString *string = [[NSString alloc] initWithData:xmlData encoding:NSWindowsCP1251StringEncoding];
	string = [string stringByReplacingOccurrencesOfString:@"encoding=\"windows-1251\"" withString:@""];
	
	//	[xmlData release];
	//	xmlData = nil;
	xmlData = [[NSMutableData dataWithData:[string dataUsingEncoding:NSUTF8StringEncoding]] retain];
}

#pragma mark Parsing support methods

static const NSUInteger kAutoreleasePoolPurgeFrequency = 20;

- (void)finishedCurrentTopic {
    [self performSelectorOnMainThread:@selector(parsedTopic:) withObject:currentTopic waitUntilDone:NO];
    // performSelectorOnMainThread: will retain the object until the selector has been performed
    // setting the local reference to nil ensures that the local reference will be released
    self.currentTopic = nil;
    countOfParsedTopics++;
    // Periodically purge the autorelease pool. The frequency of this action may need to be tuned according to the 
    // size of the objects being parsed. The goal is to keep the autorelease pool from growing too large, but 
    // taking this action too frequently would be wasteful and reduce performance.
    if (countOfParsedTopics == kAutoreleasePoolPurgeFrequency) {
        [downloadAndParsePool release];
        self.downloadAndParsePool = [[NSAutoreleasePool alloc] init];
        countOfParsedTopics = 0;
    }
}

#pragma mark NSXMLParser Parsing Callbacks

// Constants for the XML element names that will be considered during the parse. 
// Declaring these as static constants reduces the number of objects created during the run
// and is less prone to programmer error.
static NSString *kName_Item = @"item";
static NSString *kName_Title = @"title";
static NSString *kName_Category = @"category";
static NSString *kName_Creator = @"dc:creator";
static NSString *kName_Description = @"description";
static NSString *kName_ReleaseDate = @"pubDate";
static NSString *kName_Guid = @"guid";

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *) qualifiedName attributes:(NSDictionary *)attributeDict {
    //NSLog(@"%@", elementName);
	if ([elementName isEqualToString:kName_Item]) {
        self.currentTopic = [[[Topic alloc] init] autorelease];
    } else if ([elementName isEqualToString:kName_Title] 
			   || [elementName isEqualToString:kName_Category] 
			   || [elementName isEqualToString:kName_Guid] 
			   || [elementName isEqualToString:kName_Creator] 
			   || [elementName isEqualToString:kName_Description] 
			   || [elementName isEqualToString:kName_ReleaseDate]) {
        [currentString setString:@""];
        storingCharacters = YES;
    }
}

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName {
    if ([elementName isEqualToString:kName_Item]) {
        [self finishedCurrentTopic];
    } else if ([elementName isEqualToString:kName_Title]) {
		NSRegularExpression* regex = [NSRegularExpression regularExpressionWithPattern:@"[^(]+" 
																			   options:NSRegularExpressionCaseInsensitive 
																				 error:nil];
		NSArray *results = [regex matchesInString:currentString options:0 range:NSMakeRange(0, [currentString length])];
		if ([results count] > 0) {
			NSString *title = [currentString substringWithRange:[[results objectAtIndex:0] range]];
			currentTopic.title = title;
		}
		
		NSRegularExpression* regex2 = [NSRegularExpression regularExpressionWithPattern:@"(?<=\\()\\d+" 
																			   options:NSRegularExpressionCaseInsensitive 
																				 error:nil];
		NSArray *results2 = [regex2 matchesInString:currentString options:0 range:NSMakeRange(0, [currentString length])];
		if ([results2 count] > 0) {
			NSString *count = [currentString substringWithRange:[[results2 objectAtIndex:0] range]];
			currentTopic.picCount = [NSNumber numberWithInt:[count intValue]];
			//NSLog(@"%@", count);
		}
		else
			currentTopic.picCount = [NSNumber numberWithInt:1];
		
        //currentTopic.title = currentString;
    } else if ([elementName isEqualToString:kName_Category]) {
        currentTopic.category = currentString;
	} else if ([elementName isEqualToString:kName_Guid]) {
		currentTopic.guid = currentString;
    } else if ([elementName isEqualToString:kName_Creator]) {
        //currentTopic.creator = currentString;
    } else if ([elementName isEqualToString:kName_Description]) {
		NSRegularExpression* regex = [NSRegularExpression regularExpressionWithPattern:@"http\\S+(jpg|png|gif|jpeg)" 
																			   options:NSRegularExpressionCaseInsensitive 
																				 error:nil];
		NSArray *results = [regex matchesInString:currentString options:0 range:NSMakeRange(0, [currentString length])];
//		for (NSTextCheckingResult *res in results) {
//			NSLog(@"regexed: %@", [currentString substringWithRange:res.range]);
//		}
		if ([results count] > 0) {
			NSString *url = [currentString substringWithRange:[[results objectAtIndex:0] range]];
			//NSLog(@"%@", url);
			currentTopic.iconUrl = url;
		}
        currentTopic.description = currentString;
    } else if ([elementName isEqualToString:kName_ReleaseDate]) {
        currentTopic.releaseDate = [parseFormatter dateFromString:currentString];
    }
    storingCharacters = NO;
}

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string {
	//NSLog(@"foundCharacters: %@", string); // storing string is when you want the inner text
    if (storingCharacters) [currentString appendString:string];
}

/*
 A production application should include robust error handling as part of its parsing implementation.
 The specifics of how errors are handled depends on the application.
 */
- (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError {
	NSLog(@"parseError: %@", parseError);
    // Handle errors as appropriate for your application.
}

@end