//
//  ForwardGeocode.h
//

#import <Foundation/Foundation.h>
#import <libxml/xmlmemory.h>
#import <libxml/parser.h>
#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>

@interface ForwardGeocode : NSObject {
    double _Latitude;
    double _Longitude;
}
- (BOOL) geoCodeZip :(NSString *) zip;
- (double) Latitude;
- (double) Longitude;
- (void) setLatitude : (double) latitude;
- (void) setLongitude: (double) longitude;

@end

//
//  ForwardGeocode.m
//

#import "ForwardGeocode.h"

// Yahoo! PlaceFinder zip code query should look like this
// http://where.yahooapis.com/geocode?appid=ReplaceWithYourAppID&zip=66045

#define PLACEFINDERURL  @"http://where.yahooapis.com/geocode?appid=ReplaceWithYourAppID"

@implementation ForwardGeocode

- (double) Latitude
{
	return _Latitude;
}

- (double) Longitude
{
	return _Longitude;
}

- (void) setLatitude : (double) latitude
{
	_Latitude = latitude;
}

- (void) setLongitude: (double) longitude
{
	_Longitude = longitude;
}

void getOneResult(ForwardGeocode *geoCoder, xmlNodePtr curr, xmlDocPtr doc)
{
	curr = curr->xmlChildrenNode;
	xmlChar *_long, *_lat;
	
	
	if (!curr) return;
	
	while (curr && (curr->type == XML_TEXT_NODE))
		curr = curr->next;
	
	if (!curr) return;

      // skip to Latitude
      while (curr && xmlStrcmp(curr->name, (const xmlChar *)"latitude"))
      {
          curr = curr->next;
      }

      if (!curr)
          return;
	
	// Get Latitude
	if ((!xmlStrcmp(curr->name, (const xmlChar *)"latitude")) && (curr->type == XML_ELEMENT_NODE))
	{
	    _lat = xmlNodeListGetString(doc, curr->xmlChildrenNode, 1);
		
		curr = curr->next;
		while (curr && (curr->type == XML_TEXT_NODE))
			curr = curr->next;
	    if (!curr)
		{
			
			xmlFree(_lat);
			return;
		}
	} else return;

      // skip to Longitude (we know Latitude preceeds Longitude in the return set)
      while (curr && xmlStrcmp(curr->name, (const xmlChar *)"longitude"))
      {
          curr = curr->next;
      }
	
	// Get Longitude
	if ((!xmlStrcmp(curr->name, (const xmlChar *)"longitude")) && (curr->type == XML_ELEMENT_NODE))
	{
	    _long = xmlNodeListGetString(doc, curr->xmlChildrenNode, 1);
		curr = curr->next;
		while (curr && (curr->type == XML_TEXT_NODE))
			curr = curr->next;
	    if (!curr)
		{
			xmlFree(_lat);
			xmlFree(_long);
			return;
		}
	} else return;
	
	
	// Unusual coordinates for the US much less planet Earth
	double lat = -111111.0, llong = -111111.0;
	
	if (_lat) 
		lat = strtod( (const char *)_lat, NULL );
	
	if (_long) 
		llong = strtod( (const char *)_long, NULL );
	
	if ((lat != -111111.0) && (llong != -111111.0))
	{
		[geoCoder setLatitude:lat];
		[geoCoder setLongitude:llong];
	}
	
    xmlFree(_lat);
    xmlFree(_long);
}

// ResultSet is the top level container for the result
// Result contains elements associated with a single match result.
void getResult(ForwardGeocode *geoCoder, xmlNodePtr curr, xmlDocPtr doc)
{
	// null basis, we're done
	if (!curr) return;
	
	// This is the Result container, get the latitude and longitude by calling getOneResult
	if ((!xmlStrcmp(curr->name, (const xmlChar *)"Result")) && (curr->type == XML_ELEMENT_NODE))
	{
		getOneResult(geoCoder, curr, doc);
	}
	
	// This is a text node we're not interested in
	if (curr->type == XML_TEXT_NODE)
	{
		getResult(geoCoder, curr->next, doc);
	}
	
	// Top level element. We're interested in "Result" and "ResultSet"
	// Don't recurse down into other types (Error, ErrorMessage, Locale, Quality, or Found)
			
	if (curr->type == XML_ELEMENT_NODE)
	{
		if ((!xmlStrcmp(curr->name, (const xmlChar *)"Result")))
	    {
		    getResult(geoCoder, curr->next, doc);	
		}
		else if (!xmlStrcmp(curr->name, (const xmlChar *)"ResultSet"))
		{
			getResult(geoCoder, curr->xmlChildrenNode, doc);
		}
	}
	return;
}


- (BOOL) geoCodeZip :(NSString *) zip
{
	NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
	
	BOOL error = YES;
	NSError *err = nil;	
	NSString *baseString = PLACEFINDERURL;
	NSString *zipURL = [baseString stringByAppendingFormat:
						@"&zip=%@", zip];
	
	NSURL* url = [NSURL URLWithString:zipURL];

      if (!url) 
          return error;

	NSString *URLContents = [NSString stringWithContentsOfURL:url
					encoding:NSUTF8StringEncoding error:&err];
	
	if (!URLContents || ([URLContents length] == 0))
	{
		return error;
	}
	
	const char *XMLChars = [URLContents cStringUsingEncoding:NSUTF8StringEncoding];
	xmlDocPtr doc = xmlParseMemory(XMLChars, strlen(XMLChars));
	xmlNodePtr cur;
	if (doc == NULL)
	{
		return error;
	}
	cur = xmlDocGetRootElement(doc);
	if (cur)
	{
		_Latitude = -1.0;
		_Longitude = -1.0;
		getResult(self, cur, doc);
		if ((_Latitude != -1.0) || (_Longitude != -1.0))
		{
			error = NO;
		}
			
	}
			
	xmlFreeDoc(doc);
			
	[pool release];
	return error;
}



			
@end