//
//  BBCVSExporter.m
//
//  Created by Matt on 12/3/09.

#import "BBCSVExporter.h"

@implementation BBCSVExporter

+(id)exporter
{
	return [[[BBCSVExporter alloc] init] autorelease];
}

-(void)exportArrayAsCSV:(NSArray*)data toFile:(NSString*)filePath
{
	//data in this case should be an NSArray, each item of which is another NSArray, which contains
	//the field data
	//every single subarray should have exactly the same number of items (number of columns)
	//each item of the parent 'data' array is a row
	
	//This method is a bit bulky and simply provides a 'shortcut',
	//anyone processing huge amounts of data may want to refine for more efficient memory use
	
	NSMutableArray *a = [NSMutableArray array];
	NSEnumerator *e = [data objectEnumerator];
	int colCount = [[data objectAtIndex: 0] count];
	NSArray *a2;
	while((a2 = [e nextObject]))
	{
		[a addObjectsFromArray: a2];
	}
	[self exportArrayAsCSV: a numberOfColumns: colCount toFile: filePath];
}

-(void)exportArrayAsCSV:(NSArray*)data numberOfColumns:(int)cols toFile:(NSString*)filePath
{
	if(cols <= 0)
		return;
	if(!data)
		return;
	if(![data count])
		return;
	if(!filePath)
		return;
	if(![filePath length])
		return;
	
	NSEnumerator *e = [data objectEnumerator];
	id obj;
	NSMutableString *str = [NSMutableString string];
	int c = 0;
	NSMutableString *d;
	Class numberClass = [NSNumber class];
	NSMutableString *emptyStr = [NSMutableString stringWithString: @""];
	NSUInteger rep1, rep2, rep3;
	
	//******
	//Note: handling here is not terribly efficient, but it is designed for simplicity
	//and code readability. Users exporting large amounts of data may want to refine this
	//for smarter memory/CPU usage
	//******
	while((obj = [e nextObject]))
	{	
		if([[obj class] isKindOfClass: numberClass])
		{			
			//grab the string value and skip over any comma/quotation/NL checks
			d = [NSMutableString stringWithString: [obj stringValue]];
		}
		else if(obj == [NSNull null])
		{
			d = emptyStr;
		}
		else
		{
			//grab the object's human-readable form:
			d = [NSMutableString stringWithString: [obj description]];
			
			//adjust for commas and quotes if needed
			rep1 = rep2 = rep3 = 0;
			rep1 = [d replaceOccurrencesOfString: @"\"" withString:@"\"\"" options: 0 range: NSMakeRange(0,[d length])];
			if(!rep1) //do we need to enclose?
			{
				//check for commas
				rep2 = [d rangeOfString: @","].length;
				if(!rep2)
				{
					//check for newlines
					rep3 = [d rangeOfString: @"\n"].length;
				}
			}
			if(rep1 || rep2 || rep3)
			{				 
				//enclose string in quotes
				[d setString: [NSString stringWithFormat: @"\"%@\"",d]];
			}
		
		}
		
		[str appendString: d];		
		c++;
		if(c == cols)
		{
			//new row, go to a new line
			[str appendString: @"\n"];
			c = 0;
		}
		else
		{
			//new field, add a coma
			[str appendString: @","];
		}
	}
	
	//done creating string data, now output file:
	NSError *err = nil;
	NSString *finalPath;
	//lets make sure we have the proper file extension here:
	if(![[[filePath pathExtension] lowercaseString] isEqualToString: @"csv"])
	{
		finalPath = [filePath stringByDeletingPathExtension];
		finalPath = [finalPath stringByAppendingPathExtension: @"csv"];
	}
	else
	{
		//OK
		finalPath = filePath;
	}
	[str writeToFile: finalPath atomically: YES encoding: NSUTF8StringEncoding error: &err];
	if(err)
	{
		NSLog(@"err");
	}
}
@end