#import "Log.h"
#import "Preferences.h"

@implementation Log

- (id)init {

	[super init];

	[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(updateLog:) name:NSFileHandleReadCompletionNotification object:nil];
	
	currentLog = [[NSMutableString stringWithString:@""] retain];
	
	return self;
}

- (void) dealloc {

	[currentLog release];
	
	if(leftoverLogString)
		[leftoverLogString release];

	[super dealloc];
}

// Places standard output into the log window when notified
- (void)updateLog:(NSNotification *)notification {

	// Create string from new data
	NSData *data = [[notification userInfo] objectForKey:NSFileHandleNotificationDataItem];
	NSString *newPiece = [[[NSString alloc] initWithData:data encoding:[NSString defaultCStringEncoding]] autorelease];
	
	// If there's no data and there is no leftover log data, then we're done
	if(![data length] && !leftoverLogString) return;
	
	// Check to see if there is a chunk left over from the last time this method was called and append it to the beginning
	if(leftoverLogString) {
		newPiece = [leftoverLogString stringByAppendingString:newPiece];
		[leftoverLogString release];
		leftoverLogString = nil;
	}
		
	// Check to make sure the string ends with a newline character; save the last chunk if it doesn't
	if([newPiece characterAtIndex:[newPiece length] - 1] != '\n') {
		int startIndex = [newPiece rangeOfCharacterFromSet:[NSCharacterSet characterSetWithCharactersInString:@"\n"] options:NSBackwardsSearch].location + 1;
		// If there is no newline character then the whole thing will be leftover and the new piece will be blank
		if(startIndex - 1 == NSNotFound) {
			leftoverLogString = [newPiece retain];
			[[notification object] readInBackgroundAndNotify];
			return;
		}
		
		// Otherwise, everything after the last return is leftover; trim the current string accordingly
		else {
			leftoverLogString = [[newPiece substringWithRange:NSMakeRange(startIndex, [newPiece length] - startIndex)] retain];
			newPiece = [newPiece substringWithRange:NSMakeRange(0, startIndex)];
		}
	}
		
	// Adds the new piece to the current log
	[currentLog appendString:newPiece];	
	
	// Handles log buffer, chops off lines at the beginning if needed
	if([[Preferences prefs] integerForKey:@"logBufferSize"] > -1) {
		unsigned numberOfLines, index, stringLength = [currentLog length];
		for (index = 0, numberOfLines = 0; index < stringLength; numberOfLines++)
			index = NSMaxRange([currentLog lineRangeForRange:NSMakeRange(index, 0)]);
		if(numberOfLines > [[Preferences prefs] integerForKey:@"logBufferSize"]) {
			int numberOfLinesToChop = numberOfLines - [[Preferences prefs] integerForKey:@"logBufferSize"];
			int endIndex = 0;
			while(numberOfLinesToChop--) {
				endIndex = [currentLog rangeOfString:@"\n" options:nil range:NSMakeRange(endIndex, [currentLog length] - endIndex)].location + 1;
			}
			[currentLog deleteCharactersInRange:NSMakeRange(0, endIndex)];
		}
	}
	
	[[NSNotificationCenter defaultCenter] postNotificationName:@"logUpdated" object:currentLog];
	
	[[notification object] readInBackgroundAndNotify];	
}

- (NSString *)currentLog {
	return currentLog;
}

@end