//
//  Spectographer.m
//  SpectogramPrototype
//
//  Created by Joshua Moerman on 29/12/13.
//  Copyright (c) 2013 Joshua Moerman. All rights reserved.
//

#import "Spectographer.h"
#import "FFTTest.h"
#import "AudioFile.h"

UInt8 clamp_to_uint8(float x){
	if(x >= 1.0) return 255;
	if(x <= 0.0) return 0;
	return 255.0 * x;
}

@interface Spectographer (){
	FFTTest * FFTHandler;
	AudioFile * audioFile;
	float * left;
	float * right;
}

@end

@implementation Spectographer

- (id)init{
	if(self = [super init]){
		FFTHandler = [[FFTTest alloc] init];
		left = calloc(FFTHandler.acceptedSize, sizeof(float));
		right = calloc(FFTHandler.acceptedSize, sizeof(float));
	}
	return self;
}

- (void)openAudioFile:(NSURL *)url{
	audioFile = [AudioFile audioFileFromURL: url];
	assert(audioFile);
}

- (CGImageRef)generate{
	unsigned int size = FFTHandler.acceptedSize;
	unsigned int width = size/4;
	unsigned int height = size/8;
	
	char * rgba = calloc(width*height*4, sizeof(char));
	
	for(unsigned int x = 0; x < width; ++x){
		[audioFile fillLeft:left andRight:right withNumberOfSamples:size];
		[FFTHandler inPlaceFFT:left forSize:size];
		[FFTHandler inPlaceFFT:right forSize:size];
		for(unsigned int y = 0; y < height; ++y){
			unsigned int yy = height - y - 1;
			rgba[4*width*yy + 4*x + 0] = clamp_to_uint8(100.0 * left[y]);
			rgba[4*width*yy + 4*x + 1] = clamp_to_uint8(100.0 * right[y]);
			rgba[4*width*yy + 4*x + 2] = clamp_to_uint8(10.0 * (left[y] + right[y]));
			rgba[4*width*yy + 4*x + 3] = 0;
		}
	}
	
	CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
	assert(colorSpace);
	CGContextRef bitmapContext = CGBitmapContextCreate(rgba, width, height, 8, 4*width, colorSpace, (CGBitmapInfo)kCGImageAlphaNoneSkipLast);
	assert(bitmapContext);
	CGImageRef cgImage = CGBitmapContextCreateImage(bitmapContext);
	assert(cgImage);
	
	CGContextRelease(bitmapContext);
	CGColorSpaceRelease(colorSpace);
	free(rgba);
	
	return cgImage;
}

@end