/*
 * fractal-gen - Generate iteration-based fractals in PNM format
 * Copyright (c) 2015 David Phillips <dbphillipsnz@gmail.com>
 * All rights reserved
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "fractal-gen.h"

struct section_generator
{
	char *executable_name;
	void *(*generator)(void *);
};

int main(int argc, char **argv)
{
	unsigned int size, iterat, cores, i, x, y;
	unsigned int clust_id, clust_total;
	double power;
	char* bname;
	data_section* sections;
	void *(*generator)(void *);

	struct section_generator generators[] = {
		{ "mandelbrot-gen" , &generate_mandelbrot_section },
		{ "burning-ship-gen" , &generate_burning_ship_section },
		{ "burning-ship-lattice-gen" , &generate_burning_ship_lattice_section },
		{ "tricorn-gen" , &generate_tricorn_section }
		};

	// Select correct generator for the fractal type
	bname = basename(argv[0]);
	generator = NULL;
	for (i = 0; i < sizeof(generators)/sizeof(struct section_generator); i++)
		if (strcmp(bname, generators[i].executable_name) == 0)
			generator = generators[i].generator;

	if (generator == NULL)
	{
		fprintf(stderr, "Don't call this directly, call a symlink to me\n");
		return EXIT_FAILURE;
	}

	if (argc != 4 && argc != 5 && argc != 7)
	{
		fprintf(stderr, "%s size iterat power [threads]\n"
		                "%s size iterat power threads cluster-id] cluster-total\n", argv[0], argv[0]);
		return EXIT_FAILURE;
	}

	size   = atoi(argv[1]);
	iterat = atoi(argv[2]);
	power  = atof(argv[3]);

	/* Fetch or use defaults for
	 * - num cores available
	 * - our ID in cluster
	 * - total members in cluster
	 */
	cores = (argc == 5 || argc == 7)? atoi(argv[4]) : sysconf(_SC_NPROCESSORS_ONLN); 	// Screw maintainability ;)
	clust_id = argc == 7? atoi(argv[5]) : 0;
	clust_total = argc == 7? atoi(argv[6]) : 1;

	// Interlacing is column-based, can't have more workers than columns
	if (cores > size)
	{
		fprintf(stderr, "WARN: Capping number of threads to image width\n");
		cores = size;
	}

	assert(size > 0);
	assert(iterat > 0);
	assert(cores > 0);

	// Allocate memory for sections
	if ((sections = malloc(sizeof(data_section)*cores)) == NULL)
	{
		perror("malloc");
		return EXIT_FAILURE;
	}

	// Spawn all the threads! Something something interlacing
	fprintf(stderr, "Spawning %d threads:\n", cores);
	for (i = 0; i < cores; i++)
	{
		// Has to be a better way
		sections[i].core = i;
		sections[i].cores = cores;
		sections[i].clust_id = clust_id;
		sections[i].clust_total = clust_total;
		sections[i].size = size;
		sections[i].power = power;
		sections[i].iterat = iterat;

		// A bit complex, icky, will document later
		if (i < (size%cores))
			x = (size*((int)(size/cores)+1));
		else
			x = (size*(int)(size/cores));

		if ((sections[i].data = malloc(x)) == NULL)
		{
			fprintf(stderr, "\n");
			perror("malloc");
			// Free already allocated chunks of memory
			i--;
			while(i-- + 1)
				free(sections[i].data);

			free(sections);
			return EXIT_FAILURE;
		}
		fprintf(stderr, " -> Thread #%d (%d bytes data area)\r", i+1, x);
		pthread_create(&sections[i].thread, NULL, generator, &(sections[i]));
	}

	// Wait for each thread to complete
	for (i = 0; i < cores; i++)
		pthread_join(sections[i].thread, NULL);


	// Output PGM Header
	printf("P5\n%d\n%d\n255\n",size/clust_total,size);

	// Vomit the data segments back onto the screen, deinterlacing
	// TO DO: look at fwrite performance benefits over putchar
	for (y = 0; y < size; y++)
	{
		for (x = 0; x < size/clust_total; x++)
		{
			putchar(sections[y%cores].data[(y/cores)*(size/clust_total) + x]);
		}
	}

	fprintf(stderr, "\nDone\n");

	// Free the memory we allocated for point data
	for (i = 0; i < cores; i++)
		free(sections[i].data);

	free(sections);
	return 0;
}