#include "../globals.h"

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define PLUGIN_NAME "Stream"

glob_statics   my_g_stat;
glob_variables my_g_var;

// global variables
colour_hex col[256][19];    // Star, Source, Trigger, 16 targets
int        glob_idx = 0;

Uint8 my_getpixel(SDL_Surface* surface, int x, int y) {
	int    bpp = surface->format->BytesPerPixel;
	Uint8* p   = (Uint8*)surface->pixels + y * surface->pitch + x * bpp;
	/* Here p is the address to the pixel we want to retrieve */

	switch (bpp) {
	case 1:
		return *p;
	default:
		return 0; /* shouldn't happen, but avoids warnings */
	}
}

void init_plugin(glob_statics* g_stat) {
	// required since it is called specifically at load time
	// update the local glob_statics so that other functions can access it as
	// well.
	my_g_stat.debug       = g_stat->debug;
	my_g_stat.filein      = g_stat->filein;
	my_g_stat.fileout     = g_stat->fileout;
	my_g_stat.config_file = g_stat->config_file;
	my_g_stat.image_in    = g_stat->image_in;

	if (my_g_stat.debug) {
		printf("Loading %s\n", PLUGIN_NAME);
	}

	if (my_g_stat.debug > 3) {
		printf("Checking the global stats for %s\n", PLUGIN_NAME);
		printf("\tdebug = %d\n", my_g_stat.debug);
		printf("\tfilein = %s\n", my_g_stat.filein);
		printf("\tfileout = %s\n", my_g_stat.fileout);
		printf("\tconfig_file = %s\n", my_g_stat.config_file);
	}
}

void deinit_plugin(void) {
	// required since it is called specifically at unload time
	if (my_g_stat.debug) {
		printf("Unloading %s\n", PLUGIN_NAME);
	}
}

int plugin_parse(char* line) {
	// required
	// will prepare the plugin to know what to send back when receiving a
	// colour_hex in plugin_apply

	const int    size     = strlen(line);
	int          newrec   = 1;
	int          let      = 0;
	unsigned int idx      = 0;
	char         color[7] = {0};
	colour_hex   r        = 0;
	colour_hex   g        = 0;
	colour_hex   b        = 0;

	// in this case we know we should receive 18 parameters
	// 1 for slave, 1 for master and 16 for the resulting colour

	if (my_g_stat.debug > 3) {
		printf("Parsing %s\n", line);
	}

	col[glob_idx][0] = 0;
	for (int i = 0; i <= size; i++) {
		char c = (i == size ? '\n' : line[i]);
		if (c != ' ' && c != '\t' && c != '\n' && c != '\r') {
			if (newrec) {
				newrec = 0;
				idx++;
			}
			if (let < 6) {
				color[let] = c;
			}
			let++;
		} else {
			if (newrec == 0) {
				color[let] = '\0';
				if (idx == 2 && let > 0 && color[0] == '*') {
					col[glob_idx][0]   = 1;
					col[glob_idx][idx] = 0;
				} else {
					sscanf(color, "%02x%02x%02x", &r, &g, &b);
					col[glob_idx][idx] = ((r << 16) | (g << 8) | (b));
				}
			}
			newrec = 1;
			let    = 0;
		}
	}

	glob_idx++;

	return 0;
}

int calculate(Uint8 col_num, unsigned int my_x, unsigned int my_y) {
	// this function helps to identify which colour to return
	// it returns either 1 or 0 based on whether the pixel at (x,y) is of colour
	// col_num it also checks boundaries and return 0 if out of boundaries
	if (my_x > 191 || my_y > 191) {
		//    printf("out of bounds\n");
		return 0;
	} else {
		int ret = my_getpixel(my_g_stat.image_in, my_x, my_y);
		return ret == col_num;
	}
}

int has_around(colour_hex col_name) {
	// this checks if there is a chunk around (i,j) of colour col_name
	// we check the 8 directions

	long int a0 = my_getpixel(
			my_g_stat.image_in, (192 + my_g_var.global_x - 1) % 192,
			(192 + my_g_var.global_y - 1) % 192);
	long int a = my_g_stat.image_in->format->palette->colors[a0].r * 256 * 256
				 + my_g_stat.image_in->format->palette->colors[a0].g * 256
				 + my_g_stat.image_in->format->palette->colors[a0].b;
	long int b0 = my_getpixel(
			my_g_stat.image_in, (192 + my_g_var.global_x) % 192,
			(192 + my_g_var.global_y - 1) % 192);
	long int b = my_g_stat.image_in->format->palette->colors[b0].r * 256 * 256
				 + my_g_stat.image_in->format->palette->colors[b0].g * 256
				 + my_g_stat.image_in->format->palette->colors[b0].b;
	long int c0 = my_getpixel(
			my_g_stat.image_in, (192 + my_g_var.global_x + 1) % 192,
			(192 + my_g_var.global_y - 1) % 192);
	long int c = my_g_stat.image_in->format->palette->colors[c0].r * 256 * 256
				 + my_g_stat.image_in->format->palette->colors[c0].g * 256
				 + my_g_stat.image_in->format->palette->colors[c0].b;
	long int d0 = my_getpixel(
			my_g_stat.image_in, (192 + my_g_var.global_x - 1) % 192,
			(192 + my_g_var.global_y) % 192);
	long int d = my_g_stat.image_in->format->palette->colors[d0].r * 256 * 256
				 + my_g_stat.image_in->format->palette->colors[d0].g * 256
				 + my_g_stat.image_in->format->palette->colors[d0].b;
	long int e0 = my_getpixel(
			my_g_stat.image_in, (192 + my_g_var.global_x + 1) % 192,
			(192 + my_g_var.global_y) % 192);
	long int e = my_g_stat.image_in->format->palette->colors[e0].r * 256 * 256
				 + my_g_stat.image_in->format->palette->colors[e0].g * 256
				 + my_g_stat.image_in->format->palette->colors[e0].b;
	long int f0 = my_getpixel(
			my_g_stat.image_in, (192 + my_g_var.global_x - 1) % 192,
			(192 + my_g_var.global_y + 1) % 192);
	long int f = my_g_stat.image_in->format->palette->colors[f0].r * 256 * 256
				 + my_g_stat.image_in->format->palette->colors[f0].g * 256
				 + my_g_stat.image_in->format->palette->colors[f0].b;
	long int g0 = my_getpixel(
			my_g_stat.image_in, (192 + my_g_var.global_x) % 192,
			(192 + my_g_var.global_y + 1) % 192);
	long int g = my_g_stat.image_in->format->palette->colors[g0].r * 256 * 256
				 + my_g_stat.image_in->format->palette->colors[g0].g * 256
				 + my_g_stat.image_in->format->palette->colors[g0].b;
	long int h0 = my_getpixel(
			my_g_stat.image_in, (192 + my_g_var.global_x + 1) % 192,
			(192 + my_g_var.global_y + 1) % 192);
	long int h = my_g_stat.image_in->format->palette->colors[h0].r * 256 * 256
				 + my_g_stat.image_in->format->palette->colors[h0].g * 256
				 + my_g_stat.image_in->format->palette->colors[h0].b;

	long int val = col_name;

	return a == val || b == val || c == val || d == val || e == val || f == val
		   || g == val || h == val;
}

colour_hex plugin_apply(colour_hex colour, glob_variables* g_var) {
	// required
	// function called to transform a colour_hex into another one. plugin_parse
	// must have been called previously to know what to return. the
	// implementation is left to the plugin writer both plugin_parse and
	// plugin_apply are obviously plugin-specific colour is the colour at point
	// (i,j) -- (i,j) are external variables from smooth

	my_g_var.global_x  = g_var->global_x;
	my_g_var.global_y  = g_var->global_y;
	my_g_var.image_out = g_var->image_out;

	Uint8 col_num = my_getpixel(
			my_g_stat.image_in, my_g_var.global_x, my_g_var.global_y);

	// find the colour in big table
	int loc_idx = 0;
	while (loc_idx < glob_idx && col[loc_idx][1] != colour) {
		loc_idx++;
	}

	if (loc_idx >= glob_idx) {
		fprintf(stderr,
				"WARNING: loc_idx >= glob_idx. This should never happen\n");
		return colour;    // colour is not in table, so we don't treat it. This
						  // should never happen.
	}

	if (col[loc_idx][0] == 1 || has_around(col[loc_idx][2])) {
		unsigned int calc_value
				= (1
				   * calculate(
						   col_num, my_g_var.global_x, (my_g_var.global_y - 1)))
				  + (2
					 * calculate(
							 col_num, (my_g_var.global_x + 1),
							 my_g_var.global_y))
				  + (4
					 * calculate(
							 col_num, my_g_var.global_x,
							 (my_g_var.global_y + 1)))
				  + (8
					 * calculate(
							 col_num, (my_g_var.global_x - 1),
							 my_g_var.global_y));

		if (my_g_stat.debug > 4) {
			printf("calc_value is %u at (%d,%d) -- col_num = %u\n", calc_value,
				   my_g_var.global_x, my_g_var.global_y, col_num);
		}
		return col[loc_idx][calc_value + 3];    // the first 3 cells are
												// star, slave and trigger
	} else {
		// No trigger around this chunk
		return colour;
	}
}