#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <stdbool.h>

/*
 * Another World graphics convertor
 *   Only DOS version are supported
 */

#define MAX_POLYGONS 4096
#define MAX_GROUPS 2048
#define MSG_USAGE "usage: spr INPUT\n"
#define MSG_OPENERR "can't open file %s.\n"
#define MSG_WRITEERR "can't create file %s.\n"

struct polygoninfo {
	uint16_t offset;
	uint8_t color, w, h, num;
	struct {
		uint8_t x, y;
	} point[256];
};

struct groupinfo {
	uint16_t offset;
	uint8_t x, y, num;
	struct {
		uint16_t offset;
		uint8_t x, y;
		uint16_t color;
		bool group;
		int id;
	} child[256];
};

FILE *fp;

uint8_t *data;
uint16_t datalen, datapc;

struct polygoninfo poly[MAX_POLYGONS];
int polycount;
struct groupinfo group[MAX_GROUPS];
int groupcount;

uint8_t vbyte() {
	return data[datapc++];
}

uint16_t vword() {
	return (vbyte() << 8) | vbyte();
}

int findpoly(uint16_t offset) {
	for(int i = 0; i < polycount; i++) {
		if(poly[i].offset == offset)
			return i;
	}
	
	return -1;
}

int findgroup(uint16_t offset) {
	for(int i = 0; i < groupcount; i++) {
		if(group[i].offset == offset)
			return i;
	}
	
	return -1;
}

void process(bool readgroup) {
	uint16_t adr = datapc;
	uint8_t type = vbyte();
	
	if(type >= 0xC0) {
		uint8_t color = (type & 0x80) ? (type & 0x3F) : 0x0;
		uint8_t w = vbyte();
		uint8_t h = vbyte();
		uint8_t num = vbyte();
		
		if(!readgroup) {
			poly[polycount].offset = adr;
			poly[polycount].color = color;
			poly[polycount].w = w;
			poly[polycount].h = h;
			poly[polycount].num = num;
		}
		
		for(int i = 0; i < num; i++) {
			uint8_t x = vbyte();
			uint8_t y = vbyte();
			
			if(!readgroup) {
				poly[polycount].point[i].x = x;
				poly[polycount].point[i].y = y;
			}
		}
		
		if(!readgroup)
			++polycount;
	} else {
		type &= 0x3F;
		if(type == 2) {
			uint8_t x = vbyte();
			uint8_t y = vbyte();
			uint8_t childs = vbyte();
			
			if(readgroup) {
				group[groupcount].offset = adr;
				group[groupcount].x = x;
				group[groupcount].y = y;
				group[groupcount].num = childs;
			}
			
			for(int i = 0; i <= childs; i++) {
				uint16_t offset = vword();
				uint8_t xx = vbyte();
				uint8_t yy = vbyte();
				uint16_t color = 0xF;
				
				if(offset & 0x8000)
					color = vword() & 0x7F;
				
				offset = (offset & 0x7FFF) << 1;
				
				if(readgroup) {
					group[groupcount].child[i].offset = offset;
					group[groupcount].child[i].x = xx;
					group[groupcount].child[i].y = yy;
					group[groupcount].child[i].color = color;
				}
			}
			
			if(readgroup)
				++groupcount;
		} else {
			printf("invalid type %u\n", type);
			exit(1);
		}
	}
}

void linkgroups() {
	for(int i = 0; i < groupcount; i++) {
		for(int j = 0; j < group[i].num; i++) {
			uint16_t offset = group[i].child[j].offset;
			
			group[i].child[j].group = false;
			int id = findpoly(offset);
			if(id == -1) {
				group[i].child[j].group = true;
				id = findgroup(offset);
				if(id == -1) {
					printf("grouped polygon 0x%X not found\n", offset);
					exit(1);
				}
			}
			
			group[i].child[j].id = id;
		}
	}
}

uint8_t *loadfile(const char *name, uint16_t *size) {
	FILE *fp;
	if((fp = fopen(name, "r")) == NULL) {
		printf(MSG_OPENERR, name);
		exit(1);
	}
	
	fseek(fp, 0, SEEK_END);
	int s = ftell(fp);
	fseek(fp, 0, SEEK_SET);
	
	uint8_t *ptr = malloc(s);
	fread(ptr, s, 1, fp);
	fclose(fp);
	
	*size = s;
	return ptr;
}

void svg_poly(char *prefix, int id) {
	char name[256];
	snprintf(name, 256, "%s_p%i.svg", prefix, id);
	if((fp = fopen(name, "w")) == NULL) {
			printf(MSG_WRITEERR, name);
			exit(1);
	}
	
	int w = poly[id].w;
	int h = poly[id].h;
	
	if(w == 0)
		w = 1;
	if(h == 0)
		h = 1;
		
	printf("1px is p%i\n", id);
	
	fprintf(fp, "<?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"yes\"?>\n");
	fprintf(fp, "<svg xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\" width=\"%upx\" height=\"%upx\">\n", w, h);
	
	fprintf(fp, "<polygon fill=\"black\" points=\"");
	if(poly[id].num == 1) {
		fprintf(fp, "%u,%u ", poly[id].point[0].x, poly[id].point[0].y);
	} else if(poly[id].num == 2) {
		int i = 0;
		int j = 1;
		if (poly[id].point[j].x > poly[id].point[i].x) {
			fprintf(fp, "%u,%u ", poly[id].point[i].x, poly[id].point[i].y);
			fprintf(fp, "%u,%u ", poly[id].point[j].x + 1, poly[id].point[j].y);
		} else {
			fprintf(fp, "%u,%u ", poly[id].point[j].x, poly[id].point[j].y);
			fprintf(fp, "%u,%u ", poly[id].point[i].x + 1, poly[id].point[i].y);
		}
	} else {
		for(int i = 0; i < poly[id].num / 2; i++) {
			int j = poly[id].num - 1 - i;
			if (poly[id].point[j].x > poly[id].point[i].x) {
				fprintf(fp, "%u,%u ", poly[id].point[i].x, poly[id].point[i].y);
				fprintf(fp, "%u,%u ", poly[id].point[j].x + 1, poly[id].point[j].y);
			} else {
				fprintf(fp, "%u,%u ", poly[id].point[j].x, poly[id].point[j].y);
				fprintf(fp, "%u,%u ", poly[id].point[i].x + 1, poly[id].point[i].y);
			}
		}
	}
	fprintf(fp, "\"/>\n");
	
	fprintf(fp, "</svg>");
	
	fclose(fp);
}

void svg_group(char *prefix, int id) {
	char name[256];
	snprintf(name, 256, "%s_g%i.svg", prefix, id);
	if((fp = fopen(name, "w")) == NULL) {
			printf(MSG_WRITEERR, name);
			exit(1);
	}
	
	fprintf(fp, "<?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"yes\"?>\n");
	fprintf(fp, "<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\" version=\"1.1\" width=\"320px\" height=\"200px\">\n");
	
	for(int i = 0; i < group[id].num; i++) {
		char c = group[id].child[i].group ? 'g' : 'p';
		
		fprintf(fp, "<image xlink:href=\"%s_%c%i.svg\" x=\"%i\" y=\"%i\"/>", prefix, c, group[id].child[i].id, group[id].child[i].x, group[id].child[i].y);
	}
	
	fprintf(fp, "</svg>");
	
	fclose(fp);
}

int main(int argc, char **argv) {
	if(argc != 2) {
		printf(MSG_USAGE);
		exit(1);
	}

	data = loadfile(argv[1], &datalen);
	
	while(datapc < datalen)
		process(false);
	
	datapc = 0;
	while(datapc < datalen)
		process(true);
	
	linkgroups();
	
	free(data);
	
	for(int i = 0; i < polycount; i++)
		svg_poly(argv[1], i);
	
	for(int i = 0; i < groupcount; i++)
		svg_group(argv[1], i);
	
	return 0;
}