#include "web_svg.h"

#include "board.h"
#include "comp.h"

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

#include <emscripten/emscripten.h>

#define NUM_SECTORS 20
#define SECTOR_WIDTH 18.0

#define C_BLACK "#272b2c"
#define C_WHITE "#fbe3ba"
#define C_RED "#f6302f"
#define C_GREEN "#22912d"
#define C_WIRE "#909ca0"
#define C_WIRE_INNER "#d8e6ec"

struct elem {
	char *ns, *name, *content;
	int n_attrs, size_attrs;
	char **attr_names, **attr_vals;
};

struct elem *elem_init(char *ns, char *name, int size_attrs)
{
	struct elem *e = malloc(sizeof(*e));

	e->ns = ns ? strdup(ns) : NULL;
	e->name = strdup(name);

	e->n_attrs = 0;
	e->size_attrs = size_attrs;
	e->attr_names = malloc(size_attrs * sizeof(*(e->attr_names)));
	e->attr_vals = malloc(size_attrs * sizeof(*(e->attr_vals)));
	e->content = NULL;

	return e;
}

static inline struct elem *svg_elem_init(char *name, int size_attrs)
{
	return elem_init("http://www.w3.org/2000/svg", name, size_attrs);
}

void elem_free(struct elem *e)
{
	for(int i = 0; i < e->n_attrs; ++i) {
		free(e->attr_names[i]);
		free(e->attr_vals[i]);
	}

	free(e->content);
	free(e->attr_names);
	free(e->attr_vals);
	free(e->name);
	free(e);
}

void elem_add_attr(struct elem *e, char *name, char *val)
{
	if (e->n_attrs == e->size_attrs) {
		e->size_attrs *= 2;
		e->attr_names = realloc(e->attr_names,
			e->size_attrs * sizeof(*(e->attr_names)));
		e->attr_vals = realloc(e->attr_vals,
			e->size_attrs * sizeof(*(e->attr_vals)));
	}

	e->attr_names[e->n_attrs] = strdup(name);
	e->attr_vals[e->n_attrs++] = strdup(val);
}

void elem_add_attr_double(struct elem *e, char *name, double val)
{
	char str[512];
	sprintf(str, "%f", val);
	elem_add_attr(e, name, str);
}

// draws a ring if angles are equal
struct elem *gen_arc(double a1, double a2, double r1, double r2, char *col)
{
	struct ccoords cc1 = pol_to_cart((struct pcoords){
		.a = (a1 == a2 ? 1 : a2), .r = r1 });
	struct ccoords cc2 = pol_to_cart((struct pcoords){
		.a = (a1 == a2 ? 0 : a1), .r = r1 });
	struct ccoords cc3 = pol_to_cart((struct pcoords){
		.a = (a1 == a2 ? 0 : a1), .r = r2 });
	struct ccoords cc4 = pol_to_cart((struct pcoords){
		.a = (a1 == a2 ? 1 : a2), .r = r2 });

	struct elem *e = svg_elem_init("path", 2);
	elem_add_attr(e, "fill", col);

	char buf[512];
	int buflen = 0;
	buflen += sprintf(buf + buflen, "M%f %f", cc1.x, cc1.y);
	buflen += sprintf(buf + buflen, "A%f %f 0 0 0 %f %f",
		r1, r1, cc2.x, cc2.y);
	if (a1 == a2)
		buflen += sprintf(buf + buflen, "A%f %f 0 1 0 %f %f",
			r1, r1, cc1.x, cc1.y);
	buflen += sprintf(buf + buflen, "L%f %f", cc3.x, cc3.y);
	buflen += sprintf(buf + buflen, "A%f %f 0 0 1 %f %f",
		r2, r2, cc4.x, cc4.y);
	if (a1 == a2)
		buflen += sprintf(buf + buflen, "A%f %f 0 1 1 %f %f",
			r2, r2, cc3.x, cc3.y);
	buf[buflen++] = 'Z';
	buf[buflen++] = 0;
	elem_add_attr(e, "d", buf);

	return e;
}

struct elem *gen_segment(double a, double r1, double r2, char *col)
{
	return gen_arc(a - SECTOR_WIDTH/2, a + SECTOR_WIDTH/2, r1, r2, col);
}

struct elem *gen_ring(double r, double w, char *col)
{
	return gen_arc(0, 0, r - w/2, r + w/2, col);
}

struct elem *gen_circle(double r, char *col)
{
	struct elem *e = svg_elem_init("circle", 2);
	elem_add_attr(e, "fill", col);
	elem_add_attr_double(e, "r", r);

	return e;
}

struct elem *gen_line(double a, double r1, double r2, double w, char *col)
{
	struct ccoords cc1 = pol_to_cart((struct pcoords){ .a = a, .r = r1 });
	struct ccoords cc2 = pol_to_cart((struct pcoords){ .a = a, .r = r2 });

	struct elem *e = svg_elem_init("line", 6);
	elem_add_attr(e, "stroke", col);
	elem_add_attr_double(e, "x1", cc1.x);
	elem_add_attr_double(e, "y1", cc1.y);
	elem_add_attr_double(e, "x2", cc2.x);
	elem_add_attr_double(e, "y2", cc2.y);
	elem_add_attr_double(e, "stroke-width", w);

	return e;
}

int draw_spider(int elemc, struct elem **elemv)
{
	for (int i = 5; i > 1; --i) {
		elemv[elemc++] = gen_ring(OUTER_DISTS[i], WIRE_WIDTH, C_WIRE);
		elemv[elemc++] = gen_ring(OUTER_DISTS[i], WIRE_WIDTH/2, C_WIRE_INNER);
	}

	for (int i = 0; i < NUM_SECTORS; ++i) {
		double a = 90 - i*SECTOR_WIDTH - SECTOR_WIDTH/2;
		if (a < 0) a += 360;

		elemv[elemc++] = gen_line(a, OUTER_DISTS[1], OUTER_DISTS[5] + 10,
			WIRE_WIDTH, C_WIRE);
		elemv[elemc++] = gen_line(a, OUTER_DISTS[1], OUTER_DISTS[5] + 10,
			WIRE_WIDTH/2, C_WIRE_INNER);
	}

	for (int i = 1; i >= 0; --i) {
		elemv[elemc++] = gen_ring(OUTER_DISTS[i], WIRE_WIDTH, C_WIRE);
		elemv[elemc++] = gen_ring(OUTER_DISTS[i], WIRE_WIDTH/2, C_WIRE_INNER);
	}

	return elemc;
}

int draw_numbers(int elemc, struct elem **elemv)
{
	elemv[elemc++] = gen_ring(DIAMETER/2 - WIRE_WIDTH*4, WIRE_WIDTH, "#ddd");

	int r = DIAMETER/2 - 33/2;
	for (int i = 0; i < 20; ++i) {
		struct elem *e = elemv[elemc++] = svg_elem_init("text", 5);
		elem_add_attr(e, "font-size", "33");
		elem_add_attr(e, "fill", "#fff");
		elem_add_attr(e, "text-anchor", "middle");
		elem_add_attr(e, "dominant-baseline", "central");

		char buf[512];
		double a = 90 - i*SECTOR_WIDTH;
		if (a < 0) a += 360;
		struct ccoords cc = pol_to_cart((struct pcoords){ .a = a, .r = r });
		sprintf(buf, "scale(1 -1) translate(%f %f) rotate(%f)",
			cc.x, -cc.y, a <= 180 ? 90 -a : 270 -a);
		elem_add_attr(e, "transform", buf);

		e->content = malloc(3);
		sprintf(e->content, "%d", SECTORS[i]);
	}

	return elemc;
}

void append_elemv(char *sel, int elemc, struct elem **elemv)
{
	EM_ASM({elemAppendElemv($0, $1, $2, $3, $4, $5, $6, $7, $8)},
		sel, elemc, elemv,
		offsetof(struct elem, ns), offsetof(struct elem, name),
		offsetof(struct elem, content), offsetof(struct elem, n_attrs),
		offsetof(struct elem, attr_names), offsetof(struct elem, attr_vals));
}

void svg_draw_board()
{
	struct elem **elemv = malloc(200 * sizeof(*elemv));
	int elemc = 0;

	elemv[elemc++] = gen_circle(DIAMETER/2, C_BLACK);

	for (int i = 5; i > 1; --i) {
		for (int j = 0; j < NUM_SECTORS; ++j) {
			double a = 90 - j*SECTOR_WIDTH;
			if (a < 0) a += 360;
			elemv[elemc++] = gen_segment(a, OUTER_DISTS[i-1], OUTER_DISTS[i],
				i%2 ? (j%2 ? C_GREEN : C_RED) : (j%2 ? C_WHITE : C_BLACK));
		}
	}

	elemv[elemc++] = gen_circle(OUTER_DISTS[1], C_GREEN);
	elemv[elemc++] = gen_circle(OUTER_DISTS[0], C_RED);

	elemc = draw_spider(elemc, elemv);
	elemc = draw_numbers(elemc, elemv);

	append_elemv("#dartboard .base", elemc, elemv);

	for (int i = 0; i < elemc; ++i)
		free(elemv[i]);
	free(elemv);
}

void svg_draw_point(double x, double y)
{
	struct elem *e = gen_circle(8, "#33f");
	elem_add_attr(e, "stroke", "#ff0");
	elem_add_attr(e, "stroke-width", "2");
	elem_add_attr_double(e, "cx", x);
	elem_add_attr_double(e, "cy", y);

	append_elemv("#dartboard .overlay", 1, &e);
	elem_free(e);
}

void svg_clear_points()
{
	EM_ASM({elemSetContent($0, $1)}, "#dartboard .overlay", NULL);
}