#include <toml.h>

#include "util.h"
#include "font.h"

int font_compare(const node_t *a, const node_t *b) {
	const font_t *x = (const font_t *)a->data;
	const font_t *y = (const font_t *)b->data;

	return strcmp(x->name, y->name);
}

node_t *load_fonts(toml_table_t *table, const char *base_path) {
	node_t *root = NULL;

	// vast majority of projects should have only 1-2 fonts, but let's offer
	// some room in case there's more.
	for (int i = 0; i < 32; i++) {
		const char *key = toml_key_in(table, i);
		if (!key) break;
		char fullname[200];
		font_t font;

		toml_datum_t filename = toml_string_in(table, key);
		if (!filename.ok) {
			error("couldn't load font ", key);
		}
		snprintf(fullname, 200, "%s/%s", base_path, filename.u.s);
		font = font_create(key, fullname);
		root = node_insert(root, &font, font_compare);
	}
	return root;
}
font_t *font_find(node_t *root, const char *key) {
	font_t search = {.name = key};
	node_t *node = node_search(root, &search, font_compare);
	font_t *font = (font_t *)node->data;

	if (font == NULL) {
		error("couldn't find requested font ", key);
	}

	return font;
}

font_t font_create(const char *font_name, const char *filename) {
	FILE *fp;
	font_t font;
	char errbuf[200];
	map_t *map;

	printf("    Processing %s...\n", font_name);

	fp = fopen(filename, "r");

	if (!fp) {
		char str[200];
		snprintf(str, 200, "can't open %s: ", filename);
		error(str, strerror(errno));
	}
	toml_table_t *table = toml_parse_file(fp, errbuf, 200);
	fclose(fp);

#define TOML_GET_KEY(var, key, func) toml_datum_t (var) = func(table, (key));\
	if (!(var).ok) {\
		char str[200];\
		snprintf(str, 200, "key '%s' missing from", (key)); \
		error(str, filename); \
	}

	TOML_GET_KEY(name, "name", toml_string_in)
	TOML_GET_KEY(image_filename, "filename", toml_string_in)
	TOML_GET_KEY(bpp, "bits_per_pixel", toml_int_in)
	TOML_GET_KEY(width, "width", toml_int_in)
	TOML_GET_KEY(height, "height", toml_int_in)
#undef TOML_GET_KEY
	toml_table_t *mapping = toml_table_in(table, "map");

	font.name = name.u.s;
	font.image_filename = image_filename.u.s;
	font.bits_per_pixel = bpp.u.i;
	font.width = width.u.i;
	font.height = height.u.i;
	font.map_entries = map_create(mapping, &map);
	font.map = map;

	return font;
}

void font_destroy(font_t font) {
	map_destroy(font.map);
	free(font.name);
	free(font.image_filename);
}

unsigned int map_create(toml_table_t *table, map_t **map) {
	map_t *node;
	map_t *next;
	unsigned int nodes;
	map_t *root = malloc(sizeof(map_t*));
	toml_array_t *space = toml_array_in(table, " ");
	toml_datum_t spcidx = toml_int_at(space, 0);
	toml_datum_t spcwid = toml_int_at(space, 1);
	if (!spcidx.ok) {
		error("missing or inappropriate index for glyph: ' '", "");
	}
	if (!spcwid.ok) {
		error("missing or inappropriate index for glyph: ' '", "");
	}
	node = root;

	for (nodes = 1; ; nodes++) {
		const char *key = toml_key_in(table, nodes);
		if (!key) break;
		toml_array_t *val = toml_array_in(table, key);
		toml_datum_t index = toml_int_at(val, 0);
		toml_datum_t width = toml_int_at(val, 1);
		if (!index.ok) {
			error("missing or inappropriate index for glyph: ", key);
		}
		if (!width.ok) {
			error("missing or inappropriate width for glyph: ", key);
		}

		next = malloc(sizeof(map_t *));
		next->glyph = key;
		next->index = index.u.i;
		next->width = width.u.i;
		node->next = next;
		node = next;
	}
	node->next = NULL;

	*map = root;
	return nodes;
}

void map_destroy(map_t *map) {
	map_t *node = map;
	map_t *next;

	while ((next = node->next) != NULL) {
		free(node);
		node = next;
	}
}