#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <dirent.h>
#include <time.h>
#include <notcurses/notcurses.h>

#ifndef DATADIR
#define DATADIR "/usr/local"
#endif

#define STARBOX_HEIGHT 12
#define STARBOX_WIDTH 24
#define INFOBOX_WIDTH 40
#define STARBOX_MAX_TITLE ((STARBOX_WIDTH - 2) / 2)

char *pick_constellation(void) {
	char *xdg_dir = getenv("XDG_DATA_HOME");
	if (!xdg_dir)
		xdg_dir = "~/.local/share";
	size_t len = snprintf(NULL, 0, "%s/%s", xdg_dir, "stargaze");
	char *user_dir = malloc(++len);
	snprintf(user_dir, len, "%s/%s", xdg_dir, "stargaze");

	const char * const dirs[] = {
		"./stargaze/",
		user_dir,
		DATADIR "/stargaze/",
	};

	char **files = calloc(10, sizeof(*files));
	size_t nfiles = 0, max_files = 10;
	for (size_t i = 0; i < sizeof(dirs) / sizeof(*dirs); i++) {
		DIR *dir = opendir(dirs[i]);
		if (!dir)
			continue;

		struct dirent *dirent;
		while ((dirent = readdir(dir))) {
			if (dirent->d_type != DT_REG)
				continue;
			if (nfiles + 1 > max_files)
				files = (max_files += 10, realloc(files, sizeof(*files) * max_files));
			size_t len = snprintf(NULL, 0, "%s/%s", dirs[i], dirent->d_name);
			files[nfiles] = malloc(++len);
			snprintf(files[nfiles++], len, "%s/%s", dirs[i], dirent->d_name);
		}
		closedir(dir);
	}

	char *out = NULL;
	if (nfiles > 0) {
		srand(time(NULL));
		int choice = rand() % nfiles;
		out = files[choice];
		files[choice] = files[--nfiles];
	}

	for (size_t i = 0; i < nfiles; i++)
		free(files[i]);
	free(files);

	free(user_dir);
	
	return out;
}

char *name_to_fullwidth(const char *name, size_t len) {
	if (!name) return NULL;
	char *new_name = calloc((len * 3) + 1, sizeof(char));

	size_t j = 0;
	for (size_t i = 0; i < len; i++) {
		if (isalnum(name[i])) {
			uint32_t codepoint = name[i] + 0xFEE0;
			new_name[j++] = 0xE0 | (codepoint >> 12);
			new_name[j++] = 0x80 | ((codepoint >> 6) & 0x3F);
			new_name[j++] = 0x80 | (codepoint & 0x3F);
		} else {
			new_name[j++] = name[i];
		}
	}
	new_name[j] = '\0';

	return new_name;
}

enum attibute_types {
	STAR_ATTR_QUADRANT,
	STAR_ATTR_ASCENSION,
	STAR_ATTR_DECLINATION,
	STAR_ATTR_AREA,
	STAR_ATTR_STARS,
	STAR_ATTR_TOTAL
};

struct constellation {
	char *name[2];
	size_t name_len[2];
	char *display_name[2];

	struct attribute {
		char *key;
		char *shortname;
		char *symbol;
		char *value;
	} attributes[STAR_ATTR_TOTAL];

	size_t longest_attr;

	size_t n_stars, max_stars;
	struct point { size_t x, y; } stars[];
};

struct constellation *parse_constellation(const char *path) {
	FILE *fp = NULL;
	if (!(fp = fopen(path, "r"))) {
		return NULL;
	}
	struct constellation *constellation = calloc(1, sizeof(*constellation) + sizeof(*constellation->stars) * 10);
	constellation->max_stars = 10;

	char *line = NULL;
	size_t line_bufsiz;
	size_t len;
	while ((len = getline(&line, &line_bufsiz, fp)) != -1) {
		line[len - 1] = '\0';
		char *data = strchr(line, ' ');
		size_t datalen = len - (data - line);
		if (!data) continue;
		*data++ = '\0';
		if (!*data) continue;

		if (strcmp(line, "star") == 0) {
			size_t x, y;
			if (sscanf(data, "%ld %ld", &x, &y) != 2)
				continue;
			if (x >= 20 || y >= 20)
				continue;
			if (constellation->n_stars + 1 < constellation->max_stars) {
				constellation->max_stars += 5;
				constellation = realloc(constellation, sizeof(*constellation) + sizeof(*constellation->stars) * constellation->max_stars);
			}
			constellation->stars[constellation->n_stars++] = (struct point) { .x = x, .y = y };
			
			continue;
		} else if (strcmp(line, "name") == 0) {
			if (constellation->name[0])
				 continue;
			constellation->name[0] = strdup(data);
			constellation->name_len[0] = datalen;
			char *spc;

			if (constellation->name_len[0] >= STARBOX_MAX_TITLE && (spc = strchr(constellation->name[0], ' '))) {
				*spc = '\0';

				constellation->name[1] = spc + 1;
				constellation->name_len[1] = constellation->name_len[0] - (constellation->name[1] - constellation->name[0]);
				constellation->name_len[0] -= constellation->name_len[1];
			}

			constellation->display_name[0] = name_to_fullwidth(constellation->name[0],
					constellation->name_len[0] > STARBOX_MAX_TITLE ? STARBOX_MAX_TITLE : constellation->name_len[0]);
			constellation->display_name[1] = name_to_fullwidth(constellation->name[1],
					constellation->name_len[1] > STARBOX_MAX_TITLE ? STARBOX_MAX_TITLE : constellation->name_len[1]);

		} else if (strcmp(line, "quadrant") == 0) {
			if (constellation->attributes[STAR_ATTR_QUADRANT].value)
				 continue;
			constellation->attributes[STAR_ATTR_QUADRANT] = (struct attribute) {
				.shortname = "Quad",
				.key = "Quadrant",
				.symbol = "Q",
				.value = strdup(data),
			};
		} else if (strcmp(line, "ascension") == 0) {
			if (constellation->attributes[STAR_ATTR_ASCENSION].value)
				 continue;
			constellation->attributes[STAR_ATTR_ASCENSION] = (struct attribute) {
				.shortname = "Asc",
				.key = "Ascension",
				.symbol = "α",
				.value = strdup(data),
			};
		} else if (strcmp(line, "declination") == 0) {
			if (constellation->attributes[STAR_ATTR_DECLINATION].value)
				 continue;
			constellation->attributes[STAR_ATTR_DECLINATION] = (struct attribute) {
				.shortname = "Decl",
				.key = "Declination",
				.symbol = "δ",
				.value = strdup(data),
			};
		} else if (strcmp(line, "area") == 0) {
			if (constellation->attributes[STAR_ATTR_AREA].value)
				 continue;
			constellation->attributes[STAR_ATTR_AREA] = (struct attribute) {
				.shortname = "Area",
				.key = "Area",
				.symbol = "A",
				.value = strdup(data),
			};
		} else if (strcmp(line, "n_stars") == 0) {
			if (constellation->attributes[STAR_ATTR_STARS].value)
				 continue;
			constellation->attributes[STAR_ATTR_STARS] = (struct attribute) {
				.shortname = "Stars",
				.key = "Main Stars",
				.symbol = "✦",
				.value = strdup(data),
			};
		}
	}
	free(line);

	return constellation;
}

void constellation_free(struct constellation* constellation) {
	if (!constellation)
		return;
	free(constellation->name[0]);
	free(constellation->display_name[0]);
	free(constellation->display_name[1]);
	for (size_t i = 0; i < STAR_ATTR_TOTAL; i++) {
		free(constellation->attributes[i].value);
	}
	free(constellation);
}

void usage(const char* name) {
	fprintf(stderr,
"usage: %s [-s|-S] [-f <starfile>] [-c <color>] [-p <padding>]\n\
\n\
-f loads a specific starfile\n\
-c hex color for the stars and highligts\n\
-s | -S symbol or shortname form for the info box\n\
-p the padding between the star window and the info text\n\
\n\
starfiles are picked from ./stargaze, %s/share/stargaze and ${XDG_DATA_HOME}/stargaze (defaults to ~/.local/share)\n",
			name, DATADIR);
}

enum info_format {
	INFO_FULL,
	INFO_SHORT,
	INFO_SYM
};

int main(int argc, char **argv) {
	char *starfile = NULL;
	char opt;
	enum info_format format = INFO_FULL;
	struct color { int r, g, b; bool set; } color;
	size_t padding = 5;
	while ((opt = getopt(argc, argv, "hf:Ssc:")) != -1) {
		switch (opt) { case 'h':
				usage(argv[0]);
				return EXIT_SUCCESS;
			case 'S':
				format = INFO_SHORT;
				break;
			case 's':
				format = INFO_SYM;
				break;
			case 'f':
				starfile = optarg;
				break;
			case 'c':
				if (!(color.set = sscanf(optarg, "%2x%2x%2x", &color.r, &color.g, &color.b) == 3))
					fprintf(stderr, "%s is not a valid rgb hex color.\n", optarg);
				break;
			case 'p':
				padding = atoi(optarg);
				break;
			default:
				usage(argv[0]);
				return EXIT_FAILURE;
		}
	}
	if (!starfile)
		starfile = pick_constellation();
	struct constellation *constellation = parse_constellation(starfile);
	if (!constellation) {
		fputs("failed to load constellation file\n", stderr);
		return EXIT_FAILURE;
	}

	struct notcurses_options opts = {
		.flags = NCOPTION_CLI_MODE | NCOPTION_SUPPRESS_BANNERS | NCOPTION_DRAIN_INPUT,
	};
	struct notcurses *nc = notcurses_core_init(&opts, NULL);
	if (!nc) {
		fputs("failed to init notcurses\n", stderr);
		constellation_free(constellation);
		return EXIT_FAILURE;
	}

	struct ncplane *std = notcurses_stdplane(nc);

	unsigned cursor_y = ncplane_cursor_y(std);
	unsigned term_width = ncplane_dim_x(std);

	if (term_width <= STARBOX_WIDTH) {
		notcurses_stop(nc);
		constellation_free(constellation);
		fputs("terminal window\nis too small\n", stderr);
		return EXIT_FAILURE;
	}

	struct ncplane_options stargaze_opts = {
		.x = 0,
		.y = cursor_y,
		.rows = STARBOX_HEIGHT,
		.cols = term_width,
		.flags = NCPLANE_OPTION_AUTOGROW | NCPLANE_OPTION_VSCROLL,
	};
	struct ncplane *stargaze = ncplane_create(std, &stargaze_opts);

	struct ncplane_options star_opts = {
		.x = 0,
		.y = 0,
		.rows = STARBOX_HEIGHT,
		.cols = STARBOX_WIDTH,
	};
	struct ncplane *stars = ncplane_create(stargaze, &star_opts);

	struct ncplane_options info_box_opts = {
		.x = STARBOX_WIDTH,
		.y = NCALIGN_CENTER,
		.rows = STAR_ATTR_TOTAL + 2, // title and empty line
		.cols = ncplane_dim_x(stargaze) - STARBOX_WIDTH,
		.flags = NCPLANE_OPTION_VERALIGNED
	};
	struct ncplane *info_box = ncplane_create(stargaze, &info_box_opts);

	ncplane_scrollup_child(std, stargaze);

	struct nccell box[6] = { 0 };
	nccells_light_box(stars, 0, 0, &box[0], &box[1], &box[2], &box[3], &box[4], &box[5]);

	ncplane_box_sized(stars, &box[0], &box[1], &box[2], &box[3], &box[4], &box[5], STARBOX_HEIGHT, STARBOX_WIDTH,
			NCBOXGRAD_TOP | NCBOXGRAD_LEFT | NCBOXGRAD_RIGHT | NCBOXGRAD_BOTTOM);

	if (color.set) {
		ncplane_set_fg_rgb8(stars, color.r, color.g, color.b);
		ncplane_set_fg_rgb8(info_box, color.r, color.g, color.b);
	}
	ncplane_on_styles(info_box, NCSTYLE_BOLD);
	if (constellation->name[0]) {
		ncplane_putstr_aligned(stars, 0, NCALIGN_CENTER, constellation->display_name[0]);
		ncplane_putstr_yx(info_box, 0, padding, constellation->name[0]);
	}
	if (constellation->name[1]) {
		ncplane_putstr_aligned(stars, STARBOX_HEIGHT - 1, NCALIGN_CENTER, constellation->display_name[1]);
		ncplane_printf(info_box, " %s", constellation->name[1]);
	}

	for (size_t i = 0; i < constellation->n_stars; i++)
		ncplane_putstr_yx(stars, constellation->stars[i].y,  constellation->stars[i].x, "✦");

	size_t info_index = 2;
	for (size_t i = 0; i < STAR_ATTR_TOTAL; i++) {
		if (!constellation->attributes[i].value)
			continue;
		char *key = NULL;
		switch (format) {
			case INFO_FULL:
				key = constellation->attributes[i].key;
				break;
			case INFO_SHORT:
				key = constellation->attributes[i].shortname;
				break;
			case INFO_SYM:
				key = constellation->attributes[i].symbol;
				break;
		}
		if (color.set)
			ncplane_set_fg_rgb8(info_box, color.r, color.g, color.b);
		ncplane_on_styles(info_box, NCSTYLE_BOLD);
		ncplane_printf_yx(info_box, info_index++, padding, "%s: ", key);

		ncplane_set_fg_default(info_box);
		ncplane_off_styles(info_box, NCSTYLE_BOLD);
		ncplane_putstr(info_box, constellation->attributes[i].value);
	}

	notcurses_render(nc);

	constellation_free(constellation);
	notcurses_stop(nc);
	puts("\n");
}