/* Copyright (C) 2019  C. McEnroe <june@causal.agency>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#define _XOPEN_SOURCE_EXTENDED

#include <curses.h>
#include <err.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sysexits.h>
#include <unistd.h>

#include "term.h"

#ifndef A_ITALIC
#define A_ITALIC A_UNDERLINE
#endif

static short colorPair(int bg, int fg) {
	if (bg >= COLORS || fg >= COLORS) return 0;
	if (bg < 8 && fg < 8) {
		return 9 * (bg + 1) + (fg + 1);
	}

	enum {
		Base = 9 * 9,
		Ring = 256 - Base,
	};
	static struct {
		int bg, fg;
	} pairs[Ring];
	static size_t len = 0;

	short i;
	for (i = 0; i < Ring; ++i) {
		if (pairs[i].bg == bg && pairs[i].fg == fg) return Base + i;
		if (!pairs[i].bg && !pairs[i].fg) break;
	}

	i = len++ % Ring;
	pairs[i].bg = bg;
	pairs[i].fg = fg;
	init_pair(Base + i, fg, bg);
	touchwin(stdscr);
	return Base + i;
}

static void curse(void) {
	initscr();
	cbreak();
	noecho();
	start_color();
	use_default_colors();
	for (int bg = -1; bg < 8; ++bg) {
		for (int fg = -1; fg < 8; ++fg) {
			init_pair(colorPair(bg, fg), fg, bg);
		}
	}
}

static attr_t styleAttr(struct Style style) {
	attr_t attr = A_NORMAL;
	if (style.attr & Bold) attr |= A_BOLD;
	if (style.attr & Dim) attr |= A_DIM;
	if (style.attr & Italic) attr |= A_ITALIC;
	if (style.attr & Underline) attr |= A_UNDERLINE;
	if (style.attr & Blink) attr |= A_BLINK;
	if (style.attr & Reverse) attr |= A_REVERSE;
	return attr;
}

static void render(WINDOW *win, const struct Term *term) {
	for (uint y = 0; y < term->rows; ++y) {
		for (uint x = 0; x < term->cols; ++x) {
			struct Cell cell = term->cells[term->cols * y + x];
			if (!cell.ch) continue;
			wattr_set(
				win,
				styleAttr(cell.style),
				colorPair(cell.style.bg, cell.style.fg),
				NULL
			);
			mvwaddnwstr(win, y, x, &cell.ch, 1);
		}
	}
	curs_set(!!(term->mode & Cursor));
	leaveok(win, !(term->mode & Cursor));
	wmove(win, term->y, term->x);
}

int main(void) {
	int error;
	setlocale(LC_CTYPE, "");

	// TODO: Read info from file.
	const char *path = "example.sock";
	struct Term *term = termAlloc(24, 80);

	int client = socket(PF_LOCAL, SOCK_STREAM, 0);
	if (client < 0) err(EX_OSERR, "socket");

	struct sockaddr_un addr = { .sun_family = AF_LOCAL };
	strncpy(addr.sun_path, path, sizeof(addr.sun_path));
	error = connect(client, (struct sockaddr *)&addr, SUN_LEN(&addr));
	if (error) err(EX_NOINPUT, "%s", path);

	curse();
	WINDOW *win = newwin(24, 80, 0, 0);

	for (;;) {
		char buf[4096];
		ssize_t len = read(client, buf, sizeof(buf));
		if (len < 0) err(EX_IOERR, "read");

		ssize_t pos = 0;
		while (pos < len) {
			wchar_t ch;
			int n = mbtowc(&ch, &buf[pos], len - pos);
			if (n <= 0) break;
			termUpdate(term, ch);
			pos += n;
		}

		render(win, term);
		wrefresh(win);
	}
}