/* moontalk.c - @BAKE cc -O2 -std=gnu99 -Wall -Wextra -Wpedantic -Wno-format-truncation $@ -o $* \
   -D_DEFAULT_SOURCE -D_XOPEN_SOURCE=600 -lncurses -ltinfo $+
   * Written by Emil.
   * Licensed under the GPLv3 only.
   */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <time.h>
#include <errno.h>
#include <ctype.h>

#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <netinet/in.h>

#include <ncurses.h>

#define SERV "7ks473deh6ggtwqsvbqdurepv5i6iblpbkx33b6cydon3ajph73sssad.onion"
#define PORT "50000"
#define NAME "anonymous"

#define streq(a,b) (!strcmp(a,b))
#define strneq(a,b,c) (!memcmp(a,b,c))

int g_sockfd;

#define g_y LINES
#define g_x COLS

#define HELP \
	"%s [options ...]\n" \
	"\n-serv SERVER    Sets the server to connect to [default: " SERV "]" \
	"\n-port PORT      Sets the port [default: " PORT "]" \
	"\n-name NAME      Sets your display name [default: " NAME "]\n" \
	"\nControls\n" \
	"\nC-l             Refreshes the screen" \
	"\nC-w             Delete the previous word" \
	"\nC-c             Close the client" \
	"\nUp/Down         Scrolls all the way up/Scrolls down by a line\n"


/* I know, and I don't care */

#define TAB 9 /* 	 */
#define BACKSPACE 263 /* ^G */
#define C_C 4 /* ... */
#define C_D 4 /* quit */
#define	C_A 1 /* BOL */
#define	C_B 2 /* BOL */
#define C_E 5 /* EOL */
#define	C_H 8  /* BACKSPACE */
#define	C_L 12 /* REFRESH */
#define	C_U 21 /* CLR TO BOL */
#define	C_W 23 /* DELETE PREVWORD */
#define	C_L 12 /* Signal full refresh */

/****/

void disconnect(void) {
	int sockfd = g_sockfd;
	if (sockfd > -1) { close(sockfd); }
	g_sockfd = -1;
}

/* always returns an accessible socket */
int init_connection(char * serv, char * port) {
	int status, sockfd;
	struct addrinfo hints, * res;

	memset(&hints, 0, sizeof(struct addrinfo));
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;

	if ((status = getaddrinfo(serv, port, &hints, &res)) != 0) {
		perror("init_connection");
		exit(1);
	}

	if ((sockfd = socket(res->ai_family, res->ai_socktype, res->ai_protocol)) == -1)
	{ goto error; }
	if (connect(sockfd, res->ai_addr, res->ai_addrlen))
	{ goto error; }

	freeaddrinfo(res);

	g_sockfd = sockfd;
	return sockfd;
error:
	if (sockfd > -1) { close(sockfd); }
	perror("init_connection");
	exit(1);
	__builtin_unreachable();
}

//

void fillline(WINDOW * w, int y, int xstart, char c) {
	int i = xstart, x = g_x;
	for (; i < x; ++i)
	{ mvwaddch(w,y,i,c); }
}

void clearline(WINDOW * w, int y) {
	wmove(w, y, 0);
	wclrtoeol(w);
}

void sanitize(char * buf, size_t rem) {
	char * base = buf;
	buf += rem;
	while (*buf && buf - base) {
		if (*buf < ' ' || *buf > '~') {
			if (*buf != '\n')
			{ *buf = '!'; }
		}
		--buf;
	}
}

int main (int argc, char ** argv) {
	char * serv = SERV, * port = PORT, name[32] = NAME;
	int sockfd;
	{
		char * argv0 = argv[0];

		while (++argv, --argc) {
			if (streq(*argv, "-help")) {
				printf(HELP, argv0);
				exit(1);
			}
			if (argc - 1)
			{ --argc; ++argv; }
			else {
				printf("%s: %s requires argument\n", argv0, *argv);
				return 1;
			}
			if      (streq(*(argv-1), "-serv")) {
				serv = *argv;
			} else if (streq(*(argv-1), "-port")) {
				port = *argv;
			} else if (streq(*(argv-1), "-name")) {
				memset(name, 0, 31);
				strncpy(name, *argv, 31);
			}
		}

		printf("Connecting to %s:%s as %s\n", serv, port, name);

		atexit(disconnect);
		sockfd = init_connection(serv, port);
	}

	initscr();
	noecho();
	keypad(stdscr, ERR);
	nodelay(stdscr, TRUE);
	ESCDELAY = 0;
	curs_set(0);
	if (has_colors() && can_change_color()) {
		short bg, fg;
		/* leaks memory :( */
		start_color();
		for (bg = 0; bg < 8; ++bg) {
			for (fg = 0; fg < 8; ++fg) {
				init_pair(16 + fg + (bg * 8), fg, bg);
			}
		}
	}
	clear();

	#define WINCOUNT 3
	WINDOW * w[WINCOUNT];
	#define header w[0]
	#define body w[1]
	#define input w[2]

	#define SENDMAX (1 << 8) - 1
	#define RECVMAX 17663 /* (1 << 11) */

	char raw[SENDMAX + RECVMAX];
	char * sendbuf = raw, * recvbuf = raw + SENDMAX, * off = recvbuf;
	size_t sendminlen, sendlen, recvlen = 0, offlen = recvlen;
	size_t edit;

	#define TIMESTR "<%Y/%m/%d %H:%M:%S "
	#define TIMESTRMAX 21


	#define UPDATE_TIME()\
	do { \
		t = time(NULL); \
		tm = gmtime(&t); \
		strftime(sendbuf, TIMESTRMAX, TIMESTR, tm); \
		sendbuf[TIMESTRMAX - 1] = ' '; \
	} while (0)

	time_t t;
	struct tm * tm;

	useconds_t frame = 30;
	useconds_t interval = 1000000. / frame;
	int32_t ct;

	int ch, ret;
	size_t i;

	size_t namelen = strlen(name);

	edit = sendlen = sendminlen = TIMESTRMAX + namelen + 2;

	/* fill in the name */
	memcpy(sendbuf + TIMESTRMAX,           name, namelen);
	memcpy(sendbuf + TIMESTRMAX + namelen, "> ", 2);

	int inputrefresh, bodyrefresh;

hardrefresh:
	ct = 0;
	inputrefresh = bodyrefresh = 1;

	header = newwin(1, g_x, 0, 0);
	body   = newwin(g_y - 4, g_x, 1, 0);
	input  = newwin(3, g_x, g_y - 3, 0);

	fillline(header, 0, 0, '-');
	mvwprintw(header, 0, 2, " moontalk ");
	fillline(input, 0, 0, '-');

	while (1) {
		/* input */
		while ((ch = getch()) != -1) {
			if (ch == KEY_RESIZE || ch == C_L) {
				for (i = 0; i < WINCOUNT; ++i)
				{ delwin(w[i]); }
				endwin();
				erase();
				refresh();
				clear();
				flushinp();
				goto hardrefresh;
			}
			else if ((ch > 31 && ch < 127)) {
				if (sendlen + 1 < SENDMAX)
				{
					memmove(sendbuf + edit + 1, sendbuf + edit, sendlen - edit);
					sendbuf[edit++] = ch; ++sendlen;
				}
				inputrefresh = 1;
			}
			else if (ch == '\n') {
				if (sendlen == sendminlen)
				{ continue; }
				if (sendlen + 1 < SENDMAX)
				{ sendbuf[sendlen++] = '\n'; }
				if (send(sockfd, sendbuf, sendlen, 0) > 0) {
					memcpy(recvbuf + recvlen, sendbuf, (sendlen + recvlen < RECVMAX) * sendlen);
					recvlen += sendlen;
					offlen += sendlen;
				} else {
					mvwprintw(input, 1, 0, "message failed: %s", strerror(errno));
				}
				bodyrefresh = inputrefresh = 1;
				edit = sendlen = sendminlen;
			}
			else if (ch == BACKSPACE || ch == C_H) {
				inputrefresh = 1;
				if (sendlen - 1 >= sendminlen && edit - 1 >= sendminlen)
				{
					memmove(sendbuf + edit - 1, sendbuf + edit, sendlen - edit);
					--sendlen; --edit;
				}
				inputrefresh = 1;
			}
			else if (ch == KEY_LEFT) {
				if (edit > sendminlen) { --edit; }
			}
			else if (ch == KEY_RIGHT) {
				if (edit < sendlen) { ++edit; }
			}
			else if (ch == KEY_DOWN) {
				mvwprintw(input, 1, 150, "scroll down %ld", offlen);
				while ((size_t)(off - recvbuf) < recvlen && *off != '\n') { ++off; }
				if (*off == '\n') { ++off; }
				wclear(body);
				bodyrefresh = 1;
			}
			else if (ch == KEY_UP) {
				mvwprintw(input, 1, 150, "scroll up   %ld", offlen);
				if (off - 2 - recvbuf > 0) { off -= 2; }
				while (off - recvbuf > 0 && *off != '\n') { --off; }
				if (*off == '\n') { ++off; }
				bodyrefresh = 1;
			}
			else if (ch == C_W) {
				i = edit;
				while (i > sendminlen && isspace(sendbuf[i - 1])) { --i; }
				while (i > sendminlen && !isspace(sendbuf[i - 1])) { --i; }
				if (i == edit) { continue; }
				mvwprintw(input, 1, 200, "diff:%ld", sendlen - edit);
				/* memmove(sendbuf + i, sendbuf + edit, sendlen - edit); */
				/* sendlen -= edit; */
				/* edit = i; */
				/* mvwprintw(input, 1, 200, "i:%ld:%ld:sendl:%3ld", */
				/* i - sendminlen, (sendbuf + edit) - (sendbuf + i), sendlen - sendminlen); */
				inputrefresh = 1;
			}
		}
		/* update and rendering */
		if (inputrefresh) {
			clearline(input, 2);
			mvwaddnstr(input, 2, 0, sendbuf, sendlen);
			mvwchgat(input, 2, edit, 1, A_REVERSE, 0, NULL);
		}

		if (ct % frame == 0) {
			UPDATE_TIME();
		}

		if (ct % frame == 0 || bodyrefresh) {
			ret = recv(sockfd, recvbuf + recvlen, RECVMAX - recvlen, MSG_DONTWAIT);
			if (errno && errno != EAGAIN)
			{ mvwaddstr(input, 1, 0, strerror(errno)); }
			if (bodyrefresh) {
				bodyrefresh = 0;
				if (!(ret > 0))
				goto _bodyrefresh;
			}
			if (ret > 0) {
				sanitize(recvbuf + recvlen, ret);
				if (ret + recvlen < RECVMAX)
				{
					recvlen += ret;
					offlen += ret;
				}
			_bodyrefresh:
				mvwprintw(input, 1, 50, "render ct:%d ret:%d", ct, ret);
				mvwaddnstr(body, 0,0, off, offlen);
			}
		}
		refresh();
		for (i = 0; i < WINCOUNT; ++i)
		{ wnoutrefresh(w[i]); }
		doupdate();
		usleep(interval);
		++ct;
	}

	endwin();
}