/* 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.
 *
 * TODO Add proper editing facilities
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <time.h>
#include <errno.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 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_U 21 /* CLR TO BOL */
#define	C_H 8  /* BACKSPACE */
#define	C_W 23 /* DELETE PREVWORD */
#define	C_L 12 /* Signal SIGWINCH */
#define	C_R 18 /* hah not going to implement that */

#define UP    258
#define DOWN  259
#define LEFT  260
#define RIGHT 261

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

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

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

int g_y, g_x;
int g_sockfd = -1;

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

#define TITLE(str) do { mvprintw(0,0,str); fillline(0,strlen(str),'-'); } while (0)

void hardrefresh(void) {
	mvprintw(g_y - 2, 0, "max screen %d; max ours %d", (g_y - 3) * SENDMAX, RECVMAX);
	TITLE("-- MOONTALK ");
	fillline(g_y - 3, 0, '-');
}

#undef TITLE

int g_hardrefresh = 0;

void  init_screen(int x) {
	(void)x;
	signal(SIGWINCH, SIG_IGN);

	endwin();
	struct winsize w;
	ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
	g_y = w.ws_row;
	g_x = w.ws_col;
	initscr();
	raw();
	noecho();
	keypad(stdscr, ERR);
	nodelay(stdscr, TRUE);
	ESCDELAY = 0;
	clear();
	hardrefresh();
	g_hardrefresh = 1;

	signal(SIGWINCH, init_screen);
}

void stop(void) {
	int sockfd = g_sockfd;
	endwin();
	printf("stopping now. maybe you forgot torify?\n");
	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();
}

#if 0
int getanonval(char * buf, size_t len) {
	return 0;
}
#endif

int countlines(char * buf, size_t len) {
	size_t i = 0;
	for (buf += len - 1; *buf; --buf)
	{ i += (*buf == '\n'); }
	return i;
}

size_t getoff(char * buf, size_t len, size_t count, char c) {
	size_t i;
	for (i = 0; count && i < len; ++i) {
		count -= (buf[i] == c) * 1;
		++buf;
	}
	return i;
}

size_t lastline(char * buf, size_t len) {
	size_t ret;
	char * start = buf;
	for (buf += len - 1; *buf; --buf) {
		ret = (*buf == '\n') ? buf - start : 0;
		if (ret) { return ret; }
	}
	return 0;
}

void clearline(int y) {
	int x = g_x;
	int oldy, oldx;
	getyx(stdscr, oldy, oldx);
	move(y, x);
	clrtoeol();
	move(oldy, oldx);
}

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


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

	int sockfd;

	while (++argv, --argc) {
		if (streq(*argv, "-help")) {
			printf("%s: HELP\n", argv0);
			return 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);
		}
	}

	init_screen(-1);
	move(1,0);
	printw("Connecting to %s:%s as %s\n", serv, port, name);
	printw("g_y: %d; g_x: %d\n", g_y, g_x);
	refresh();
	clear();

	atexit(stop);
	sockfd = init_connection(serv, port);

	char raw[SENDMAX + RECVMAX];
	char * sendbuf = raw, * recvbuf = raw + SENDMAX;
	size_t sendminlen;
	size_t sendlen = sendminlen, recvlen = 1;

	time_t t;
	struct tm * tm;
	useconds_t frame = 25;
	useconds_t interval = 1000000 / frame;
	int32_t ct = 0;
	int lc, off;
	int ch;
	int ret;

	sendminlen = TIMESTRMAX;
	UPDATE_TIME();

	memcpy(sendbuf + sendminlen, name, strlen(name));
	sendminlen += strlen(name);
	memcpy(sendbuf + sendminlen, "> ", 2);
	sendminlen += 2;
	sendlen = sendminlen;

	hardrefresh();
	mvaddnstr(g_y - 1, 0, sendbuf, sendlen);

	while (1) {
		/* update */
		if (ct % (frame)  == 0) {
			UPDATE_TIME();
			mvaddnstr(g_y - 1, 0, sendbuf, sendlen);
		}
		if (ct % (frame * 2) == 0) {
			ret = recv(sockfd, recvbuf + recvlen, RECVMAX - recvlen, MSG_DONTWAIT);
			if (ret > 0 || g_hardrefresh) {
				recvlen += ret;
				lc = countlines(recvbuf, recvlen);
				off = lc - g_y - 4;
				off = getoff(recvbuf, recvlen, (off > 0) * off, '\n');
				mvaddnstr(1, 0, recvbuf + off, recvlen - off);
				g_hardrefresh = 0;
			}
		}
		/* send */
		while ((ch = getch()) != -1) {
			if (ch == '\n') {
				if (sendlen == sendminlen) { continue; }
				UPDATE_TIME();
				sendbuf[sendlen++] = '\n'; /* terminator */
				send(sockfd, sendbuf, sendlen, 0);
				memcpy(recvbuf + recvlen, sendbuf, (sendlen + recvlen < RECVMAX) * sendlen);
				recvlen += sendlen;
				mvaddnstr(1, 0, recvbuf, recvlen);
				mvaddch(g_y - 1, sendminlen, ' ');
				clearline(g_y - 1);
				sendlen = sendminlen;
			}
			else if (ch == C_D) {
				exit(0);
			}
			else if (ch == BACKSPACE) {
				clearline(g_y - 1);
				if (sendlen - 1 >= sendminlen)
				{ mvaddch(g_y - 1, --sendlen, ' '); }
				mvaddnstr(g_y - 1, 0, sendbuf, sendlen);
				move(g_y - 1, sendlen);
			}
			else if (ch > 31 && ch < 127) {
				if (sendlen + 1 < SENDMAX)
				{ sendbuf[sendlen++] = ch; }
				mvaddnstr(g_y - 1, 0, sendbuf, sendlen);
			}
		}
		move(g_y - 1, sendlen);
		++ct;
		refresh();
		usleep(interval);
	}
	return 0;
}