/* vcc/cmd.c 
 * 
 * This file is part of vcc. 
 * 
 * vcc is free software: you can redistribute it and/or modify 
 * it under the terms of the GNU General Public License as published by 
 * the Free Software Foundation, either version 3 of the License, or 
 * (at your option) any later version. 
 * 
 * vcc 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 General Public License for more details. 
 * 
 * You should have received a copy of the GNU General Public License 
 * along with vcc. If not, see <https://www.gnu.org/licenses/>
 */ 




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

#include <sys/stat.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <poll.h>
#include <signal.h>

#include <klist.h>
#include <vcc/vcc.h>
#include <vcc/version.h>
#include <vcc/pretty.h>



int do_cmd_help(char *);
int do_cmd_quit(char *);
int do_cmd_ls(char *);
int do_cmd_rate(char *);
int do_cmd_newse(char *);
int do_cmd_currs(char *);
int do_cmd_swtch(char *);
int do_cmd_lsse(char *);
int do_cmd_uinfo(char *);
int do_cmd_lself(char *);
int do_cmd_incr(char *);
int do_cmd_cqd(char *);
int do_cmd_ban(char *);
int do_cmd_unban(char *);
int do_cmd_encry(char *);

int read_msg(struct vcc_request *);
int vcc_create_session(char *name);
int get_user_info(char *usrname);
int incr_score(char *username, int incr);
int send_msg(char *msg, char *s);
int send_msg_encrypted(char *msg, char *s);
int encrypt(char *s);

extern struct klist_node banned_people;
extern char usrname[];
extern int rate;
extern int current_sid;
extern int self_level;

int get_users(void);
int get_sessions(void);
int join_session(int sid);

int did_warn = 0;

struct cmdtable {
	char 		*cmd;
	int 		(* do_cmd) (char *);
	char 		*help;
} cmdtab[] = {
	{ "-help", do_cmd_help, "Show information about every message. " }, 
	{ "-quit", do_cmd_quit, "Disconnect to server and exit vcc. " }, 
	{ "-ls", do_cmd_ls, "List all users online now. " }, 
	{ "-rate", do_cmd_rate, "Change message refresh rate. " }, 
	{ "-newse", do_cmd_newse, "Create a new session. " }, 
	{ "-currs", do_cmd_currs, "Get current session id. " }, 
	{ "-swtch", do_cmd_swtch, "Switch to another session. " }, 
	{ "-lsse", do_cmd_lsse, "List all sessions created. " }, 
	{ "-uinfo", do_cmd_uinfo, "Get one's information. " }, 
	{ "-lself", do_cmd_lself, "Reload information of myself. " }, 
	{ "-incr", do_cmd_incr, "Increase one's score (root required). " }, 
	{ "-cqd", do_cmd_cqd, "Raise CQD. " }, 
	{ "-ban", do_cmd_ban, "Don't receive more messages from somebody. " }, 
	{ "-unban", do_cmd_unban, "Receive more messages from somebody. " },
	{ "-encry", do_cmd_encry, "Send an encrypted message. " }, 

	{ NULL, NULL, NULL }
};

#define clear_line() 	fprintf(stderr, "\033[2K\r")
#define __unused 	__attribute__((unused))


int do_cmd(char *s) {
	struct cmdtable 	*t;
	char 			*p;
	int 			len;

	p = s;

	for (len = 0; *p && !isspace(*p); len++) 
		p++;
	for (t = cmdtab; t->cmd; t++) 
		if (!strncmp(t->cmd, s, len)) 
			return t->do_cmd(s);
	
	pretty_unknown_cmd(s);

	return 0;
}


int do_cmd_help(char *s) {
	struct cmdtable *t;

	(void) s;

	for (t = cmdtab; t->cmd; t++) 
		pretty_cmd_help(t->cmd, t->help);
	
	return 0;
}


int do_cmd_quit(char *s) {
	(void) s;

	printf("bye. \n");
	exit(0);

	return 0;
}


int do_cmd_ls(char *s) {
	(void) s;

	get_users();

	return 0;
}


int do_cmd_rate(char *s) {
	int n;

	(void) s;

	printf("Current rate: %d Hz\n", rate / 1000);
	fprintf(stderr, "New rate (0 < rate <= 100): ");
	scanf("%d", &n);

	if (n > 100) {
		fprintf(stderr, "*** too fast. \n"
				"0 < rate <= 100\n");

		return 1;
	}

	if (n <= 0) {
		fprintf(stderr, "*** too slow. \n"
				"0 < rate <= 100\n");

		return 1;
	}

	rate = 1000 / n;
	printf("New rate: %d Hz\n", n);

	return 0;
}


int do_cmd_ls_bh(struct vcc_request *req) {
	int n, i;

	n = ntohl(req->uid);

	clear_line();

	if (unlikely(ntohl(req->reqtype) != REQ_CTL_USRS)) {
		fprintf(stderr, "--- do_cmd_ls_bh: bad package. \n");

		return 1;
	}

	for (i = 0; i < n; i++) 
		printf("%s\n", req->msg + i * USRNAME_SIZE);

	pretty_prompt(usrname);

	return 0;
}


int do_cmd_lsse(char *s) {
	(void) s;

	get_sessions();

	return 0;
}


int do_cmd_lsse_bh(struct vcc_request *req) {
	int n, i;

	n = ntohl(req->uid);

	clear_line();

	if (unlikely(ntohl(req->reqtype) != REQ_CTL_SESS)) {
		fprintf(stderr, "--- do_cmd_ls_bh: bad package. \n");

		return 1;
	}

	for (i = 0; i < n; i++) 
		printf("%s\n", req->msg + i * USRNAME_SIZE);

	pretty_prompt(usrname);

	return 0;
}


int do_cmd_newse(char *s) {
	char sname[USRNAME_SIZE];

	(void) s;

	fprintf(stderr, "Name of new session: ");
	scanf("%s", sname);

	vcc_create_session(sname);
	printf("Session create request sent. \n");

	return 0;
}


int do_cmd_currs(char *s) {
	(void) s;

	printf("Current session id: %d\n", current_sid);

	return 0;
}


int do_cmd_swtch(char *s) {
	int sid;

	(void) s;

	printf("Old session id: %d\n", current_sid);
	fprintf(stderr, "New session id: ");
	scanf("%d", &sid);

	current_sid = sid;
	join_session(current_sid);

	return 0;
}


int lself = 0;

int do_cmd_uinfo(char *s) {
	char name[USRNAME_SIZE];

	if (!lself) {
		(void) s;

		fprintf(stderr, "username: ");
		scanf("%s", name);

		get_user_info(name);
	}

	else 
		/* s is the usrname of myself */

		get_user_info(s);

	return 0;
}


struct user {
	int 	score;
	int 	level;

	char 	usrname[USRNAME_SIZE];

	/* it's blank */
	char 	passwd[PASSWD_SIZE];
};


int do_cmd_uinfo_bh(struct vcc_request *req) {
	struct user *u = (struct user *) req->msg;
	
	clear_line();

	if (ntohl(req->uid) == -1u) {
		printf("user not found. \n");
		pretty_prompt(usrname);

		return 1;
	}

	if (lself) {
		lself = 0;
		self_level = ntohl(u->level);

		printf("Level of yourself: %d\n", self_level);
	}

	else {
		printf("%s's info: \n", u->usrname);
		printf("\tscore\tlevel\n");
		printf("\t%5d\t%d\n", ntohl(u->score), ntohl(u->level));
	}

	pretty_prompt(usrname);
	
	return 0;
}

int do_cmd_lself(char *s) {
	(void) s;

	lself = 1;
	do_cmd_uinfo(usrname);
	
	return 0;
}


int do_cmd_incr(char *s) {
	char name[USRNAME_SIZE];
	int incr;

	(void) s;

	fprintf(stderr, "username: ");
	scanf("%s", name);

	fprintf(stderr, "increment: ");
	scanf("%d", &incr);

	incr_score(name, incr);

	return 0;
}


int do_cmd_incr_bh(struct vcc_request *req) {
	clear_line();

	if (!ntohl(req->uid)) 
		printf("Sucessfully. \n");

	else 
		printf("*** failed. \n");

	pretty_prompt(usrname);

	return 0;
}


int do_cmd_cqd(char *s) {
	(void) s;

	send_msg("CQD", usrname);

	return 0;
}


int do_cmd_ban(char *s) {
	char 			*people_name, people_arr[USRNAME_SIZE];
	struct klist_node	*i;

	(void) s;

	fprintf(stderr, "Enter the user to ban: ");
	scanf("%s", people_arr);

	people_name = strdup(people_arr);

	for (i = banned_people.next; i != &banned_people; i = i->next) {
		if (!strcmp(people_name, i->usrname)) {
			fprintf(stderr, "User %s is already banned", people_name);
			free(people_name);
			return 0;
		}
	}
	i = malloc(sizeof(struct klist_node));
	klist_init(i);
	i->usrname = people_name;
	klist_add(&banned_people, i);

	return 0;
}

int do_cmd_unban(char *s) {
	char 			*people_name;
	struct klist_node 	*i;

	(void) s;

	people_name = malloc(USRNAME_SIZE + 1);

	fprintf(stderr, "Enter the user to unban: ");
	scanf("%s", people_name);
	
	for (i = banned_people.next; i != &banned_people; i = i->next) {
		if (!strcmp(people_name, i->usrname)) {
			klist_del(&banned_people, i);
			free(i->usrname);
			free(i);

			break;
		}
	}

	free(people_name);
	return 0;
}


static char const warn_msg[] = {
	"warning: encrypting messages are not always usable. in usual, that man which \n"
	"talks with you gets something f**king, in the starting, or even all the message \n" 
	"is some f**king guys. \n"
	"do you want to continue? (y/N) "
};


static int show_warn_msg(void) {
	char c;

	fprintf(stderr, "%s", warn_msg);

	for (;;) {
		read(0, &c, 1);

		if (c == 'y' || c == 'Y') 
			return 0;

		else if (c == 'n' || c == 'N') 
			return 1;

		printf("Please answer y / n\n");
	}

	return 1;
}


int do_cmd_encry(char *s) {
	char msg[MSG_SIZE];

	(void) s;

	memset(msg, 0, MSG_SIZE);

	if (!did_warn) {
		did_warn = 1;

		if (show_warn_msg()) 
			return 0;
	}

	fprintf(stderr, "Message: ");
	scanf("%s", msg);

	encrypt(msg);
	send_msg_encrypted(msg, usrname);

	return 0;
}