#ifndef BOT_H

#include <libircclient.h>

#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <signal.h>
#include <sys/time.h>

extern syntax_setter_t syntax_functions[];

static irc_session_t * session;
static irc_callbacks_t callbacks;

static inline
void irc_message(const char * const message) {
	irc_cmd_msg(session, channel, message);
}

static inline
void irc_private_message(const char * const user, const char * const message) {
	irc_cmd_msg(session, user, message);
}

static inline
char * username_root(const char * const fullname){
	char * r = (char *)fullname;
	while (*(r++) != '!') { ; }
	asprintf(&r, "From %.*s:", (int)(r - fullname)-1, fullname);
	return r;
}

typedef struct {
	int is_active;
	char * user;
	language_t language;
	struct itimerval timer;
	char * buffer[128];			// XXX: no overflow detection/avertion
	unsigned int buffer_head;   //       is implemented on this bunch
} request_t;

void init_request(request_t * request) {
	request->is_active = 0;
	request->timer.it_value.tv_sec     = 0;
	request->timer.it_value.tv_usec    = 0;
	request->timer.it_interval.tv_sec  = 0;
	request->timer.it_interval.tv_usec = 0;
	request->buffer_head = 0;
}

request_t   request_queue__[message_queue_size];
request_t * request_queue[message_queue_size];
unsigned int request_queue_head = 0;

static inline
void touch_request_timer(request_t * request) {
	request->timer.it_value.tv_sec = message_timeout;
	setitimer(ITIMER_REAL, &(request->timer), NULL);
}

void activate_request(request_t * request) {
	request->is_active = 1;

	/* message header */
	char * short_name = username_root(request->user);
	irc_message(short_name);
	free(short_name);
}

request_t * take_request(const char * const user, language_t language) {
	for (unsigned int i = 0; i < request_queue_head; i++) {
		if(!strcmp(request_queue[i]->user, user)) {
			return request_queue[i];
		}
	}

	if (request_queue_head == message_queue_size) {
		return NULL;
	}

	request_t * request = request_queue[request_queue_head];

	request->language  = language;
	request->user      = strdup(user);

	if (request_queue_head == 0) {
		activate_request(request);
	}

	++request_queue_head;

	char * log_message;
	asprintf(&log_message, "Took message: %p (%d)", (void*)request, request_queue_head);
	log_notice(log_message);
	free(log_message);

	return request;
}

void drop_reqest() {
	request_t * request = request_queue[0];

	if (message_queue_size > 1) {
		for (unsigned int i = 0; i < request_queue_head; i++) {
			request_queue[i] = request_queue[i+1];
		}
		request_queue[request_queue_head] = request;
	}
	
	--request_queue_head;

	request->is_active = 0;
	free(request->user);

	if (request_queue_head) {
		activate_request(request_queue[0]);
		for (unsigned int i = 0; i < request_queue[0]->buffer_head; i++) {
			irc_message(request_queue[0]->buffer[i]);
			free(request_queue[0]->buffer[i]);
		}
		request_queue[0]->buffer_head = 0;
		touch_request_timer(request_queue[0]);
	}

	char * log_message;
	asprintf(&log_message, "Dropped message: %p (%d)", (void*)request, request_queue_head);
	log_notice(log_message);
	free(log_message);
}

void on_message_timeout(int unused) {
	(void)unused;

	/* message footer */
	irc_message("--");

	drop_reqest(request_queue);
}

static
language_t translate_language(const char * const language) {
	if (!strcmp(language, "C") || !strcmp(language, "C++")) {
		return C;
	} else if (!strcmp(language, "ADA")) {
		return ADA;
	}
	return -1;
}

static
void irc_help() {
	irc_message(PROGRAM_NAME " "
#include "version.inc"
				);
	irc_message(PROGRAM_NAME " is a code highlighting IRC bot."
					" You may direct message it with your code or commands."
				);
	irc_message("Syntax:");
	irc_message("  !help               // print help");
	irc_message("  !<language>         // set language for next message");
	irc_message("  <code>              // echo this code");
	irc_message("  !<language> <code>  // set language and echo code");
	irc_message("--");
}

// XXX: msg ChanServ IDENTIFY?
static
void event_connect(irc_session_t * session,
							const char	* event,
							const char	* origin,
							const char ** params,
							unsigned int count) {
	(void)event;
	(void)origin;
	(void)params;
	(void)count;

	log_notice("IRC connection secured.");
	irc_cmd_join(session, channel, 0);
	char * buffer;
	asprintf(&buffer, "Joined destination channel: `%s`.", channel);
	log_notice(buffer);
	free(buffer);
}

static
void event_privmsg(irc_session_t * session,
                   const char  * event,
                   const char  * origin,
                   const char ** params,
                   unsigned int count) {
	(void)session;
	(void)event;
	(void)count;

	char * const message_guard = strdup(params[1]);
	char *       message       = message_guard;
	char * terminator;
	int is_code = 1;

	/* Is command */
	if (*message == '!') {
		terminator = message;
		while (*terminator != ' ') {
			if (*terminator == '\0') {
				is_code = 0;
				break;
			}
			++terminator;
		}
		*terminator = '\0';
		/* */
		if (!strcmp(message, "!help")) {
			irc_help();
			goto END;
		}
		/* get language */
		for (char * s = message + 1; *s != '\0'; s++) {
			*s = toupper(*s);
		}
		int l = translate_language(message + 1);
		message = terminator + 1;
		if (l != -1) {
			language = l;
			syntax_count = 0;
			syntax_functions[language]();
		}
	}

	/* Is code */
	if (is_code) {
		request_t * request = take_request(origin, language);
		if (!request) {
			irc_private_message(origin, message_queue_full_message);
			goto END;
		}

		if (request->is_active) {
			touch_request_timer(request);
			irc_message(syntax_highlight(message));
		} else {
			request->buffer[request->buffer_head++] = strdup(syntax_highlight(message));
		}
	}

	END:
	free(message_guard);
}

static
void event_channel(irc_session_t * session,
                   const char  * event,
                   const char  * origin,
                   const char ** params,
                   unsigned int count) {
	(void) session;
	(void) event;
	(void) origin;
	(void) count;

	const char * const message = params[1];

	if (!strncmp(message, "!help", sizeof("!help")-1)) {
		irc_help();
	}
}


int connect_bot(const char * const server, const short port) {
	memset(&callbacks, 0, sizeof(callbacks));
	callbacks.event_connect = event_connect;
	callbacks.event_privmsg = event_privmsg;
	callbacks.event_channel = event_channel;
	session = irc_create_session(&callbacks);

	if (!session) {
		log_error("Error creating IRC session.");
		return 1;
	} else {
		log_notice("IRC Session initialized.");
	}

	for (unsigned int i = 0; i < message_queue_size; i++) {
		request_queue[i] = &request_queue__[i];
		init_request(request_queue[i]);
	}
	signal(SIGALRM, on_message_timeout);

	irc_connect(session,
	            server,
	            port,
	            password,
	            username,
	            username,
	            username
	);

	return 0;
}

int connection_loop(void) {
	if (irc_run(session) != 0) {
		log_error("Error running IRC session\n"
			"Possible issue: bad URL, no network connection, bad port, refused connection.");
	}
	return 0;
}

#define BOT_H
#endif