/*
 * help.c -- commands for giving help 
 */

#include "copyright.h"
#include "config.h"

#include <fcntl.h>

#include "mudconf.h"
#include "config.h"
#include "db.h"
#include "interface.h"
#include "externs.h"
#include "help.h"
#include "htab.h"
#include "alloc.h"

/*
 * Pointers to this struct is what gets stored in the help_htab's 
 */
struct help_entry {
	int pos;					/*
								 * Position, copied from help_indx 
								 */
	char original;				/*
								 * 1 for the longest name for a topic. 0 for
								 * * * * abbreviations 
								 */
	char *key;					/*
								 * The key this is stored under. 
								 */
};

int helpindex_read(HASHTAB * htab, char *filename)
{
	help_indx entry;
	char *p;
	int count;
	FILE *fp;
	struct help_entry *htab_entry;

	/*
	 * Let's clean out our hash table, before we throw it away. 
	 */
	for(htab_entry = (struct help_entry *) hash_firstentry(htab);
		htab_entry; htab_entry = (struct help_entry *) hash_nextentry(htab)) {
		free(htab_entry->key);
		free(htab_entry);
	}

	hashflush(htab, 0);
	if((fp = fopen(filename, "r")) == NULL) {
		STARTLOG(LOG_PROBLEMS, "HLP", "RINDX") {
			p = alloc_lbuf("helpindex_read.LOG");
			sprintf(p, "Can't open %s for reading.", filename);
			log_text(p);
			free_lbuf(p);
			ENDLOG;
		}
		return -1;
	}
	count = 0;
	while ((fread((char *) &entry, sizeof(help_indx), 1, fp)) == 1) {

		/*
		 * Lowercase the entry and add all leftmost substrings. * * * 
		 * 
		 * * Substrings already added will be rejected by hashadd. 
		 */
		for(p = entry.topic; *p; p++)
			*p = ToLower(*p);

		htab_entry = (struct help_entry *) malloc(sizeof(struct help_entry));

		htab_entry->pos = entry.pos;
		htab_entry->original = 1;	/*
									 * First is the longest 
									 */
		htab_entry->key = (char *) malloc(strlen(entry.topic) + 1);
		StringCopy(htab_entry->key, entry.topic);
		while (p > entry.topic) {
			p--;
			if(!isspace(*p)) {
				if((hashadd(entry.topic, (int *) htab_entry, htab)) == 0)
					count++;
				else {
					free(htab_entry->key);
					free(htab_entry);
				}
			} else {
				free(htab_entry->key);
				free(htab_entry);
			}
			*p = '\0';
			htab_entry =
				(struct help_entry *) malloc(sizeof(struct help_entry));

			htab_entry->pos = entry.pos;
			htab_entry->original = 0;
			htab_entry->key = (char *) malloc(strlen(entry.topic) + 1);
			StringCopy(htab_entry->key, entry.topic);
		}
		free(htab_entry->key);
		free(htab_entry);
	}
	fclose(fp);
	hashreset(htab);
	return count;
}

void helpindex_load(dbref player)
{
	int news, help, whelp;
	int phelp, wnhelp;

	phelp = helpindex_read(&mudstate.plushelp_htab, mudconf.plushelp_indx);
	wnhelp = helpindex_read(&mudstate.wiznews_htab, mudconf.wiznews_indx);
	news = helpindex_read(&mudstate.news_htab, mudconf.news_indx);
	help = helpindex_read(&mudstate.help_htab, mudconf.help_indx);
	whelp = helpindex_read(&mudstate.wizhelp_htab, mudconf.whelp_indx);
	if((player != NOTHING) && !Quiet(player))
		notify_printf(player,
					  "Index entries: News...%d  Help...%d  Wizhelp...%d  +Help...%d  Wiznews...%d",
					  news, help, whelp, phelp, wnhelp);
}

void helpindex_init(void)
{
	hashinit(&mudstate.news_htab, 30 * HASH_FACTOR);
	hashinit(&mudstate.help_htab, 400 * HASH_FACTOR);
	hashinit(&mudstate.wizhelp_htab, 400 * HASH_FACTOR);
	hashinit(&mudstate.plushelp_htab, 400 * HASH_FACTOR);
	hashinit(&mudstate.wiznews_htab, 400 * HASH_FACTOR);

	helpindex_load(NOTHING);
}

void help_write(dbref player, char *topic, HASHTAB * htab, char *filename,
				int eval)
{
	FILE *fp;
	char *p, *line, *bp, *str, *result;
	int offset;
	struct help_entry *htab_entry;
	char matched;
	char *topic_list = NULL, *buffp;

	if(*topic == '\0')
		topic = (char *) "help";
	else
		for(p = topic; *p; p++)
			*p = ToLower(*p);
	htab_entry = (struct help_entry *) hashfind(topic, htab);
	if(htab_entry)
		offset = htab_entry->pos;
	else {
		matched = 0;
		for(htab_entry = (struct help_entry *) hash_firstentry(htab);
			htab_entry != NULL;
			htab_entry = (struct help_entry *) hash_nextentry(htab)) {
			if(htab_entry->original && quick_wild(topic, htab_entry->key)) {
				if(matched == 0) {
					matched = 1;
					topic_list = alloc_lbuf("help_write");
					buffp = topic_list;
				}
				safe_str(htab_entry->key, topic_list, &buffp);
				safe_str((char *) "  ", topic_list, &buffp);
			}
		}
		if(matched == 0)
			notify_printf(player, "No entry for '%s'.", topic);
		else {
			notify_printf(player,
						  "Here are the entries which match '%s':", topic);
			*buffp = '\0';
			notify(player, topic_list);
			free_lbuf(topic_list);
		}
		return;
	}
	if((fp = fopen(filename, "r")) == NULL) {
		notify(player, "Sorry, that function is temporarily unavailable.");
		STARTLOG(LOG_PROBLEMS, "HLP", "OPEN") {
			line = alloc_lbuf("help_write.LOG.open");
			sprintf(line, "Can't open %s for reading.", filename);
			log_text(line);
			free_lbuf(line);
			ENDLOG;
		}
		return;
	}
	if(fseek(fp, offset, 0) < 0L) {
		notify(player, "Sorry, that function is temporarily unavailable.");
		STARTLOG(LOG_PROBLEMS, "HLP", "SEEK") {
			line = alloc_lbuf("help_write.LOG.seek");
			sprintf(line, "Seek error in file %s.", filename);
			log_text(line);
			free_lbuf(line);
			ENDLOG;
		}
		fclose(fp);

		return;
	}
	line = alloc_lbuf("help_write");
	result = alloc_lbuf("help_write.2");
	for(;;) {
		if(fgets(line, LBUF_SIZE - 1, fp) == NULL)
			break;
		if(line[0] == '&')
			break;
		for(p = line; *p != '\0'; p++)
			if(*p == '\n')
				*p = '\0';
		if(eval) {
			str = line;
			bp = result;
			exec(result, &bp, 0, player, player,
				 EV_NO_COMPRESS | EV_FIGNORE | EV_EVAL, &str,
				 (char **) NULL, 0);
			*bp = '\0';
			notify(player, result);
		} else
			notify(player, line);
	}
	fclose(fp);
	free_lbuf(line);
	free_lbuf(result);
}

/*
 * ---------------------------------------------------------------------------
 * * do_help: display information from new-format news and help files
 */

void do_help(dbref player, dbref cause, int key, char *message)
{
	char *buf;

	switch (key) {
	case HELP_HELP:
		help_write(player, message, &mudstate.help_htab, mudconf.help_file,
				   0);
		break;
	case HELP_NEWS:
		help_write(player, message, &mudstate.news_htab, mudconf.news_file,
				   EVAL_ALL_NEWS);
		break;
	case HELP_WIZHELP:
		help_write(player, message, &mudstate.wizhelp_htab,
				   mudconf.whelp_file, 0);
		break;
	case HELP_PLUSHELP:
		help_write(player, message, &mudstate.plushelp_htab,
				   mudconf.plushelp_file, 1);
		break;
	case HELP_WIZNEWS:
#ifdef DO_PARSE_WIZNEWS
		help_write(player, message, &mudstate.wiznews_htab,
				   mudconf.wiznews_file, 1);
#else
		help_write(player, message, &mudstate.wiznews_htab,
				   mudconf.wiznews_file, 0);
#endif
		break;
	default:
		STARTLOG(LOG_BUGS, "BUG", "HELP") {
			buf = alloc_mbuf("do_help.LOG");
			sprintf(buf, "Unknown help file number: %d", key);
			log_text(buf);
			free_mbuf(buf);
			ENDLOG;
		}
	}
}