/*
 * history.c: stuff to handle command line history 
 *
 *
 * Written By Michael Sandrof
 *
 * Copyright(c) 1990 
 *
 * See the COPYRIGHT file, or do a HELP IRCII COPYRIGHT 
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif


#include "irc.h"

#include "ircaux.h"
#include "vars.h"
#include "history.h"
#include "output.h"
#include "input.h"
#include "tcommand.h"

static char *history_match (char *);
static void add_to_history_list (int, char *);
static char *get_from_history_buffer (int);

typedef struct HistoryStru
{
	int number;
	char *stuff;
	struct HistoryStru *next;
	struct HistoryStru *prev;
}
History;

/* command_history: pointer to head of command_history list */
static History *command_history_head = NULL;
static History *command_history_tail = NULL;
static History *command_history_pos = NULL;

/* hist_size: the current size of the command_history array */
static int hist_size = 0;

/* hist_count: the absolute counter for the history list */
static int hist_count = 0;

/*
 * last_dir: the direction (next or previous) of the last get_from_history()
 * call.... reset by add to history 
 */
static int last_dir = -1;

/*
 * history pointer
 */
static History *tmp = NULL;

/*
 * history_match: using wild_match(), this finds the latest match in the
 * history file and returns it as the function result.  Returns null if there
 * is no match.  Note that this sticks a '*' at the end if one is not already
 * there. 
 */
static char *
history_match (char *match)
{
	char *ptr;
	char *match_str = NULL;

	if (*(match + strlen (match) - 1) == '*')
		malloc_strcpy (&match_str, match);
	else
	{
		match_str = (char *) new_malloc (strlen (match) + 2);
		strcpy (match_str, match);
		strcat (match_str, "*");
	}
	if (get_int_var (HISTORY_VAR))
	{
		if ((last_dir == -1) || (tmp == (History *) NULL))
			tmp = command_history_head;
		else
			tmp = tmp->next;
		for (; tmp; tmp = tmp->next)
		{
			ptr = tmp->stuff;
			while (ptr && strchr (get_string_var (CMDCHARS_VAR), *ptr))
				ptr++;

			if (wild_match (match_str, ptr))
			{
				new_free (&match_str);
				last_dir = PREV;
				return (tmp->stuff);
			}
		}
	}
	last_dir = -1;
	new_free (&match_str);
	return NULL;
}

/* shove_to_history: a key binding that saves the current line into
 * the history and then deletes the whole line.  Useful for when you
 * are in the middle of a big line and need to "get out" to do something
 * else quick for just a second, and you dont want to have to retype
 * everything all over again
 */
extern void 
shove_to_history (char unused, char *not_used)
{
	add_to_history (get_input ());
	input_clear_line (unused, not_used);
}

static void 
add_to_history_list (int cnt, char *stuff)
{
	History *new;

	if (get_int_var (HISTORY_VAR) == 0)
		return;
	if ((hist_size == get_int_var (HISTORY_VAR)) && command_history_tail)
	{
		if (hist_size == 1)
		{
			malloc_strcpy (&command_history_tail->stuff, stuff);
			return;
		}
		new = command_history_tail;
		command_history_tail = command_history_tail->prev;
		command_history_tail->next = NULL;
		new_free (&new->stuff);
		new_free ((char **) &new);
		if (command_history_tail == NULL)
			command_history_head = NULL;
	}
	else
		hist_size++;
	new = (History *) new_malloc (sizeof (History));
	new->stuff = NULL;
	new->number = cnt;
	new->next = command_history_head;
	new->prev = NULL;
	malloc_strcpy (&(new->stuff), stuff);
	if (command_history_head)
		command_history_head->prev = new;
	command_history_head = new;
	if (command_history_tail == NULL)
		command_history_tail = new;
	command_history_pos = NULL;
}

/*
 * set_history_size: adjusts the size of the command_history to be size. If
 * the array is not yet allocated, it is set to size and all the entries
 * nulled.  If it exists, it is resized to the new size with a realloc.  Any
 * new entries are nulled. 
 */
void 
set_history_size (Window * win, char *unused, int size)
{
	int i, cnt;
	History *ptr;

	if (size < hist_size)
	{
		cnt = hist_size - size;
		for (i = 0; i < cnt; i++)
		{
			ptr = command_history_tail;
			command_history_tail = ptr->prev;
			new_free (&(ptr->stuff));
			new_free ((char **) &ptr);
		}
		if (command_history_tail == NULL)
			command_history_head = NULL;
		else
			command_history_tail->next = NULL;
		hist_size = size;
	}
}

/*
 * add_to_history: adds the given line to the history array.  The history
 * array is a circular buffer, and add_to_history handles all that stuff. It
 * automagically allocted and deallocated memory as needed 
 */
void 
add_to_history (char *line)
{
	char *ptr;

	if (line && *line)
	{
		while (line)
		{
			if ((ptr = sindex (line, "\n\r")) != NULL)
				*(ptr++) = '\0';
			add_to_history_list (hist_count, line);
			last_dir = PREV;
			hist_count++;
			line = ptr;
		}
	}
}

static char *
get_from_history_buffer (int which)
{
	if ((get_int_var (HISTORY_VAR) == 0) || (hist_size == 0))
		return NULL;
	/*
	 * if (last_dir != which) { last_dir = which; get_from_history(which); }
	 */
	if (which == NEXT)
	{
		if (command_history_pos)
		{
			if (command_history_pos->prev)
				command_history_pos = command_history_pos->prev;
			else
				command_history_pos = command_history_tail;
		}
		else
		{
			add_to_history (get_input ());
			command_history_pos = command_history_tail;
		}
		return (command_history_pos->stuff);
	}
	else
	{
		if (command_history_pos)
		{
			if (command_history_pos->next)
				command_history_pos = command_history_pos->next;
			else
				command_history_pos = command_history_head;
		}
		else
		{
			add_to_history (get_input ());
			command_history_pos = command_history_head;
		}
		return (command_history_pos->stuff);
	}
}

/*
 * get_history: gets the next history entry, either the PREV entry or the
 * NEXT entry, and sets it to the current input string 
 */
extern void 
get_history (int which)
{
	char *ptr;

	if ((ptr = get_from_history (which)) != NULL)
	{
		set_input (ptr);
		update_input (UPDATE_ALL);
	}

}

char *
get_from_history (int which)
{
	return (get_from_history_buffer (which));
}

/* history: the /HISTORY command, shows the command history buffer. */
void
cmd_history (struct command *cmd, char *args)
{
	int cnt, max;
	char *value;
	History *tmp;

	if (get_int_var (HISTORY_VAR))
	{
		say ("Command History:");
		if ((value = next_arg (args, &args)) != NULL)
		{
			if ((max = my_atol (value)) > get_int_var (HISTORY_VAR))
				max = get_int_var (HISTORY_VAR);
		}
		else
			max = get_int_var (HISTORY_VAR);
		for (tmp = command_history_tail, cnt = 0; tmp && (cnt < max);
		     tmp = tmp->prev, cnt++)
			put_it ("%d: %s", tmp->number, tmp->stuff);
	}
}

/*
 * do_history: This finds the given history entry in either the history file,
 * or the in memory history buffer (if no history file is given). It then
 * returns the found entry as its function value, or null if the entry is not
 * found for some reason.  Note that this routine mallocs the string returned  
 */
char *
do_history (char *com, char *rest)
{
	History *tmp;
	int hist_num;
	char *ptr, *ret = NULL;
	static char *last_com = NULL;

	if (!com || !*com)
	{
		if (last_com)
			com = last_com;
		else
			com = empty_string;
	}
	else
		malloc_strcpy (&last_com, com);

	if (!is_number (com))
	{
		if ((ptr = history_match (com)) != NULL)
		{
			if (rest && *rest)
				ret = m_sprintf ("%s %s", ptr, rest);
			else
				malloc_strcpy (&ret, ptr);
		}
		else
			say ("No Match");
		return (ret);
	}

	hist_num = my_atol (com);

	for (tmp = command_history_head; tmp; tmp = tmp->next)
	{
		if (tmp->number == hist_num)
		{
			if (rest && *rest)
				ret = m_sprintf ("%s %s", tmp->stuff, rest);
			else
				malloc_strcpy (&ret, tmp->stuff);
			return (ret);
		}
	}
	say ("No such history entry: %d", hist_num);
	return NULL;
}
