/*
 * Copyright (C) 1997-2001 Id Software, Inc.
 *
 * This program 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 2 of the License, or (at your option)
 * any later version.
 *
 * This program 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
 * this program; if not, write to the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */
/* cmd.c -- Quake script command processing module */

#include "qcommon.h"

#define	MAX_ALIAS_NAME	32

typedef struct cmdalias_s {
	struct cmdalias_s *next;
	char	name[MAX_ALIAS_NAME];
	char    *value;
} cmdalias_t;

cmdalias_t     *cmd_alias;

qboolean	cmd_wait;

#define	ALIAS_LOOP_COUNT	16
int		alias_count;	/* for detecting runaway loops */


/*
 * ============ Cmd_Wait_f
 *
 * Causes execution of the remainder of the command buffer to be delayed until
 * next frame.  This allows commands like: bind g "impulse 5 ; +attack ; wait
 * ; -attack ; impulse 2" ============
 */
void
Cmd_Wait_f(void)
{
	cmd_wait = true;
}


/*
 *
 * ============================================================================
 *
 * COMMAND BUFFER
 *
 * ============================================================================
 */

sizebuf_t	cmd_text;
byte		cmd_text_buf[8192];
char		defer_text_buf[8192];

/*
 * ============ Cbuf_Init ============
 */
void
Cbuf_Init(void)
{
	SZ_Init(&cmd_text, cmd_text_buf, sizeof(cmd_text_buf));
}

/*
 * ============ Cbuf_AddText
 *
 * Adds command text at the end of the buffer ============
 */
void
Cbuf_AddText(char *text)
{
	int		l;

	l = strlen(text);

	if (cmd_text.cursize + l >= cmd_text.maxsize) {
		Com_Printf("Cbuf_AddText: overflow\n");
		return;
	}
	SZ_Write(&cmd_text, text, strlen(text));
}


/*
 * ============ Cbuf_InsertText
 *
 * Adds command text immediately after the current command Adds a \n to the text
 * FIXME: actually change the command buffer to do less copying ============
 */
void
Cbuf_InsertText(char *text)
{
	char           *temp;
	int		templen;

	/* copy off any commands still remaining in the exec buffer */
	templen = cmd_text.cursize;
	if (templen) {
		temp = Z_Malloc(templen);
		memcpy(temp, cmd_text.data, templen);
		SZ_Clear(&cmd_text);
	} else
		temp = NULL;	/* shut up compiler */

	/* add the entire text of the file */
	Cbuf_AddText(text);

	/* add the copied off data */
	if (templen) {
		SZ_Write(&cmd_text, temp, templen);
		Z_Free(temp);
	}
}


/*
 * ============ Cbuf_CopyToDefer ============
 */
void
Cbuf_CopyToDefer(void)
{
	memcpy(defer_text_buf, cmd_text_buf, cmd_text.cursize);
	defer_text_buf[cmd_text.cursize] = 0;
	cmd_text.cursize = 0;
}

/*
 * ============ Cbuf_InsertFromDefer ============
 */
void
Cbuf_InsertFromDefer(void)
{
	Cbuf_InsertText(defer_text_buf);
	defer_text_buf[0] = 0;
}


/*
 * ============ Cbuf_ExecuteText ============
 */
void
Cbuf_ExecuteText(int exec_when, char *text)
{
	switch (exec_when) {
		case EXEC_NOW:
		Cmd_ExecuteString(text);
		break;
	case EXEC_INSERT:
		Cbuf_InsertText(text);
		break;
	case EXEC_APPEND:
		Cbuf_AddText(text);
		break;
	default:
		Com_Error(ERR_FATAL, "Cbuf_ExecuteText: bad exec_when");
	}
}

/*
 * ============ Cbuf_Execute ============
 */
void
Cbuf_Execute(void)
{
	int		i;
	char           *text;
	char		line[1024];
	int		quotes;

	alias_count = 0;	/* don't allow infinite alias loops */

	while (cmd_text.cursize) {
		/* find a \n or ; line break */
		text = (char *)cmd_text.data;

		quotes = 0;
		for (i = 0; i < cmd_text.cursize; i++) {
			if (text[i] == '"')
				quotes++;
			if (!(quotes & 1) && text[i] == ';')
				break;	/* don't break if inside a quoted string */
			if (text[i] == '\n')
				break;
		}

		/* sku - removed potentional buffer overflow vulnerability */
		if (i > sizeof(line) - 1) {
			i = sizeof(line) - 1;
		}
		memcpy(line, text, i);
		line[i] = 0;

		/*
		 * delete the text from the command buffer and move remaining
		 * commands down
		 */

		/*
		 * this is necessary because commands (exec, alias) can
		 * insert data at the
		 */
		/* beginning of the text buffer */

		if (i == cmd_text.cursize)
			cmd_text.cursize = 0;
		else {
			i++;
			cmd_text.cursize -= i;
			memmove(text, text + i, cmd_text.cursize);
		}

		/* execute the command line */
		Cmd_ExecuteString(line);

		if (cmd_wait) {

			/*
			 * skip out while text still remains in buffer,
			 * leaving it
			 */
			/* for next frame */
			cmd_wait = false;
			break;
		}
	}
}


/*
 * =============== Cbuf_AddEarlyCommands
 *
 * Adds command line parameters as script statements Commands lead with a +, and
 * continue until another +
 *
 * Set commands are added early, so they are guaranteed to be set before the
 * client and server initialize for the first time.
 *
 * Other commands are added late, after all initialization is complete.
 * ===============
 */
void
Cbuf_AddEarlyCommands(qboolean clear)
{
	int		i;
	char           *s;

	for (i = 0; i < COM_Argc(); i++) {
		s = COM_Argv(i);
		if (strcmp(s, "+set"))
			continue;
		Cbuf_AddText(va("set %s %s\n", COM_Argv(i + 1), COM_Argv(i + 2)));
		if (clear) {
			COM_ClearArgv(i);
			COM_ClearArgv(i + 1);
			COM_ClearArgv(i + 2);
		}
		i += 2;
	}
}

/*
 * ================= Cbuf_AddLateCommands
 *
 * Adds command line parameters as script statements Commands lead with a + and
 * continue until another + or - quake +vid_ref gl +map amlev1
 *
 * Returns true if any late commands were added, which will keep the demoloop
 * from immediately starting =================
 */
qboolean
Cbuf_AddLateCommands(void)
{
	int		i, j;
	int		s;
	char           *text, *build, c;
	int		argc;
	qboolean	ret;

	/* build the combined string to parse from */
	s = 0;
	argc = COM_Argc();
	for (i = 1; i < argc; i++) {
		s += strlen(COM_Argv(i)) + 1;
	}
	if (!s)
		return false;

	text = Z_Malloc(s + 1);
	text[0] = 0;
	for (i = 1; i < argc; i++) {
		strcat(text, COM_Argv(i));
		if (i != argc - 1)
			strcat(text, " ");
	}

	/* pull out the commands */
	build = Z_Malloc(s + 1);
	build[0] = 0;

	for (i = 0; i < s - 1; i++) {
		if (text[i] == '+') {
			i++;

			for (j = i; (text[j] != '+') && (text[j] != '-') && (text[j] != 0); j++);

			c = text[j];
			text[j] = 0;

			strcat(build, text + i);
			strcat(build, "\n");
			text[j] = c;
			i = j - 1;
		}
	}

	ret = (build[0] != 0);
	if (ret)
		Cbuf_AddText(build);

	Z_Free(text);
	Z_Free(build);

	return ret;
}


/*
 *
 * ============================================================================
 * ==
 *
 * SCRIPT COMMANDS
 *
 * ===============
 * ==============================================================
 */


/*
 * =============== Cmd_Exec_f ===============
 */
void
Cmd_Exec_f(void)
{
	char           *f, *f2;
	int		len;

	if (Cmd_Argc() != 2) {
		Com_Printf("exec <filename> : execute a script file\n");
		return;
	}
	len = FS_LoadFile(Cmd_Argv(1), (void **)&f);
	if (!f) {
		Com_Printf("couldn't exec %s\n", Cmd_Argv(1));
		return;
	}
	Com_Printf("execing %s\n", Cmd_Argv(1));

	/* the file doesn't have a trailing 0, so we need to copy it off */
	f2 = Z_Malloc(len + 1);
	memcpy(f2, f, len);
	f2[len] = 0;

	Cbuf_InsertText(f2);

	Z_Free(f2);
	FS_FreeFile(f);
}


/*
 * =============== Cmd_Echo_f
 *
 * Just prints the rest of the line to the console ===============
 */
void
Cmd_Echo_f(void)
{
	int		i;

	for (i = 1; i < Cmd_Argc(); i++)
		Com_Printf("%s ", Cmd_Argv(i));
	Com_Printf("\n");
}

/*
 * =============== Cmd_Alias_f
 *
 * Creates a new command that executes a command string (possibly ; seperated)
 * ===============
 */
void
Cmd_Alias_f(void)
{
	cmdalias_t     *a;
	char		cmd[1024];
	int		i, c;
	char           *s;

	if (Cmd_Argc() == 1) {
		Com_Printf("Current alias commands:\n");
		for (a = cmd_alias; a; a = a->next)
			Com_Printf("%s : %s\n", a->name, a->value);
		return;
	}
	s = Cmd_Argv(1);
	if (strlen(s) >= MAX_ALIAS_NAME) {
		Com_Printf("Alias name is too long\n");
		return;
	}
	/* if the alias already exists, reuse it */
	for (a = cmd_alias; a; a = a->next) {
		if (!strcmp(s, a->name)) {
			Z_Free(a->value);
			break;
		}
	}

	if (!a) {
		a = Z_Malloc(sizeof(cmdalias_t));
		a->next = cmd_alias;
		cmd_alias = a;
	}
	Q_strncpyz(a->name, s, sizeof(a->name));

	/* copy the rest of the command line */
	cmd[0] = '\0';		/* start out with a null string */
	c = Cmd_Argc();
	for (i = 2; i < c; i++) {
		strncat(cmd, Cmd_Argv(i), sizeof(cmd) - strlen(cmd) - 1);
		if (i != (c - 1))
			strncat(cmd, " ", sizeof(cmd) - strlen(cmd) - 1);
	}
	strncat(cmd, "\n", sizeof(cmd) - strlen(cmd) - 1);

	a->value = CopyString(cmd);
}

/*
 * ===========================================================================
 *
 * COMMAND EXECUTION
 *
 * ===========================================================================
 */

typedef struct cmd_function_s {
	struct cmd_function_s *next;
	char           *name;
	xcommand_t	function;
} cmd_function_t;


static int	cmd_argc;
static char    *cmd_argv[MAX_STRING_TOKENS];
static char    *cmd_null_string = "";
static char	cmd_args[MAX_STRING_CHARS];

static cmd_function_t *cmd_functions;	/* possible commands to execute */

/*
 * ============ Cmd_Argc ============
 */
int
Cmd_Argc(void)
{
	return cmd_argc;
}

/*
 * ============ Cmd_Argv ============
 */
char           *
Cmd_Argv(int arg)
{
	if ((unsigned)arg >= cmd_argc)
		return cmd_null_string;
	return cmd_argv[arg];
}

/*
 * ============ Cmd_Args
 *
 * Returns a single string containing argv(1) to argv(argc()-1) ============
 */
char           *
Cmd_Args(void)
{
	return cmd_args;
}


/*
 * ====================== Cmd_MacroExpandString ======================
 */
char           *
Cmd_MacroExpandString(char *text)
{
	int		i, j, count, len;
	qboolean	inquote;
	char           *scan;
	static char	expanded[MAX_STRING_CHARS];
	char		temporary[MAX_STRING_CHARS];
	char           *token, *start;

	inquote = false;
	scan = text;

	len = strlen(scan);
	if (len >= MAX_STRING_CHARS) {
		Com_Printf("Line exceeded %i chars, discarded.\n", MAX_STRING_CHARS);
		return NULL;
	}
	count = 0;

	for (i = 0; i < len; i++) {
		if (scan[i] == '"')
			inquote ^= 1;
		if (inquote)
			continue;	/* don't expand inside quotes */
		if (scan[i] != '$')
			continue;
		/* scan out the complete macro */
		start = scan + i + 1;
		token = COM_Parse(&start);
		if (!start)
			continue;

		token = Cvar_VariableString(token);

		j = strlen(token);
		len += j;
		if (len >= MAX_STRING_CHARS) {
			Com_Printf("Expanded line exceeded %i chars, discarded.\n", MAX_STRING_CHARS);
			return NULL;
		}
		strncpy(temporary, scan, i);
		strcpy(temporary + i, token);
		strcpy(temporary + i + j, start);

		strcpy(expanded, temporary);
		scan = expanded;
		i--;

		if (++count == 100) {
			Com_Printf("Macro expansion loop, discarded.\n");
			return NULL;
		}
	}

	if (inquote) {
		Com_Printf("Line has unmatched quote, discarded.\n");
		return NULL;
	}
	return scan;
}


/*
 * ============ Cmd_TokenizeString
 *
 * Parses the given string into command line tokens. $Cvars will be expanded
 * unless they are in a quoted token ============
 */
void
Cmd_TokenizeString(char *text, qboolean macroExpand)
{
	int		i;
	char           *com_token;

	/* clear the args from the last string */
	for (i = 0; i < cmd_argc; i++)
		Z_Free(cmd_argv[i]);

	cmd_argc = 0;
	cmd_args[0] = 0;

	/* macro expand the text */
	if (macroExpand)
		text = Cmd_MacroExpandString(text);
	if (!text)
		return;

	while (1) {
		/* skip whitespace up to a /n */
		while (*text && *text <= ' ' && *text != '\n') {
			text++;
		}

		if (*text == '\n') {	/* a newline seperates commands in
					 * the buffer */
			text++;
			break;
		}
		if (!*text)
			return;

		/* set cmd_args to everything after the first arg */
		if (cmd_argc == 1) {
			int		l;

			/* strcpy (cmd_args, text); */

			/*
			 * sku - removed potentional buffer overflow
			 * vulnerability
			 */
			Q_strncpyz(cmd_args, text, sizeof(cmd_args));

			/* strip off any trailing whitespace */
			l = strlen(cmd_args) - 1;
			for (; l >= 0; l--)
				if (cmd_args[l] <= ' ')
					cmd_args[l] = 0;
				else
					break;
		}
		com_token = COM_Parse(&text);
		if (!text)
			return;

		if (cmd_argc < MAX_STRING_TOKENS) {
			cmd_argv[cmd_argc] = Z_Malloc(strlen(com_token) + 1);
			Q_strncpyz(cmd_argv[cmd_argc], com_token, strlen(com_token) + 1);
			cmd_argc++;
		}
	}

}


/*
 * ============ Cmd_AddCommand ============
 */
void
Cmd_AddCommand(char *cmd_name, xcommand_t function)
{
	cmd_function_t *cmd;

	/* fail if the command is a variable name */
	if (Cvar_VariableString(cmd_name)[0]) {
		Com_Printf("Cmd_AddCommand: %s already defined as a var\n", cmd_name);
		return;
	}
	/* fail if the command already exists */
	for (cmd = cmd_functions; cmd; cmd = cmd->next) {
		if (!strcmp(cmd_name, cmd->name)) {
			Com_Printf("Cmd_AddCommand: %s already defined\n", cmd_name);
			return;
		}
	}

	cmd = Z_Malloc(sizeof(cmd_function_t));
	cmd->name = cmd_name;
	cmd->function = function;
	cmd->next = cmd_functions;
	cmd_functions = cmd;
}

/*
 * ============ Cmd_RemoveCommand ============
 */
void
Cmd_RemoveCommand(char *cmd_name)
{
	cmd_function_t *cmd, **back;

	back = &cmd_functions;
	while (1) {
		cmd = *back;
		if (!cmd) {
			Com_Printf("Cmd_RemoveCommand: %s not added\n", cmd_name);
			return;
		}
		if (!strcmp(cmd_name, cmd->name)) {
			*back = cmd->next;
			Z_Free(cmd);
			return;
		}
		back = &cmd->next;
	}
}

/*
 * ============ Cmd_Exists ============
 */
qboolean
Cmd_Exists(char *cmd_name)
{
	cmd_function_t *cmd;

	for (cmd = cmd_functions; cmd; cmd = cmd->next) {
		if (!strcmp(cmd_name, cmd->name))
			return true;
	}

	return false;
}



/*
 * ============ Cmd_CompleteCommand ============
 */
char		retval[256];

char           *
Cmd_CompleteCommand(char *partial)
{
	cmd_function_t *cmd;
	int		len, i, o, p;
	cmdalias_t     *a;
	cvar_t         *cvar;
	char           *pmatch[1024];
	qboolean	diff = false;

	len = strlen(partial);

	if (!len)
		return NULL;

	/* check for exact match */
	for (cmd = cmd_functions; cmd; cmd = cmd->next)
		if (!strcmp(partial, cmd->name))
			return cmd->name;
	for (a = cmd_alias; a; a = a->next)
		if (!strcmp(partial, a->name))
			return a->name;
	for (cvar = cvar_vars; cvar; cvar = cvar->next)
		if (!strcmp(partial, cvar->name))
			return cvar->name;

	for (i = 0; i < 1024; i++)
		pmatch[i] = NULL;
	i = 0;

	/* check for partial match */
	for (cmd = cmd_functions; cmd; cmd = cmd->next)
		if (!strncmp(partial, cmd->name, len)) {
			pmatch[i] = cmd->name;
			i++;
		}
	for (a = cmd_alias; a; a = a->next)
		if (!strncmp(partial, a->name, len)) {
			pmatch[i] = a->name;
			i++;
		}
	for (cvar = cvar_vars; cvar; cvar = cvar->next)
		if (!strncmp(partial, cvar->name, len)) {
			pmatch[i] = cvar->name;
			i++;
		}
	if (i) {
		if (i == 1)
			return pmatch[0];

		Com_Printf("\nListing matches for '%s'...\n", partial);
		for (o = 0; o < i; o++)
			Com_Printf("  %s\n", pmatch[o]);

		strcpy(retval, "");
		p = 0;
		while (!diff && p < 256) {
			retval[p] = pmatch[0][p];
			for (o = 0; o < i; o++) {
				if (p > strlen(pmatch[o]))
					continue;
				if (retval[p] != pmatch[o][p]) {
					retval[p] = 0;
					diff = true;
				}
			}
			p++;
		}
		Com_Printf("Found %i matches\n", i);
		return retval;
	}
	return NULL;
}

qboolean
Cmd_IsComplete(char *command)
{
	cmd_function_t *cmd;
	cmdalias_t     *a;
	cvar_t         *cvar;

	/* check for exact match */
	for (cmd = cmd_functions; cmd; cmd = cmd->next)
		if (!strcmp(command, cmd->name))
			return true;
	for (a = cmd_alias; a; a = a->next)
		if (!strcmp(command, a->name))
			return true;
	for (cvar = cvar_vars; cvar; cvar = cvar->next)
		if (!strcmp(command, cvar->name))
			return true;

	return false;
}



/*
 * ============ Cmd_ExecuteString
 *
 * A complete command line has been parsed, so try to execute it FIXME:
 * lookupnoadd the token to speed search? ============
 */
void
Cmd_ExecuteString(char *text)
{
	cmd_function_t *cmd;
	cmdalias_t     *a;

	Cmd_TokenizeString(text, true);

	/* execute the command line */
	if (!Cmd_Argc())
		return;		/* no tokens */

	/* check functions */
	for (cmd = cmd_functions; cmd; cmd = cmd->next) {
		if (!Q_strcasecmp(cmd_argv[0], cmd->name)) {
			if (!cmd->function) {	/* forward to server command */
				Cmd_ExecuteString(va("cmd %s", text));
			} else
				cmd->function();
			return;
		}
	}

	/* check alias */
	for (a = cmd_alias; a; a = a->next) {
		if (!Q_strcasecmp(cmd_argv[0], a->name)) {
			if (++alias_count == ALIAS_LOOP_COUNT) {
				Com_Printf("ALIAS_LOOP_COUNT\n");
				return;
			}
			Cbuf_InsertText(a->value);
			return;
		}
	}

	/* check cvars */
	if (Cvar_Command())
		return;

	/* send it as a server command if we are connected */
	Cmd_ForwardToServer();
}

/*
 * ============ Cmd_List_f ============
 */
void
Cmd_List_f(void)
{
	cmd_function_t *cmd;
	int		i;

	i = 0;
	for (cmd = cmd_functions; cmd; cmd = cmd->next, i++)
		Com_Printf("%s\n", cmd->name);
	Com_Printf("%i commands\n", i);
}

/*
 * ============ Cmd_Init ============
 */
void
Cmd_Init(void)
{
	//
	/* register our commands */
	//
	Cmd_AddCommand("cmdlist", Cmd_List_f);
	Cmd_AddCommand("exec", Cmd_Exec_f);
	Cmd_AddCommand("echo", Cmd_Echo_f);
	Cmd_AddCommand("alias", Cmd_Alias_f);
	Cmd_AddCommand("wait", Cmd_Wait_f);
}