/*
Copyright (C) 1996-2001 Id Software, Inc.
Copyright (C) 2002-2009 John Fitzgibbons and others
Copyright (C) 2010-2014 QuakeSpasm developers

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.

*/

#pragma once

// cmd.h -- Command buffer and command execution

//===========================================================================

/*

Any number of commands can be added in a frame, from several different sources.
Most commands come from either keybindings or console line input, but remote
servers can also send across commands and entire text files can be execed.

The + command line options are also added to the command buffer.

The game starts with a Cbuf_AddText ("exec quake.rc\n"); Cbuf_Execute ();

*/

void Cbuf_Init (void);
// allocates an initial text buffer that will grow as needed

void Cbuf_AddText (const char *text);
// as new commands are generated from the console or keybindings,
// the text is added to the end of the command buffer.

void Cbuf_InsertText (const char *text);
// when a command wants to issue other commands immediately, the text is
// inserted at the beginning of the buffer, before any remaining unexecuted
// commands.

void Cbuf_Execute (void);
// Pulls off \n terminated lines of text from the command buffer and sends
// them through Cmd_ExecuteString.  Stops when the buffer is empty.
// Normally called once per frame, but may be explicitly invoked.
// Do not call inside a command function!

//===========================================================================

/*

Command execution takes a null terminated string, breaks it into tokens,
then searches for a command or variable that matches the first token.

Commands can come from three sources, but the handler functions may choose
to dissallow the action or forward it to a remote server if the source is
not apropriate.

*/

typedef void (*xcommand_t) (void);



namespace command {
	enum class source {
		client,
		command
	};

	extern	source	last_source;

	struct alias {
		std::string name;
		std::string value;
	};

	struct definition {
		std::string name{};
		xcommand_t func{nullptr};

		definition(const std::string &name, const xcommand_t func) {
			this->name = name;
			this->func = func;
		}
	};

	using definition_view = std::ranges::elements_view<std::ranges::ref_view<std::map<std::string, definition, std::less<>>>, 1>;
	using alias_view = std::ranges::elements_view<std::ranges::ref_view<std::map<std::string, alias, std::less<>>>, 1>;


	void init();

	void add(const std::string &name, xcommand_t cmd);
	std::optional<std::string> complete(const std::string &partial);
	bool exists(std::string_view lookup);

	int argc();
	std::optional<std::string> argv(int arg);
	std::string args();

	int check_parm(const std::string &parm);

	void tokenize_string(const std::string &text);

	void execute_string(const std::string &text, source src);

	void forward_to_server();

	definition_view get_commands();

	alias_view get_aliases();
}

// called by the init functions of other parts of the program to
// register commands and functions to call for them.
// The cmd_name is referenced later, so it should not be in temp memory

// used by the cvar code to check for cvar / command name overlap

// attempts to match a partial command for automatic command line completion
// returns NULL if nothing fits

// Returns the position (1 to argc-1) in the command's argument list
// where the given parameter apears, or 0 if not present

// Parses a single line of text into arguments and tries to execute it.
// The text can come from the command buffer, a remote client, or stdin.

// adds the current command line as a clc_stringcmd to the client message.
// things like godmode, noclip, etc, are commands directed to the server,
// so when they are typed in at the console, they will need to be forwarded.

// used by command functions to send output to either the graphics console or
// passed as a print message to the client