/** 
 * @file lldispatcher.cpp
 * @brief Implementation of the dispatcher object.
 *
 * Copyright (c) 2004-$CurrentYear$, Linden Research, Inc.
 * $License$
 */

#include "linden_common.h"

#include "lldispatcher.h"

#include <algorithm>
#include "llstl.h"
#include "message.h"

///----------------------------------------------------------------------------
/// Class lldispatcher
///----------------------------------------------------------------------------


LLDispatcher::LLDispatcher()
{
}

LLDispatcher::~LLDispatcher()
{
}

bool LLDispatcher::isHandlerPresent(const key_t& name) const
{
	if(mHandlers.find(name) != mHandlers.end())
	{
		return true;
	}
	return false;
}

void LLDispatcher::copyAllHandlerNames(keys_t& names) const
{
	// copy the names onto the vector we are given
	std::transform(
		mHandlers.begin(),
		mHandlers.end(),
		std::back_insert_iterator<keys_t>(names),
		llselect1st<dispatch_map_t::value_type>());
}

bool LLDispatcher::dispatch(
	const key_t& name,
	const LLUUID& invoice,
	const sparam_t& strings) const
{
	dispatch_map_t::const_iterator it = mHandlers.find(name);
	if(it != mHandlers.end())
	{
		LLDispatchHandler* func = (*it).second;
		return (*func)(this, name, invoice, strings);
	}
	return false;
}

LLDispatchHandler* LLDispatcher::addHandler(
	const key_t& name, LLDispatchHandler* func)
{
	dispatch_map_t::iterator it = mHandlers.find(name);
	LLDispatchHandler* old_handler = NULL;
	if(it != mHandlers.end())
	{
		old_handler = (*it).second;
		mHandlers.erase(it);
	}
	if(func)
	{
		// only non-null handlers so that we don't have to worry about
		// it later.
		mHandlers.insert(dispatch_map_t::value_type(name, func));
	}
	return old_handler;
}

// static
bool LLDispatcher::unpackMessage(
		LLMessageSystem* msg,
		LLDispatcher::key_t& method,
		LLUUID& invoice,
		LLDispatcher::sparam_t& parameters)
{
	char buf[MAX_STRING];	/*Flawfinder: ignore*/
	msg->getStringFast(_PREHASH_MethodData, _PREHASH_Method, MAX_STRING, buf);
	method.assign(buf);
	msg->getUUIDFast(_PREHASH_MethodData, _PREHASH_Invoice, invoice);
	S32 size;
	S32 count = msg->getNumberOfBlocksFast(_PREHASH_ParamList);
	for (S32 i = 0; i < count; ++i)
	{
		// we treat the SParam as binary data (since it might be an 
		// LLUUID in compressed form which may have embedded \0's,)
		size = msg->getSizeFast(_PREHASH_ParamList, i, _PREHASH_Parameter);
		msg->getBinaryDataFast(
			_PREHASH_ParamList, _PREHASH_Parameter,
			buf, size, i, MAX_STRING-1);

		// If the last byte of the data is 0x0, this is either a normally
		// packed string, or a binary packed UUID (which for these messages
		// are packed with a 17th byte 0x0).  Unpack into a std::string
		// without the trailing \0, so "abc\0" becomes std::string("abc", 3)
		// which matches const char* "abc".
		if (size > 0
			&& buf[size-1] == 0x0)
		{
			// special char*/size constructor because UUIDs may have embedded
			// 0x0 bytes.
			std::string binary_data(buf, size-1);
			parameters.push_back(binary_data);
		}
		else
		{
			// This is either a NULL string, or a string that was packed 
			// incorrectly as binary data, without the usual trailing '\0'.
			std::string string_data(buf, size);
			parameters.push_back(string_data);
		}
	}
	return true;
}