#include "precompiled.h"

const char *MPlugin::s_rPrintLoadTime[][4] = {
	// SL_SIMPLE		// SL_SHOW	// SL_ALLOWED					// SL_NOW
	{ "never",			"Never",	"never",						"never" },					// PT_NEVER
	{ "startup",		"Start",	"at server startup",			"during server startup" },	// PT_STARTUP
	{ "changelevel",	"Chlvl",	"at changelevel",				"during changelevel" },		// PT_CHANGELEVEL
	{ "anytime",		"ANY",		"at any time",					"during map" },				// PT_ANYTIME
	{ "pausable",		"Pause",	"at any time, and pausable",	"for requested pause" },	// PT_ANYPAUSE
};

// ReSharper disable once CppPossiblyUninitializedMember
MPlugin::MPlugin()
{
}

// ReSharper disable once CppPossiblyUninitializedMember
MPlugin::MPlugin(int index) : m_index(index)
{
}

// Parse a line from plugins.ini into a plugin.
bool MPlugin::ini_parseline(char *line)
{
	char buf[1024];
	strncpy(buf, line, sizeof buf - 1);
	buf[sizeof buf - 1] = '\0';

	trimbuf(buf);

	// skip empty lines
	if (buf[0] == '\0') {
		return false;
	}

	// skip comments
	if (buf[0] == '#' || buf[0] == ';' || !Q_strncmp(buf, "//", 2)) {
		return false;
	}

	// grab platform ("win32" or "linux")
	char* ptr_token;
	char* token = strtok_r(buf, " \t", &ptr_token);
	if (!token) {
		return false;
	}

	if (!strcmp(token, "linux"))
		m_platform = SP_LINUX;
	else
		m_platform = SP_WINDOWS;

	// grab filename
	token = strtok_r(nullptr, " \t\r\n", &ptr_token);
	if (!token) {
		return false;
	}

	Q_strncpy(m_filename, token, sizeof m_filename - 1);
	m_filename[sizeof m_filename - 1] = '\0';
	normalize_path(m_filename);

	// Store name of just the actual _file_, without dir components.
	char* cp = Q_strrchr(m_filename, '/');
	if (cp)
		m_file = cp + 1;
	else
		m_file = m_filename;

	// Grab description.
	// Just get the the rest of the line, minus line-termination.
	token = strtok_r(nullptr, "\n\r", &ptr_token);
	if (token) {
		token = token + strspn(token, " \t"); // skip whitespace
		Q_strncpy(m_desc, token, sizeof m_desc - 1);
		m_desc[sizeof m_desc - 1] = '\0';
	}
	else {
		// If no description is specified, temporarily use plugin file,
		// until plugin can be queried, and desc replaced with info->name.
		Q_snprintf(m_desc, sizeof m_desc, "<%s>", m_file);
	}

	// Make full pathname (from gamedir if relative, remove "..",
	// backslashes, etc).
	full_gamedir_path(m_filename, m_pathname);

	m_source = PS_INI;
	m_status = PL_VALID;
	return true;
}

// Parse a line from console "load" command into a plugin.
bool MPlugin::cmd_parseline(const char *line)
{
	char buf[NAME_MAX + PATH_MAX + MAX_DESC_LEN];
	char *ptr_token;

	Q_strncpy(buf, line, sizeof buf - 1);
	buf[sizeof buf - 1] = '\0';

	// remove "load"
	char* token = strtok_r(buf, " \t", &ptr_token);
	if (!token)
		return false;

	// grab filename
	token = strtok_r(nullptr, " \t", &ptr_token);
	if (!token)
		return false;

	Q_strncpy(m_filename, token, sizeof m_filename - 1);
	m_filename[sizeof m_filename - 1] = '\0';
	normalize_path(m_filename);

	// store name of just the actual _file_, without dir components
	char* cp = Q_strrchr(m_filename, '/');
	if (cp)
		m_file = cp + 1;
	else
		m_file = m_filename;

	// Grab description.
	// Specify no delimiter chars, as we just want the rest of the line.
	token = strtok_r(nullptr, "", &ptr_token);
	if (token) {
		token = token + strspn(token, " \t"); // skip whitespace
		Q_strncpy(m_desc, token, sizeof m_desc - 1);
		m_desc[sizeof m_desc - 1] = '\0';
	}
	else {
		// if no description is specified, temporarily use plugin file,
		// until plugin can be queried, and desc replaced with info->name.
		Q_snprintf(m_desc, sizeof m_desc, "<%s>", m_file);
	}

	// Make full pathname (from gamedir if relative, remove "..",
	// backslashes, etc).
	full_gamedir_path(m_filename, m_pathname);

	m_source = PS_CMD;
	m_status = PL_VALID;
	return true;
}

// Parse a filename string from PEXT_LOAD_PLUGIN_BY_ *function into a plugin.
bool MPlugin::plugin_parseline(const char *fname, int loader_index)
{
	m_source_plugin_index = loader_index;

	Q_strncpy(m_filename, fname, sizeof m_filename - 1);
	m_filename[sizeof m_filename - 1] = '\0';
	normalize_path(m_filename);

	//store just name of the actual _file, without path
	char* cp = Q_strrchr(m_filename, '/');
	if (cp)
		m_file = cp + 1;
	else
		m_file = m_filename;

	//grab description
	//temporarily use plugin file until plugin can be queried
	Q_snprintf(m_desc, sizeof m_desc, "<%s>", m_file);

	//make full pathname
	full_gamedir_path(m_filename, m_pathname);

	m_source = PS_PLUGIN;
	m_status = PL_VALID;

	return true;
}

// Make sure this plugin has the necessary minimal information.
bool MPlugin::check_input()
{
	// doublecheck our input/state
	if (m_status < PL_VALID) {
		META_ERROR("dll: Tried to operate on plugin[%d] with a non-valid status (%d)", m_index, str_status());
		return false;
	}
	if (!m_file || !m_file[0]) {
		META_ERROR("dll: Tried to operate on plugin[%d] with an empty file", m_index);
		return false;
	}
	if (!m_filename[0]) {
		META_ERROR("dll: Tried to operate on plugin[%d] with an empty filename", m_index);
		return false;
	}
	if (!m_pathname[0]) {
		META_ERROR("dll: Tried to operate on plugin[%d] with an empty pathname", m_index);
		return false;
	}
	if (!m_desc[0]) {
		// if no description is specified, temporarily use plugin file,
		// until plugin can be queried, and desc replaced with info->name.
		Q_snprintf(m_desc, sizeof m_desc, "<%s>", m_file);
	}

	return true;
}

// Try to resolve a plugin's filename as a (possibly partial) path to an
// actual filename on disk, to facilitate easier console load-command
// arguments. Uses resolve_dirs and resolve_suffix below.
// Example paths that it tries:
//    filename
//    Gamedir/filename.dll, Gamedir/filename.so
//    Gamedir/filename_i386.so
//    Gamedir/dlls/filename_mm_i386.so
//    Gamedir/dlls/filename_MM_i386.so
bool MPlugin::resolve()
{
	if (!check_input()) {
		return false;
	}

	char* found, tempbuf[MAX_PATH];
	if (is_abs_path(m_filename))
		found = resolve_suffix(m_filename, tempbuf, sizeof tempbuf);
	else
		found = resolve_dirs(m_filename, tempbuf, sizeof tempbuf);

	if (!found) {
		META_DEBUG(2, "Couldn't resolve '%s' to file", m_filename);
		return false;
	}

	META_DEBUG(2, "Resolved '%s' to file '%s'", m_filename, found);

	// store pathname: the resolved path (should be absolute)
	Q_strncpy(m_pathname, found, sizeof m_pathname - 1);
	m_pathname[sizeof m_pathname - 1] = '\0';

	// store file: the name of the file (without dir)
	char* cp = Q_strrchr(m_pathname, '/');
	if (cp)
		m_file = cp + 1;
	else
		m_file = m_pathname;

	const char* filename = m_pathname;

	// store pathname: the gamedir relative path, or an absolute path
	size_t len = Q_strlen(g_GameDLL.gamedir);
	if (!Q_strnicmp(m_pathname, g_GameDLL.gamedir, len))
		filename += len + 1;

	Q_strncpy(m_filename, filename, sizeof m_filename - 1);
	m_filename[sizeof m_filename - 1] = '\0';
	return true;
}

// For the given path, tries to find file in several possible
// directories.
// Try:
//     GAMEDIR/filename
//     GAMEDIR/dlls/filename
char *MPlugin::resolve_dirs(const char *path, char *tempbuf, size_t maxlen) const
{
	// try in gamedir
	Q_snprintf(tempbuf, maxlen, "%s/%s", g_GameDLL.gamedir, path);
	if (is_valid_path(tempbuf))
		return tempbuf;

	// try other file prefixes in gamedir
	char buf[MAX_PATH];
	strncpy(buf, tempbuf, sizeof buf - 1);
	buf[sizeof buf - 1] = '\0';

	char* found = resolve_suffix(buf, tempbuf, maxlen);
	if (found)
		return found;

	// try in gamedir/dlls/
	Q_snprintf(tempbuf, maxlen, "%s/dlls/%s", g_GameDLL.gamedir, path);
	if (is_valid_path(tempbuf))
		return tempbuf;

	strncpy(buf, tempbuf, sizeof buf - 1);
	buf[sizeof buf - 1] = '\0';

	// try other file prefixes for this path
	return resolve_suffix(buf, tempbuf, maxlen);
}

// For the given path, tries several different filename suffixes.
// Try:
//     path
//     path_mm
//     path_MM
//     path.so (linux), path.dll (win32)
//     path_i386.so, path_i486.so, etc (if linux)
char* MPlugin::resolve_suffix(const char *path, char *tempbuf, size_t bufsize) const
{
	if (Q_strstr(path, PLATFORM_DLEXT) && is_valid_path(path)) {
		strncpy(tempbuf, path, bufsize - 1);
		tempbuf[bufsize - 1] = '\0';
		return tempbuf;
	}

	// try with ext
	Q_snprintf(tempbuf, bufsize, "%s%s", path, PLATFORM_DLEXT);
	if (is_valid_path(tempbuf))
		return tempbuf;

	// try add suffix
	if (!Q_strstr(path, "_mm")) {
		char buf[MAX_PATH];
		Q_snprintf(buf, sizeof buf, "%s_mm", path);

		char* found = resolve_suffix(buf, tempbuf, bufsize);
		if (found)
			return found;
	}

#ifndef _WIN32
	for (size_t i = 0; i < arraysize(g_platform_postfixes); i++) {
		Q_snprintf(tempbuf, bufsize, "%s%s", path, g_platform_postfixes[i]);
		if (is_valid_path(tempbuf))
			return tempbuf;
	}
#endif

	return nullptr;
}

// Check if a given plugin is the same but possibly for a
// different platform. A match is considered to be found if
// 1.  the filename without the path is the same, or
// 2a. for an attached plugin the logtag is the same, or
// 2b. the description is the same, or
// 3.  a significant part of the filename is the same.
// A significant part of a plugin name is currently defined to:
//  the part up to a known platform postfix as determined by
//  the is_platform_postfix() function (see above), or
//  the part up to the last dot, if one exists.
bool MPlugin::platform_match(MPlugin *other) const
{
	if (m_status == PL_EMPTY || other->status() == PL_EMPTY)
		return false;

	if (!Q_strcmp(m_file, other->file()))
		return true;

	if (m_status >= PL_OPENED && other->status() >= PL_OPENED && !Q_strcmp(m_info->logtag, other->info()->logtag))
		return true;

	if (m_desc[0] != '\0' && other->description()[0] != '0' && !Q_stricmp(m_desc, other->description()))
		return true;

	const char* end = Q_strrchr(m_file, '_');
	if (!end || !is_platform_postfix(end))
		end = Q_strrchr(m_file, '.');

	const char* other_end = Q_strrchr(other->file(), '_');
	if (!other_end || !is_platform_postfix(other_end))
		other_end = Q_strrchr(other->file(), '.');

	if (!end || !other_end)
		return false;

	int prefixlen = end - m_file;
	if (other_end - other->file() != prefixlen)
		return false;

	if (!Q_strncmp(m_file, other->file(), prefixlen))
		return true;

	return false;
}

// Load a plugin; query, check allowed time, attach.
bool MPlugin::load(PLUG_LOADTIME now)
{
	if (!check_input()) {
		return false;
	}
	if (m_status >= PL_RUNNING) {
		META_ERROR("dll: Not loading plugin '%s'; already loaded (status=%s)", m_desc, str_status());
		return false;
	}
	if (m_action != PA_LOAD && m_action != PA_ATTACH) {
		META_ERROR("dll: Not loading plugin '%s'; not marked for load (action=%s)", m_desc, str_action());
		return false;
	}

	if (m_status < PL_OPENED) {
		// query plugin; open file and get info about it
		if (!query()) {
			META_ERROR("dll: Skipping plugin '%s'; couldn't query", m_desc);
			if (!m_sys_module.unload()) {
				META_ERROR("dll: Couldn't close plugin file '%s': %s", m_file, "invalid handle");
			}
			m_status = PL_BADFILE;
			m_info = nullptr; //prevent crash
			return false;
		}
		m_status = PL_OPENED;
	}

	// are we allowed to attach this plugin at this time?
	if (m_info->loadable < now) {
		if (m_info->loadable > PT_STARTUP) {
			// will try to attach again at next opportunity
			META_DEBUG(2, "dll: Delaying load plugin '%s'; can't attach now: allowed=%s; now=%s", m_desc, str_loadable(), str_loadtime(now, SL_SIMPLE));
			return false;
		}

		META_DEBUG(2, "dll: Failed load plugin '%s'; can't attach now: allowed=%s; now=%s", m_desc, str_loadable(), str_loadtime(now, SL_SIMPLE));
		// don't try to attach again later
		m_action = PA_NONE;
		return false;
	}

	// attach plugin; get function tables
	if (!attach(now)) {
		META_ERROR("dll: Failed to attach plugin '%s'", m_desc);
		// Note we don't dlclose() here, since we're returning PL_FAILED,
		// which implies that it's been dlopened and queried successfully.
		// Doing so causes crashes, because things like "meta list" try to
		// look at *info, which is in the DLL memory space and unaccessible
		// (segfault) after dlclosed.
		m_status = PL_FAILED;
		return false;
	}

	m_status = PL_RUNNING;
	m_action = PA_NONE;

	// If not loading at server startup, then need to call plugin's
	// GameInit, since we've passed that.
	if (now != PT_STARTUP && m_dllapi_table && m_dllapi_table->pfnGameInit) {
		m_dllapi_table->pfnGameInit();
	}
	// If loading during map, then I'd like to call plugin's
	// ServerActivate, since we've passed that.  However, I'm not sure what
	// arguments to give it...  So, we'll just have to say for the
	// moment that plugins that are loadable during a map can't need to
	// hook ServerActivate.

	META_LOG("dll: Loaded plugin '%s': %s v%s %s, %s", m_desc, m_info->name, m_info->version, m_info->date, m_info->author);
	return true;
}

// Unload a plugin.  Check time, detach.
bool MPlugin::unload(PLUG_LOADTIME now, PL_UNLOAD_REASON reason)
{
	if (!check_input()) {
		return false;
	}
	if (m_status < PL_RUNNING) {
		if (reason != PNL_CMD_FORCED && reason != PNL_RELOAD) {
			META_ERROR("dll: Not unloading plugin '%s'; already unloaded (status=%s)", m_desc, str_status());
			return false;
		}
	}
	if (m_action != PA_UNLOAD && m_action != PA_RELOAD) {
		META_WARNING("dll: Not unloading plugin '%s'; not marked for unload (action=%s)", m_desc, str_action());
		return false;
	}

	// Are we allowed to detach this plugin at this time?
	// If forcing unload, we disregard when plugin wants to be unloaded.
	if (m_info && m_info->unloadable < now) {
		if (reason == PNL_CMD_FORCED) {
			META_DEBUG(2, "dll: Forced unload plugin '%s' overriding allowed times: allowed=%s; now=%s", m_desc, str_unloadable(), str_loadtime(now, SL_SIMPLE));
		}
		else {
			if (m_info->unloadable > PT_STARTUP) {
				META_DEBUG(2, "dll: Delaying unload plugin '%s'; can't detach now: allowed=%s; now=%s", m_desc, str_unloadable(), str_loadtime(now, SL_SIMPLE));
				// caller should give message to user
				// try to unload again at next opportunity
				return false;
			}

			META_DEBUG(2, "dll: Failed unload plugin '%s'; can't detach now: allowed=%s; now=%s", m_desc, str_unloadable(), str_loadtime(now, SL_SIMPLE));
			// don't try to unload again later
			m_action = PA_NONE;
			return false;
		}
	}

	// If unloading during map, then I'd like to call plugin's
	// ServerDeactivate.  However, I don't want to do this until I start
	// calling ServerActivate when loading during map, since the SDK
	// indicates these two routines should match call for call.

	// detach plugin
	if (!detach(now, reason)) {
		if (reason == PNL_RELOAD) {
			META_DEBUG(2, "dll: Reload plugin '%s' overriding failed detach", m_desc);
		}
		else if (reason == PNL_CMD_FORCED) {
			META_DEBUG(2, "dll: Forced unload plugin '%s' overriding failed detach");
		}
		else {
			META_WARNING("dll: Failed to detach plugin '%s'; ", m_desc);
			return false;
		}
	}

	g_plugins->clear_source_plugin_index(m_index);

	// successful detach, or forced unload

	// Unmark registered commands for this plugin (by index number).
	g_regCmds->remove(m_index);
	// Unmark registered cvars for this plugin (by index number).
	g_regCvars->disable(m_index);

	// Close the file.  Note: after this, attempts to reference any memory
	// locations in the file will produce a segfault.
	if (!m_sys_module.unload()) {
		// If DLL cannot be closed, OS is badly broken or we are giving invalid handle.
		// So we don't return here but instead remove plugin from our listings.
		META_WARNING("dll: Couldn't close plugin file '%s': %s", m_file, "invalid handle");
	}

	if (m_action == PA_UNLOAD) {
		m_status = PL_EMPTY;
	}
	else if (m_action == PA_RELOAD) {
		m_status = PL_VALID;
		m_action = PA_LOAD;
	}

	clear();

	META_LOG("dll: Unloaded plugin '%s' for reason '%s'", m_desc, str_reason(reason));
	meta_rebuild_callbacks();
	return true;
}

// Reload a plugin; unload and load again.
bool MPlugin::reload(PLUG_LOADTIME now, PL_UNLOAD_REASON reason)
{
	if (!check_input()) {
		return false;
	}
	// Are we allowed to load this plugin at this time?
	// If we cannot load the plugin after unloading it, we keep it.
	if (m_info && m_info->loadable < now) {
		if (m_info->loadable > PT_STARTUP) {
			META_DEBUG(2, "dll: Delaying reload plugin '%s'; would not be able to reattach now: allowed=%s; now=%s", m_desc, str_loadable(), str_loadtime(now, SL_SIMPLE));
			// caller should give message to user
			// try to reload again at next opportunity
			return false;
		}

		META_DEBUG(2, "dll: Failed reload plugin '%s'; would not be able to reattach now: allowed=%s; now=%s", m_desc, str_loadable(), str_loadtime(now, SL_SIMPLE));
		// don't try to reload again later
		m_action = PA_NONE;
		return false;
	}

	if (m_status < PL_RUNNING) {
		META_WARNING("dll: Plugin '%s' isn't running; Forcing unload plugin for reloading", m_desc);
		reason = PNL_RELOAD;
	}

	if (!unload(now, reason)) {
		META_WARNING("dll: Failed to unload plugin '%s' for reloading", m_desc);
		return false;
	}

	if (!load(now)) {
		META_WARNING("dll: Failed to reload plugin '%s' after unloading", m_desc);
		return false;
	}

	return true;
}

// Pause a plugin; temporarily disabled for API routines.
bool MPlugin::pause()
{
	if (m_status == PL_PAUSED) {
		META_ERROR("Not pausing plugin '%s'; already paused", m_desc);
		return false;
	}
	if (m_status != PL_RUNNING) {
		META_ERROR("Cannot pause plugin '%s'; not currently running (status=%s)", m_desc, str_status());
		return false;
	}

	// are we allowed to pause this plugin?
	if (m_info->unloadable < PT_ANYPAUSE) {
		META_ERROR("Cannot pause plugin '%s'; not allowed by plugin (allowed=%s)", m_desc, str_unloadable());
		m_action = PA_NONE;
		return false;
	}

	m_status = PL_PAUSED;
	META_LOG("Paused plugin '%s'", m_desc);
	return true;
}

// Unpause a plugin.
bool MPlugin::unpause()
{
	if (m_status != PL_PAUSED) {
		META_ERROR("Cannot unpause plugin '%s'; not currently paused (status=%s)", m_desc, str_status());
		return false;
	}

	m_status = PL_RUNNING;
	META_LOG("Unpaused plugin '%s'", m_desc);
	return true;
}

// Retry pending action, presumably from a previous failure.
bool MPlugin::retry(PLUG_LOADTIME now, PL_UNLOAD_REASON reason)
{
	if (m_action == PA_LOAD || m_action == PA_ATTACH)
		return load(now);
	if (m_action == PA_UNLOAD)
		return unload(now, reason);
	if (m_action == PA_RELOAD)
		return reload(now, reason);

	META_ERROR("No pending action to retry for plugin '%s'; (status=%s, action=%s)", m_desc, str_status(), str_action());
	return false;
}

template<typename T>
void free_table(T& table)
{
	if (table) {
		Q_free(table);
		table = nullptr;
	}
}

// Clear a plugin (it failed a previous action and should be
// removed from the list, or it's being unloaded).
bool MPlugin::clear()
{
	if (m_status != PL_FAILED && m_status != PL_BADFILE && m_status != PL_EMPTY && m_status != PL_OPENED) {
		META_ERROR("Cannot clear plugin '%s'; not marked as failed, empty, or open (status=%s)", m_desc, str_status());
		return false;
	}
	// If file is open, close the file.  Note: after this, attempts to
	// reference any memory locations in the file will produce a segfault.
	if (!m_sys_module.unload()) {
		META_ERROR("dll: Couldn't close plugin file '%s': %s", m_file, "invalid handle");
		m_status = PL_FAILED;
		return false;
	}

	free_table(m_gamedll_funcs.dllapi_table);
	free_table(m_gamedll_funcs.newapi_table);
	free_table(m_dllapi_table);
	free_table(m_dllapi_post_table);
	free_table(m_newapi_table);
	free_table(m_newapi_post_table);
	free_table(m_engine_table);
	free_table(m_engine_post_table);

	m_status = PL_EMPTY;
	m_action = PA_NULL;
	m_info = nullptr;
	m_time_loaded = 0;
	m_dllapi_table = nullptr;
	m_dllapi_post_table = nullptr;
	m_newapi_table = nullptr;
	m_newapi_post_table = nullptr;
	m_engine_table = nullptr;
	m_engine_post_table = nullptr;
	m_gamedll_funcs.dllapi_table = nullptr;
	m_gamedll_funcs.newapi_table = nullptr;
	m_source_plugin_index = 0;
	m_unloader_index = 0;
	m_is_unloader = false;

	return true;
}

// Unload a plugin from plugin request
bool MPlugin::plugin_unload(plid_t plid, PLUG_LOADTIME now, PL_UNLOAD_REASON reason)
{
	MPlugin *pl_unloader = g_plugins->find(plid);

	if (!pl_unloader) {
		META_WARNING("dll: Not unloading plugin '%s'; plugin that requested unload is not found.", m_desc);
		return false;
	}
	if (pl_unloader->index() == m_index) {
		META_WARNING("dll: Not unloading plugin '%s'; Plugin tried to unload itself.", m_desc);
		return false;
	}
	if (m_is_unloader) {
		META_WARNING("dll: Not unloading plugin '%s'; Plugin is unloading plugin that tried to unload it.", m_desc);
		return false;
	}

	m_unloader_index = pl_unloader->index();

	//block unloader from being unloaded by other plugin
	pl_unloader->m_is_unloader = true;

	//try unload
	PLUG_ACTION old_action = m_action;
	m_action = PA_UNLOAD;

	if (unload(now, reason)) {
		META_DEBUG(1, "Unloaded plugin '%s'", m_desc);
		pl_unloader->m_is_unloader = false;
		return true;
	}

	pl_unloader->m_is_unloader = false;
	m_action = old_action;

	return false;
}

// Query a plugin:
//  - dlopen() the file, store the handle
//  - dlsym() and call:
//	    Meta_Init (if present) - tell dll it'll be used as a metamod plugin
//	    GiveFnptrsToDll - give engine function ptrs
//	    Meta_Query - say "hi" and get info about plugin
bool MPlugin::query()
{
	// open the plugin DLL
	if (!m_sys_module.load(m_pathname)) {
		META_ERROR("dll: Failed query plugin '%s'; Couldn't open file '%s': %s", m_desc, m_pathname, m_sys_module.getloaderror());
		return false;
	}

	// First, we check to see if they have a Meta_Query.  We would normally
	// dlsym this just prior to calling it, after having called
	// GiveFnptrsToDll, but things like standalone-DLL bots do all their
	// startup in GiveFnptrsToDll, and trying to load them as metamod
	// plugins creates all sorts of crashes.  So, we do a trivial check
	// first to see if the DLL looks like a metamod plugin before
	// proceeding with the normal order.  Note that we still have to call
	// GiveFnptrsToDll before Meta_Query, because the latter typically uses
	// engine functions like AlertMessage, which have to be passed along via
	// GiveFnptrsToDll.
	auto pfn_query = (META_QUERY_FN)m_sys_module.getsym("Meta_Query");
	if (!pfn_query) {
		META_ERROR("dll: Failed query plugin '%s'; Couldn't find Meta_Query(): %s", m_desc, "function not found");
		// caller will dlclose()
		return false;
	}

	// Call Meta_Init, if present.  This is an optional plugin routine to
	// allow plugin to do any special initializing or other processing
	// prior to the standard query/attach procedure.
	//
	// In particular, this should allow for DLL's that can operate as both
	// a standalone dll AND a metamod plugin.  This routine has to be
	// called _before_ GiveFnptrsToDll, since the dll will usually do all
	// its startup processing in GiveFn, and has to know at that point
	// whether it needs to do just mm plugin startup, or all the extra
	// startup needed for a standalone DLL.
	//
	// This passes nothing and returns nothing, and the routine in the
	// plugin can NOT use any g_engine functions, as they haven't been
	// provided yet (done next, in GiveFnptrsToDll).
	auto pfn_init = (META_INIT_FN)m_sys_module.getsym("Meta_Init");
	if (pfn_init) {
		pfn_init();
		META_DEBUG(6, "dll: Plugin '%s': Called Meta_Init()", m_desc);
	}
	else {
		META_DEBUG(5, "dll: no Meta_Init present in plugin '%s'", m_desc);
		// don't return; not an error
	}

	// pass on engine function table and globals to plugin
	auto pfn_give_engfuncs = (GIVE_ENGINE_FUNCTIONS_FN)m_sys_module.getsym("GiveFnptrsToDll");
	if (!pfn_give_engfuncs) {
		META_ERROR("dll: Failed query plugin '%s'; Couldn't find GiveFnptrsToDll(): %s", m_desc, "function not found");
		return false;
	}

	pfn_give_engfuncs(g_engine.pl_funcs, g_engine.globals);
	META_DEBUG(6, "dll: Plugin '%s': Called GiveFnptrsToDll()", m_desc);

	// Call plugin's Meta_Query(), to pass our meta interface version, and get
	// plugin's info structure.
	m_info = nullptr;

	// Make a copy of the meta_util function table for each plugin, for the
	// same reason.
	Q_memcpy(&m_mutil_funcs, &g_MetaUtilFunctions, sizeof m_mutil_funcs);

	if (pfn_query(META_INTERFACE_VERSION, &m_info, &m_mutil_funcs) != TRUE) {
		META_ERROR("dll: Failed query plugin '%s'; Meta_Query returned error", m_desc);
	}
	else {
		META_DEBUG(6, "dll: Plugin '%s': Called Meta_Query() successfully", m_desc);
	}

	// Check for interface differences...  Generally, a difference in major
	// version will be incompatible, and a plugin that expects a later
	// minor version will be incompatible (it's expecting things that this
	// Metamod won't be supplying).  g_plugins that use an older minor
	// version will still work, as backward-compability within major
	// version is expected (forward-compatibility is not).
	//
	// Note, this check is done regardless of whether meta_query returns an
	// error.
	if (!m_info) {
		META_ERROR("dll: Failed query plugin '%s'; Empty info structure", m_desc);
		// caller will dlclose()
		return false;
	}

	if (Q_strcmp(m_info->ifvers, META_INTERFACE_VERSION)) {
		int mmajor, mminor, pmajor, pminor;
		META_DEBUG(3, "dll: Note: Plugin '%s' interface version didn't match; expected %s, found %s", m_desc, META_INTERFACE_VERSION, m_info->ifvers);
		sscanf(META_INTERFACE_VERSION, "%i:%i", &mmajor, &mminor);
		sscanf(m_info->ifvers, "%i:%i", &pmajor, &pminor);
		// If plugin has later interface version, it's incompatible
		// (update metamod).
		if (pmajor > mmajor || (pmajor == mmajor && pminor > mminor)) {
			META_ERROR("dll: Plugin '%s' requires a newer version of Metamod (Metamod needs at least interface %s not the current %s)", m_desc, m_info->ifvers, META_INTERFACE_VERSION);
			return false;
		}
		// If plugin has older major interface version, it's incompatible
		// (update plugin).
		if (pmajor < mmajor) {
			META_ERROR("dll: Plugin '%s' is out of date and incompatible with this version of Metamod; please find a newer version of the plugin (plugin needs at least interface %s not the current %s)", m_desc, META_INTERFACE_VERSION, m_info->ifvers);
			return false;
		}
		// Plugin has identical major, with older minor.  This is supposed to be
		// backwards compatible, so we warn, but we still accept it.
		if (pmajor == mmajor && pminor < mminor)
			META_LOG("dll: Note: plugin '%s' is using an older interface version (%s), not the latest interface version (%s); there might be an updated version of the plugin", m_desc, m_info->ifvers, META_INTERFACE_VERSION);
		else
			META_LOG("dll: Plugin '%s': unexpected version comparision; metavers=%s, mmajor=%d, mminor=%d; plugvers=%s, pmajor=%d, pminor=%d", m_desc, META_INTERFACE_VERSION, mmajor, mminor, m_info->ifvers, pmajor, pminor);

		if (pmajor != mmajor) {
			META_ERROR("dll: Rejected plugin '%s' due to interface version incompatibility (mm=%s, pl=%s)", m_desc, META_INTERFACE_VERSION, m_info->ifvers);
			// caller will dlclose()
			return false;
		}
	}

	// Replace temporary desc with plugin's internal name.
	if (m_desc[0] == '<') {
		Q_strncpy(m_desc, m_info->name, sizeof m_desc - 1);
		m_desc[sizeof m_desc - 1] = '\0';
	}

	META_DEBUG(6, "dll: Plugin '%s': Query successful", m_desc);
	return true;
}

template<typename getter_t, typename table_t>
bool get_function_table_from_plugin(const char* pl_desc, int ifvers_mm, getter_t getter, const char* getter_name, table_t*& table, size_t table_size = sizeof(table_t))
{
	int ifvers_pl = ifvers_mm;

	if (getter) {
		if (!table)
			table = (table_t *)Q_calloc(1, table_size);
		if (getter(table, &ifvers_pl)) {
			META_DEBUG(3, "dll: Plugin '%s': Found %s", pl_desc, getter_name);
			return true;
		}

		META_ERROR("dll: Failure calling %s in plugin '%s'", getter_name, pl_desc);
		if (ifvers_pl != ifvers_mm)
			META_ERROR("dll: Interface version didn't match; expected %d, found %d", ifvers_mm, ifvers_pl);
	}
	else {
		META_DEBUG(5, "dll: Plugin '%s': No %s", pl_desc, getter_name);
		if (table)
			Q_free(table);
		table = nullptr;
	}

	return false;
}

template<typename getter_t, typename table_t>
bool get_function_table_from_plugin_old(const char* pl_desc, int ifvers_mm, getter_t getter, const char* getter_name, table_t*& table, size_t table_size = sizeof(table_t))
{
	if (getter) {
		if (!table)
			table = (table_t *)Q_calloc(1, table_size);
		if (getter(table, ifvers_mm)) {
			META_DEBUG(3, "dll: Plugin '%s': Found %s", pl_desc, getter_name);
			return true;
		}

		META_ERROR("dll: Failure calling %s in plugin '%s'", getter_name, pl_desc);
	}
	else {
		META_DEBUG(5, "dll: Plugin '%s': No %s", pl_desc, getter_name);
		if (table)
			Q_free(table);
		table = nullptr;
	}

	return false;
}

// Attach a plugin:
//	- dlsym() and call:
//	    Meta_Attach - get table of api tables, give meta_globals
//  - if provided by plugin, call various "Get" function pointers,
//    and store resulting function tables:
//		GetEntityAPI			(std)
//		GetEntityAPI2			(std sdk2)
//		GetNewDLLFunctions		(std sdk2)
//
//		GetEntityAPI_Post		(meta)
//		GetEntityAPI2_Post		(meta)
//		GetNewDLLFunctions_Post	(meta)
//
//		GetEngineFunctions		(meta)
//		GetEngineFunctions_Post	(meta)
bool MPlugin::attach(PLUG_LOADTIME now)
{
	// Make copy of gameDLL's function tables for each plugin, so we don't
	// risk the plugins screwing with the tables everyone uses.
	if (g_GameDLL.funcs.dllapi_table && !m_gamedll_funcs.dllapi_table) {
		m_gamedll_funcs.dllapi_table = (DLL_FUNCTIONS *)Q_malloc(sizeof(DLL_FUNCTIONS));
		if (!m_gamedll_funcs.dllapi_table) {
			META_ERROR("dll: Failed attach plugin '%s': Failed malloc() for dllapi_table");
			return false;
		}
		Q_memcpy(m_gamedll_funcs.dllapi_table, g_GameDLL.funcs.dllapi_table, sizeof(DLL_FUNCTIONS));
	}
	if (g_GameDLL.funcs.newapi_table && !m_gamedll_funcs.newapi_table) {
		m_gamedll_funcs.newapi_table = (NEW_DLL_FUNCTIONS *)Q_malloc(sizeof(NEW_DLL_FUNCTIONS));
		if (!m_gamedll_funcs.newapi_table) {
			META_ERROR("dll: Failed attach plugin '%s': Failed malloc() for newapi_table");
			return false;
		}
		Q_memcpy(m_gamedll_funcs.newapi_table, g_GameDLL.funcs.newapi_table, sizeof(NEW_DLL_FUNCTIONS));
	}
	auto pfn_attach = (META_ATTACH_FN)m_sys_module.getsym("Meta_Attach");
	if (!pfn_attach) {
		META_ERROR("dll: Failed attach plugin '%s': Couldn't find Meta_Attach(): %s", m_desc, "function not found");
		return false;
	}

	META_FUNCTIONS meta_table = {};

	// get table of function tables,
	// give public meta globals
	qboolean ret = pfn_attach(now, &meta_table, &g_metaGlobals, &m_gamedll_funcs);
	if (ret != TRUE) {
		META_ERROR("dll: Failed attach plugin '%s': Error from Meta_Attach(): %d", m_desc, ret);
		return false;
	}

	META_DEBUG(6, "dll: Plugin '%s': Called Meta_Attach() successfully", m_desc);

	// Look for API-NEW interface in plugin.  We do this before API2/API, because
	// that's what the engine appears to do..
	// [But we only do this if the gamedll provides these, so that we don't
	// give a plugin the idea that we'll call them, when in fact we won't
	// (since we don't export them to the engine when the gamedll doesn't
	// provide them).]
	// We now do this even when the gamedll doesn't provide these because
	// the plugins might want to use new functions like CvarValue() also
	// with older gamedlls which do not use the API-NEW themselves.
	// It is yet unknown if this causes any problems in the engine.
	get_function_table_from_plugin(m_desc, NEW_DLL_FUNCTIONS_VERSION, meta_table.pfnGetNewDLLFunctions, "GetNewDLLFunctions", m_newapi_table);
	get_function_table_from_plugin(m_desc, NEW_DLL_FUNCTIONS_VERSION, meta_table.pfnGetNewDLLFunctions_Post, "GetNewDLLFunctions_Post", m_newapi_post_table);

	// Look for API2 interface in plugin; preferred over API-1.
	get_function_table_from_plugin(m_desc, INTERFACE_VERSION, meta_table.pfnGetEntityAPI2, "GetEntityAPI2", m_dllapi_table);
	get_function_table_from_plugin(m_desc, INTERFACE_VERSION, meta_table.pfnGetEntityAPI2_Post, "GetEntityAPI2_Post", m_dllapi_post_table);

	// Look for old-style API in plugin, if API2 interface wasn't found.
	if (!m_dllapi_table && !m_dllapi_post_table) {
		get_function_table_from_plugin_old(m_desc, INTERFACE_VERSION, meta_table.pfnGetEntityAPI, "GetEntityAPI", m_dllapi_table);
		get_function_table_from_plugin_old(m_desc, INTERFACE_VERSION, meta_table.pfnGetEntityAPI_Post, "GetEntityAPI_Post", m_dllapi_post_table);
	}

	get_function_table_from_plugin(m_desc, ENGINE_INTERFACE_VERSION, meta_table.pfnGetEngineFunctions, "GetEngineFunctions", m_engine_table);
	get_function_table_from_plugin(m_desc, ENGINE_INTERFACE_VERSION, meta_table.pfnGetEngineFunctions_Post, "GetEngineFunctions_Post", m_engine_post_table);

	m_time_loaded = time(nullptr);
	return true;
}

// Inform plugin we're going to unload it.
bool MPlugin::detach(PLUG_LOADTIME now, PL_UNLOAD_REASON reason)
{
	// If we have no handle, i.e. no dll loaded, we return true because the
	// dll is obviously detached. We shouldn't call DLSYM() with a nullptr
	// handle since this will DLSYM() ourself.
	if (!m_sys_module.gethandle())
		return true;

	auto pfn_detach = (META_DETACH_FN)m_sys_module.getsym("Meta_Detach");
	if (!pfn_detach) {
		META_ERROR("dll: Error detach plugin '%s': Couldn't find Meta_Detach(): %s", m_desc, "function not found");
		// caller will dlclose()
		return false;
	}

	int ret = pfn_detach(now, reason);
	if (ret != TRUE) {
		META_ERROR("dll: Failed detach plugin '%s': Error from Meta_Detach(): %d", m_desc, ret);
		return false;
	}

	META_DEBUG(6, "dll: Plugin '%s': Called Meta_Detach() successfully", m_desc);
	return true;
}

template<typename table_t, typename info_t>
void show_table(const char* table_name, table_t* table, info_t* info_begin, bool post)
{
	if (table) {
		META_CONS("%s functions:", table_name);

		size_t count = 0;

		for (auto n = info_begin; n->name[0] != '\0'; n++) {
			if (*(size_t *)(size_t(table) + n->offset)) {
				META_CONS("   %s%s", Q_strstr(n->name, "::") + 2, post ? "_Post" : "");
				count++;
			}
		}

		META_CONS("%d functions (%s)", count, table_name);
	}
	else
		META_CONS("No %s functions.", table_name);
}

// List information about plugin to console.
void MPlugin::show()
{
	char *cp;
	const int width = 13;

	META_CONS("%*s: %s", width, "name", m_info ? m_info->name : "(nil)");
	META_CONS("%*s: %s", width, "desc", m_desc);
	META_CONS("%*s: %s", width, "status", str_status());
	META_CONS("%*s: %s", width, "action", str_action());
	META_CONS("%*s: %s", width, "filename", m_filename);
	META_CONS("%*s: %s", width, "file", m_file);
	META_CONS("%*s: %s", width, "pathname", m_pathname);
	META_CONS("%*s: %d", width, "index", m_index);
	META_CONS("%*s: %s", width, "source", str_source());
	META_CONS("%*s: %s", width, "loadable", str_loadable(SL_ALLOWED));
	META_CONS("%*s: %s", width, "unloadable", str_unloadable(SL_ALLOWED));
	META_CONS("%*s: %s", width, "version", m_info ? m_info->version : "(nil)");
	META_CONS("%*s: %s", width, "date", m_info ? m_info->date : "(nil)");
	META_CONS("%*s: %s", width, "author", m_info ? m_info->author : "(nil)");
	META_CONS("%*s: %s", width, "url", m_info ? m_info->url : "(nil)");
	META_CONS("%*s: %s", width, "logtag", m_info ? m_info->logtag : "(nil)");
	META_CONS("%*s: %s", width, "ifvers", m_info ? m_info->ifvers : "(nil)");

	// ctime() includes newline at EOL
	char* tstr = ctime(&m_time_loaded);
	if ((cp = Q_strchr(tstr, '\n')))
		*cp = '\0';

	META_CONS("%*s: %s", width, "last loaded", tstr);
	// XXX show file time ?

	show_table("DLLAPI", m_dllapi_table, &g_dllapi_info.pfnGameInit, false);
	show_table("DLLAPI Post", m_dllapi_post_table, &g_dllapi_info.pfnGameInit, true);

	show_table("NEWAPI", m_newapi_table, &g_newapi_info.pfnOnFreeEntPrivateData, false);
	show_table("NEWAPI Post", m_newapi_post_table, &g_newapi_info.pfnOnFreeEntPrivateData, true);

	show_table("Engine", m_engine_table, &g_engineapi_info.pfnPrecacheModel, false);
	show_table("Engine Post", m_engine_post_table, &g_engineapi_info.pfnPrecacheModel, true);

	g_regCmds->show(m_index);
	g_regCvars->show(m_index);

	if (g_plugins->found_child_plugins(m_index))
		g_plugins->show(m_index);
	else
		META_CONS("No child plugins.");
}

// Check whether the file on disk looks like it's been updated since we
// last loaded the plugin.
bool MPlugin::newer_file() const
{
	struct stat st;

	if (stat(m_pathname, &st) != 0) {
		META_ERROR("ini: Skipping plugin, couldn't stat file '%s': %s", m_pathname, strerror(errno));
		return false;
	}

	time_t file_time = max(st.st_ctime, st.st_mtime);
	META_DEBUG(5, "newer_file? file=%s; load=%d, file=%d; ctime=%d, mtime=%d", m_file, m_time_loaded, file_time, st.st_ctime, st.st_mtime);
	if (file_time > m_time_loaded)
		return true;

	return false;
}

// Return a string describing status of plugin.
// SIMPLE is the default.
// SHOW is max 4 chars, for "show" output.
const char *MPlugin::str_status(STR_STATUS fmt) const
{
	bool show = fmt == ST_SHOW;
	switch (m_status) {
	case PL_EMPTY:		return show ? "empt" : "empty";
	case PL_VALID:		return show ? "info" : "valid";
	case PL_BADFILE:	return show ? "badf" : "badfile";
	case PL_OPENED:		return show ? "open" : "opened";
	case PL_FAILED:		return show ? "fail" : "failed";
	case PL_RUNNING:	return show ? "RUN" : "running";
	case PL_PAUSED:		return show ? "PAUS" : "paused";
	default:			return UTIL_VarArgs(show ? "UNK%d" : "unknown (%d)", m_status);
	}
}

// Return a string (one word) describing requested action for plugin.
// SIMPLE is the default.
// SHOW is max 4 chars, for "show" output.
const char *MPlugin::str_action(STR_ACTION fmt) const
{
	bool show = fmt == ST_SHOW;
	switch (m_action) {
	case PA_NULL:		return "null";
	case PA_NONE:		return show ? " -  " : "none";
	case PA_KEEP:		return "keep";
	case PA_LOAD:		return "load";
	case PA_ATTACH:		return show ? "atch" : "attach";
	case PA_UNLOAD:		return show ? "unld" : "unload";
	case PA_RELOAD:		return show ? "relo" : "reload";
	default:			return UTIL_VarArgs(show ? "UNK%d" : "unknown (%d)", m_action);
	}
}

// Return a string describing how the plugin was loaded.
const char *MPlugin::str_source(STR_SOURCE fmt) const
{
	bool show = fmt == SO_SHOW;
	switch (m_source) {
	case PS_INI: return show ? "ini" : "ini file";
	case PS_CMD: return show ? "cmd" : "console command";
	case PS_PLUGIN:
	if (m_source_plugin_index <= 0)
		return show ? "plUN" : "unloaded plugin";
	return show ? UTIL_VarArgs("pl%d", m_source_plugin_index) : UTIL_VarArgs("plugin [%s]", g_plugins->find(m_source_plugin_index)->description());
	default: return UTIL_VarArgs(show ? "UNK%d" : "unknown (%d)", m_source);
	}
}

// Return a string describing why a plugin is to be unloaded.
const char *MPlugin::str_reason(PL_UNLOAD_REASON reason) const
{
	switch (reason) {
	case PNL_NULL:			return "null";
	case PNL_INI_DELETED:	return "deleted from ini file";
	case PNL_FILE_NEWER:	return "file on disk is newer";
	case PNL_COMMAND:		return "server command";
	case PNL_CMD_FORCED:	return "forced by server command";
	case PNL_PLUGIN:		return UTIL_VarArgs("%s (request from plugin[%d])", str_reason(PNL_NULL), m_unloader_index);
	case PNL_PLG_FORCED:	return UTIL_VarArgs("%s (forced request from plugin[%d])", str_reason(PNL_NULL), m_unloader_index);
	case PNL_RELOAD:		return "reloading";
	default:				return UTIL_VarArgs("unknown (%d)", reason);
	}
}

// Return a string describing given plugin loadtime.
// SIMPLE is the default.
// SHOW is max 3 chars, for "show" output.
// ALLOWED is in terms of when it's allowed to load/unload.
// NOW is to describe current situation of load/unload attempt.
const char *MPlugin::str_loadtime(PLUG_LOADTIME ptime, STR_LOADTIME fmt)
{
	if (ptime >= PT_NEVER || ptime <= PT_ANYPAUSE)
		return s_rPrintLoadTime[ptime][fmt];

	return UTIL_VarArgs((fmt == SL_SHOW) ? "UNK-%i" : "unknown (%i)", ptime);
}

const char* MPlugin::str_loadable() const
{
	return m_info ? str_loadtime(m_info->loadable, SL_SIMPLE) : " -";
}

const char* MPlugin::str_unloadable() const
{
	return m_info ? str_loadtime(m_info->unloadable, SL_SIMPLE) : " -";
}

const char* MPlugin::str_loadable(STR_LOADTIME fmt) const
{
	return m_info ? str_loadtime(m_info->loadable, fmt) : " -";
}

const char* MPlugin::str_unloadable(STR_LOADTIME fmt) const
{
	return m_info ? str_loadtime(m_info->unloadable, fmt) : " -";
}

PLUG_STATUS MPlugin::status() const
{
	return m_status;
}

PLUG_ACTION MPlugin::action() const
{
	return m_action;
}

const char* MPlugin::description() const
{
	return m_desc;
}

plugin_info_t* MPlugin::info() const
{
	return m_info;
}

int MPlugin::index() const
{
	return m_index;
}

int MPlugin::source_index() const
{
	return m_source_plugin_index;
}

const char* MPlugin::file() const
{
	return m_file;
}

const char* MPlugin::filename() const
{
	return m_filename;
}

const char* MPlugin::pathname() const
{
	return m_pathname;
}

const CSysModule& MPlugin::sys_module() const
{
	return m_sys_module;
}

size_t MPlugin::status_ptr()
{
	return size_t(&m_status);
}

void MPlugin::set_action(PLUG_ACTION action)
{
	m_action = action;
}