// Copyright 2005-2019 The Mumble Developers. All rights reserved.
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file at the root of the
// Mumble source tree or at <https://www.mumble.info/LICENSE>.

#include "ACL.h"
#include "Channel.h"
#include "Group.h"
#include "User.h"

#ifdef MURMUR
#include "ServerUser.h"

#include <QtCore/QStack>
#endif

ChanACL::ChanACL(Channel *chan) : QObject(chan) {
	bApplyHere = true;
	bApplySubs = true;
	bInherited = false;

	iUserId = -1;

	c = chan;
	if (c)
		c->qlACL << this;
}

// Check permissions.
// This will always return true for the superuser,
// and will return false if a user isn't allowed to
// traverse to the channel. (Need "read" in all preceeding channels)

#ifdef MURMUR

bool ChanACL::hasPermission(ServerUser *p, Channel *chan, QFlags<Perm> perm, ACLCache *cache) {
	Permissions granted = effectivePermissions(p, chan, cache);

	return ((granted & perm) != None);
}

// Return effective permissions.
QFlags<ChanACL::Perm> ChanACL::effectivePermissions(ServerUser *p, Channel *chan, ACLCache *cache) {
	// Superuser
	if (p->iId == 0) {
		return static_cast<Permissions>(All &~ (Speak|Whisper));
	}

	Permissions granted = 0;

	if (cache) {
		QHash<Channel *, Permissions> *h = cache->value(p);
		if (h)
			granted = h->value(chan);
	}

	if (granted & Cached) {
		return granted;
	}

	QStack<Channel *> chanstack;
	Channel *ch = chan;

	while (ch) {
		chanstack.push(ch);
		ch = ch->cParent;
	}

	// Default permissions
	Permissions def = Traverse | Enter | Speak | Whisper | TextMessage;

	granted = def;

	bool traverse = true;
	bool write = false;
	ChanACL *acl;

	while (! chanstack.isEmpty()) {
		ch = chanstack.pop();
		if (! ch->bInheritACL)
			granted = def;

		foreach(acl, ch->qlACL) {
			bool matchUser = (acl->iUserId != -1) && (acl->iUserId == p->iId);
			bool matchGroup = Group::isMember(chan, ch, acl->qsGroup, p);
			if (matchUser || matchGroup) {
				if (acl->pAllow & Traverse)
					traverse = true;
				if (acl->pDeny & Traverse)
					traverse = false;
				if (acl->pAllow & Write)
					write = true;
				if (acl->pDeny & Write)
					write = false;
				if (ch->iId == 0 && chan == ch && acl->bApplyHere) {
					if (acl->pAllow & Kick)
						granted |= Kick;
					if (acl->pAllow & Ban)
						granted |= Ban;
					if (acl->pAllow & Register)
						granted |= Register;
					if (acl->pAllow & SelfRegister)
						granted |= SelfRegister;
				}
				if ((ch==chan && acl->bApplyHere) || (ch!=chan && acl->bApplySubs)) {
					granted |= (acl->pAllow & ~(Kick|Ban|Register|SelfRegister|Cached));
					granted &= ~acl->pDeny;
				}
			}
		}
		if (! traverse && ! write) {
			granted = None;
			break;
		}
	}

	if (granted & Write) {
		granted |= Traverse|Enter|MuteDeafen|Move|MakeChannel|LinkChannel|TextMessage|MakeTempChannel;
		if (chan->iId == 0)
			granted |= Kick|Ban|Register|SelfRegister;
	}

	if (cache) {
		if (! cache->contains(p))
			cache->insert(p, new QHash<Channel *, Permissions>);

		cache->value(p)->insert(chan, granted | Cached);
	}

	return granted;
}

#else

QString ChanACL::whatsThis(Perm p) {
	switch (p) {
		case None:
			return tr("This represents no privileges.");
		case Write:
			return tr("This represents total access to the channel, including the ability to change group and ACL information. "
			          "This privilege implies all other privileges.");
		case Traverse:
			return tr("This represents the permission to traverse the channel. If a user is denied this privilege, he will be "
			          "unable to access this channel and any sub-channels in any way, regardless of other permissions in the "
			          "sub-channels.");
		case Enter:
			return tr("This represents the permission to join the channel. If you have a hierarchical channel structure, you "
			          "might want to give everyone Traverse, but restrict Enter in the root of your hierarchy.");
		case Speak:
			return tr("This represents the permission to speak in a channel. Users without this privilege will be suppressed by "
			          "the server (seen as muted), and will be unable to speak until they are unmuted by someone with the "
			          "appropriate privileges.");
		case Whisper:
			return tr("This represents the permission to whisper to this channel from the outside. This works exactly like the <i>speak</i> "
			          "privilege, but applies to packets spoken with the Whisper key held down. This may be used to broadcast to a hierarchy "
			          "of channels without linking.");
		case MuteDeafen:
			return tr("This represents the permission to mute and deafen other users. Once muted, a user will stay muted "
			          "until he is unmuted by another privileged user or reconnects to the server.");
		case Move:
			return tr("This represents the permission to move a user to another channel or kick him from the server. To actually "
			          "move the user, either the moving user must have Move privileges in the destination channel, or "
			          "the user must normally be allowed to enter the channel. Users with this privilege can move users "
			          "into channels the target user normally wouldn't have permission to enter.");
		case MakeChannel:
			return tr("This represents the permission to make sub-channels. The user making the sub-channel will be added to the "
			          "admin group of the sub-channel.");
		case MakeTempChannel:
			return tr("This represents the permission to make a temporary subchannel. The user making the sub-channel will be added to the "
			          "admin group of the sub-channel. Temporary channels are not stored and disappear when the last user leaves.");
		case LinkChannel:
			return tr("This represents the permission to link channels. Users in linked channels hear each other, as long as "
			          "the speaking user has the <i>speak</i> privilege in the channel of the listener. You need the link "
			          "privilege in both channels to create a link, but just in either channel to remove it.");
		case TextMessage:
			return tr("This represents the permission to write text messages to other users in this channel.");
		case Kick:
			return tr("This represents the permission to forcibly remove users from the server.");
		case Ban:
			return tr("This represents the permission to permanently remove users from the server.");
		case Register:
			return tr("This represents the permission to register and unregister users on the server.");
		case SelfRegister:
			return tr("This represents the permission to register oneself on the server.");
		default:
			break;
	}
	return QString();
}

#endif

QString ChanACL::permName(QFlags<Perm> p) {
	QStringList qsl;
	for (int i=0;i<=31;++i) {
		if (p & (1<<i))
			qsl << permName(static_cast<Perm>(1<<i));
	}
	return qsl.join(QLatin1String(", "));
}

QString ChanACL::permName(Perm p) {
	switch (p) {
		case None:
			return tr("None");
		case Write:
			return tr("Write ACL");
		case Traverse:
			return tr("Traverse");
		case Enter:
			return tr("Enter");
		case Speak:
			return tr("Speak");
		case Whisper:
			return tr("Whisper");
		case MuteDeafen:
			return tr("Mute/Deafen");
		case Move:
			return tr("Move");
		case MakeChannel:
			return tr("Make channel");
		case MakeTempChannel:
			return tr("Make temporary");
		case LinkChannel:
			return tr("Link channel");
		case TextMessage:
			return tr("Text message");
		case Kick:
			return tr("Kick");
		case Ban:
			return tr("Ban");
		case Register:
			return tr("Register User");
		case SelfRegister:
			return tr("Register Self");
		default:
			break;
	}
	return QString();
}