/*
    Copyright (C) 2000-2007 Paul Davis 

    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., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <dlfcn.h>

#include <pbd/compose.h>
#include <pbd/error.h>
#include <pbd/pathscanner.h>

#include <control_protocol/control_protocol.h>

#include <ardour/session.h>
#include <ardour/control_protocol_manager.h>

using namespace ARDOUR;
using namespace std;
using namespace PBD;

#include "i18n.h"

ControlProtocolManager* ControlProtocolManager::_instance = 0;
const string ControlProtocolManager::state_node_name = X_("ControlProtocols");

ControlProtocolManager::ControlProtocolManager ()
{
	if (_instance == 0) {
		_instance = this;
	}

	_session = 0;
}

ControlProtocolManager::~ControlProtocolManager()
{
	Glib::Mutex::Lock lm (protocols_lock);

	for (list<ControlProtocol*>::iterator i = control_protocols.begin(); i != control_protocols.end(); ++i) {
		delete (*i);
	}

	control_protocols.clear ();

	
	for (list<ControlProtocolInfo*>::iterator p = control_protocol_info.begin(); p != control_protocol_info.end(); ++p) {
		delete (*p);
	}

	control_protocol_info.clear();
}

void
ControlProtocolManager::set_session (Session& s)
{
	_session = &s;
	_session->GoingAway.connect (mem_fun (*this, &ControlProtocolManager::drop_session));

	for (list<ControlProtocolInfo*>::iterator i = control_protocol_info.begin(); i != control_protocol_info.end(); ++i) {
		if ((*i)->requested || (*i)->mandatory) {
			instantiate (**i);
			(*i)->requested = false;

			if ((*i)->protocol && (*i)->state) {
				(*i)->protocol->set_state (*(*i)->state);
			}
		}
	}
}

void
ControlProtocolManager::drop_session ()
{
	_session = 0;

	{
		Glib::Mutex::Lock lm (protocols_lock);
		for (list<ControlProtocol*>::iterator p = control_protocols.begin(); p != control_protocols.end(); ++p) {
			delete *p;
		}
		control_protocols.clear ();
		
		for (list<ControlProtocolInfo*>::iterator p = control_protocol_info.begin(); p != control_protocol_info.end(); ++p) {
			// otherwise the ControlProtocol instances are not recreated in set_session
			(*p)->requested = true;
			(*p)->protocol = 0;
		}
	}
}

ControlProtocol*
ControlProtocolManager::instantiate (ControlProtocolInfo& cpi)
{
	if (_session == 0) {
		return 0;
	}

	cpi.descriptor = get_descriptor (cpi.path);

	if (cpi.descriptor == 0) {
		error << string_compose (_("control protocol name \"%1\" has no descriptor"), cpi.name) << endmsg;
		return 0;
	}

	if ((cpi.protocol = cpi.descriptor->initialize (cpi.descriptor, _session)) == 0) {
		error << string_compose (_("control protocol name \"%1\" could not be initialized"), cpi.name) << endmsg;
		return 0;
	}

	Glib::Mutex::Lock lm (protocols_lock);
	control_protocols.push_back (cpi.protocol);

	return cpi.protocol;
}

int
ControlProtocolManager::teardown (ControlProtocolInfo& cpi)
{
	if (!cpi.protocol) {
		return 0;
	}

	if (!cpi.descriptor) {
		return 0;
	}

	if (cpi.mandatory) {
		return 0;
	}

	cpi.descriptor->destroy (cpi.descriptor, cpi.protocol);
	
	{
		Glib::Mutex::Lock lm (protocols_lock);
		list<ControlProtocol*>::iterator p = find (control_protocols.begin(), control_protocols.end(), cpi.protocol);
		if (p != control_protocols.end()) {
			control_protocols.erase (p);
		} else {
			cerr << "Programming error: ControlProtocolManager::teardown() called for " << cpi.name << ", but it was not found in control_protocols" << endl;
		}

		list<ControlProtocolInfo*>::iterator p2 = find (control_protocol_info.begin(), control_protocol_info.end(), &cpi);
		if (p2 != control_protocol_info.end()) {
			control_protocol_info.erase (p2);
		} else {
			cerr << "Programming error: ControlProtocolManager::teardown() called for " << cpi.name << ", but it was not found in control_protocol_info" << endl;
		}
	}
	
	cpi.protocol = 0;
	dlclose (cpi.descriptor->module);
	return 0;
}

static bool protocol_filter (const string& str, void *arg)
{
	/* Not a dotfile, has a prefix before a period, suffix is "so", or "dylib" */
	
	return str[0] != '.' 
	  && ((str.length() > 3 && str.find (".so") == (str.length() - 3))
	      || (str.length() > 6 && str.find (".dylib") == (str.length() - 6)));
}

void
ControlProtocolManager::load_mandatory_protocols ()
{
	if (_session == 0) {
		return;
	}

	for (list<ControlProtocolInfo*>::iterator i = control_protocol_info.begin(); i != control_protocol_info.end(); ++i) {
		if ((*i)->mandatory && ((*i)->protocol == 0)) {
			info << string_compose (_("Instantiating mandatory control protocol %1"), (*i)->name) << endmsg;
			instantiate (**i);
		}
	}
}

void
ControlProtocolManager::discover_control_protocols (string path)
{
	vector<string *> *found;
	PathScanner scanner;

	info << string_compose (_("looking for control protocols in %1"), path) << endmsg;

	found = scanner (path, protocol_filter, 0, false, true);

	for (vector<string*>::iterator i = found->begin(); i != found->end(); ++i) {
		control_protocol_discover (**i);
		delete *i;
	}

	delete found;
}

int
ControlProtocolManager::control_protocol_discover (string path)
{
	ControlProtocolDescriptor* descriptor;

	if ((descriptor = get_descriptor (path)) != 0) {

		ControlProtocolInfo* cpi = new ControlProtocolInfo ();

		if (!descriptor->probe (descriptor)) {
			info << string_compose (_("Control protocol %1 not usable"), descriptor->name) << endmsg;
		} else {

			cpi->descriptor = descriptor;
			cpi->name = descriptor->name;
			cpi->path = path;
			cpi->protocol = 0;
			cpi->requested = false;
			cpi->mandatory = descriptor->mandatory;
			cpi->supports_feedback = descriptor->supports_feedback;
			cpi->state = 0;
			
			control_protocol_info.push_back (cpi);
			
			info << string_compose(_("Control surface protocol discovered: \"%1\""), cpi->name) << endmsg;
		}

		dlclose (descriptor->module);
	}

	return 0;
}

ControlProtocolDescriptor*
ControlProtocolManager::get_descriptor (string path)
{
	void *module;
	ControlProtocolDescriptor *descriptor = 0;
	ControlProtocolDescriptor* (*dfunc)(void);
	const char *errstr;

	if ((module = dlopen (path.c_str(), RTLD_NOW)) == 0) {
		error << string_compose(_("ControlProtocolManager: cannot load module \"%1\" (%2)"), path, dlerror()) << endmsg;
		return 0;
	}


	dfunc = (ControlProtocolDescriptor* (*)(void)) dlsym (module, "protocol_descriptor");

	if ((errstr = dlerror()) != 0) {
		error << string_compose(_("ControlProtocolManager: module \"%1\" has no descriptor function."), path) << endmsg;
		error << errstr << endmsg;
		dlclose (module);
		return 0;
	}

	descriptor = dfunc();
	if (descriptor) {
		descriptor->module = module;
	} else {
		dlclose (module);
	}

	return descriptor;
}

void
ControlProtocolManager::foreach_known_protocol (sigc::slot<void,const ControlProtocolInfo*> method)
{
	for (list<ControlProtocolInfo*>::iterator i = control_protocol_info.begin(); i != control_protocol_info.end(); ++i) {
		method (*i);
	}
}

ControlProtocolInfo*
ControlProtocolManager::cpi_by_name (string name)
{
	for (list<ControlProtocolInfo*>::iterator i = control_protocol_info.begin(); i != control_protocol_info.end(); ++i) {
		if (name == (*i)->name) {
			return *i;
		}
	}
	return 0;
}

int
ControlProtocolManager::set_state (const XMLNode& node)
{
	XMLNodeList clist;
	XMLNodeConstIterator citer;
	XMLProperty* prop;

	clist = node.children();

	for (citer = clist.begin(); citer != clist.end(); ++citer) {
		if ((*citer)->name() == X_("Protocol")) {

			prop = (*citer)->property (X_("active"));

			if (prop && prop->value() == X_("yes")) {
				if ((prop = (*citer)->property (X_("name"))) != 0) {
					ControlProtocolInfo* cpi = cpi_by_name (prop->value());
					if (cpi) {
						if (!(*citer)->children().empty()) {
							cpi->state = (*citer)->children().front ();
						} else {
							cpi->state = 0;
						}
						
						if (_session) {
							instantiate (*cpi);
						} else {
							cpi->requested = true;
						}
					}
				}
			}
		}    
	}
	return 0;
}

XMLNode&
ControlProtocolManager::get_state (void)
{
	XMLNode* root = new XMLNode (state_node_name);
	Glib::Mutex::Lock lm (protocols_lock);

	for (list<ControlProtocolInfo*>::iterator i = control_protocol_info.begin(); i != control_protocol_info.end(); ++i) {

		XMLNode * child;

		if ((*i)->protocol) {
			child = &((*i)->protocol->get_state());
			child->add_property (X_("active"), "yes");
			// should we update (*i)->state here?  probably.
			root->add_child_nocopy (*child);
		}
		else if ((*i)->state) {
			// keep ownership clear
			root->add_child_copy (*(*i)->state);
		}
		else {
			child = new XMLNode (X_("Protocol"));
			child->add_property (X_("name"), (*i)->name);
			child->add_property (X_("active"), "no");
			root->add_child_nocopy (*child);
		}
	}

	return *root;
}

void
ControlProtocolManager::set_protocol_states (const XMLNode& node)
{
	XMLNodeList nlist;
	XMLNodeConstIterator niter;
	XMLProperty* prop;

	nlist = node.children();

	for (niter = nlist.begin(); niter != nlist.end(); ++niter) {

		XMLNode* child = (*niter);

		if ((prop = child->property ("name")) == 0) {
			error << _("control protocol XML node has no name property. Ignored.") << endmsg;
			continue;
		}

		ControlProtocolInfo* cpi = cpi_by_name (prop->value());

		if (!cpi) {
			warning << string_compose (_("control protocol \"%1\" is not known. Ignored"), prop->value()) << endmsg;
			continue;
		}

		/* copy the node so that ownership is clear */

		cpi->state = new XMLNode (*child);
	}
}