/*]  Copyright (c) 2009-2010, Charles McGarvey  [**************************
**]  All rights reserved.
*
* vi:ts=4 sw=4 tw=75
*
* Distributable under the terms and conditions of the 2-clause BSD license;
* see the file COPYING for a complete text of the license.
*
**************************************************************************/

#include <queue>

#include <boost/algorithm/string.hpp>
#include <boost/weak_ptr.hpp>

#include <stlplus/portability/file_system.hpp>

#include "hash.hh"
#include "resource.hh"

#if HAVE_CONFIG_H
#include "../config.h"
#endif

#ifdef USE_HOTLOADING
#include <sys/inotify.h>
#include <sys/ioctl.h>
#endif

#ifndef BUF_SIZE
#define BUF_SIZE 4096
#endif


namespace moof {
	

static std::vector<std::string> search_paths_;

typedef boost::weak_ptr<resource> resource_weakptr;
static hash<std::string,resource_weakptr,hash_function> resource_table_;

// static member
resource::type_lookup_ptr resource::type_lookup_;


#ifdef USE_HOTLOADING
static hash<int,std::string,hash_function> monitor_lookup_;
static int monitor_fd_ = inotify_init1(IN_NONBLOCK);
#endif

int resource::reload_as_needed()
{
	int num_resources = 0;

#ifdef USE_HOTLOADING
	log_info("hotloading?");
	char bytes[BUF_SIZE];
	int num_bytes;
	if (0 < (num_bytes = read(monitor_fd_, bytes, num_bytes)))
	{
		char* end = bytes + num_bytes;
		char* byte = bytes;

		log_warning("num_bytes:", num_bytes);
		log_error("1");

		while (byte < end)
		{
			struct inotify_event* event = (struct inotify_event*)byte;

			if (event->mask & IN_IGNORED)
			{
				log_warning("watch", event->wd, "removed");
			}

			log_error("2");
			hash<int,std::string,hash_function>::iterator it;
			it = monitor_lookup_.find(event->wd);
			if (it != monitor_lookup_.end())
			{
				log_error("3");
				std::string path = (*it).second;
				monitor_lookup_.erase(it);
				resource::reload(path);
			}

			byte += sizeof(*event) + event->len;

			++num_resources;
		}
	}
#endif

	return num_resources;
}


resource::~resource()
{
#ifdef USE_HOTLOADING
	inotify_rm_watch(monitor_fd_, wd_);
#endif
}


resource_ptr resource::load(const std::string& path)
{
	std::string extension = stlplus::extension_part(path);

	if (!find(path)) return resource_ptr();

	hash<std::string,resource_weakptr,hash_function>::iterator it;
	it = resource_table_.find(path);
	if (it != resource_table_.end())
	{
		resource_weakptr rsrc = (*it).second;
		resource_ptr locked = rsrc.lock();
		if (locked) return locked;
	}

	std::map<std::string,loader_ptr>::iterator jt;
	jt = type_lookup_->find(extension);
	if (jt != type_lookup_->end())
	{
		resource_ptr rsrc((*jt).second->load(path));
		rsrc->set_loader(path, (*jt).second);
		resource_table_[path] = rsrc;

#ifdef USE_HOTLOADING
		int wd = inotify_add_watch(monitor_fd_,
				path.c_str(), IN_MODIFY);
		rsrc->set_watch_descriptor(wd);
		monitor_lookup_[wd] = path;
#endif

		log_info("loaded", rsrc.get());
		return rsrc;
	}

	return resource_ptr();
}


resource_ptr resource::reload(std::string& path)
{
	log_info("reloading...", path);
	hash<std::string,resource_weakptr,hash_function>::iterator it;
	it = resource_table_.find(path);
	if (it != resource_table_.end())
	{
		resource_weakptr rsrc = (*it).second;
		resource_ptr locked = rsrc.lock();
		if (locked)
		{
			locked->reload();
			return locked;
		}
	}

	return load(path);
}

void resource::reload()
{
	log_info("reloaded", path_);

	resource* resource = loader_->load(path_);
	//*this = *resource;
	resource_ = resource->resource_;
	typeinfo_ = resource->typeinfo_;
	unloader_ = resource->unloader_;

#ifdef USE_HOTLOADING
	int wd = inotify_add_watch(monitor_fd_,
			path_.c_str(), IN_MODIFY);
	set_watch_descriptor(wd);
	monitor_lookup_[wd] = path_;
#endif

	delete resource;
}


void resource::add_search_paths(const std::string& paths)
{
	std::vector<std::string> pathList;
	boost::split(pathList, paths, boost::is_any_of(":"));

	add_search_paths(pathList);
}

void resource::add_search_paths(const std::vector<std::string>& pathList)
{
	std::vector<std::string>::const_iterator it;
	for (it = pathList.begin(); it != pathList.end(); ++it)
	{
		std::string path(*it);

		ASSERT(!path.empty() && "empty search path string");

		// add a slash if there isn't one already
		if (*path.rbegin() != '/') path += '/';

#if defined(_WIN32)
		//boost::replace_all(path, "/", "\\");
#endif

		search_paths_.push_back(path);
		log_info << "added search path " << path << std::endl;
	}
}


bool resource::find(const std::string& path)
{
	FILE* file = open_file(path);
	if (file)
	{
		fclose(file);
		return true;
	}

	return false;
}

FILE* resource::open_file(const std::string& path, const std::string& mode)
{
#if defined(_WIN32)
	// windows always has to be a little different
	//boost::replace_all(path, "/", "\\");
#endif

	std::vector<std::string>::iterator it;
	for (it = search_paths_.begin(); it != search_paths_.end(); ++it)
	{
		// check path relative to search path
		std::string complete_path(*it);
		complete_path += path;

		FILE* file = fopen(complete_path.c_str(), mode.c_str());
		if (file) return file;
	}

	// last ditch effort; maybe it's already a path to a valid resource
	return fopen(path.c_str(), mode.c_str());
}


} // namespace moof