#include "recentfiles.h"
#include "resource.h"

static bool setRegString(HKEY key, const std::string &name, const std::string &value)
{
	return ERROR_SUCCESS == RegSetValueEx(key, name.c_str(), 0, REG_SZ, (BYTE *)value.c_str(), (DWORD)value.size());
}

static bool getRegString(HKEY key, const std::string &name, std::string &out)
{
	DWORD size = 0;
	DWORD type = 0;
	if (ERROR_SUCCESS != RegQueryValueEx(key, name.c_str(), 0, &type, (LPBYTE)NULL, &size)) return false;
	if (REG_SZ != type) return false;

	out.resize(size);
	DWORD ret = RegQueryValueEx(key, name.c_str(), 0, &type, (LPBYTE)&out[0], &size);
	while (out.size() > 0 && out[out.size() - 1] == '\0') out.resize(out.size() - 1);

	assert(ret == ERROR_SUCCESS);
	assert(REG_SZ == type);
	assert(size == out.size() + 1);

	return true;
}

void RecentFiles::load(HKEY key)
{
	for (size_t i = 0; i < 5; ++i)
	{
		std::string fileName;
		if (getRegString(key, getEntryName(i), fileName))
		{
			mruList.push_back(fileName);
		}
	}

	if (mruList.size() > 0) update();
}

void RecentFiles::save(HKEY key)
{
	std::list<std::string>::const_iterator it;
	size_t i;
	for (i = 0, it = mruList.begin(); it != mruList.end(); ++it, ++i)
	{
		assert(i <= 5);
		setRegString(key, getEntryName(i), *it);
	}
}

void RecentFiles::insert(const std::string &fileName)
{
	mruList.remove(fileName); // remove, if present
	mruList.push_front(fileName); // add to front
	while (mruList.size() > 5) mruList.pop_back(); // remove old entries
}

void RecentFiles::update()
{
	while (0 != RemoveMenu(mruFileMenu, 0, MF_BYPOSITION));

	std::list<std::string>::const_iterator it;
	size_t i;
	for (i = 0, it = mruList.begin(); it != mruList.end(); ++it, ++i)
	{
		assert(i <= 5);
		std::string menuEntry = std::string("&");
		menuEntry += char('1' + i);
		menuEntry += " ";
		menuEntry += *it;
		AppendMenu(mruFileMenu, MF_STRING, ID_RECENTFILES_FILE1 + i, menuEntry.c_str());
	}
}

bool RecentFiles::getEntry(size_t index, std::string &out) const
{
	std::list<std::string>::const_iterator it;
	size_t i;
	for (i = 0, it = mruList.begin(); it != mruList.end(); ++it, ++i)
	{
		if (i == index)
		{
			out = *it;
			return true;
		}
	}
	return false;
}