// Copyright (c) 2009 - 2026 kio@little-bat.de
// BSD-2-Clause license
// https://opensource.org/licenses/BSD-2-Clause

#include "RecentFilesMenu.h"
#include "Qt/Settings.h"
#include "unix/files.h"
#include <QList>
#include <QSettings>


namespace zxsp
{

/*	Max. files per list:
 */
#define MAX_ENTRIES 20


// *******************************************************************
//						RecentFilesList
// *******************************************************************

/*	Class representing one recent files list:
	- preferences key
	- list of file paths
	- list of menus with this list (usually one)
*/
class RecentFilesList : public QObject
{
public:
	cstr					key;
	QStringList				fpaths;
	QList<RecentFilesMenu*> menus;

	RecentFilesList(cstr key);
	void clear_list();
	void add_file(QString);
};


/*	Create a recent files list:
	- reads in the preferences
	- removes any disappeared files from the list
	- truncates list to MAX_ENTRIES
*/
RecentFilesList::RecentFilesList(cstr key) : key(key), fpaths(settings.value(key).toStringList())
{
	for (int i = 0; i < fpaths.count(); i++)
	{
		if (!is_file(fpaths.at(i).toUtf8().data())) fpaths.removeAt(i--);
	}
	while (fpaths.count() > MAX_ENTRIES) { fpaths.removeLast(); }
}


/*	Clear list
	- clear list
	- write empty list back to file
	- update all menues
*/
void RecentFilesList::clear_list()
{
	fpaths.clear();
	for (int i = 0; i < menus.count(); i++) { menus.at(i)->clear_menu(); }
	settings.setValue(key, fpaths);
}


/*	Add filepath to list
	- add filepath at start of list
	- truncate list to MAX_ENTRIES
	- update all menues
*/
void RecentFilesList::add_file(QString fpath)
{
	int oldidx = fpaths.indexOf(fpath);
	if (oldidx == 0) return;									  // ist schon drin und ist auch schon ganz oben
	if (oldidx != -1) fpaths.removeAt(oldidx);					  // von alter position entfernen
	fpaths.insert(0, fpath);									  // ganz oben einfügen
	while (fpaths.count() > MAX_ENTRIES) { fpaths.removeLast(); } // Listenlänge begrenzen
	for (int i = 0; i < menus.count(); i++) { menus.at(i)->add_file(fpath, oldidx); } // Menüs informieren
	settings.setValue(key, fpaths);													  // settings aktualisieren
}


/*	All known recent files lists:
	Must match enum ListId.
*/
static QList<RecentFilesList*> recent_files = QList<RecentFilesList*>()						//
											  << new RecentFilesList("recent_files")		//
											  << new RecentFilesList("recent_plus3_disks")	//
											  << new RecentFilesList("recent_zxsp_tapes")	//
											  << new RecentFilesList("recent_zx80_tapes")	//
											  << new RecentFilesList("recent_zx81_tapes")	//
											  << new RecentFilesList("recent_ace_tapes")	//
											  << new RecentFilesList("recent_if2_roms")		//
											  << new RecentFilesList("recent_tcc_roms")		//
											  << new RecentFilesList("recent_divide_roms")	//
											  << new RecentFilesList("recent_divide_disks") //
											  << new RecentFilesList("recent_zx81_roms");	// Chroma81


/*	global function: clear recent files list[id]
 */
void clearRecentFiles(ListId id) { recent_files.at(id)->clear_list(); }

/*	global function: Add file to recent files list[id]
 */
void addRecentFile(ListId id, QString fpath) { recent_files.at(id)->add_file(fpath); }

/*	global function: Get file from recent files list[id]
 */
QString getRecentFile(ListId id, int position)
{
	QStringList& list = recent_files.at(id)->fpaths;
	if (list.count() > position) return list.at(position);
	else return "";
}


// *******************************************************************
//						RecentFilesMenu
// *******************************************************************


/*	Create a "recent files" QMenu
	id   = recent files list id
	callback = function (closure) to be called to open a recent file

	populates itself with filenames and a "clear menu" entry
	adds itself to it's RecentFilesList's list of menus
*/
RecentFilesMenu::RecentFilesMenu(ListId id, QWidget* owner, std::function<void(cstr)> callback) :
	QMenu(owner),
	_list_id(id),
	_callback(callback)
{
	RecentFilesList* mylist = recent_files.at(id);

	for (int i = 0; i < mylist->fpaths.count(); i++)
	{
		QString	 fpath = mylist->fpaths.at(i);
		QString	 fname = fpath.mid(fpath.lastIndexOf('/') + 1);
		QAction* a	   = new QAction(fname, this);
		connect(a, &QAction::triggered, [=]() { _callback(fpath.toUtf8().data()); });
		addAction(a);
	}

	addSeparator();
	QAction* a = new QAction("Clear menu", this);
	connect(a, &QAction::triggered, mylist, &RecentFilesList::clear_list);
	addAction(a);

	mylist->menus.append(this);
}


/*	Destructor
	remove myself from my RecentFilesList's list of menus
*/
RecentFilesMenu::~RecentFilesMenu()
{
	RecentFilesList* mylist = recent_files.at(_list_id);
	mylist->menus.removeOne(this);
}

/*	clear this menu
	only leaving the separator and the "clear menu" entry
	called from my RecentFilesList.clear_list()
*/
void RecentFilesMenu::clear_menu()
{
	clear();
	addSeparator();
	QAction* a = new QAction("Clear menu", this);
	connect(a, &QAction::triggered, recent_files.at(_list_id), &RecentFilesList::clear_list);
	addAction(a);
}

/*	Add filename to start of this menu
	truncates list to MAX_ENTRIES
	called from my RecentFilesList.add_file()
*/
void RecentFilesMenu::add_file(QString fpath, int oldidx)
{
	if (oldidx != -1) removeAction(actions().at(oldidx));

	QString	 fname = fpath.mid(fpath.lastIndexOf('/') + 1);
	QAction* a	   = new QAction(fname, this);
	connect(a, &QAction::triggered, [=]() { _callback(fpath.toUtf8().data()); });

	assert(actions().count() != 0);
	insertAction(actions().at(0), a);

	while (actions().count() > MAX_ENTRIES + 2) removeAction(actions().at(MAX_ENTRIES));
}

} // namespace zxsp