From 9b1543ae2dabe45cad205f422d1dc396b3858b40 Mon Sep 17 00:00:00 2001
From: Elias Aebi <eyelash@users.noreply.github.com>
Date: Sun, 11 Feb 2024 19:44:01 +0100
Subject: [PATCH] gral_directory_monitor

---
 gral.h           |  1 +
 gral_linux.c     |  4 ++++
 gral_macos.m     |  4 ++++
 gral_windows.cpp | 58 +++++++++++++++++++++++++++++++++++++++++++-----
 4 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/gral.h b/gral.h
index acc2b8f..4bcf42c 100644
--- a/gral.h
+++ b/gral.h
@@ -181,6 +181,7 @@ void gral_file_remove(char const *path);
 void gral_directory_create(char const *path);
 void gral_directory_iterate(char const *path, void (*callback)(char const *name, void *user_data), void *user_data);
 void gral_directory_remove(char const *path);
+void gral_directory_monitor(char const *path, void (*callback)(void *user_data), void *user_data);
 
 
 /*=========
diff --git a/gral_linux.c b/gral_linux.c
index e5d9648..d7a81f2 100644
--- a/gral_linux.c
+++ b/gral_linux.c
@@ -768,6 +768,10 @@ void gral_directory_remove(char const *path) {
 	rmdir(path);
 }
 
+void gral_directory_monitor(char const *path, void (*callback)(void *user_data), void *user_data) {
+	// TODO: implement
+}
+
 
 /*=========
     TIME
diff --git a/gral_macos.m b/gral_macos.m
index 47a8a8f..c14f9e7 100644
--- a/gral_macos.m
+++ b/gral_macos.m
@@ -803,6 +803,10 @@ void gral_directory_remove(char const *path) {
 	rmdir(path);
 }
 
+void gral_directory_monitor(char const *path, void (*callback)(void *user_data), void *user_data) {
+	// TODO: implement
+}
+
 
 /*=========
     TIME
diff --git a/gral_windows.cpp b/gral_windows.cpp
index f38f0dc..44cb418 100644
--- a/gral_windows.cpp
+++ b/gral_windows.cpp
@@ -563,12 +563,17 @@ int gral_application_run(gral_application *application, int argc_, char **argv_)
 	}
 	LocalFree(argv);
 	MSG message;
-	while (GetMessage(&message, NULL, 0, 0)) {
-		TranslateMessage(&message);
-		DispatchMessage(&message);
+	while (TRUE) {
+		while (PeekMessage(&message, NULL, 0, 0, PM_REMOVE)) {
+			if (message.message == WM_QUIT) {
+				application->iface.quit(application->user_data);
+				return 0;
+			}
+			TranslateMessage(&message);
+			DispatchMessage(&message);
+		}
+		MsgWaitForMultipleObjectsEx(0, NULL, INFINITE, QS_ALLINPUT, MWMO_ALERTABLE);
 	}
-	application->iface.quit(application->user_data);
-	return 0;
 }
 
 
@@ -1171,6 +1176,49 @@ void gral_directory_remove(char const *path) {
 	RemoveDirectory(utf8_to_utf16(path));
 }
 
+class gral_directory_watcher {
+	HANDLE directory;
+	OVERLAPPED overlapped;
+	void (*callback)(void *user_data);
+	void *user_data
+	char buffer[4096];
+	static void completion_routine(DWORD dwErrorCode, DWORD dwNumberOfBytesTransfered, LPOVERLAPPED lpOverlapped) {
+		gral_directory_watcher *watcher = (gral_directory_watcher *)lpOverlapped->hEvent;
+		DWORD offset = 0;
+		while (TRUE) {
+			PFILE_NOTIFY_INFORMATION information = (PFILE_NOTIFY_INFORMATION)(watcher->buffer + offset);
+			if (information->Action != FILE_ACTION_RENAMED_OLD_NAME) {
+				watcher->callback(watcher->user_data);
+			}
+			if (information->NextEntryOffset == 0) {
+				break;
+			}
+			offset += information->NextEntryOffset;
+		}
+		watcher->watch();
+	}
+public:
+	gral_directory_watcher(char const *path, void (*callback)(void *user_data), void *user_data) {
+		directory = CreateFile(utf8_to_utf16(path), FILE_LIST_DIRECTORY, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED, NULL);
+		ZeroMemory(&overlapped, sizeof(overlapped));
+		overlapped.hEvent = this;
+		this->callback = callback;
+		this->user_data = user_data;
+	}
+	~gral_directory_watcher() {
+		CloseHandle(directory);
+	}
+	void watch() {
+		const DWORD notify_filter = FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME | FILE_NOTIFY_CHANGE_ATTRIBUTES | FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE | FILE_NOTIFY_CHANGE_LAST_ACCESS | FILE_NOTIFY_CHANGE_CREATION | FILE_NOTIFY_CHANGE_SECURITY;
+		ReadDirectoryChangesW(directory, buffer, sizeof(buffer), FALSE, notify_filter, NULL, &overlapped, completion_routine);
+	}
+};
+
+void gral_directory_monitor(char const *path, void (*callback)(void *user_data), void *user_data) {
+	gral_directory_watcher *watcher = new gral_directory_watcher(path, callback, user_data);
+	watcher->watch();
+}
+
 
 /*=========
     TIME