From fe4fe5ceffc481b14a6353bd268164d781db48f9 Mon Sep 17 00:00:00 2001
From: Nico Weber <thakis@chromium.org>
Date: Sun, 24 Sep 2023 19:01:01 -0400
Subject: [PATCH] MacPDF: Support opening password-protected PDFs

This is a bit janky for several reasons:
* `initialize` is now no longer called on a bg thread
* sheet UI is janky both visually and from an implementation PoV

But hey, it works for now.
---
 Meta/Lagom/Contrib/MacPDF/LagomPDFDocument.mm | 54 +++++++++++++++++--
 1 file changed, 50 insertions(+), 4 deletions(-)

diff --git a/Meta/Lagom/Contrib/MacPDF/LagomPDFDocument.mm b/Meta/Lagom/Contrib/MacPDF/LagomPDFDocument.mm
index 12ba0432aa..e90c5cf351 100644
--- a/Meta/Lagom/Contrib/MacPDF/LagomPDFDocument.mm
+++ b/Meta/Lagom/Contrib/MacPDF/LagomPDFDocument.mm
@@ -20,13 +20,57 @@
 
 @implementation LagomPDFDocument
 
+- (void)promptForPassword:(NSWindow*)window
+{
+    auto alert = [[NSAlert alloc] init];
+    alert.messageText = @"Password";
+    [alert addButtonWithTitle:@"OK"];
+    [alert addButtonWithTitle:@"Cancel"];
+
+    auto textField = [[NSSecureTextField alloc] initWithFrame:NSMakeRect(0, 0, 200, 24)];
+    alert.accessoryView = textField;
+    alert.window.initialFirstResponder = textField;
+
+    // Without this, the window's not visible yet and the sheet can't attach to it.
+    // FIXME: This causes the window to change position after restoring, so this isn't quite right either.
+    //        Probably nicest to put the password prompt right in the window, instead of in a sheet.
+    [window orderFront:self];
+
+    [alert beginSheetModalForWindow:window
+                  completionHandler:^(NSModalResponse response) {
+                      if (response == NSAlertFirstButtonReturn) {
+                          NSString* password = [textField stringValue];
+                          StringView password_view { [password UTF8String], strlen([password UTF8String]) };
+                          if (!self->_doc->security_handler()->try_provide_user_password(password_view)) {
+                              warnln("invalid password '{}'", password);
+                              [self performSelector:@selector(promptForPassword:) withObject:window];
+                              return;
+                          }
+                          [self initializePDF];
+                      } else if (response == NSAlertSecondButtonReturn) {
+                          [self close];
+                      }
+                  }];
+}
+
 - (PDF::PDFErrorOr<NonnullRefPtr<PDF::Document>>)load:(NSData*)data
 {
+    // Runs on background thread, can't interact with UI.
     auto document = TRY(PDF::Document::create(ReadonlyBytes { [data bytes], [data length] }));
-    TRY(document->initialize());
     return document;
 }
 
+- (void)initializePDF
+{
+    // FIXME: on background thread?
+    if (auto err = _doc->initialize(); err.is_error()) {
+        // FIXME: show error?
+        NSLog(@"failed to load 2: %@", @(err.error().message().characters()));
+    } else {
+        [_pdfView setDocument:_doc->make_weak_ptr()];
+    }
+}
+
 - (NSString*)windowNibName
 {
     // Override to return the nib file name of the document.
@@ -39,7 +83,11 @@
     [super windowControllerDidLoadNib:aController];
 
     if (_doc) {
-        [_pdfView setDocument:_doc->make_weak_ptr()];
+        if (auto handler = _doc->security_handler(); handler && !handler->has_user_password()) {
+            [self promptForPassword:aController.window];
+            return;
+        }
+        [self initializePDF];
     }
 }
 
@@ -71,8 +119,6 @@
     if (auto doc_or = [self load:data]; !doc_or.is_error()) {
         _doc = doc_or.value();
         _data = data;
-        //        [self pageChanged];
-
         return YES;
     } else {
         NSLog(@"failed to load: %@", @(doc_or.error().message().characters()));