Use backend for extracting cloze text to type

Closes #2311

proto/anki/card_rendering.proto

@@ -27,6 +27,8 @@ service CardRenderingService {
   rpc DecodeIriPaths(generic.String) returns (generic.String);
   rpc StripHtml(StripHtmlRequest) returns (generic.String);
   rpc CompareAnswer(CompareAnswerRequest) returns (generic.String);
+  rpc ExtractClozeForTyping(ExtractClozeForTypingRequest)
+      returns (generic.String);
 }
 
 message ExtractAVTagsRequest {
@@ -138,3 +140,8 @@ message CompareAnswerRequest {
   string expected = 1;
   string provided = 2;
 }
+
+message ExtractClozeForTypingRequest {
+  string text = 1;
+  uint32 ordinal = 2;
+}

pylib/anki/collection.py

@@ -1219,6 +1219,9 @@ class Collection(DeprecatedNamesMixin):
     def compare_answer(self, expected: str, provided: str) -> str:
         return self._backend.compare_answer(expected=expected, provided=provided)
 
+    def extract_cloze_for_typing(self, text: str, ordinal: int) -> str:
+        return self._backend.extract_cloze_for_typing(text=text, ordinal=ordinal)
+
     # Timeboxing
     ##########################################################################
     # fixme: there doesn't seem to be a good reason why this code is in main.py

qt/aqt/reviewer.py

@@ -630,23 +630,8 @@ class Reviewer:
 
         return re.sub(self.typeAnsPat, repl, buf)
 
-    def _contentForCloze(self, txt: str, idx: int) -> str:
-        matches = re.findall(r"\{\{c%s::(.+?)\}\}" % idx, txt, re.DOTALL)
-        if not matches:
-            return None
-
-        def noHint(txt: str) -> str:
-            if "::" in txt:
-                return txt.split("::")[0]
-            return txt
-
-        matches = [noHint(txt) for txt in matches]
-        uniqMatches = set(matches)
-        if len(uniqMatches) == 1:
-            txt = matches[0]
-        else:
-            txt = ", ".join(matches)
-        return txt
+    def _contentForCloze(self, txt: str, idx: int) -> str | None:
+        return self.mw.col.extract_cloze_for_typing(txt, idx) or None
 
     def _getTypedAnswer(self) -> None:
         self.web.evalWithCallback("getTypedAnswer();", self._onTypedAnswer)

rslib/src/backend/cardrendering.rs

@@ -4,6 +4,7 @@
 use super::Backend;
 use crate::card_rendering::extract_av_tags;
 use crate::card_rendering::strip_av_tags;
+use crate::cloze::extract_cloze_for_typing;
 use crate::latex::extract_latex;
 use crate::latex::extract_latex_expanding_clozes;
 use crate::latex::ExtractedLatex;
@@ -12,6 +13,7 @@ use crate::notetype::CardTemplateSchema11;
 use crate::notetype::RenderCardOutput;
 use crate::pb;
 pub(super) use crate::pb::card_rendering::cardrendering_service::Service as CardRenderingService;
+use crate::pb::card_rendering::ExtractClozeForTypingRequest;
 use crate::prelude::*;
 use crate::template::RenderedNode;
 use crate::text::decode_iri_paths;
@@ -164,6 +166,15 @@ impl CardRenderingService for Backend {
     ) -> Result<pb::generic::String> {
         Ok(compare_answer(&input.expected, &input.provided).into())
     }
+
+    fn extract_cloze_for_typing(
+        &self,
+        input: ExtractClozeForTypingRequest,
+    ) -> Result<pb::generic::String> {
+        Ok(extract_cloze_for_typing(&input.text, input.ordinal as u16)
+            .to_string()
+            .into())
+    }
 }
 
 fn rendered_nodes_to_proto(

rslib/src/cloze.rs

@@ -306,6 +306,21 @@ pub fn reveal_cloze_text_only(text: &str, cloze_ord: u16, question: bool) -> Cow
     output.join(", ").into()
 }
 
+pub fn extract_cloze_for_typing(text: &str, cloze_ord: u16) -> Cow<str> {
+    let mut output = Vec::new();
+    for node in &parse_text_with_clozes(text) {
+        reveal_cloze_text_in_nodes(node, cloze_ord, false, &mut output);
+    }
+    if output.is_empty() {
+        "".into()
+    } else if output.iter().min() == output.iter().max() {
+        // If all matches are identical text, they get collapsed into a single entry
+        output.pop().unwrap().into()
+    } else {
+        output.join(", ").into()
+    }
+}
+
 /// If text contains any LaTeX tags, render the front and back
 /// of each cloze deletion so that LaTeX can be generated. If
 /// no LaTeX is found, returns an empty string.
@@ -419,6 +434,19 @@ mod test {
         );
     }
 
+    #[test]
+    fn clozes_for_typing() {
+        assert_eq!(extract_cloze_for_typing("{{c2::foo}}", 1), "");
+        assert_eq!(
+            extract_cloze_for_typing("{{c1::foo}} {{c1::bar}} {{c1::foo}}", 1),
+            "foo, bar, foo"
+        );
+        assert_eq!(
+            extract_cloze_for_typing("{{c1::foo}} {{c1::foo}} {{c1::foo}}", 1),
+            "foo"
+        );
+    }
+
     #[test]
     fn nested_cloze_plain_text() {
         assert_eq!(