empty card handling

proto/backend.proto

@@ -83,6 +83,7 @@ message BackendInput {
         AddNoteIn add_note = 67;
         Note update_note = 68;
         int64 get_note = 69;
+        Empty get_empty_cards = 70;
     }
 }
 
@@ -145,6 +146,7 @@ message BackendOutput {
         int64 add_note = 67;
         Empty update_note = 68;
         Note get_note = 69;
+        EmptyCardsReport get_empty_cards = 70;
 
         BackendError error = 2047;
     }
@@ -628,3 +630,14 @@ message AddNoteIn {
     Note note = 1;
     int64 deck_id = 2;
 }
+
+message EmptyCardsReport {
+    string report = 1;
+    repeated NoteWithEmptyCards notes = 2;
+}
+
+message NoteWithEmptyCards {
+    int64 note_id = 1;
+    repeated int64 card_ids = 2;
+    bool will_delete_note = 3;
+}

rslib/ftl/empty-cards.ftl

@@ -1,3 +1,6 @@
-empty-cards-card-line =
-    Empty card numbers: {$card-numbers}
-    Fields: {$fields}
+empty-cards-for-note-type = Empty cards for { $notetype }:
+empty-cards-count-line =
+  { $empty_count } of { $existing_count } cards empty ({ $template_names }).
+empty-cards-window-title = Empty Cards
+empty-cards-preserve-notes-checkbox = Keep notes with no valid cards
+empty-cards-delete-button = Delete

rslib/src/backend/mod.rs

@@ -344,6 +344,7 @@ impl Backend {
                 OValue::UpdateNote(pb::Empty {})
             }
             Value::GetNote(nid) => OValue::GetNote(self.get_note(nid)?),
+            Value::GetEmptyCards(_) => OValue::GetEmptyCards(self.get_empty_cards()?),
         })
     }
 
@@ -996,6 +997,26 @@ impl Backend {
                 .map(Into::into)
         })
     }
+
+    fn get_empty_cards(&self) -> Result<pb::EmptyCardsReport> {
+        self.with_col(|col| {
+            let mut empty = col.empty_cards()?;
+            let report = col.empty_cards_report(&mut empty)?;
+
+            let mut outnotes = vec![];
+            for (_ntid, notes) in empty {
+                outnotes.extend(notes.into_iter().map(|e| pb::NoteWithEmptyCards {
+                    note_id: e.nid.0,
+                    will_delete_note: e.empty.len() == e.current_count,
+                    card_ids: e.empty.into_iter().map(|(_ord, id)| id.0).collect(),
+                }))
+            }
+            Ok(pb::EmptyCardsReport {
+                report,
+                notes: outnotes,
+            })
+        })
+    }
 }
 
 fn translate_arg_to_fluent_val(arg: &pb::TranslateArgValue) -> FluentValue {

rslib/src/notetype/cardgen.rs

@@ -84,13 +84,14 @@ impl CardGenContext<'_> {
         &self,
         note: &Note,
         existing: &[AlreadyGeneratedCardInfo],
+        ensure_not_empty: bool,
     ) -> Vec<CardToGenerate> {
         let extracted = extract_data_from_existing_cards(existing);
         let cards = match self.notetype.config.kind() {
             NoteTypeKind::Normal => self.new_cards_required_normal(note, &extracted),
             NoteTypeKind::Cloze => self.new_cards_required_cloze(note, &extracted),
         };
-        if extracted.existing_ords.is_empty() && cards.is_empty() {
+        if extracted.existing_ords.is_empty() && cards.is_empty() && ensure_not_empty {
             // if there are no existing cards and no cards will be generated,
             // we add card 0 to ensure the note always has at least one card
             vec![CardToGenerate {
@@ -157,7 +158,7 @@ impl CardGenContext<'_> {
 }
 
 // this could be reworked in the future to avoid the extra vec allocation
-fn group_generated_cards_by_note(
+pub(super) fn group_generated_cards_by_note(
     items: Vec<AlreadyGeneratedCardInfo>,
 ) -> Vec<(NoteID, Vec<AlreadyGeneratedCardInfo>)> {
     let mut out = vec![];
@@ -225,7 +226,7 @@ impl Collection {
         existing: &[AlreadyGeneratedCardInfo],
         target_deck_id: Option<DeckID>,
     ) -> Result<()> {
-        let cards = ctx.new_cards_required(note, &existing);
+        let cards = ctx.new_cards_required(note, &existing, true);
         if cards.is_empty() {
             return Ok(());
         }

rslib/src/notetype/emptycards.rs

@@ -0,0 +1,137 @@
+// Copyright: Ankitects Pty Ltd and contributors
+// License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
+
+use super::{
+    cardgen::group_generated_cards_by_note, CardGenContext, NoteType, NoteTypeID, NoteTypeKind,
+};
+use crate::{
+    card::CardID,
+    collection::Collection,
+    err::Result,
+    i18n::{tr_args, TR},
+    notes::NoteID,
+};
+use std::collections::HashSet;
+use std::fmt::Write;
+
+pub struct EmptyCardsForNote {
+    pub nid: NoteID,
+    // (ordinal, card id)
+    pub empty: Vec<(u32, CardID)>,
+    pub current_count: usize,
+}
+
+impl Collection {
+    fn empty_cards_for_notetype(&self, nt: &NoteType) -> Result<Vec<EmptyCardsForNote>> {
+        let ctx = CardGenContext::new(nt, self.usn()?);
+        let existing_cards = self.storage.existing_cards_for_notetype(nt.id)?;
+        let by_note = group_generated_cards_by_note(existing_cards);
+        let mut out = Vec::with_capacity(by_note.len());
+
+        for (nid, existing) in by_note {
+            let note = self.storage.get_note(nid)?.unwrap();
+            let cards = ctx.new_cards_required(&note, &[], false);
+            let nonempty_ords: HashSet<_> = cards.into_iter().map(|c| c.ord).collect();
+            let current_count = existing.len();
+            let empty: Vec<_> = existing
+                .into_iter()
+                .filter_map(|e| {
+                    if !nonempty_ords.contains(&e.ord) {
+                        Some((e.ord, e.id))
+                    } else {
+                        None
+                    }
+                })
+                .collect();
+            out.push(EmptyCardsForNote {
+                nid,
+                empty,
+                current_count,
+            })
+        }
+
+        Ok(out)
+    }
+
+    pub fn empty_cards(&mut self) -> Result<Vec<(NoteTypeID, Vec<EmptyCardsForNote>)>> {
+        self.get_all_notetypes()?
+            .into_iter()
+            .map(|(id, nt)| self.empty_cards_for_notetype(&nt).map(|v| (id, v)))
+            .collect()
+    }
+
+    /// Create a report on empty cards. Mutates the provided data to sort ordinals.
+    pub fn empty_cards_report(
+        &mut self,
+        empty: &mut [(NoteTypeID, Vec<EmptyCardsForNote>)],
+    ) -> Result<String> {
+        let nts = self.get_all_notetypes()?;
+        let mut buf = String::new();
+        for (ntid, notes) in empty {
+            if !notes.is_empty() {
+                let nt = nts.get(ntid).unwrap();
+                write!(
+                    buf,
+                    "<div><b>{}</b></div><ol>",
+                    self.i18n.trn(
+                        TR::EmptyCardsForNoteType,
+                        tr_args!["notetype"=>nt.name.clone()],
+                    )
+                )
+                .unwrap();
+
+                for note in notes {
+                    note.empty.sort_unstable();
+                    let templates = match nt.config.kind() {
+                        // "Front, Back"
+                        NoteTypeKind::Normal => note
+                            .empty
+                            .iter()
+                            .map(|(ord, _)| {
+                                nt.templates
+                                    .get(*ord as usize)
+                                    .map(|t| t.name.clone())
+                                    .unwrap_or_default()
+                            })
+                            .collect::<Vec<_>>()
+                            .join(", "),
+                        // "Cloze 1, 3"
+                        NoteTypeKind::Cloze => format!(
+                            "{} {}",
+                            self.i18n.tr(TR::NotetypesClozeName),
+                            note.empty
+                                .iter()
+                                .map(|(ord, _)| (ord + 1).to_string())
+                                .collect::<Vec<_>>()
+                                .join(", ")
+                        ),
+                    };
+                    let class = if note.current_count == note.empty.len() {
+                        "allempty"
+                    } else {
+                        ""
+                    };
+                    write!(
+                        buf,
+                        "<li class={}>[anki:nid:{}] {}</li>",
+                        class,
+                        note.nid,
+                        self.i18n.trn(
+                            TR::EmptyCardsCountLine,
+                            tr_args![
+                            "empty_count"=>note.empty.len(),
+                            "existing_count"=>note.current_count,
+                            "template_names"=>templates
+                            ],
+                        )
+                    )
+                    .unwrap();
+                }
+
+                buf.push_str("</ol>");
+            }
+        }
+
+        Ok(buf)
+    }
+}

rslib/src/notetype/mod.rs

@@ -2,6 +2,7 @@
 // License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
 mod cardgen;
+mod emptycards;
 mod fields;
 mod schema11;
 mod schemachange;