lib/search/word_search: pagination

lib/search/word_search.dart

@@ -13,6 +13,7 @@ import 'package:jadb/models/word_search/word_search_sense_language_source.dart';
 import 'package:jadb/models/word_search/word_search_sources.dart';
 import 'package:jadb/models/word_search/word_search_xref_entry.dart';
 import 'package:jadb/util/sqlite_utils.dart';
+import 'package:jadb/util/text_filtering.dart';
 import 'package:sqflite_common/sqlite_api.dart';
 
 // TODO: Support globs
@@ -23,21 +24,61 @@ import 'package:sqflite_common/sqlite_api.dart';
 
 // TODO: Support mixing kana and romaji
 
-Future<List<WordSearchResult>?> searchWordWithDbConnection(
-  DatabaseExecutor connection,
-  String word, {
-  bool isKana = true,
-}) async {
-  if (word.isEmpty) {
-    return null;
+enum SearchMode {
+  Auto,
+  English,
+  Kanji,
+  MixedKanji,
+  Kana,
+  MixedKana,
+}
+
+SearchMode _determineSearchMode(String word) {
+  final bool containsKanji = kanjiRegex.hasMatch(word);
+  final bool containsAscii = RegExp(r'[A-Za-z]').hasMatch(word);
+
+  if (containsKanji && containsAscii) {
+    return SearchMode.MixedKanji;
+  } else if (containsKanji) {
+    return SearchMode.Kanji;
+  } else if (containsAscii) {
+    return SearchMode.English;
+  } else if (word.contains(hiraganaRegex) || word.contains(katakanaRegex)) {
+    return SearchMode.Kana;
+  } else {
+    return SearchMode.MixedKana;
   }
+}
+
+Future<List<int>> _fetchEntryIds(DatabaseExecutor connection, String word,
+    SearchMode searchMode, int pageSize, int? offset) async {
+  assert(
+    searchMode != SearchMode.Auto,
+    'Search mode should not be auto when fetching entry IDs',
+  );
+  assert(
+    word.isNotEmpty,
+    'Word should not be empty when fetching entry IDs',
+  );
 
   late final List<int> entryIds;
-  if (isKana) {
+  if (searchMode == SearchMode.Kanji) {
+    entryIds = (await connection.query(
+      'JMdict_EntryByKanji',
+      where: 'kanji LIKE ?',
+      whereArgs: ['%$word%'],
+      limit: pageSize,
+      offset: offset,
+    ))
+        .map((row) => row['entryId'] as int)
+        .toList();
+  } else if (searchMode == SearchMode.Kana) {
     entryIds = (await connection.query(
       'JMdict_EntryByKana',
       where: 'kana LIKE ?',
-      whereArgs: ['$word%'],
+      whereArgs: ['%$word%'],
+      limit: pageSize,
+      offset: offset,
     ))
         .map((row) => row['entryId'] as int)
         .toList();
@@ -45,12 +86,42 @@ Future<List<WordSearchResult>?> searchWordWithDbConnection(
     entryIds = (await connection.query(
       'JMdict_EntryByEnglish',
       where: 'english LIKE ?',
-      whereArgs: ['$word%'],
+      whereArgs: ['%$word%'],
+      limit: pageSize,
+      offset: offset,
     ))
         .map((row) => row['entryId'] as int)
         .toList();
   }
 
+  return entryIds;
+}
+
+Future<List<WordSearchResult>?> searchWordWithDbConnection(
+  DatabaseExecutor connection,
+  String word, {
+  SearchMode searchMode = SearchMode.Auto,
+  int page = 0,
+  int pageSize = 10,
+}) async {
+  if (word.isEmpty) {
+    return null;
+  }
+
+  if (searchMode == SearchMode.Auto) {
+    searchMode = _determineSearchMode(word);
+  }
+
+  final offset = page * pageSize;
+
+  final List<int> entryIds = await _fetchEntryIds(
+    connection,
+    word,
+    searchMode,
+    pageSize,
+    offset,
+  );
+
   if (entryIds.isEmpty) {
     return [];
   }
@@ -270,7 +341,7 @@ Future<List<WordSearchResult>?> searchWordWithDbConnection(
     kanjiElementInfos_query.then((value) => kanjiElementInfos = value),
   ]);
 
-  return _regroupWordSearchResults(
+  final result = _regroupWordSearchResults(
     entryIds: entryIds,
     readingElements: readingElements,
     kanjiElements: kanjiElements,
@@ -293,6 +364,8 @@ Future<List<WordSearchResult>?> searchWordWithDbConnection(
     readingElementRestrictions: readingElementRestrictions,
     kanjiElementInfos: kanjiElementInfos,
   );
+
+  return result;
 }
 
 List<WordSearchResult> _regroupWordSearchResults({