Proper char count implementation

src/lib/util/count-chars.ts

@@ -0,0 +1,35 @@
+import type { Page } from "$lib/types";
+
+/**
+ * @license BSD-3-Clause
+ * Copyright (c) 2023, ッツ Reader Authors
+ * All rights reserved.
+ */
+
+// isNotJapaneseRegex aquired from ttsu reader
+// https://github.com/ttu-ttu/ebook-reader/blob/main/apps/web/src/lib/functions/get-character-count.ts
+
+export function countChars(line: string) {
+  const isNotJapaneseRegex = /[^0-9A-Z○◯々-〇〻ぁ-ゖゝ-ゞァ-ヺー０-９Ａ-Ｚｦ-ﾝ\p{Radical}\p{Unified_Ideograph}]+/gimu
+  const cleaned = line.replace(isNotJapaneseRegex, '')
+  return cleaned.length;
+}
+
+export function getCharCount(pages: Page[], currentPage?: number) {
+  if (pages && pages.length > 0) {
+    const max = currentPage || pages.length
+    let charCount = 0;
+
+    for (let i = 0; i < max; i++) {
+      const blocks = pages[i].blocks;
+
+      blocks.forEach((block) => {
+        block.lines.forEach((line) => {
+          charCount += countChars(line);
+        });
+      });
+    }
+
+    return charCount;
+  }
+}