Account for decimals in unread chapter count (#335)

* Account for decimals in unread chapter count

This removes reliance on Chapter.chapterNumber (which is nullable)

* Account for almost all considerations for unread chapter count

* Lint

* Account for gaps in chapter numbers

* Use sourceId instead of title

src/util/comparison.ts

@@ -46,6 +46,35 @@ export function selectMostSimilarChapter(original: Chapter, options: Chapter[]):
  return null;
 }
 
+function consolidateAndSortChapters(chapterList: Chapter[]): Chapter[] {
+ const grouped: { [index: string]: Chapter[] } = {};
+ chapterList.forEach((chapter: Chapter) => {
+ const key = chapter.chapterNumber === '' ? chapter.sourceId : chapter.chapterNumber;
+
+ if (grouped[key] === undefined) {
+ grouped[key] = [];
+ }
+
+ grouped[key].push(chapter);
+ });
+
+ const chapters: Chapter[] = [];
+ Object.keys(grouped).forEach((key) => {
+ const groupedChapters = grouped[key];
+
+ let chapter = groupedChapters.find((chap) => chap.read);
+ if (chapter === undefined) {
+ [chapter] = groupedChapters;
+ }
+
+ chapters.push(chapter);
+ });
+
+ return chapters.sort(
+ (a: Chapter, b: Chapter) => parseFloat(a.chapterNumber) - parseFloat(b.chapterNumber)
+ );
+}
+
 /**
  * Get the number of unread chapters from a list.
  * This function calculates a value using the Chapter.chapterNumber field and read status of each
@@ -56,15 +85,30 @@ export function selectMostSimilarChapter(original: Chapter, options: Chapter[]):
 export function getNumberUnreadChapters(chapterList: Chapter[]): number {
  let highestRead = 0;
  let highestReleased = 0;
+ let previousChapNumber = 0;
+ let cumulativeGaps = 1;
 
- chapterList.forEach((chapter: Chapter) => {
+ const chapters = consolidateAndSortChapters(chapterList);
+
+ chapters.forEach((chapter: Chapter, index: number) => {
+ let absoluteNumber = cumulativeGaps + index;
  const chapterNumber = parseFloat(chapter.chapterNumber);
- if (chapter.read && chapterNumber > highestRead) {
- highestRead = chapterNumber;
+
+ const gap = Math.ceil(chapterNumber - previousChapNumber) - 1;
+ if (gap > 1) {
+ // A gap between chapters was found. Account for this in the absolute numbers
+ absoluteNumber += gap;
+ cumulativeGaps += gap;
+ }
+
+ if (chapter.read && absoluteNumber > highestRead) {
+ highestRead = absoluteNumber;
  }
- if (chapterNumber > highestReleased) {
- highestReleased = chapterNumber;
+ if (absoluteNumber > highestReleased) {
+ highestReleased = absoluteNumber;
  }
+
+ previousChapNumber = chapterNumber;
  });
 
  return Math.ceil(highestReleased - highestRead);