3 files changed, 100 insertions, 16 deletions

diff --git a/apps/proxy/src/index.js b/apps/proxy/src/index.js
index 4f18ba44..26121f10 100644
--- a/apps/proxy/src/index.js
+++ b/apps/proxy/src/index.js
@@ -135,6 +135,7 @@ const parseMangaPayload = async (request) => {
 	return manga
 		.map((entry) => ({
 			anilistId: Number(entry?.anilistId),
+			progress: entry?.progress ? Number(entry.progress) : 0,
 			status: String(entry?.status || ""),
 			startYear: entry?.startYear ? Number(entry.startYear) : null,
 			nativeTitle: entry?.nativeTitle || null,
@@ -203,6 +204,43 @@ const queueBootstrap = (env, manga) =>
 		})
 		.filter(Boolean);
 
+const parseOptionalNumber = (value) => {
+	if (value === null || value === undefined || value === "") return null;
+
+	const number = Number.parseFloat(String(value));
+
+	return Number.isFinite(number) ? number : null;
+};
+
+const recommendedVolumeText = (volumeChapterBoundaries, progress) => {
+	if (!volumeChapterBoundaries || !Number.isFinite(progress) || progress <= 0)
+		return null;
+
+	let recommended = null;
+	let recommendedNumber = null;
+
+	for (const [volumeText, chapterBoundary] of Object.entries(
+		volumeChapterBoundaries,
+	)) {
+		const volumeNumber = parseOptionalNumber(volumeText);
+		const boundaryNumber = parseOptionalNumber(chapterBoundary);
+
+		if (
+			volumeNumber === null ||
+			boundaryNumber === null ||
+			boundaryNumber > progress
+		)
+			continue;
+
+		if (recommendedNumber === null || volumeNumber > recommendedNumber) {
+			recommended = String(volumeNumber);
+			recommendedNumber = volumeNumber;
+		}
+	}
+
+	return recommended;
+};
+
 const handleMangaChapterCounts = async (request, env, ctx) => {
 	if (!hasSupabaseConfig(env))
 		return jsonResponse(
@@ -215,25 +253,35 @@ const handleMangaChapterCounts = async (request, env, ctx) => {
 
 	if (!manga.length) return jsonResponse(request, { data: {} });
 
+	const mangaById = new Map(manga.map((entry) => [entry.anilistId, entry]));
 	const anilistIds = manga.map((entry) => entry.anilistId);
 	const [existingRows, failureRows] = await Promise.all([
 		getMangadexRowsByAniListIds(env, anilistIds),
 		getMangadexFailureRowsByAniListIds(env, anilistIds),
 	]);
-	const existingIds = new Set(existingRows.map((row) => row.anilist_id));
+	const existingRowsById = new Map(
+		existingRows.map((row) => [row.anilist_id, row]),
+	);
 	const recentFailures = new Set(
 		failureRows
 			.filter((row) => isRecentFailure(row, bootstrapRetryMinutes(env)))
 			.map((row) => row.anilist_id),
 	);
-	const missingRows = manga.filter(
-		(entry) =>
-			!existingIds.has(entry.anilistId) && !recentFailures.has(entry.anilistId),
-	);
-	const pendingRows = missingRows.filter((entry) =>
+	const rowsNeedingBackfill = manga.filter((entry) => {
+		const row = existingRowsById.get(entry.anilistId);
+
+		if (!row) return !recentFailures.has(entry.anilistId);
+
+		return (
+			entry.progress > 0 &&
+			row.volume_chapter_boundaries === null &&
+			!recentFailures.has(entry.anilistId)
+		);
+	});
+	const pendingRows = rowsNeedingBackfill.filter((entry) =>
 		bootstrapInFlight.has(entry.anilistId),
 	);
-	const queueableRows = missingRows.filter(
+	const queueableRows = rowsNeedingBackfill.filter(
 		(entry) => !bootstrapInFlight.has(entry.anilistId),
 	);
 
@@ -245,15 +293,21 @@ const handleMangaChapterCounts = async (request, env, ctx) => {
 		);
 
 	const data = Object.fromEntries(
-		existingRows.map((row) => [
-			String(row.anilist_id),
-			{
-				chapter: row.latest_en_chapter_number,
-				...(row.latest_en_volume_text === null
-					? {}
-					: { volumeText: row.latest_en_volume_text }),
-			},
-		]),
+		existingRows.map((row) => {
+			const entry = mangaById.get(row.anilist_id);
+			const volumeText = recommendedVolumeText(
+				row.volume_chapter_boundaries,
+				entry?.progress || 0,
+			);
+
+			return [
+				String(row.anilist_id),
+				{
+					chapter: row.latest_en_chapter_number,
+					...(volumeText === null ? {} : { volumeText }),
+				},
+			];
+		}),
 	);
 	const pending = [
 		...new Set(
diff --git a/apps/proxy/src/mangadex.js b/apps/proxy/src/mangadex.js
index d2a42154..dea33e70 100644
--- a/apps/proxy/src/mangadex.js
+++ b/apps/proxy/src/mangadex.js
@@ -223,9 +223,37 @@ const chooseLatestAggregateChapter = (volumes) => {
 	return latest;
 };
 
+const buildVolumeChapterBoundaries = (volumes) => {
+	const boundaries = {};
+
+	for (const [volumeKey, volumeEntry] of Object.entries(volumes || {})) {
+		const chapters = volumeEntry?.chapters || {};
+
+		for (const chapterEntry of Object.values(chapters)) {
+			const volumeText =
+				chapterEntry?.volume || volumeEntry?.volume || volumeKey || null;
+			const volumeNumber = parseOptionalNumber(volumeText);
+			const chapterNumber = parseOptionalNumber(chapterEntry?.chapter || null);
+
+			if (volumeNumber === null || chapterNumber === null) continue;
+
+			const key = String(volumeNumber);
+			const current = boundaries[key];
+
+			if (current === undefined || chapterNumber > current)
+				boundaries[key] = chapterNumber;
+		}
+	}
+
+	return Object.keys(boundaries).length ? boundaries : null;
+};
+
 const buildIndexedRow = (manga, mangadexId, aggregateResponse) => {
 	const now = new Date().toISOString();
 	const latest = chooseLatestAggregateChapter(aggregateResponse?.volumes);
+	const volumeChapterBoundaries = buildVolumeChapterBoundaries(
+		aggregateResponse?.volumes,
+	);
 
 	return {
 		anilist_id: manga.anilistId,
@@ -233,6 +261,7 @@ const buildIndexedRow = (manga, mangadexId, aggregateResponse) => {
 		latest_en_chapter_text: latest?.chapterText || null,
 		latest_en_chapter_number: latest?.chapterNumber || null,
 		latest_en_volume_text: latest?.volumeText || null,
+		volume_chapter_boundaries: volumeChapterBoundaries,
 		latest_en_chapter_id: latest?.chapterId || null,
 		latest_chapter_updated_at: now,
 		last_seen_at: now,
diff --git a/apps/proxy/src/supabase.js b/apps/proxy/src/supabase.js
index 314caf59..b0038844 100644
--- a/apps/proxy/src/supabase.js
+++ b/apps/proxy/src/supabase.js
@@ -4,6 +4,7 @@ const INDEX_COLUMNS = [
 	"latest_en_chapter_text",
 	"latest_en_chapter_number",
 	"latest_en_volume_text",
+	"volume_chapter_boundaries",
 	"latest_en_chapter_id",
 	"latest_chapter_updated_at",
 	"last_seen_at",