money: quick-add bar, server-filtered transactions page, CSV import dedupe + Revolut statements

src/lib/money-tracker/quick-add.ts

@@ -0,0 +1,73 @@
+export type SuggestionSource = {
+	description: string;
+	amountCents: number;
+	accountId: number | null;
+	date: string;
+};
+
+export type Suggestion = {
+	key: string;
+	description: string;
+	/** Most common amount for this description (latest wins ties). */
+	amountCents: number;
+	/** Account used most recently with this description. */
+	accountId: number | null;
+	count: number;
+	lastDate: string;
+};
+
+/** Past descriptions ranked by use, each with its usual amount and latest account. */
+export function descriptionSuggestions(rows: SuggestionSource[], today: string): Suggestion[] {
+	const groups = new Map<
+		string,
+		{
+			description: string;
+			amounts: Map<number, number>;
+			accountId: number | null;
+			count: number;
+			lastDate: string;
+			lastAmount: number;
+		}
+	>();
+	for (const row of rows) {
+		if (row.date > today) continue;
+		const key = row.description.trim().toLowerCase();
+		if (!key) continue;
+		const group = groups.get(key) ?? {
+			description: row.description.trim(),
+			amounts: new Map(),
+			accountId: row.accountId,
+			count: 0,
+			lastDate: '',
+			lastAmount: row.amountCents
+		};
+		group.count++;
+		group.amounts.set(row.amountCents, (group.amounts.get(row.amountCents) ?? 0) + 1);
+		if (row.date >= group.lastDate) {
+			group.lastDate = row.date;
+			group.description = row.description.trim();
+			group.accountId = row.accountId;
+			group.lastAmount = row.amountCents;
+		}
+		groups.set(key, group);
+	}
+	return [...groups.entries()]
+		.map(([key, group]) => {
+			let amountCents = group.lastAmount;
+			let best = group.amounts.get(amountCents) ?? 0;
+			for (const [value, uses] of group.amounts)
+				if (uses > best) {
+					best = uses;
+					amountCents = value;
+				}
+			return {
+				key,
+				description: group.description,
+				amountCents,
+				accountId: group.accountId,
+				count: group.count,
+				lastDate: group.lastDate
+			};
+		})
+		.sort((a, b) => b.count - a.count || b.lastDate.localeCompare(a.lastDate));
+}