import { test } from "node:test";
import assert from "node:assert/strict";
import { calculateBucketUsage } from "../lib/shared/bucket-usage";

const today = "2026-02-11";

test("calculateBucketUsage matches tag subset", () => {
    const bucket = { tags: ["groceries", "weekly"], necessity: "BOTH" as const, windowDays: 30 };
    const entries = [
        { amountDollars: 20, occurredAt: "2026-02-10", necessity: "NECESSARY" as const, tags: ["groceries", "weekly", "extra"], entryType: "SPENDING" as const },
        { amountDollars: 15, occurredAt: "2026-02-10", necessity: "NECESSARY" as const, tags: ["groceries"], entryType: "SPENDING" as const }
    ];

    const result = calculateBucketUsage(bucket, entries, today);
    assert.equal(result.totalUsage, 20);
    assert.equal(result.matchedCount, 1);
});

test("calculateBucketUsage ignores non-spending entries", () => {
    const bucket = { tags: ["rent"], necessity: "BOTH" as const, windowDays: 30 };
    const entries = [
        { amountDollars: 500, occurredAt: "2026-02-10", necessity: "NECESSARY" as const, tags: ["rent"], entryType: "INCOME" as const }
    ];

    const result = calculateBucketUsage(bucket, entries, today);
    assert.equal(result.totalUsage, 0);
    assert.equal(result.matchedCount, 0);
});

test("calculateBucketUsage applies windowDays filtering", () => {
    const bucket = { tags: [], necessity: "BOTH" as const, windowDays: 3 };
    const entries = [
        { amountDollars: 10, occurredAt: "2026-02-11", necessity: "NECESSARY" as const, tags: [], entryType: "SPENDING" as const },
        { amountDollars: 10, occurredAt: "2026-02-09", necessity: "NECESSARY" as const, tags: [], entryType: "SPENDING" as const },
        { amountDollars: 10, occurredAt: "2026-02-08", necessity: "NECESSARY" as const, tags: [], entryType: "SPENDING" as const }
    ];

    const result = calculateBucketUsage(bucket, entries, today);
    assert.equal(result.totalUsage, 20);
    assert.equal(result.matchedCount, 2);
});

test("calculateBucketUsage accepts all when bucket necessity is BOTH", () => {
    const bucket = { tags: [], necessity: "BOTH" as const, windowDays: 30 };
    const entries = [
        { amountDollars: 12, occurredAt: "2026-02-10", necessity: "NECESSARY" as const, tags: [], entryType: "SPENDING" as const },
        { amountDollars: 8, occurredAt: "2026-02-10", necessity: "UNNECESSARY" as const, tags: [], entryType: "SPENDING" as const }
    ];

    const result = calculateBucketUsage(bucket, entries, today);
    assert.equal(result.totalUsage, 20);
    assert.equal(result.matchedCount, 2);
});

test("calculateBucketUsage halves BOTH entries when bucket not BOTH", () => {
    const bucket = { tags: [], necessity: "NECESSARY" as const, windowDays: 30 };
    const entries = [
        { amountDollars: 10, occurredAt: "2026-02-10", necessity: "BOTH" as const, tags: [], entryType: "SPENDING" as const },
        { amountDollars: 10, occurredAt: "2026-02-10", necessity: "UNNECESSARY" as const, tags: [], entryType: "SPENDING" as const }
    ];

    const result = calculateBucketUsage(bucket, entries, today);
    assert.equal(result.totalUsage, 5);
    assert.equal(result.matchedCount, 1);
});