import { describe, expect, it } from "vitest";
import { hpForVariant, hpRange } from "../hp-range.js";

describe("hpRange", () => {
	it("derives min and max from a formula with a positive modifier", () => {
		const range = hpRange({ average: 16, formula: "3d6 + 6" });
		expect(range).toEqual({ min: 9, average: 16, max: 24 });
	});

	it("derives min and max from a formula without a modifier", () => {
		const range = hpRange({ average: 40, formula: "9d8" });
		expect(range).toEqual({ min: 9, average: 40, max: 72 });
	});

	it("subtracts a negative modifier", () => {
		const range = hpRange({ average: 45, formula: "10d8 - 5" });
		expect(range).toEqual({ min: 5, average: 45, max: 75 });
	});

	it("treats an en dash as a minus sign", () => {
		// Bundled bestiary data contains e.g. "2d6 – 2" (U+2013).
		const range = hpRange({ average: 5, formula: "2d6 – 2" });
		expect(range).toEqual({ min: 1, average: 5, max: 10 });
	});

	it("never drops below 1 HP when the modifier exceeds the dice", () => {
		const range = hpRange({ average: 1, formula: "1d4 - 10" });
		expect(range?.min).toBe(1);
		expect(range?.max).toBe(1);
	});

	it("handles large pools without whitespace", () => {
		expect(hpRange({ average: 256, formula: "19d12+133" })).toEqual({
			min: 152,
			average: 256,
			max: 361,
		});
	});

	it("returns null for a missing formula", () => {
		expect(hpRange({ average: 7, formula: "" })).toBeNull();
	});

	it("returns null for prose instead of a dice pool", () => {
		expect(
			hpRange({ average: 0, formula: "equal to the summoner's" }),
		).toBeNull();
	});

	it("returns null for a flat number", () => {
		expect(hpRange({ average: 50, formula: "50" })).toBeNull();
	});

	it("returns null for a pool with zero dice or zero sides", () => {
		expect(hpRange({ average: 0, formula: "0d6" })).toBeNull();
		expect(hpRange({ average: 0, formula: "2d0" })).toBeNull();
	});

	it("returns null for compound formulas it cannot reason about", () => {
		expect(hpRange({ average: 20, formula: "2d6 + 2d8" })).toBeNull();
	});
});

describe("hpForVariant", () => {
	const range = { min: 9, average: 16, max: 24 };

	it("returns the average when no variant is set", () => {
		expect(hpForVariant(range, undefined)).toBe(16);
	});

	it("returns the minimum for the min variant", () => {
		expect(hpForVariant(range, "min")).toBe(9);
	});

	it("returns the maximum for the max variant", () => {
		expect(hpForVariant(range, "max")).toBe(24);
	});
});