import { describe, expect, it } from "vitest";
import {
	calculateInitiative,
	formatInitiativeModifier,
} from "../initiative.js";

describe("calculateInitiative", () => {
	it("returns positive modifier for creature with expertise (Aboleth: DEX 9, CR 10, proficiency 2)", () => {
		const result = calculateInitiative({
			dexScore: 9,
			cr: "10",
			initiativeProficiency: 2,
		});
		// DEX mod = floor((9-10)/2) = -1, PB for CR 10 = 4, -1 + 2*4 = +7
		expect(result.modifier).toBe(7);
		expect(result.passive).toBe(17);
	});

	it("returns negative modifier for low DEX with no proficiency", () => {
		const result = calculateInitiative({
			dexScore: 8,
			cr: "1",
			initiativeProficiency: 0,
		});
		// DEX mod = floor((8-10)/2) = -1, 0 * PB = 0, -1 + 0 = -1
		expect(result.modifier).toBe(-1);
		expect(result.passive).toBe(9);
	});

	it("returns zero modifier for DEX 10 with no proficiency", () => {
		const result = calculateInitiative({
			dexScore: 10,
			cr: "1",
			initiativeProficiency: 0,
		});
		expect(result.modifier).toBe(0);
		expect(result.passive).toBe(10);
	});

	it("adds single proficiency bonus (multiplier 1)", () => {
		const result = calculateInitiative({
			dexScore: 14,
			cr: "5",
			initiativeProficiency: 1,
		});
		// DEX mod = +2, PB for CR 5 = 3, 2 + 1*3 = 5
		expect(result.modifier).toBe(5);
		expect(result.passive).toBe(15);
	});

	it("adds double proficiency bonus (multiplier 2 / expertise)", () => {
		const result = calculateInitiative({
			dexScore: 14,
			cr: "5",
			initiativeProficiency: 2,
		});
		// DEX mod = +2, PB for CR 5 = 3, 2 + 2*3 = 8
		expect(result.modifier).toBe(8);
		expect(result.passive).toBe(18);
	});

	it("handles no proficiency (multiplier 0) — reduces to raw DEX modifier", () => {
		const result = calculateInitiative({
			dexScore: 14,
			cr: "5",
			initiativeProficiency: 0,
		});
		// DEX mod = +2, 0 * PB = 0, 2 + 0 = 2
		expect(result.modifier).toBe(2);
		expect(result.passive).toBe(12);
	});

	it("handles negative result even with proficiency (very low DEX)", () => {
		const result = calculateInitiative({
			dexScore: 3,
			cr: "0",
			initiativeProficiency: 1,
		});
		// DEX mod = floor((3-10)/2) = -4, PB for CR 0 = 2, -4 + 1*2 = -2
		expect(result.modifier).toBe(-2);
		expect(result.passive).toBe(8);
	});

	it("handles fractional CR values", () => {
		const result = calculateInitiative({
			dexScore: 12,
			cr: "1/4",
			initiativeProficiency: 1,
		});
		// DEX mod = +1, PB for CR 1/4 = 2, 1 + 1*2 = 3
		expect(result.modifier).toBe(3);
		expect(result.passive).toBe(13);
	});
});

describe("formatInitiativeModifier", () => {
	it("formats positive modifier with plus sign", () => {
		expect(formatInitiativeModifier(7)).toBe("+7");
	});

	it("formats negative modifier with U+2212 minus sign", () => {
		expect(formatInitiativeModifier(-1)).toBe("\u22121");
	});

	it("formats zero modifier with plus sign", () => {
		expect(formatInitiativeModifier(0)).toBe("+0");
	});
});