import type { HpRange, HpVariant } from "@initiative/domain";
import {
	combatantId,
	creatureId,
	EMPTY_UNDO_REDO_STATE,
} from "@initiative/domain";
import { describe, expect, it } from "vitest";
import { type EncounterState, encounterReducer } from "../use-encounter.js";

// An ogre with 3d6 + 6 hit points.
const RANGE: HpRange = { min: 9, average: 16, max: 24 };

function stateWithCreature(
	maxHp: number,
	currentHp: number,
	hpVariant?: HpVariant,
): EncounterState {
	return {
		encounter: {
			combatants: [
				{
					id: combatantId("c-1"),
					name: "Ogre",
					maxHp,
					currentHp,
					creatureId: creatureId("mm:ogre"),
					...(hpVariant !== undefined && { hpVariant }),
				},
			],
			activeIndex: 0,
			roundNumber: 1,
		},
		undoRedoState: EMPTY_UNDO_REDO_STATE,
		events: [],
		nextId: 1,
		lastCreatureId: null,
	};
}

function setVariant(state: EncounterState, variant: HpVariant | undefined) {
	return encounterReducer(state, {
		type: "set-hp-variant",
		id: combatantId("c-1"),
		variant,
		range: RANGE,
	});
}

describe("set-hp-variant", () => {
	it("raises max HP to the maximum roll and stores the variant", () => {
		const next = setVariant(stateWithCreature(16, 16), "max");
		const c = next.encounter.combatants[0];
		expect(c.maxHp).toBe(24);
		expect(c.currentHp).toBe(24);
		expect(c.hpVariant).toBe("max");
	});

	it("lowers max HP to the minimum roll", () => {
		const next = setVariant(stateWithCreature(16, 16), "min");
		const c = next.encounter.combatants[0];
		expect(c.maxHp).toBe(9);
		expect(c.hpVariant).toBe("min");
	});

	it("returns to the average and clears the variant", () => {
		const next = setVariant(stateWithCreature(24, 24, "max"), undefined);
		const c = next.encounter.combatants[0];
		expect(c.maxHp).toBe(16);
		expect(c.hpVariant).toBeUndefined();
	});

	it("does not rename the combatant", () => {
		const next = setVariant(stateWithCreature(16, 16), "max");
		expect(next.encounter.combatants[0].name).toBe("Ogre");
	});

	it("is undoable", () => {
		const start = stateWithCreature(16, 16);
		const next = setVariant(start, "max");
		const undone = encounterReducer(next, { type: "undo" });
		expect(undone.encounter.combatants[0].maxHp).toBe(16);
		expect(undone.encounter.combatants[0].hpVariant).toBeUndefined();
	});

	it("leaves state untouched for an unknown combatant", () => {
		const start = stateWithCreature(16, 16);
		const next = encounterReducer(start, {
			type: "set-hp-variant",
			id: combatantId("c-99"),
			variant: "max",
			range: RANGE,
		});
		expect(next).toBe(start);
	});
});