// Contract tests for runtime/skills/index.js. Run with: node --test runtime/skills
//
// We avoid spinning up a real mineflayer bot — synthetic skills are
// registered via _registerForTest and exercise every branch of runSkill:
// preconditions, timeout, exception, validate, recover.

import { test } from "node:test";
import assert from "node:assert/strict";

import { runSkill, RUNNER_CODES, _registerForTest } from "./index.js";

const ctx = {}; // skills under test ignore ctx fully

test("unknown skill returns unknown_skill code", async () => {
	const res = await runSkill("does.not.exist", ctx);
	assert.equal(res.ok, false);
	assert.equal(res.code, RUNNER_CODES.UNKNOWN_SKILL);
});

test("preconditions gate execution", async () => {
	const teardown = _registerForTest({
		id: "test.precondition-block",
		title: "blocked",
		timeoutMs: 1000,
		preconditions: () => ({ ok: false, code: "missing_x", detail: "no x" }),
		execute: async () => {
			throw new Error("should not run");
		},
	});
	try {
		const res = await runSkill("test.precondition-block", ctx);
		assert.equal(res.ok, false);
		assert.equal(res.code, "missing_x");
		assert.equal(res.detail, "no x");
	} finally {
		teardown();
	}
});

test("gather.logs precondition refuses nearby hostiles", async () => {
	const bot = { registry: { blocksByName: { oak_log: { id: 1 } } } };
	const res = await runSkill("gather.logs", {
		bot,
		snapshot: { closestHostile: { name: "drowned", distance: 6.1 } },
	});
	assert.equal(res.ok, false);
	assert.equal(res.code, "no_target");
	assert.match(res.detail, /unsafe to gather logs: drowned 6\.1 blocks away/);
});

test("preconditions that throw produce precondition_failed", async () => {
	const teardown = _registerForTest({
		id: "test.precondition-throw",
		preconditions: () => {
			throw new Error("kaboom");
		},
		execute: async () => ({ ok: true }),
	});
	try {
		const res = await runSkill("test.precondition-throw", ctx);
		assert.equal(res.ok, false);
		assert.equal(res.code, RUNNER_CODES.PRECONDITION_FAILED);
		assert.match(res.detail, /kaboom/);
	} finally {
		teardown();
	}
});

test("timeout fires and recover is called", async () => {
	let recovered = false;
	const teardown = _registerForTest({
		id: "test.timeout",
		timeoutMs: 50,
		preconditions: () => ({ ok: true }),
		execute: () =>
			new Promise((resolve) => {
				// never resolves within the timeout
				setTimeout(() => resolve({ ok: true }), 500);
			}),
		recover: () => {
			recovered = true;
			return { hint: "retry-later" };
		},
	});
	try {
		const res = await runSkill("test.timeout", ctx);
		assert.equal(res.ok, false);
		assert.equal(res.code, RUNNER_CODES.TIMEOUT);
		assert.equal(recovered, true);
		assert.deepEqual(res.recovery, { hint: "retry-later" });
	} finally {
		teardown();
	}
});

test("execute throw -> threw code with recovery hint", async () => {
	const teardown = _registerForTest({
		id: "test.throws",
		preconditions: () => ({ ok: true }),
		execute: async () => {
			throw new Error("oops");
		},
		recover: (ctx, result) => ({ saw: result.code }),
	});
	try {
		const res = await runSkill("test.throws", ctx);
		assert.equal(res.ok, false);
		assert.equal(res.code, RUNNER_CODES.THREW);
		assert.match(res.detail, /oops/);
		assert.deepEqual(res.recovery, { saw: RUNNER_CODES.THREW });
	} finally {
		teardown();
	}
});

test("happy path returns done with worldDelta", async () => {
	const teardown = _registerForTest({
		id: "test.happy",
		preconditions: () => ({ ok: true }),
		execute: async () => ({ ok: true, code: "done", detail: { count: 4 }, worldDelta: { gathered: 4 } }),
	});
	try {
		const res = await runSkill("test.happy", ctx);
		assert.equal(res.ok, true);
		assert.equal(res.code, "done");
		assert.deepEqual(res.worldDelta, { gathered: 4 });
	} finally {
		teardown();
	}
});

test("validate failure flips ok to false with validation_failed", async () => {
	let recoverArgs = null;
	const teardown = _registerForTest({
		id: "test.validate-fail",
		preconditions: () => ({ ok: true }),
		execute: async () => ({ ok: true, code: "done", worldDelta: { x: 1 } }),
		validate: () => false,
		recover: (ctx, result) => {
			recoverArgs = result;
			return null;
		},
	});
	try {
		const res = await runSkill("test.validate-fail", ctx);
		assert.equal(res.ok, false);
		assert.equal(res.code, RUNNER_CODES.VALIDATION_FAILED);
		assert.ok(recoverArgs);
		assert.equal(recoverArgs.code, RUNNER_CODES.VALIDATION_FAILED);
	} finally {
		teardown();
	}
});

test("result missing code defaults to runner DONE on success", async () => {
	const teardown = _registerForTest({
		id: "test.no-code",
		preconditions: () => ({ ok: true }),
		execute: async () => ({ ok: true }),
	});
	try {
		const res = await runSkill("test.no-code", ctx);
		assert.equal(res.ok, true);
		assert.equal(res.code, RUNNER_CODES.DONE);
	} finally {
		teardown();
	}
});