// diag.physics — one-shot ground truth probe. Tests whether
// setControlState("forward"), setControlState("jump"), and bot.dig
// actually do anything on this server. Writes results to the diary so
// the operator can inspect later. NOT for production loops — it has
// side effects (1-2 blocks moved if forward works) and we don't want
// to dispatch it every tick.
//
// Triggered by: explicit IPC command (cmd:probe-physics) or by the
// curriculum once if the bot has been "working" but its position
// hasn't changed by more than 4 blocks in 5 min. We add the curriculum
// trigger in a follow-up.

import { info, warn } from "../log.js";
import { appendDiary } from "../state-store.js";

function withTimeout(promise, ms, label) {
	let timer;
	const timeout = new Promise((_, reject) => {
		timer = setTimeout(() => reject(new Error(`${label} timed out after ${ms / 1000}s`)), ms);
	});
	return Promise.race([promise, timeout]).finally(() => clearTimeout(timer));
}

async function probeForward(bot, durationMs = 2_000) {
	const before = bot.entity.position.clone();
	try {
		bot.setControlState("forward", true);
		await new Promise((r) => setTimeout(r, durationMs));
	} finally {
		bot.setControlState("forward", false);
	}
	const after = bot.entity.position;
	const dx = after.x - before.x;
	const dz = after.z - before.z;
	const dist = Math.hypot(dx, dz);
	return { before, after: after.clone(), dist, works: dist > 0.5 };
}

async function probeJump(bot) {
	const startY = bot.entity.position.y;
	let maxY = startY;
	const start = Date.now();
	try {
		bot.setControlState("jump", true);
		while (Date.now() - start < 800) {
			await new Promise((r) => setTimeout(r, 50));
			if (bot.entity.position.y > maxY) maxY = bot.entity.position.y;
		}
	} finally {
		bot.setControlState("jump", false);
	}
	return { startY, maxY, deltaY: maxY - startY, works: maxY - startY > 0.4 };
}

async function probeDig(bot) {
	const ds = ["sand", "dirt", "grass_block", "stone", "cobblestone", "gravel", "oak_log", "oak_leaves", "leaves"];
	const target = bot.findBlock({
		matching: (b) => b && b.position && ds.includes(b.name) && b.position.y >= bot.entity.position.y - 3,
		maxDistance: 6,
	});
	if (!target) return { works: false, reason: "no soft block within 6 to test on" };

	const tPos = target.position.clone();
	const tName = target.name;
	try {
		await withTimeout(bot.lookAt(tPos.offset(0.5, 0.5, 0.5), true), 2_000, "lookAt");
	} catch {}
	try {
		await withTimeout(bot.dig(target), 12_000, "dig");
	} catch (e) {
		return { works: false, reason: `dig threw: ${e.message}`, name: tName, at: tPos };
	}
	const after = bot.blockAt(tPos);
	const gone = !after || after.name === "air" || after.name === "cave_air" || after.name === "void_air";
	return { works: gone, before: tName, after: after?.name ?? "(none)", at: tPos };
}

export const skill = Object.freeze({
	id: "diag.physics",
	title: "Probe forward/jump/dig and report",
	timeoutMs: 30_000,
	preconditions(ctx) {
		if (!ctx?.bot) return { ok: false, code: "no_bot", detail: "bot missing" };
		return { ok: true };
	},
	async execute(ctx) {
		const bot = ctx.bot;
		info("action", "diag.physics: starting probe");

		const fwd = await probeForward(bot);
		info("action", `diag.physics: forward Δ=${fwd.dist.toFixed(2)} (${fwd.works ? "OK" : "BROKEN"})`);

		const jmp = await probeJump(bot);
		info("action", `diag.physics: jump ΔY=${jmp.deltaY.toFixed(2)} (${jmp.works ? "OK" : "BROKEN"})`);

		const dig = await probeDig(bot);
		info("action", `diag.physics: dig ${dig.before ?? "?"}→${dig.after ?? "?"} (${dig.works ? "OK" : "BROKEN"}: ${dig.reason ?? ""})`);

		const summary = `physics probe: forward=${fwd.works ? "ok" : "BROKEN"}(Δ${fwd.dist.toFixed(1)}) jump=${jmp.works ? "ok" : "BROKEN"}(Δy${jmp.deltaY.toFixed(1)}) dig=${dig.works ? "ok" : "BROKEN"}(${dig.before ?? "no-target"}→${dig.after ?? "?"})`;
		appendDiary(summary);

		return {
			ok: true,
			code: "done",
			detail: {
				forward: fwd,
				jump: jmp,
				dig: dig,
			},
			worldDelta: {
				probe: {
					forwardWorks: fwd.works,
					jumpWorks: jmp.works,
					digWorks: dig.works,
				},
			},
		};
	},
});