import assert from "node:assert/strict";
import test from "node:test";
import { WebSocket } from "ws";
import { LinkRegistry } from "../src/link-server.js";
import { handleMcpRequest } from "../src/mcp-server.js";

test("probe-computers returns no computers message when registry is empty", async () => {
  const registry = new LinkRegistry();
  assert.equal(await registry.probeComputers(10), "No computers connected.");
});

test("probe-computers aggregates multiple successful responses", async () => {
  const registry = new LinkRegistry();
  const computer1 = new FakeSocket();
  const computer2 = new FakeSocket();

  registry.register({ computerId: 12, label: "base-turtle", ws: computer1 as unknown as WebSocket, connectedAt: 1, lastSeenAt: 1 });
  registry.register({ computerId: 13, label: "miner-1", ws: computer2 as unknown as WebSocket, connectedAt: 1, lastSeenAt: 1 });

  const promise = registry.probeComputers(50);
  computer1.respond(registry, 12, "pong from 12 (Label: base-turtle)");
  computer2.respond(registry, 13, "pong from 13 (Label: miner-1)");

  assert.equal(await promise, "pong from 12 (Label: base-turtle)\npong from 13 (Label: miner-1)");
});

test("probe-computers reports timeout for a connected computer that does not answer", async () => {
  const registry = new LinkRegistry();
  registry.register({ computerId: 14, label: "farm-turtle", ws: new FakeSocket() as unknown as WebSocket, connectedAt: 1, lastSeenAt: 1 });

  assert.equal(await registry.probeComputers(5), "timeout from 14 (Label: farm-turtle)");
});

test("MCP tool call returns text content", async () => {
  const registry = new LinkRegistry();
  const response = await handleMcpRequest(
    { jsonrpc: "2.0", id: 1, method: "tools/call", params: { name: "probe-computers", arguments: {} } },
    registry,
    10,
  );

  assert.deepEqual(response, {
    jsonrpc: "2.0",
    id: 1,
    result: { content: [{ type: "text", text: "No computers connected." }] },
  });
});

class FakeSocket {
  sent: unknown[] = [];

  send(data: unknown): void {
    this.sent.push(data);
  }

  close(): void {
    return;
  }

  respond(registry: LinkRegistry, computerId: number, result: string): void {
    const last = this.sent.at(-1);
    assert.equal(typeof last, "string");
    const request = JSON.parse(last as string) as { id: string };
    registry.handleFrame(this as unknown as WebSocket, JSON.stringify({ type: "response", id: request.id, ok: true, result }));

    assert.equal(computerId > 0, true);
  }
}