nEngine/packages/mcp/test/player-namespace.test.ts

import { mkdtemp, mkdir, rm, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { describe, expect, it } from "vitest";
import { createEngine, type CropDef, type DialogueDef, type ItemDef, type PlantingSystem, type ShopDef } from "@nengine/core";
import { createEngineNamespaces, McpGateway } from "../src/index.js";

const TIME_YAML = [
  "id: default",
  "dayLengthTicks: 480",
  "seasons:",
  "  - { name: spring, dayCount: 28 }",
  "start: { day: 1, season: spring }",
  "",
].join("\n");

const FARM_YAML = [
  "id: farm",
  "width: 5",
  "height: 5",
  'tilesetRef: "tiles"',
  "spawn: { x: 0, y: 0 }",
  "layers:",
  "  - name: ground",
  "    data:",
  "      - [grass, grass, water, water, water]",
  "      - [grass, grass, water, water, water]",
  "      - [grass, grass, grass, grass, grass]",
  "      - [grass, grass, grass, grass, grass]",
  "      - [grass, grass, grass, grass, grass]",
  "",
].join("\n");

const PARSNIP_SEED: ItemDef = { id: "parsnip-seed", name: "Parsnip Seed", kind: "seed", stackable: true };
const PARSNIP: ItemDef = { id: "parsnip", name: "Parsnip", kind: "material", stackable: true };

const PARSNIP_CROP: CropDef = {
  id: "parsnip",
  seedItem: "parsnip-seed",
  stages: [
    { name: "sprout", days: 1, waterRequired: true },
    { name: "mature", days: 1, waterRequired: false },
  ],
  seasons: ["spring"],
  drops: [{ itemId: "parsnip", qty: 1 }],
};

const GENERAL_STORE: ShopDef = {
  id: "general-store",
  buys: [{ itemId: "parsnip", price: 30 }],
  sells: [{ itemId: "parsnip-seed", price: 20, stock: 99 }],
};

const WELCOME: DialogueDef = {
  id: "welcome",
  startNode: "hello",
  nodes: [
    { id: "hello", text: "Welcome!", choices: [{ text: "Thanks", to: "farewell" }] },
    { id: "farewell", text: "See ya" },
  ],
};

interface Setup {
  engine: ReturnType<typeof createEngine>;
  gateway: McpGateway;
  close: () => Promise<void>;
}

async function setup(): Promise<Setup> {
  const tmp = await mkdtemp(join(tmpdir(), "farm-player-ns-"));
  await mkdir(join(tmp, "maps"), { recursive: true });
  await writeFile(join(tmp, "time.yaml"), TIME_YAML);
  await writeFile(join(tmp, "maps", "farm.yaml"), FARM_YAML);

  const engine = createEngine({ contentDir: tmp });
  const gateway = new McpGateway();
  for (const namespace of createEngineNamespaces(engine, { gateway })) {
    gateway.register(namespace);
  }
  await engine.start();
  engine.registry.register("item", PARSNIP_SEED);
  engine.registry.register("item", PARSNIP);
  engine.registry.register("crop", PARSNIP_CROP);
  engine.registry.register("shop", GENERAL_STORE);
  engine.registry.register("dialogue", WELCOME);
  return {
    engine,
    gateway,
    close: async () => {
      await engine.stop();
      await rm(tmp, { recursive: true, force: true });
    },
  };
}

async function callText(gateway: McpGateway, name: string, args: Record<string, unknown> = {}): Promise<{
  ok: boolean;
  text: string;
}> {
  const result = await gateway.callTool(name, args);
  return { ok: result.isError !== true, text: result.content[0]?.text ?? "" };
}

describe("player namespace", () => {
  it("player.intent move relocates the player entity", async () => {
    const { engine, gateway, close } = await setup();
    try {
      const moved = await callText(gateway, "player.intent", { action: "move", tile: { x: 3, y: 2 } });
      expect(moved.ok).toBe(true);
      expect(JSON.parse(moved.text)).toEqual({ action: "move", tile: { x: 3, y: 2 }, ok: true, detail: "moved to (3,2)" });
      expect(engine.world.get("player")).toMatchObject({ x: 3, y: 2 });
    } finally {
      await close();
    }
  });

  it("player.intent interact follows the priority order: till → sow → water → harvest", async () => {
    const { engine, gateway, close } = await setup();
    try {
      const inv = engine.systems.get("inventory");
      const growth = engine.systems.get("growth");
      if (!inv || !growth) throw new Error("systems not booted");

      const tilled = await callText(gateway, "player.intent", { action: "interact", tile: { x: 2, y: 2 } });
      expect(JSON.parse(tilled.text)).toMatchObject({ ok: true, detail: "tilled plot" });

      inv.give("parsnip-seed", 1);
      const sown = await callText(gateway, "player.intent", { action: "interact", tile: { x: 2, y: 2 } });
      expect(JSON.parse(sown.text)).toMatchObject({ ok: true, detail: "sowed Parsnip Seed" });
      expect(inv.count("parsnip-seed")).toBe(0);

      const watered = await callText(gateway, "player.intent", { action: "interact", tile: { x: 2, y: 2 } });
      expect(JSON.parse(watered.text)).toMatchObject({ ok: true, detail: "watered plot" });

      const notReady = await callText(gateway, "player.intent", { action: "interact", tile: { x: 2, y: 2 } });
      expect(notReady.ok).toBe(false);
      expect(notReady.text).toMatch(/player\.intent: crop parsnip is not ready to harvest/);

      const planting = engine.systems.get<PlantingSystem>("planting");
      if (!planting) throw new Error("planting system not booted");
      growth.forceStage("plot:2:2", 1);
      const harvested = await callText(gateway, "player.intent", { action: "interact", tile: { x: 2, y: 2 } });
      expect(JSON.parse(harvested.text)).toMatchObject({ ok: true, detail: "harvested parsnip" });
      expect(inv.count("parsnip")).toBe(1);
    } finally {
      await close();
    }
  });

  it("player.intent validates action and tile arguments", async () => {
    const { gateway, close } = await setup();
    try {
      const badAction = await callText(gateway, "player.intent", { action: "dance", tile: { x: 1, y: 1 } });
      expect(badAction.ok).toBe(false);
      expect(badAction.text).toMatch(/action must be one of "move", "interact", "buy", "sell", "talk", "choose", "select-seed"/);

      const badTile = await callText(gateway, "player.intent", { action: "move", tile: { x: 1.5, y: 0 } });
      expect(badTile.ok).toBe(false);
      expect(badTile.text).toMatch(/non-negative integers/);

      const water = await callText(gateway, "player.intent", { action: "move", tile: { x: 2, y: 0 } });
      expect(water.ok).toBe(false);
      expect(water.text).toMatch(/player\.intent: intent\.move: tile \(2,0\) is not walkable/);
    } finally {
      await close();
    }
  });

  it("resource player://state reads the live player entity", async () => {
    const { gateway, close } = await setup();
    try {
      await callText(gateway, "player.intent", { action: "move", tile: { x: 4, y: 4 } });
      const state = await gateway.readResource("player://state");
      expect(JSON.parse(state.contents[0]?.text ?? "{}")).toMatchObject({ id: "player", type: "player", x: 4, y: 4 });
    } finally {
      await close();
    }
  });

  it("player.* exposes no prompts (runtime-entity namespace)", async () => {
    const { gateway, close } = await setup();
    try {
      const prompts = gateway.listPrompts().map((prompt) => prompt.name);
      expect(prompts.some((name) => name.startsWith("player."))).toBe(false);
    } finally {
      await close();
    }
  });

  it("player.intent buy/sell/talk/choose/select-seed drive the extended actions", async () => {
    const { engine, gateway, close } = await setup();
    try {
      const player = engine.world.get("player");
      if (!player) throw new Error("player entity not seeded");
      player.gold = 100;

      const bought = await callText(gateway, "player.intent", {
        action: "buy",
        shopId: "general-store",
        itemId: "parsnip-seed",
        qty: 2,
      });
      expect(bought.ok).toBe(true);
      expect(JSON.parse(bought.text)).toMatchObject({
        action: "buy",
        ok: true,
        detail: { shopId: "general-store", itemId: "parsnip-seed", qty: 2, total: 40, gold: 60 },
      });

      const missingItem = await callText(gateway, "player.intent", { action: "buy", shopId: "general-store" });
      expect(missingItem.ok).toBe(false);
      expect(missingItem.text).toMatch(/buy requires itemId/);

      engine.world.create({ id: "npc:clerk", type: "npc", x: 3, y: 3, dialogue: "welcome" });
      const talked = await callText(gateway, "player.intent", { action: "talk", npcId: "npc:clerk" });
      expect(talked.ok).toBe(true);
      expect(JSON.parse(talked.text)).toMatchObject({ action: "talk", ok: true, detail: { dialogueId: "welcome" } });

      const chosen = await callText(gateway, "player.intent", { action: "choose", index: 0 });
      expect(chosen.ok).toBe(true);
      expect(JSON.parse(chosen.text)).toMatchObject({ action: "choose", ok: true, detail: { nodeId: "farewell" } });

      const selected = await callText(gateway, "player.intent", { action: "select-seed", seedItemId: "parsnip-seed" });
      expect(selected.ok).toBe(true);
      expect(JSON.parse(selected.text)).toMatchObject({
        action: "select-seed",
        ok: true,
        detail: { selectedSeed: "parsnip-seed" },
      });
      expect(engine.world.get("player")).toMatchObject({ selectedSeed: "parsnip-seed" });

      const notASeed = await callText(gateway, "player.intent", { action: "select-seed", seedItemId: "hoe" });
      expect(notASeed.ok).toBe(false);
      expect(notASeed.text).toMatch(/hoe is not a seed item/);
    } finally {
      await close();
    }
  });
});