import { test } from "node:test";
import assert from "node:assert/strict";
import { compile } from "../src/core/loader.js";
import { GameWorld } from "../src/core/world.js";
import { DialogueRunner } from "../src/core/dialogue.js";
import { Emitter } from "../src/core/events.js";
import { readFileSync } from "node:fs";

const example = JSON.parse(readFileSync(new URL("../example/game.json", import.meta.url), "utf8"));

function setup() {
  const c = compile(example);
  const w = new GameWorld(c);
  const em = new Emitter();
  const lines = [];
  em.on("dialogueLine", (ev) => lines.push(ev));
  let now = 0;
  const d = new DialogueRunner(c, w, em);
  d.clock = () => now;
  return { c, w, em, d, lines, advance: (ms) => { now += ms; d.tick(now); } };
}

test("start emits first line and exposes choices", () => {
  const { d, lines } = setup();
  d.start("barkeep_intro");
  assert.equal(lines.length, 1);
  assert.equal(lines[0].speaker, "barkeep");
  const choices = d.choices();
  assert.equal(choices.length, 2);
  assert.equal(choices[0].text, "What's in the mug?");
});

test("choosing branches and auto-advancing nodes time out", () => {
  const { d, lines, advance } = setup();
  d.start("barkeep_intro");
  d.choose(0);                       // -> mug node (auto-advance, has next)
  assert.equal(lines.length, 2);
  assert.ok(lines[1].text.includes("never a mug"));
  assert.equal(d.world.flags.heardAboutMug, true);   // onEnter fired
  advance(10000);                    // hold elapsed -> back to greet
  assert.equal(lines.length, 3);
  assert.equal(d.current().node, "greet");
});

test("end choice closes the dialogue", () => {
  const { d, em } = setup();
  let ended = 0;
  em.on("dialogueEnd", () => ended++);
  d.start("barkeep_intro");
  d.choose(1);
  assert.equal(d.active, null);
  assert.equal(ended, 1);
});

test("choice conditions hide options", () => {
  const c = compile(structuredClone(example));
  c.dialogues.barkeep_intro.nodes.greet.choices[0].conditions = { flag: "hasClue" };
  const w = new GameWorld(c);
  const d = new DialogueRunner(c, w, new Emitter());
  d.start("barkeep_intro");
  assert.equal(d.choices().length, 1);
  w.flags.hasClue = true;
  assert.equal(d.choices().length, 2);
});

test("mid-dialogue state survives snapshot/restore", () => {
  const { d, w } = setup();
  d.start("barkeep_intro");
  d.choose(0);
  const snap = w.snapshot();
  assert.equal(snap.dialogueState.barkeep_intro.node, "mug");
  const w2 = new GameWorld(setup().c);
  w2.restore(snap);
  assert.equal(w2.dialogueState.barkeep_intro.node, "mug");
});

test("choice effects apply to the world", () => {
  const spec = structuredClone(example);
  spec.dialogues.barkeep_intro.nodes.greet.choices[0].effects = [{ setFlag: "askedAboutMug" }];
  const c = compile(spec);
  const w = new GameWorld(c);
  const d = new DialogueRunner(c, w, new Emitter());
  d.start("barkeep_intro");
  d.choose(0);
  assert.equal(w.flags.askedAboutMug, true);
});

test("unknown dialogue/node errors loudly", () => {
  const { d } = setup();
  assert.throws(() => d.start("nope"), /unknown dialogue/);
});