import { describe, it, expect } from "vitest";
import { signal, computed, ReactiveRoot, reactiveComponent, reactiveElement } from "../src/core/reactive.js";
import { h, createComponent } from "../src/core/h.js";
import { isUElement } from "../src/core/schema.js";
import type { UNode } from "../src/core/schema.js";

describe("ReactiveRoot.dispose()", () => {
  it("prevents future effect fires from subscribe()", () => {
    const root = new ReactiveRoot(h("div", null, "initial"));
    const received: UNode[] = [];
    root.subscribe((n) => received.push(n));
    expect(received.length).toBe(1);
    root.update(() => h("div", null, "second"));
    expect(received.length).toBe(2);
    root.dispose();
    root.update(() => h("div", null, "third"));
    expect(received.length).toBe(2);
  });

  it("prevents future effect fires from render()", () => {
    const events: { type: string; id: string; payload: unknown }[] = [];
    const root = new ReactiveRoot(h("div", null, "hello"));
    root.render((e) => events.push(e));
    expect(events.length).toBe(1);
    root.dispose();
    root.update(() => h("div", null, "world"));
    expect(events.length).toBe(1);
  });

  it("is idempotent — safe to call twice", () => {
    const root = new ReactiveRoot(h("div", null, "initial"));
    const received: UNode[] = [];
    root.subscribe((n) => received.push(n));
    root.dispose();
    root.dispose();
    root.update(() => h("div", null, "after"));
    expect(received.length).toBe(1);
  });

  it("clears renderDisposer", () => {
    const root = new ReactiveRoot(h("div", null, "x"));
    const stop = root.render(() => {});
    root.dispose();
    stop();
  });

  it("iterates all subscriber disposers and calls each", () => {
    const root = new ReactiveRoot(h("div", null, "initial"));
    const received1: UNode[] = [];
    const received2: UNode[] = [];
    root.subscribe((n) => received1.push(n));
    root.subscribe((n) => received2.push(n));
    root.dispose();
    root.update(() => h("div", null, "after"));
    expect(received1.length).toBe(1);
    expect(received2.length).toBe(1);
  });
});

describe("subscribe() unsubscribe removes from tracking", () => {
  it("unsubscribe removes disposer from tracking", () => {
    const root = new ReactiveRoot(h("div", null, "initial"));
    const received: UNode[] = [];
    const unsub = root.subscribe((n) => received.push(n));
    expect(received.length).toBe(1);
    unsub();
    root.update(() => h("div", null, "after-disconnect"));
    expect(received.length).toBe(1);
  });

  it("unsubscribe is idempotent — safe to call twice", () => {
    const root = new ReactiveRoot(h("div", null, "initial"));
    const received: UNode[] = [];
    const unsub = root.subscribe((n) => received.push(n));
    unsub();
    unsub();
    root.update(() => h("div", null, "after"));
    expect(received.length).toBe(1);
  });

  it("other subscribers still fire after one unsubscribes", () => {
    const root = new ReactiveRoot(h("div", null, "initial"));
    const received1: UNode[] = [];
    const received2: UNode[] = [];
    const unsub1 = root.subscribe((n) => received1.push(n));
    root.subscribe((n) => received2.push(n));
    unsub1();
    root.update(() => h("div", null, "updated"));
    expect(received1.length).toBe(1);
    expect(received2.length).toBe(2);
  });
});

describe("reactiveComponent.dispose()", () => {
  it("prevents future computed evaluations", () => {
    const MyComp = createComponent("MyComp", (props) => h("div", null, props.text as string));
    const propsSignal = signal({ text: "hello" });
    let evalCount = 0;
    const nodeSignal = computed(() => {
      evalCount++;
      return MyComp(propsSignal.value);
    });
    const node = nodeSignal.value;
    expect(evalCount).toBe(1);
    expect(isUElement(node)).toBe(true);

    const reactive = reactiveComponent(MyComp, propsSignal);
    reactive.dispose();
    propsSignal.value = { text: "world" };
    expect(reactive.signal.value).toBeUndefined();
  });

  it("is idempotent — safe to call twice", () => {
    const MyComp = createComponent("MyComp", (props) => h("div", null, props.text as string));
    const propsSignal = signal({ text: "hello" });
    const reactive = reactiveComponent(MyComp, propsSignal);
    reactive.dispose();
    reactive.dispose();
  });
});

describe("reactiveElement.dispose()", () => {
  it("cleans up the underlying computed subscription", () => {
    const propsSignal = signal({ class: "initial" });
    const childSignal = signal<UNode>("child-text");
    const reactive = reactiveElement("div", propsSignal, [childSignal]);
    expect(reactive.signal.value).toBeDefined();
    reactive.dispose();
    expect(reactive.signal.value).toBeUndefined();
  });

  it("is idempotent — safe to call twice", () => {
    const propsSignal = signal({});
    const reactive = reactiveElement("div", propsSignal, []);
    reactive.dispose();
    reactive.dispose();
  });
});

describe("render() disposes previous render effect on re-call", () => {
  it("calling render() twice disposes the first effect", () => {
    const root = new ReactiveRoot(h("div", null, "initial"));
    const events1: unknown[] = [];
    const events2: unknown[] = [];
    root.render(() => events1.push(1));
    expect(events1.length).toBe(1);
    root.render(() => events2.push(2));
    expect(events2.length).toBe(1);
    root.update(() => h("div", null, "after"));
    expect(events1.length).toBe(1);
    expect(events2.length).toBe(2);
  });
});