import {
  createApp,
  defineComponent,
  h,
  nextTick,
  onMounted,
  onUnmounted,
  type Component,
} from "vue";
import { afterEach, describe, expect, it } from "vitest";
import {
  above,
  back,
  createOriginScene,
  defineOriginChoreography,
  forward,
  OriginScene,
  originView,
  replace,
  under,
} from "../src";

const mountedApps: Array<ReturnType<typeof createApp>> = [];

afterEach(() => {
  for (const app of mountedApps.splice(0)) app.unmount();
  document.body.innerHTML = "";
});

function component(name: string): Component {
  return defineComponent({
    name,
    render: () => h("div", { "data-test-view": name }, name),
  });
}

const layeredMotion = defineOriginChoreography({
  name: "test-layered-motion",
  effects: ({ progress }) => ({
    source: { transform: `translateX(${-progress * 100}px)` },
    target: { transform: `translateX(${(1 - progress) * 100}px)` },
  }),
});

const partialDrawerOpen = defineOriginChoreography({
  name: "test-partial-drawer-open",
  persistAtRest: true,
  effects: ({ progress }) => ({
    source: { transform: `translateX(${progress * 66.6667}%)` },
    target: { transform: `translateX(${(progress - 1) * 66.6667}%)` },
  }),
});

const partialDrawerClose = defineOriginChoreography({
  name: "test-partial-drawer-close",
  effects: ({ progress }) => ({
    source: { transform: `translateX(${-progress * 66.6667}%)` },
    target: { transform: `translateX(${(1 - progress) * 66.6667}%)` },
  }),
});

describe("origin-relative scene graph", () => {
  it("composes X→Y and Y→Z as independent transform layers", async () => {
    const x = originView(component("X"), undefined, { key: "x" });
    const y = originView(component("Y"), undefined, { key: "y" });
    const z = originView(component("Z"), undefined, { key: "z" });
    const scene = createOriginScene({ initial: x });
    const xKey = scene.nodes.value[0]!.key;

    const xy = await scene.begin(xKey, above(y, layeredMotion));
    xy.update(0.5);
    const yz = await scene.begin(xy.targetKey, above(z, layeredMotion));
    yz.update(0.25);

    /*
     * Y inherits the target half of X→Y, then adds its own source half of
     * Y→Z. Z inherits X→Y as well, but receives Y→Z's target half.
     */
    expect(scene.styleForNode(xy.targetKey).transform).toBe(
      "translateX(50px) translateX(-25px)",
    );
    expect(scene.styleForNode(xy.targetKey)).toMatchObject({
      position: "absolute",
      inset: "0",
      width: "100%",
      height: "100%",
    });
    expect(scene.styleForNode(yz.targetKey).transform).toBe(
      "translateX(50px) translateX(75px)",
    );
    expect(scene.nodes.value.map((node) => node.view.name)).toEqual([
      "X",
      "Y",
      "Z",
    ]);
  });

  it("splices completed operations in either order without losing descendants", async () => {
    const scene = createOriginScene({
      initial: originView(component("X"), undefined, { key: "x" }),
    });
    const xKey = scene.nodes.value[0]!.key;
    const xy = await scene.begin(
      xKey,
      above(originView(component("Y"), undefined, { key: "y" }), layeredMotion),
    );
    xy.update(0.8);
    const yz = await scene.begin(
      xy.targetKey,
      above(originView(component("Z"), undefined, { key: "z" }), layeredMotion),
    );
    yz.update(0.6);

    // Completing the newer edge first parks Y while Z replaces it as the
    // visual target. Y remains mounted as Z's retained previous entry.
    await yz.finish({ commit: true, animate: false });
    expect(scene.nodes.value.map((node) => node.view.name)).toEqual([
      "X",
      "Y",
      "Z",
    ]);
    expect(
      scene.nodes.value.find((node) => node.view.name === "Y")?.state,
    ).toBe("parked");
    expect(scene.operations.value).toHaveLength(1);
    expect(scene.operations.value[0]?.targetKey).toBe(yz.targetKey);
    expect(scene.styleForNode(yz.targetKey).transform).toMatch(
      /^translateX\(19\.9.+px\)$/,
    );

    await xy.finish({ commit: true, animate: false });
    expect(
      scene.nodes.value.map((node) => [node.view.name, node.state]),
    ).toEqual([
      ["X", "parked"],
      ["Y", "parked"],
      ["Z", "active"],
    ]);
    expect(scene.operations.value).toHaveLength(0);
    expect(scene.styleForNode(yz.targetKey).transform).toBe("none");
    expect(scene.styleForNode(xKey).visibility).toBe("hidden");
  });

  it("does not remount a target when its incoming operation is collapsed", async () => {
    let yMounts = 0;
    const X = component("X");
    const Y = defineComponent({
      name: "Y",
      setup() {
        onMounted(() => {
          yMounts += 1;
        });
        return () => h("div", "Y");
      },
    });
    const Z = component("Z");
    const scene = createOriginScene({
      initial: originView(X, undefined, { key: "x" }),
    });
    const host = document.createElement("div");
    document.body.append(host);
    const app = createApp({
      render: () => h(OriginScene, { scene }),
    });
    mountedApps.push(app);
    app.mount(host);
    expect(
      (host.querySelector(".nvo-scene") as HTMLElement | null)?.style.position,
    ).toBe("relative");

    const xy = await scene.begin(
      scene.nodes.value[0]!.key,
      above(originView(Y, undefined, { key: "y" }), layeredMotion),
    );
    const yz = await scene.begin(
      xy.targetKey,
      above(originView(Z, undefined, { key: "z" }), layeredMotion),
    );
    await nextTick();
    expect(yMounts).toBe(1);
    expect(
      (host.querySelector('[data-origin-view="Y"]') as HTMLElement | null)
        ?.style.position,
    ).toBe("absolute");

    // Y remains the same flat, keyed host while X→Y disappears around it.
    await xy.finish({ commit: true, animate: false });
    await nextTick();
    expect(yMounts).toBe(1);
    expect(scene.nodes.value.map((node) => node.view.name)).toEqual([
      "X",
      "Y",
      "Z",
    ]);

    await yz.cancel({ animate: false });
    expect(
      scene.nodes.value.map((node) => [node.view.name, node.state]),
    ).toEqual([
      ["X", "parked"],
      ["Y", "active"],
    ]);
  });

  it("reuses the retained previous node and pops only the current entry on back", async () => {
    let xMounts = 0;
    let xUnmounts = 0;
    let yUnmounts = 0;

    const X = defineComponent({
      name: "X",
      props: {
        message: {
          type: String,
          required: true,
        },
      },
      setup() {
        onMounted(() => {
          xMounts += 1;
        });
        onUnmounted(() => {
          xUnmounts += 1;
        });
        return () =>
          h(
            "div",
            {
              "data-scroll": "feed",
              style: { height: "100px", overflow: "auto" },
            },
            h("div", { style: { height: "2000px" } }, "Feed"),
          );
      },
    });
    const Y = defineComponent({
      name: "Y",
      setup() {
        onUnmounted(() => {
          yUnmounts += 1;
        });
        return () => h("div", "Y");
      },
    });
    const x = originView(X, { message: "original" }, { key: "x" });
    const y = originView(Y, undefined, { key: "y" });
    const scene = createOriginScene({ initial: x });
    const host = document.createElement("div");
    document.body.append(host);
    const app = createApp({
      render: () => h(OriginScene, { scene }),
    });
    mountedApps.push(app);
    app.mount(host);
    await nextTick();

    const xKey = scene.nodes.value[0]!.key;
    const originalScroller = host.querySelector(
      '[data-scroll="feed"]',
    ) as HTMLElement;
    originalScroller.scrollTop = 842;

    const xy = await scene.begin(xKey, forward(y, layeredMotion));
    await xy.finish({ commit: true, animate: false });
    await nextTick();

    const yContext = scene.contextFor(xy.targetKey);
    expect(yContext.previous).toBe(x);
    expect(yContext.history).toEqual([x]);
    expect(xMounts).toBe(1);
    expect(xUnmounts).toBe(0);
    expect(scene.nodes.value.find((node) => node.key === xKey)?.state).toBe(
      "parked",
    );
    expect(host.querySelector('[data-scroll="feed"]')).toBe(originalScroller);
    expect(originalScroller.scrollTop).toBe(842);

    const yx = await scene.begin(xy.targetKey, back(layeredMotion));
    expect(yx.targetKey).toBe(xKey);
    await nextTick();
    expect(host.querySelector('[data-scroll="feed"]')).toBe(originalScroller);
    expect(originalScroller.scrollTop).toBe(842);

    await yx.finish({ commit: true, animate: false });
    await nextTick();
    expect(scene.nodes.value.map((node) => node.key)).toEqual([xKey]);
    expect(scene.contextFor(xKey).history).toEqual([]);
    expect(scene.nodes.value[0]?.state).toBe("active");
    expect(xMounts).toBe(1);
    expect(xUnmounts).toBe(0);
    expect(yUnmounts).toBe(1);
    expect(originalScroller.scrollTop).toBe(842);
  });

  it("re-parks the retained target when a back operation is cancelled", async () => {
    const x = originView(component("X"), undefined, { key: "x" });
    const y = originView(component("Y"), undefined, { key: "y" });
    const scene = createOriginScene({ initial: x });
    const xKey = scene.nodes.value[0]!.key;
    const xy = await scene.begin(xKey, above(y, layeredMotion));
    await xy.finish({ commit: true, animate: false });

    const yx = await scene.begin(
      xy.targetKey,
      under(x, layeredMotion, { history: "back" }),
    );
    expect(yx.targetKey).toBe(xKey);
    await yx.cancel({ animate: false });

    expect(scene.operations.value).toHaveLength(0);
    expect(
      scene.nodes.value.map((node) => [node.view.name, node.state]),
    ).toEqual([
      ["X", "parked"],
      ["Y", "active"],
    ]);
  });

  it("replaces the current entry and makes back skip the removed instance", async () => {
    let paymentUnmounts = 0;
    const home = originView(component("Home"), undefined, { key: "home" });
    const Payment = defineComponent({
      name: "Payment",
      setup() {
        onUnmounted(() => {
          paymentUnmounts += 1;
        });
        return () => h("div", "Payment");
      },
    });
    const payment = originView(Payment, undefined, { key: "payment" });
    const confirmation = originView(component("Confirmation"), undefined, {
      key: "confirmation",
    });
    const scene = createOriginScene({ initial: home });
    const host = document.createElement("div");
    document.body.append(host);
    const app = createApp({
      render: () => h(OriginScene, { scene }),
    });
    mountedApps.push(app);
    app.mount(host);
    await nextTick();
    const homeKey = scene.nodes.value[0]!.key;

    const openPayment = await scene.begin(
      homeKey,
      forward(payment, layeredMotion),
    );
    await openPayment.finish({ commit: true, animate: false });

    const confirmPayment = await scene.begin(
      openPayment.targetKey,
      replace(confirmation, layeredMotion),
    );
    await confirmPayment.finish({ commit: true, animate: false });
    await nextTick();

    expect(
      scene.nodes.value.map((node) => [node.view.name, node.state]),
    ).toEqual([
      ["Home", "parked"],
      ["Confirmation", "active"],
    ]);
    expect(paymentUnmounts).toBe(1);

    const confirmationContext = scene.contextFor(confirmPayment.targetKey);
    expect(confirmationContext.previous).toBe(home);
    expect(confirmationContext.history).toEqual([home]);

    const returnHome = await scene.begin(
      confirmPayment.targetKey,
      back(layeredMotion),
    );
    expect(returnHome.targetKey).toBe(homeKey);
    await returnHome.finish({ commit: true, animate: false });
    expect(scene.nodes.value.map((node) => node.view.name)).toEqual(["Home"]);
  });

  it("restores the current entry when an interactive replace is cancelled", async () => {
    const home = originView(component("Home"), undefined, { key: "home" });
    const payment = originView(component("Payment"), undefined, {
      key: "payment",
    });
    const confirmation = originView(component("Confirmation"), undefined, {
      key: "confirmation",
    });
    const scene = createOriginScene({ initial: home });
    const homeKey = scene.nodes.value[0]!.key;
    const openPayment = await scene.begin(
      homeKey,
      forward(payment, layeredMotion),
    );
    await openPayment.finish({ commit: true, animate: false });

    const confirmPayment = await scene.begin(
      openPayment.targetKey,
      replace(confirmation, layeredMotion),
    );
    await confirmPayment.cancel({ animate: false });

    expect(
      scene.nodes.value.map((node) => [node.view.name, node.state]),
    ).toEqual([
      ["Home", "parked"],
      ["Payment", "active"],
    ]);
    expect(scene.contextFor(openPayment.targetKey).history).toEqual([home]);
  });

  it("can replace an initial root without manufacturing history", async () => {
    const scene = createOriginScene({
      initial: originView(component("Welcome"), undefined, { key: "welcome" }),
    });
    const welcomeKey = scene.nodes.value[0]!.key;
    const replacement = await scene.begin(
      welcomeKey,
      replace(
        originView(component("Signed in"), undefined, { key: "signed-in" }),
        layeredMotion,
      ),
    );
    await replacement.finish({ commit: true, animate: false });

    expect(scene.roots.value).toEqual([replacement.targetKey]);
    expect(scene.nodes.value.map((node) => node.view.name)).toEqual([
      "Signed in",
    ]);
    expect(scene.contextFor(replacement.targetKey)).toMatchObject({
      canGoBack: false,
      history: [],
      previous: undefined,
    });
  });

  it("can replace a target while its incoming push is still settling", async () => {
    const home = originView(component("Home"), undefined, { key: "home" });
    const payment = originView(component("Payment"), undefined, {
      key: "payment",
    });
    const confirmation = originView(component("Confirmation"), undefined, {
      key: "confirmation",
    });
    const scene = createOriginScene({ initial: home });
    const homeKey = scene.nodes.value[0]!.key;
    const openPayment = await scene.begin(
      homeKey,
      forward(payment, layeredMotion),
    );
    openPayment.update(0.8, 1);

    const paymentSettlement = openPayment.finish({ commit: true });
    const confirmPayment = await scene.begin(
      openPayment.targetKey,
      replace(confirmation, layeredMotion),
    );
    await confirmPayment.finish({ commit: true, animate: false });
    await paymentSettlement;

    expect(scene.operations.value).toHaveLength(0);
    expect(
      scene.nodes.value.map((node) => [node.view.name, node.state]),
    ).toEqual([
      ["Home", "parked"],
      ["Confirmation", "active"],
    ]);
    expect(scene.contextFor(confirmPayment.targetKey).history).toEqual([home]);
  });

  it("keeps a partial push connected at rest and restores it after cancelled back", async () => {
    const page = originView(component("Page"), undefined, { key: "page" });
    const drawer = originView(component("Drawer"), undefined, {
      key: "drawer",
    });
    const scene = createOriginScene({ initial: page });
    const pageKey = scene.nodes.value[0]!.key;

    const openDrawer = await scene.begin(
      pageKey,
      forward(drawer, partialDrawerOpen),
    );
    await openDrawer.finish({ commit: true, animate: false });

    expect(scene.operations.value).toHaveLength(0);
    expect(scene.roots.value).toEqual([pageKey]);
    expect(
      scene.nodes.value.map((node) => [node.view.name, node.state]),
    ).toEqual([
      ["Page", "exposed"],
      ["Drawer", "active"],
    ]);
    expect(scene.styleForNode(pageKey).transform).toBe("translateX(66.6667%)");
    expect(scene.styleForNode(pageKey).pointerEvents).toBe("none");
    expect(scene.styleForNode(openDrawer.targetKey).transform).toBe(
      "translateX(0%)",
    );

    const closeDrawer = await scene.begin(
      openDrawer.targetKey,
      back(partialDrawerClose),
    );
    expect(scene.styleForNode(pageKey).transform).toBe("translateX(66.6667%)");
    await closeDrawer.cancel({ animate: false });

    expect(scene.operations.value).toHaveLength(0);
    expect(scene.roots.value).toEqual([pageKey]);
    expect(
      scene.nodes.value.map((node) => [node.view.name, node.state]),
    ).toEqual([
      ["Page", "exposed"],
      ["Drawer", "active"],
    ]);
    expect(scene.styleForNode(pageKey).transform).toBe("translateX(66.6667%)");

    const committedClose = await scene.begin(
      openDrawer.targetKey,
      back(partialDrawerClose),
    );
    await committedClose.finish({ commit: true, animate: false });

    expect(scene.nodes.value.map((node) => [node.key, node.state])).toEqual([
      [pageKey, "active"],
    ]);
    expect(scene.roots.value).toEqual([pageKey]);
    expect(scene.styleForNode(pageKey).transform).toBe("none");
  });

  it("hands an immediate back gesture from a settling push to the same instances", async () => {
    const x = originView(component("X"), undefined, { key: "x" });
    const y = originView(component("Y"), undefined, { key: "y" });
    const scene = createOriginScene({ initial: x });
    const xKey = scene.nodes.value[0]!.key;
    const xy = await scene.begin(xKey, above(y, layeredMotion));
    xy.update(0.8, 1);

    const forwardSettlement = xy.finish({ commit: true });
    const yx = await scene.begin(
      xy.targetKey,
      under(x, layeredMotion, { history: "back" }),
    );
    expect(yx.targetKey).toBe(xKey);
    await yx.finish({ commit: true, animate: false });
    await forwardSettlement;

    expect(scene.operations.value).toHaveLength(0);
    expect(scene.nodes.value.map((node) => [node.key, node.state])).toEqual([
      [xKey, "active"],
    ]);
  });
});