// @vitest-environment happy-dom
import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";

import { emptyLayout, leaves, type Layout } from "./layout.js";
import { splitLeaf } from "./layout.js";
import { createMultiView, type MultiView } from "./multiview.js";
import type { ConnectionPool } from "./connections.js";
import type { SidebarHandle } from "./catalog.js";

function stubFetch(): void {
  vi.stubGlobal(
    "fetch",
    vi.fn(async (input: RequestInfo | URL) => {
      const url = String(input);
      const body = url.includes("/api/info")
        ? { hostname: "h", version: "0", home_dir: "/home/user", presets: [] }
        : url.includes("/api/projects")
          ? []
          : url.includes("/api/names")
            ? { names: ["allegro-cello"] }
            : undefined;
      return new Response(JSON.stringify(body), { status: 200 });
    }),
  );
}

function fakePool(): ConnectionPool {
  return {
    setVisible() {},
    setFocus() {},
  } as unknown as ConnectionPool;
}

function fakeSidebar(): SidebarHandle {
  return {
    el: document.createElement("aside"),
    setActive() {},
    setHighlights() {},
    dispose() {},
  };
}

function makeMv(layout: Layout): MultiView {
  return createMultiView({
    pool: fakePool(),
    layout,
    sidebar: fakeSidebar(),
    infoFor: () => ({ name: "sess", command: "bash" }),
    onDisconnect: () => {},
    renderWelcome: () => document.createElement("div"),
  });
}

/** Drain the microtask queue so the draft form's async seed application lands. */
async function flush(): Promise<void> {
  for (let i = 0; i < 20; i++) await Promise.resolve();
}

describe("multiview openDraft (#62)", () => {
  beforeEach(() => {
    stubFetch();
    document.body.replaceChildren();
  });

  afterEach(() => {
    vi.unstubAllGlobals();
  });

  it("turns an empty tab into a draft pane", async () => {
    const layout = emptyLayout();
    const mv = makeMv(layout);
    document.body.appendChild(mv.el);

    mv.openDraft();
    await flush();

    const ls = leaves(layout.tabs[0].root);
    expect(ls).toHaveLength(1);
    expect(ls[0].sessionId).toBeNull();
    expect(ls[0].draft).not.toBeNull();
    expect(mv.el.querySelector(".mv-draft")).toBeTruthy();
  });

  it("splits the focused session pane into a fresh draft", async () => {
    const layout = emptyLayout();
    const tab = layout.tabs[0];
    const first = splitLeaf(tab, "", "s1", "row", true);
    tab.focusedLeafId = first;
    const mv = makeMv(layout);
    document.body.appendChild(mv.el);
    mv.render();

    mv.openDraft();
    await flush();

    const ls = leaves(tab.root);
    expect(ls).toHaveLength(2);
    expect(ls[0].sessionId).toBe("s1");
    const draftLeaf = ls.find((l) => l.sessionId === null)!;
    expect(draftLeaf.draft).not.toBeNull();
    expect(tab.focusedLeafId).toBe(draftLeaf.id);
    expect(mv.el.querySelectorAll(".mv-pane")).toHaveLength(2);
  });

  it("reuses the focused pane when it is already empty", async () => {
    const layout = emptyLayout();
    const tab = layout.tabs[0];
    const first = splitLeaf(tab, "", "s1", "row", true);
    const empty = splitLeaf(tab, first, null, "row", true);
    tab.focusedLeafId = empty;
    const mv = makeMv(layout);
    document.body.appendChild(mv.el);
    mv.render();

    mv.openDraft();
    await flush();

    const ls = leaves(tab.root);
    expect(ls).toHaveLength(2);
    const target = ls.find((l) => l.id === empty)!;
    expect(target.draft).not.toBeNull();
    expect(tab.focusedLeafId).toBe(empty);
  });

  it("keeps the draft form instance when an unrelated session closes (#68)", async () => {
    const layout = emptyLayout();
    const tab = layout.tabs[0];
    const s1 = splitLeaf(tab, "", "s1", "row", true);
    const draftLeaf = splitLeaf(tab, s1, null, "row", true);
    tab.focusedLeafId = draftLeaf;
    const mv = makeMv(layout);
    document.body.appendChild(mv.el);
    mv.render();
    await flush();

    const nameInput = mv.el.querySelector(".mv-draft input[name=name]") as HTMLInputElement;
    nameInput.value = "wip";
    nameInput.dispatchEvent(new Event("input"));
    await flush();
    expect(leaves(tab.root).find((l) => l.id === draftLeaf)?.draft?.name).toBe("wip");

    const formBefore = mv.el.querySelector(".mv-draft");
    mv.closeSession("s1");
    await flush();

    expect(mv.el.querySelector(".mv-draft")).toBe(formBefore);
    expect((mv.el.querySelector(".mv-draft input[name=name]") as HTMLInputElement).value).toBe("wip");
  });

  it("reuses an already-synced empty pane instead of splitting (#72)", async () => {
    const layout = emptyLayout();
    const tab = layout.tabs[0];
    const first = splitLeaf(tab, "", "s1", "row", true);
    const empty = splitLeaf(tab, first, null, "row", true);
    tab.focusedLeafId = empty;
    const mv = makeMv(layout);
    document.body.appendChild(mv.el);
    mv.render();
    // Let the mounted form's loadProjects() settle and auto-sync its picked
    // defaults into leaf.draft before openDraft runs (#72's dead-branch window).
    await flush();
    expect(leaves(tab.root).find((l) => l.id === empty)?.draft).not.toBeNull();

    mv.openDraft();
    await flush();

    expect(leaves(tab.root)).toHaveLength(2);
    expect(tab.focusedLeafId).toBe(empty);
  });

  it("keeps a seed after reusing an already-synced empty pane (#72)", async () => {
    const layout = emptyLayout();
    const tab = layout.tabs[0];
    const first = splitLeaf(tab, "", "s1", "row", true);
    const empty = splitLeaf(tab, first, null, "row", true);
    tab.focusedLeafId = empty;
    const mv = makeMv(layout);
    document.body.appendChild(mv.el);
    mv.render();
    await flush();

    mv.openDraft({ cwd: "/home/user/proj", command: "claude" });
    await flush();

    const leaf = leaves(tab.root).find((l) => l.id === empty)!;
    expect(leaf.draft?.cwd).toBe("/home/user/proj");
    expect(leaf.draft?.command).toBe("claude");
    const cwdRaw = mv.el.querySelector(".mv-draft .cwd-raw") as HTMLInputElement;
    expect(cwdRaw.value).toBe("/home/user/proj");
  });

  it("seeds a clone's cwd and command into the draft", async () => {
    const layout = emptyLayout();
    const mv = makeMv(layout);
    document.body.appendChild(mv.el);

    mv.openDraft({ cwd: "/home/user/proj", command: "claude" });
    await flush();

    const leaf = leaves(layout.tabs[0].root)[0];
    expect(leaf.draft?.cwd).toBe("/home/user/proj");
    expect(leaf.draft?.command).toBe("claude");
  });
});

describe("multiview pane-drag swap (#73)", () => {
  beforeEach(() => {
    stubFetch();
    document.body.replaceChildren();
  });

  afterEach(() => {
    vi.unstubAllGlobals();
    vi.restoreAllMocks();
  });

  /** Drag `sourcePane`'s title onto `targetPane`'s center, as the real pane
   *  drag handler does — modelled after the pointer sequence in runDrag()/
   *  updateDock() in multiview.ts, since neither is exposed on MultiView. */
  async function dragPaneOntoCenter(sourcePane: HTMLElement, targetPane: HTMLElement): Promise<void> {
    // The real drag-start gate requires the pointerdown target to sit inside
    // an `.attach-header` (attach.ts's session title bar). Draft panes mount
    // no such element, so stand one in for the gate check itself.
    const marker = document.createElement("div");
    marker.className = "attach-header";
    sourcePane.appendChild(marker);

    vi.spyOn(targetPane, "getBoundingClientRect").mockReturnValue({
      left: 100,
      top: 0,
      width: 100,
      height: 100,
      right: 200,
      bottom: 100,
      x: 100,
      y: 0,
      toJSON() {},
    } as DOMRect);
    (document as unknown as { elementsFromPoint: (x: number, y: number) => Element[] }).elementsFromPoint = () => [
      targetPane,
    ];

    marker.dispatchEvent(
      new PointerEvent("pointerdown", { clientX: 0, clientY: 0, bubbles: true, cancelable: true }),
    );
    window.dispatchEvent(
      new PointerEvent("pointermove", { clientX: 150, clientY: 50, bubbles: true, cancelable: true }),
    );
    window.dispatchEvent(new PointerEvent("pointerup", { clientX: 150, clientY: 50, bubbles: true, cancelable: true }));
    await flush();
  }

  it("moves each draft's form along with its data when two draft panes are swapped", async () => {
    const layout = emptyLayout();
    const tab = layout.tabs[0];
    const leaf1 = splitLeaf(tab, "", null, "row", true);
    const leaf2 = splitLeaf(tab, leaf1, null, "row", true);
    const mv = makeMv(layout);
    document.body.appendChild(mv.el);
    mv.render();
    await flush();

    const paneOf = (leafId: string) => mv.el.querySelector(`[data-leaf-id="${leafId}"]`) as HTMLElement;
    const nameInputOf = (leafId: string) => paneOf(leafId).querySelector("input[name=name]") as HTMLInputElement;

    nameInputOf(leaf1).value = "west";
    nameInputOf(leaf1).dispatchEvent(new Event("input"));
    nameInputOf(leaf2).value = "east";
    nameInputOf(leaf2).dispatchEvent(new Event("input"));
    await flush();
    expect(leaves(tab.root).find((l) => l.id === leaf1)?.draft?.name).toBe("west");
    expect(leaves(tab.root).find((l) => l.id === leaf2)?.draft?.name).toBe("east");

    await dragPaneOntoCenter(paneOf(leaf1), paneOf(leaf2));

    // The leaf data swaps (already correct pre-fix)...
    expect(leaves(tab.root).find((l) => l.id === leaf1)?.draft?.name).toBe("east");
    expect(leaves(tab.root).find((l) => l.id === leaf2)?.draft?.name).toBe("west");
    // ...and the mounted forms must follow, not stay behind showing the old
    // pane's values (#73).
    expect(nameInputOf(leaf1).value).toBe("east");
    expect(nameInputOf(leaf2).value).toBe("west");
  });
});