import { StrictMode, type ReactNode } from "react";
import { renderHook } from "@testing-library/react";
import { describe, expect, it, vi } from "vitest";
import {
  composerIdentity,
  composerInsertionText,
  useStablePluginComposerCapability,
} from "./composer-capability";

/** One mounted task-chat composer, used wherever the identity is incidental. */
const COMPOSER = "task-chat:t1:s1";

function strictWrapper({ children }: { children: ReactNode }) {
  return <StrictMode>{children}</StrictMode>;
}

describe("composerInsertionText", () => {
  it("trims and ignores an empty transcript", () => {
    expect(composerInsertionText("   ", "a")).toBe("");
    expect(composerInsertionText("", "")).toBe("");
  });

  it("adds one space only when the preceding character is not whitespace", () => {
    expect(composerInsertionText("  world  ", "o")).toBe(" world");
    expect(composerInsertionText("world", " ")).toBe("world");
    expect(composerInsertionText("world", "\n")).toBe("world");
    expect(composerInsertionText("world", "")).toBe("world");
  });
});

describe("composerIdentity", () => {
  it("separates surfaces, tasks and sessions", () => {
    const ids = [
      composerIdentity("task-chat", "t1", "s1"),
      composerIdentity("task-chat", "t1", "s2"),
      composerIdentity("task-chat", "t2", "s1"),
      composerIdentity("quick-chat", "t1", "s1"),
      composerIdentity("task-create", null, null),
      composerIdentity("new-session", "t1", null),
    ];
    expect(new Set(ids).size).toBe(ids.length);
  });

  it("is stable for the same composer", () => {
    expect(composerIdentity("task-chat", "t1", "s1")).toBe(
      composerIdentity("task-chat", "t1", "s1"),
    );
  });
});

describe("useStablePluginComposerCapability", () => {
  it("keeps one capability object across re-renders", () => {
    const { result, rerender } = renderHook(
      (submittable: boolean) =>
        useStablePluginComposerCapability(
          {
            insertText: () => true,
            focus: () => true,
            submit: async () => submittable,
          },
          COMPOSER,
        ),
      { initialProps: false },
    );

    const first = result.current;
    rerender(true);
    expect(result.current).toBe(first);
  });

  it("revalidates the native gate at call time rather than at handout time", async () => {
    const { result, rerender } = renderHook(
      (submittable: boolean) =>
        useStablePluginComposerCapability(
          {
            insertText: () => true,
            focus: () => true,
            submit: async () => submittable,
          },
          COMPOSER,
        ),
      { initialProps: false },
    );

    // A plugin that captured the capability while submit was blocked...
    const captured = result.current;
    await expect(captured.submit()).resolves.toEqual({ status: "blocked" });

    // ...still submits once the native form becomes submittable.
    rerender(true);
    await expect(captured.submit()).resolves.toEqual({ status: "submitted" });
  });

  it("survives a StrictMode remount so a long-running plugin action still works", async () => {
    const insertText = vi.fn(() => true);
    const { result } = renderHook(
      () =>
        useStablePluginComposerCapability(
          {
            insertText,
            focus: () => true,
            submit: async () => true,
          },
          COMPOSER,
        ),
      { wrapper: strictWrapper },
    );

    expect(result.current.insertText("hello")).toEqual({ status: "inserted" });
    await expect(result.current.submit()).resolves.toEqual({ status: "submitted" });
    expect(insertText).toHaveBeenCalledWith("hello");
  });

  it("revokes the previous handle when the composer's identity changes", async () => {
    // Task chat is not remounted on a session switch (ChatInputContainer is
    // keyed only by clarificationKey), so without an identity key a handle
    // captured on session A would retarget session B's editor.
    const { result, rerender } = renderHook(
      (identity: string) =>
        useStablePluginComposerCapability(
          {
            insertText: () => true,
            focus: () => true,
            submit: async () => true,
          },
          identity,
        ),
      { initialProps: COMPOSER },
    );

    const capturedOnSessionA = result.current;
    rerender("task-chat:t1:s2");

    expect(result.current).not.toBe(capturedOnSessionA);
    expect(capturedOnSessionA.insertText("late transcript")).toEqual({ status: "unavailable" });
    await expect(capturedOnSessionA.submit()).resolves.toEqual({ status: "unavailable" });
    // The freshly issued handle drives the new composer normally.
    expect(result.current.insertText("hello")).toEqual({ status: "inserted" });
  });

  it("fails closed once the composer unmounts", async () => {
    const insertText = vi.fn(() => true);
    const { result, unmount } = renderHook(() =>
      useStablePluginComposerCapability(
        {
          insertText,
          focus: () => true,
          submit: async () => true,
        },
        COMPOSER,
      ),
    );

    const captured = result.current;
    unmount();

    expect(captured.insertText("hello")).toEqual({ status: "unavailable" });
    expect(captured.focus()).toEqual({ status: "unavailable" });
    await expect(captured.submit()).resolves.toEqual({ status: "unavailable" });
    expect(insertText).not.toHaveBeenCalled();
  });
});