import React from "react";
import { act, renderHook, waitFor } from "@testing-library/react";
import { beforeEach, describe, expect, it, vi } from "vitest";
import { useCopilotKit } from "../../providers/CopilotKitProvider";
import { CopilotKitCoreRuntimeConnectionStatus } from "@copilotkit/core";

vi.mock("../../providers/CopilotKitProvider", () => ({
  useCopilotKit: vi.fn(),
}));

const mockUseCopilotKit = useCopilotKit as ReturnType<typeof vi.fn>;
const phoenix = vi.hoisted(() => ({
  sockets: [] as any[],
}));

vi.mock("phoenix", () => {
  class MockPush {
    private callbacks = new Map<string, (payload?: unknown) => void>();

    receive(status: string, callback: (payload?: unknown) => void): MockPush {
      this.callbacks.set(status, callback);
      return this;
    }

    trigger(status: string, payload?: unknown): void {
      this.callbacks.get(status)?.(payload);
    }
  }

  class MockChannel {
    topic: string;
    params: Record<string, unknown>;
    left = false;
    channels: MockChannel[] = [];

    private handlers = new Map<
      string,
      Array<{ ref: number; callback: (payload: unknown) => void }>
    >();
    private joinPush = new MockPush();
    private nextRef = 1;

    constructor(topic = "", params: Record<string, unknown> = {}) {
      this.topic = topic;
      this.params = params;
    }

    on(event: string, callback: (payload: unknown) => void): number {
      if (!this.handlers.has(event)) {
        this.handlers.set(event, []);
      }
      const ref = this.nextRef++;
      this.handlers.get(event)!.push({ ref, callback });
      return ref;
    }

    off(event: string, ref?: number): void {
      if (!this.handlers.has(event)) {
        return;
      }
      if (ref === undefined) {
        this.handlers.delete(event);
        return;
      }

      this.handlers.set(
        event,
        this.handlers.get(event)!.filter((entry) => entry.ref !== ref),
      );
    }

    join(): MockPush {
      return this.joinPush;
    }

    leave(): void {
      this.left = true;
    }

    serverPush(event: string, payload: unknown): void {
      for (const entry of this.handlers.get(event) ?? []) {
        entry.callback(payload);
      }
    }
  }

  class MockSocket {
    url: string;
    opts: Record<string, unknown>;
    connected = false;
    disconnected = false;
    channels: MockChannel[] = [];

    private errorHandlers: Array<(error?: unknown) => void> = [];
    private openHandlers: Array<() => void> = [];

    constructor(url = "", opts: Record<string, unknown> = {}) {
      this.url = url;
      this.opts = opts;
      phoenix.sockets.push(this);
    }

    connect(): void {
      this.connected = true;
    }

    disconnect(): void {
      this.disconnected = true;
    }

    channel(topic: string, params: Record<string, unknown> = {}): MockChannel {
      const channel = new MockChannel(topic, params);
      this.channels.push(channel);
      return channel;
    }

    onError(callback: (error?: unknown) => void): void {
      this.errorHandlers.push(callback);
    }

    onOpen(callback: () => void): void {
      this.openHandlers.push(callback);
    }

    triggerError(error?: unknown): void {
      for (const handler of this.errorHandlers) {
        handler(error);
      }
    }

    triggerOpen(): void {
      for (const handler of this.openHandlers) {
        handler();
      }
    }
  }

  return { Socket: MockSocket };
});

const fetchMock = vi.fn();
globalThis.fetch = fetchMock;

function getMockSockets(): any[] {
  return phoenix.sockets;
}

function setupCopilotKit(runtimeUrl = "http://localhost:4000") {
  mockUseCopilotKit.mockReturnValue({
    copilotkit: {
      runtimeUrl,
      runtimeConnectionStatus: CopilotKitCoreRuntimeConnectionStatus.Connected,
      headers: { Authorization: "Bearer test-token" },
      intelligence: {
        wsUrl: "ws://localhost:4000/client",
      },
    },
  });
}

function jsonResponse(body: unknown, status = 200) {
  return Promise.resolve({
    ok: status >= 200 && status < 300,
    status,
    json: () => Promise.resolve(body),
    text: () => Promise.resolve(JSON.stringify(body)),
  });
}

const defaultInput = { agentId: "agent-1" };

const sampleThreads = [
  {
    id: "t-1",
    organizationId: "org-1",
    agentId: "agent-1",
    createdById: "user-1",
    name: "Thread One",
    archived: false,
    createdAt: "2026-01-01T00:00:00Z",
    updatedAt: "2026-01-01T00:00:00Z",
  },
  {
    id: "t-2",
    organizationId: "org-1",
    agentId: "agent-1",
    createdById: "user-1",
    name: "Thread Two",
    archived: false,
    createdAt: "2026-01-02T00:00:00Z",
    updatedAt: "2026-01-02T00:00:00Z",
  },
];

const { useThreads } = await import("../use-threads");

describe("useThreads", () => {
  beforeEach(() => {
    phoenix.sockets.splice(0);
    fetchMock.mockReset();
    setupCopilotKit();
  });

  it("fetches threads and subscribes to the user metadata channel", async () => {
    fetchMock
      .mockReturnValueOnce(
        jsonResponse({ threads: sampleThreads, joinCode: "jc-1" }),
      )
      .mockReturnValueOnce(jsonResponse({ joinToken: "jt-1" }));

    const { result } = renderHook(() => useThreads(defaultInput));

    await waitFor(() => {
      expect(result.current.isLoading).toBe(false);
    });

    expect(result.current.threads.map((thread) => thread.id)).toEqual([
      "t-2",
      "t-1",
    ]);
    expect(result.current.error).toBeNull();
    expect(fetchMock).toHaveBeenCalledWith(
      expect.stringContaining("/threads?agentId=agent-1"),
      expect.objectContaining({ method: "GET" }),
    );
    expect(fetchMock).toHaveBeenCalledWith(
      expect.stringContaining("/threads/subscribe"),
      expect.objectContaining({ method: "POST" }),
    );

    const socket = getMockSockets()[0];
    expect(socket.connected).toBe(true);
    expect(socket.channels[0].topic).toBe("user_meta:jc-1");
  });

  it("stores fetch failures in error state", async () => {
    fetchMock.mockReturnValue(jsonResponse({}, 500));

    const { result } = renderHook(() => useThreads(defaultInput));

    await waitFor(() => {
      expect(result.current.isLoading).toBe(false);
    });

    expect(result.current.error?.message).toContain("500");
    expect(result.current.threads).toEqual([]);
  });

  it("does not fetch when runtimeUrl is not configured", async () => {
    setupCopilotKit("");

    const { result } = renderHook(() => useThreads(defaultInput));

    await waitFor(() => {
      expect(result.current.isLoading).toBe(false);
    });

    expect(fetchMock).not.toHaveBeenCalled();
    expect(result.current.error?.message).toBe("Runtime URL is not configured");
  });

  it("updates local state directly from realtime metadata events", async () => {
    fetchMock
      .mockReturnValueOnce(
        jsonResponse({ threads: sampleThreads, joinCode: "jc-1" }),
      )
      .mockReturnValueOnce(jsonResponse({ joinToken: "jt-1" }));

    const { result } = renderHook(() => useThreads(defaultInput));

    await waitFor(() => {
      expect(result.current.isLoading).toBe(false);
    });

    const channel = getMockSockets()[0].channels[0];

    act(() => {
      channel.serverPush("thread_metadata", {
        operation: "updated",
        threadId: "t-1",
        userId: "user-1",
        organizationId: "org-1",
        occurredAt: "2026-01-03T00:00:00Z",
        thread: {
          ...sampleThreads[0],
          name: "Renamed Thread",
          updatedAt: "2026-01-03T00:00:00Z",
        },
      });
    });

    await waitFor(() => {
      expect(result.current.threads[0].name).toBe("Renamed Thread");
    });

    expect(fetchMock).toHaveBeenCalledTimes(2);
  });

  it("applies realtime metadata without client-side user filtering", async () => {
    fetchMock
      .mockReturnValueOnce(
        jsonResponse({ threads: sampleThreads, joinCode: "jc-1" }),
      )
      .mockReturnValueOnce(jsonResponse({ joinToken: "jt-1" }));

    const { result } = renderHook(() => useThreads(defaultInput));

    await waitFor(() => {
      expect(result.current.isLoading).toBe(false);
    });

    act(() => {
      getMockSockets()[0].channels[0].serverPush("thread_metadata", {
        operation: "deleted",
        threadId: "t-2",
        userId: "user-2",
        organizationId: "org-1",
        occurredAt: "2026-01-03T00:00:00Z",
        deleted: { id: "t-2" },
      });
    });

    await waitFor(() => {
      expect(result.current.threads).toHaveLength(1);
    });
  });

  it("renames a thread through the runtime contract", async () => {
    fetchMock
      .mockReturnValueOnce(
        jsonResponse({ threads: sampleThreads, joinCode: "jc-1" }),
      )
      .mockReturnValueOnce(jsonResponse({ joinToken: "jt-1" }))
      .mockReturnValueOnce(jsonResponse({}));

    const { result } = renderHook(() => useThreads(defaultInput));

    await waitFor(() => {
      expect(result.current.isLoading).toBe(false);
    });

    await act(async () => {
      await result.current.renameThread("t-1", "Renamed");
    });

    const [url, options] = fetchMock.mock.calls[2];
    expect(url).toContain("/threads/t-1");
    expect(options.method).toBe("PATCH");
    expect(JSON.parse(options.body)).toMatchObject({
      agentId: "agent-1",
      name: "Renamed",
    });
  });

  it("archives and deletes threads through the runtime contract", async () => {
    fetchMock
      .mockReturnValueOnce(
        jsonResponse({ threads: sampleThreads, joinCode: "jc-1" }),
      )
      .mockReturnValueOnce(jsonResponse({ joinToken: "jt-1" }))
      .mockReturnValueOnce(jsonResponse({}))
      .mockReturnValueOnce(jsonResponse({}));

    const { result } = renderHook(() => useThreads(defaultInput));

    await waitFor(() => {
      expect(result.current.isLoading).toBe(false);
    });

    await act(async () => {
      await result.current.archiveThread("t-2");
      await result.current.deleteThread("t-1");
    });

    expect(fetchMock.mock.calls[2][0]).toContain("/threads/t-2/archive");
    expect(fetchMock.mock.calls[2][1].method).toBe("POST");
    expect(JSON.parse(fetchMock.mock.calls[2][1].body)).toMatchObject({
      agentId: "agent-1",
    });

    expect(fetchMock.mock.calls[3][0]).toContain("/threads/t-1");
    expect(fetchMock.mock.calls[3][1].method).toBe("DELETE");
    expect(JSON.parse(fetchMock.mock.calls[3][1].body)).toMatchObject({
      agentId: "agent-1",
    });
  });

  it("exposes thread-scoped pagination properties", async () => {
    fetchMock
      .mockReturnValueOnce(
        jsonResponse({
          threads: sampleThreads,
          joinCode: "jc-1",
          nextCursor: "cursor-abc",
        }),
      )
      .mockReturnValueOnce(jsonResponse({ joinToken: "jt-1" }));

    const { result } = renderHook(() => useThreads(defaultInput));

    await waitFor(() => {
      expect(result.current.isLoading).toBe(false);
    });

    expect(result.current).toHaveProperty("hasMoreThreads");
    expect(result.current).toHaveProperty("isFetchingMoreThreads");
    expect(result.current).toHaveProperty("fetchMoreThreads");
    expect(result.current).not.toHaveProperty("hasNextPage");
    expect(result.current).not.toHaveProperty("isFetchingNextPage");
    expect(result.current).not.toHaveProperty("fetchNextPage");

    expect(result.current.hasMoreThreads).toBe(true);
    expect(result.current.isFetchingMoreThreads).toBe(false);
    expect(typeof result.current.fetchMoreThreads).toBe("function");
  });

  it("does not expose organizationId or createdById on threads", async () => {
    fetchMock
      .mockReturnValueOnce(
        jsonResponse({ threads: sampleThreads, joinCode: "jc-1" }),
      )
      .mockReturnValueOnce(jsonResponse({ joinToken: "jt-1" }));

    const { result } = renderHook(() => useThreads(defaultInput));

    await waitFor(() => {
      expect(result.current.isLoading).toBe(false);
    });

    for (const thread of result.current.threads) {
      expect(thread).not.toHaveProperty("organizationId");
      expect(thread).not.toHaveProperty("createdById");
      expect(thread).toHaveProperty("id");
      expect(thread).toHaveProperty("agentId");
      expect(thread).toHaveProperty("name");
      expect(thread).toHaveProperty("archived");
      expect(thread).toHaveProperty("createdAt");
      expect(thread).toHaveProperty("updatedAt");
    }
  });

  it("tears down sockets after repeated connection failures", async () => {
    fetchMock
      .mockReturnValueOnce(
        jsonResponse({ threads: sampleThreads, joinCode: "jc-1" }),
      )
      .mockReturnValueOnce(jsonResponse({ joinToken: "jt-1" }));

    renderHook(() => useThreads(defaultInput));

    await waitFor(() => {
      expect(getMockSockets().length).toBe(1);
    });

    const socket = getMockSockets()[0];
    const channel = socket.channels[0];

    act(() => {
      for (let index = 0; index < 5; index += 1) {
        socket.triggerError();
      }
    });

    expect(channel.left).toBe(true);
    expect(socket.disconnected).toBe(true);
  });

  it("tears down the active socket on unmount", async () => {
    fetchMock
      .mockReturnValueOnce(
        jsonResponse({ threads: sampleThreads, joinCode: "jc-1" }),
      )
      .mockReturnValueOnce(jsonResponse({ joinToken: "jt-1" }));

    const { unmount } = renderHook(() => useThreads(defaultInput));

    await waitFor(() => {
      expect(getMockSockets().length).toBe(1);
    });

    const socket = getMockSockets()[0];
    const channel = socket.channels[0];

    unmount();

    expect(channel.left).toBe(true);
    expect(socket.disconnected).toBe(true);
  });

  it("waits for runtimeConnectionStatus=Connected before fetching /threads", async () => {
    // Start in Connecting — hook should hold off on dispatching any request
    // so the initial list fetch includes wsUrl and avoids a redundant second
    // call once /info resolves.
    mockUseCopilotKit.mockReturnValue({
      copilotkit: {
        runtimeUrl: "http://localhost:4000",
        runtimeConnectionStatus:
          CopilotKitCoreRuntimeConnectionStatus.Connecting,
        headers: { Authorization: "Bearer test-token" },
        intelligence: undefined,
      },
    });

    fetchMock
      .mockReturnValueOnce(
        jsonResponse({ threads: sampleThreads, joinCode: "jc-1" }),
      )
      .mockReturnValueOnce(jsonResponse({ joinToken: "jt-1" }));

    const { result, rerender } = renderHook(() => useThreads(defaultInput));

    // Give effects a tick to settle; no fetch should occur while Connecting.
    await new Promise((resolve) => setTimeout(resolve, 20));
    expect(fetchMock).not.toHaveBeenCalled();

    // While waiting for Connected, the hook must surface isLoading=true so
    // consumers don't render an empty-state flash before the first fetch
    // is even dispatched. The store's own isLoading is false at this
    // point (no contextChanged action yet), so the hook synthesizes it.
    expect(result.current.isLoading).toBe(true);
    expect(result.current.threads).toEqual([]);

    // Flip to Connected with wsUrl populated, re-render. The effect now
    // dispatches exactly one list fetch (+ one subscribe after it lands).
    mockUseCopilotKit.mockReturnValue({
      copilotkit: {
        runtimeUrl: "http://localhost:4000",
        runtimeConnectionStatus:
          CopilotKitCoreRuntimeConnectionStatus.Connected,
        headers: { Authorization: "Bearer test-token" },
        intelligence: { wsUrl: "ws://localhost:4000/client" },
      },
    });

    rerender();

    await waitFor(() => {
      expect(fetchMock).toHaveBeenCalledWith(
        expect.stringContaining("/threads?agentId=agent-1"),
        expect.objectContaining({ method: "GET" }),
      );
    });

    // Exactly the expected pair — no speculative list call before Connected.
    const listCalls = fetchMock.mock.calls.filter(
      ([url]) => typeof url === "string" && /\/threads\?agentId=/.test(url),
    );
    expect(listCalls).toHaveLength(1);

    // After the fetch settles, isLoading returns to false.
    await waitFor(() => {
      expect(result.current.isLoading).toBe(false);
    });
  });
});