import { createElement, useEffect } from "react";
import { act, render } from "@testing-library/react";
import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";

import { useRuntimeSyncController } from "@/features/agents/operations/useRuntimeSyncController";
import type { AgentState } from "@/features/agents/state/store";

import {
  executeAgentReconcileCommands,
  runAgentReconcileOperation,
} from "@/features/agents/operations/agentReconcileOperation";
import {
  executeHistorySyncCommands,
  runHistorySyncOperation,
} from "@/features/agents/operations/historySyncOperation";
import type { GatewayGapInfo } from "@/lib/gateway/GatewayClient";

vi.mock("@/features/agents/operations/historySyncOperation", () => ({
  runHistorySyncOperation: vi.fn(async () => []),
  executeHistorySyncCommands: vi.fn(),
}));

vi.mock("@/features/agents/operations/agentReconcileOperation", () => ({
  runAgentReconcileOperation: vi.fn(async () => []),
  executeAgentReconcileCommands: vi.fn(),
}));

const createAgent = (overrides?: Partial<AgentState>): AgentState => ({
  agentId: "agent-1",
  name: "Agent One",
  sessionKey: "agent:agent-1:main",
  status: "idle",
  sessionCreated: true,
  awaitingUserInput: false,
  hasUnseenActivity: false,
  outputLines: [],
  lastResult: null,
  lastDiff: null,
  runId: null,
  runStartedAt: null,
  streamText: null,
  thinkingTrace: null,
  latestOverride: null,
  latestOverrideKind: null,
  lastAssistantMessageAt: null,
  lastActivityAt: null,
  latestPreview: null,
  lastUserMessage: null,
  draft: "",
  sessionSettingsSynced: true,
  historyLoadedAt: null,
  historyFetchLimit: null,
  historyFetchedCount: null,
  historyMaybeTruncated: false,
  toolCallingEnabled: true,
  showThinkingTraces: true,
  model: "openai/gpt-5",
  thinkingLevel: "medium",
  avatarSeed: "seed-1",
  avatarUrl: null,
  ...(overrides ?? {}),
});

type RuntimeSyncControllerValue = ReturnType<typeof useRuntimeSyncController>;

type RenderControllerContext = {
  getValue: () => RuntimeSyncControllerValue;
  rerenderWith: (
    overrides: Partial<Parameters<typeof useRuntimeSyncController>[0]>
  ) => void;
  unmount: () => void;
  dispatch: ReturnType<typeof vi.fn>;
  clearRunTracking: ReturnType<typeof vi.fn>;
  call: ReturnType<typeof vi.fn>;
  onGap: ReturnType<typeof vi.fn>;
  getGapHandler: () => ((info: GatewayGapInfo) => void) | null;
  unsubscribeGap: ReturnType<typeof vi.fn>;
};

const renderController = (
  overrides?: Partial<Parameters<typeof useRuntimeSyncController>[0]>
): RenderControllerContext => {
  const dispatch = vi.fn();
  const clearRunTracking = vi.fn();
  const call = vi.fn(async (method: string) => {
    if (method === "status") {
      return { sessions: { recent: [], byAgent: [] } };
    }
    if (method === "sessions.preview") {
      return { ts: 123, previews: [] };
    }
    return {};
  });
  let gapHandler: ((info: GatewayGapInfo) => void) | null = null;
  const unsubscribeGap = vi.fn();
  const onGap = vi.fn((handler: (info: GatewayGapInfo) => void) => {
    gapHandler = handler;
    return unsubscribeGap;
  });

  let currentParams: Parameters<typeof useRuntimeSyncController>[0] = {
    client: {
      call,
      onGap,
    } as never,
    status: "connected",
    agents: [createAgent({ status: "running", historyLoadedAt: 1000, runId: "run-1" })],
    focusedAgentId: null,
    focusedAgentRunning: false,
    dispatch,
    clearRunTracking,
    isDisconnectLikeError: () => false,
    defaultHistoryLimit: 200,
    maxHistoryLimit: 5000,
    ...(overrides ?? {}),
  };

  const valueRef: { current: RuntimeSyncControllerValue | null } = { current: null };

  const Probe = ({
    params,
    onValue,
  }: {
    params: Parameters<typeof useRuntimeSyncController>[0];
    onValue: (value: RuntimeSyncControllerValue) => void;
  }) => {
    const value = useRuntimeSyncController(params);
    useEffect(() => {
      onValue(value);
    }, [onValue, value]);
    return createElement("div", { "data-testid": "probe" }, "ok");
  };

  const rendered = render(
    createElement(Probe, {
      params: currentParams,
      onValue: (value) => {
        valueRef.current = value;
      },
    })
  );

  return {
    getValue: () => {
      if (!valueRef.current) {
        throw new Error("runtime sync controller value unavailable");
      }
      return valueRef.current;
    },
    rerenderWith: (nextOverrides) => {
      currentParams = {
        ...currentParams,
        ...nextOverrides,
      };
      rendered.rerender(
        createElement(Probe, {
          params: currentParams,
          onValue: (value) => {
            valueRef.current = value;
          },
        })
      );
    },
    unmount: () => {
      rendered.unmount();
    },
    dispatch,
    clearRunTracking,
    call,
    onGap,
    getGapHandler: () => gapHandler,
    unsubscribeGap,
  };
};

describe("useRuntimeSyncController", () => {
  const mockedRunHistorySyncOperation = vi.mocked(runHistorySyncOperation);
  const mockedExecuteHistorySyncCommands = vi.mocked(executeHistorySyncCommands);
  const mockedRunAgentReconcileOperation = vi.mocked(runAgentReconcileOperation);
  const mockedExecuteAgentReconcileCommands = vi.mocked(executeAgentReconcileCommands);

  beforeEach(() => {
    vi.useFakeTimers();
    mockedRunHistorySyncOperation.mockReset();
    mockedRunHistorySyncOperation.mockResolvedValue([]);
    mockedExecuteHistorySyncCommands.mockReset();
    mockedRunAgentReconcileOperation.mockReset();
    mockedRunAgentReconcileOperation.mockResolvedValue([]);
    mockedExecuteAgentReconcileCommands.mockReset();
  });

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

  it("runs reconcile immediately and every 3000ms while connected then cleans up", async () => {
    const ctx = renderController({
      focusedAgentId: null,
      focusedAgentRunning: false,
    });

    await act(async () => {
      await Promise.resolve();
    });
    expect(mockedRunAgentReconcileOperation).toHaveBeenCalledTimes(1);

    await vi.advanceTimersByTimeAsync(2999);
    expect(mockedRunAgentReconcileOperation).toHaveBeenCalledTimes(1);

    await vi.advanceTimersByTimeAsync(1);
    expect(mockedRunAgentReconcileOperation).toHaveBeenCalledTimes(2);

    await vi.advanceTimersByTimeAsync(3000);
    expect(mockedRunAgentReconcileOperation).toHaveBeenCalledTimes(3);

    ctx.unmount();
    await vi.advanceTimersByTimeAsync(6000);
    expect(mockedRunAgentReconcileOperation).toHaveBeenCalledTimes(3);
  });

  it("polls focused running history every 4500ms and stops when focus no longer running", async () => {
    const ctx = renderController({
      agents: [createAgent({ status: "running", historyLoadedAt: 1234 })],
      focusedAgentId: "agent-1",
      focusedAgentRunning: true,
    });

    await act(async () => {
      await Promise.resolve();
    });
    expect(mockedRunHistorySyncOperation).toHaveBeenCalledTimes(1);

    await vi.advanceTimersByTimeAsync(4500);
    expect(mockedRunHistorySyncOperation).toHaveBeenCalledTimes(2);

    ctx.rerenderWith({
      agents: [createAgent({ status: "idle", historyLoadedAt: 1234 })],
      focusedAgentId: "agent-1",
      focusedAgentRunning: false,
    });

    await vi.advanceTimersByTimeAsync(9000);
    expect(mockedRunHistorySyncOperation).toHaveBeenCalledTimes(2);
  });

  it("bootstraps history only for connected sessions missing loaded history", async () => {
    renderController({
      status: "connected",
      focusedAgentId: null,
      focusedAgentRunning: false,
      agents: [
        createAgent({ agentId: "agent-1", sessionCreated: true, historyLoadedAt: null }),
        createAgent({ agentId: "agent-2", sessionCreated: true, historyLoadedAt: 1234 }),
        createAgent({ agentId: "agent-3", sessionCreated: false, historyLoadedAt: null }),
      ],
    });

    await act(async () => {
      await Promise.resolve();
    });

    const bootstrappedAgentIds = mockedRunHistorySyncOperation.mock.calls
      .map(([arg]) => (arg as { agentId: string }).agentId)
      .filter((agentId) => agentId === "agent-1" || agentId === "agent-2" || agentId === "agent-3");

    expect(bootstrappedAgentIds).toContain("agent-1");
    expect(bootstrappedAgentIds).not.toContain("agent-2");
    expect(bootstrappedAgentIds).not.toContain("agent-3");
  });

  it("loads summary snapshot when status transitions to connected", async () => {
    const ctx = renderController({
      status: "disconnected",
      focusedAgentId: null,
      focusedAgentRunning: false,
      agents: [createAgent({ sessionCreated: true, historyLoadedAt: 1234 })],
    });

    expect(ctx.call).not.toHaveBeenCalledWith("status", {});

    ctx.rerenderWith({ status: "connected" });
    await act(async () => {
      await Promise.resolve();
    });

    expect(ctx.call).toHaveBeenCalledWith("status", {});
    expect(ctx.call).toHaveBeenCalledWith("sessions.preview", {
      keys: ["agent:agent-1:main"],
      limit: 8,
      maxChars: 240,
    });
  });

  it("handles gap recovery by triggering summary refresh and reconcile", async () => {
    const warnSpy = vi.spyOn(console, "warn").mockImplementation(() => {});
    const ctx = renderController({
      agents: [createAgent({ status: "running", historyLoadedAt: 1234, runId: "run-1" })],
    });

    await act(async () => {
      await Promise.resolve();
    });
    expect(ctx.onGap).toHaveBeenCalledTimes(1);
    const handler = ctx.getGapHandler();
    if (!handler) {
      throw new Error("expected gap handler to be registered");
    }

    mockedRunAgentReconcileOperation.mockClear();
    ctx.call.mockClear();

    await act(async () => {
      handler({ expected: 10, received: 11 });
      await Promise.resolve();
    });
    expect(ctx.call).toHaveBeenCalledWith("status", {});
    expect(ctx.call).toHaveBeenCalledWith("sessions.preview", {
      keys: ["agent:agent-1:main"],
      limit: 8,
      maxChars: 240,
    });
    expect(mockedRunAgentReconcileOperation).toHaveBeenCalledTimes(1);
    expect(warnSpy).toHaveBeenCalledWith("Gateway event gap expected 10, received 11.");
  });

  it("unsubscribes gap listener on unmount", () => {
    const ctx = renderController();
    ctx.unmount();
    expect(ctx.unsubscribeGap).toHaveBeenCalledTimes(1);
  });

  it("clears history in-flight tracking when requested", async () => {
    const inFlightSeen: boolean[] = [];
    mockedRunHistorySyncOperation.mockImplementation(
      async ({ agentId, getAgent, inFlightSessionKeys }) => {
        const agent = getAgent(agentId);
        if (!agent) return [];
        const sessionKey = agent.sessionKey;
        inFlightSeen.push(inFlightSessionKeys.has(sessionKey));
        inFlightSessionKeys.add(sessionKey);
        return [];
      }
    );

    const ctx = renderController({
      status: "disconnected",
      agents: [createAgent({ sessionKey: "agent:agent-1:main", historyLoadedAt: null })],
      focusedAgentId: null,
      focusedAgentRunning: false,
    });

    await act(async () => {
      await ctx.getValue().loadAgentHistory("agent-1");
    });
    await act(async () => {
      await ctx.getValue().loadAgentHistory("agent-1");
    });
    act(() => {
      ctx.getValue().clearHistoryInFlight("agent:agent-1:main");
    });
    await act(async () => {
      await ctx.getValue().loadAgentHistory("agent-1");
    });

    expect(inFlightSeen).toEqual([false, true, false]);
  });
});