import { act, cleanup, fireEvent, render, screen, waitFor } from "@testing-library/react";
import { afterEach, describe, expect, it, vi } from "vitest";
import type { ActiveThread } from "@/lib/threads/active-threads";

const sessionMocks = vi.hoisted(() => {
  const startedAt = "2026-08-27T10:00:00Z";
  const updatedAt = "2026-08-27T12:00:00Z";
  return {
    startedAt,
    updatedAt,
    sessionLists: new Map<string, Array<Record<string, unknown>>>(),
    sessionErrors: new Map<string, string | null>(),
    sessionLoaded: new Map<string, boolean>(),
    sessionLoaders: new Map<string, ReturnType<typeof vi.fn>>(),
    useTaskSessions: vi.fn((taskId: string) => {
      let sessions = sessionMocks.sessionLists.get(taskId);
      if (!sessions) {
        sessions = [
          {
            id: `session-${taskId}`,
            task_id: taskId,
            state: "RUNNING" as const,
            is_primary: true,
            started_at: sessionMocks.startedAt,
            updated_at: sessionMocks.updatedAt,
          },
        ];
        sessionMocks.sessionLists.set(taskId, sessions);
      }
      return {
        sessions,
        isLoading: false,
        isLoaded: sessionMocks.sessionLoaded.get(taskId) ?? true,
        error: sessionMocks.sessionErrors.get(taskId) ?? null,
        loadSessions: sessionMocks.sessionLoaders.get(taskId) ?? vi.fn(),
      };
    }),
  };
});

vi.mock("./thread-conversation", () => ({
  ThreadConversation: ({ sessionId }: { sessionId: string }) => (
    <div data-testid={`thread-conversation-${sessionId}`} />
  ),
}));

vi.mock("@/hooks/use-task-sessions", () => ({
  useTaskSessions: sessionMocks.useTaskSessions,
}));

vi.mock("@/components/state-provider", () => ({
  useAppStore: (selector: (state: { agentProfiles: { items: [] } }) => unknown) =>
    selector({ agentProfiles: { items: [] } }),
}));

import { ThreadsBoard } from "./threads-board";

afterEach(() => {
  cleanup();
  sessionMocks.useTaskSessions.mockClear();
  sessionMocks.sessionLists.clear();
  sessionMocks.sessionErrors.clear();
  sessionMocks.sessionLoaded.clear();
  sessionMocks.sessionLoaders.clear();
});

const COLUMN_A = "thread-column-a";
const FOCUSED_ATTR = "data-focused";
const COLUMN_B = "thread-column-b";
const TASK_A = "a";
const PRIMARY_SESSION_A = "session-a-primary";
const BUILDER_SESSION_A = "session-a-builder";
const PRIMARY_CONVERSATION_A = `thread-conversation-${PRIMARY_SESSION_A}`;
const BUILDER_CONVERSATION_A = `thread-conversation-${BUILDER_SESSION_A}`;

function thread(overrides: Partial<ActiveThread> & { taskId: string }): ActiveThread {
  return {
    title: `Task ${overrides.taskId}`,
    workflowId: "wf-1",
    workflowName: "Delivery",
    stepTitle: "Build",
    sessionId: `session-${overrides.taskId}`,
    sessionState: "RUNNING",
    pendingAction: null,
    activeSubagentCount: 0,
    queuedPromptCount: 0,
    lastActivityAt: "2026-08-27T10:00:00Z",
    ...overrides,
  };
}

describe("ThreadsBoard — basic layout", () => {
  it("renders one column per active thread, in the order it was given", () => {
    render(
      <ThreadsBoard
        threads={[thread({ taskId: "a" }), thread({ taskId: "b" })]}
        onOpenTask={() => {}}
      />,
    );

    const columns = screen.getAllByTestId(/^thread-column-/);
    expect(columns.map((column) => column.getAttribute("data-testid"))).toEqual([
      COLUMN_A,
      COLUMN_B,
    ]);
  });

  it("mounts the live conversation inside each column", () => {
    render(<ThreadsBoard threads={[thread({ taskId: "a" })]} onOpenTask={() => {}} />);

    expect(screen.getByTestId("thread-conversation-session-a")).not.toBeNull();
  });

  it("keeps thirty task shells mounted without mounting thirty conversations", () => {
    const threads = Array.from({ length: 30 }, (_, index) =>
      thread({ taskId: `task-${String(index + 1).padStart(2, "0")}` }),
    );

    render(<ThreadsBoard threads={threads} onOpenTask={() => {}} />);

    expect(screen.getAllByTestId(/^thread-column-/)).toHaveLength(30);
    expect(screen.getAllByTestId(/^thread-conversation-/)).toHaveLength(1);
    const sessionListTaskIds = [
      ...new Set(sessionMocks.useTaskSessions.mock.calls.map(([taskId]) => taskId)),
    ];
    expect(sessionListTaskIds).toEqual(["task-01", "task-02"]);
  });

  it("keeps the snap pager through the mobile breakpoint", () => {
    render(
      <ThreadsBoard
        threads={[thread({ taskId: "a" }), thread({ taskId: "b" })]}
        onOpenTask={() => {}}
      />,
    );

    expect(screen.getByTestId("threads-board").className).toContain("md:snap-none");
    expect(screen.getByTestId(COLUMN_A).className).toContain("md:w-auto");
    expect(screen.getByTestId(COLUMN_A).className).not.toContain("sm:w-auto");
  });

  it("labels a thread with its task title, workflow and step", () => {
    render(
      <ThreadsBoard
        threads={[thread({ taskId: "a", title: "Fix the flaky test" })]}
        onOpenTask={() => {}}
      />,
    );

    expect(screen.getByText("Fix the flaky test")).not.toBeNull();
    expect(screen.getByText("Delivery")).not.toBeNull();
    expect(screen.getByText("Build")).not.toBeNull();
  });
});

describe("ThreadsBoard — session list loading", () => {
  it("shows a local retry after the initial session list fails, then renders after success", async () => {
    const retry = vi.fn(async () => {
      sessionMocks.sessionErrors.set("a", null);
      sessionMocks.sessionLoaded.set("a", true);
    });
    sessionMocks.sessionErrors.set("a", "service unavailable");
    sessionMocks.sessionLoaded.set("a", false);
    sessionMocks.sessionLoaders.set("a", retry);

    const props = { threads: [thread({ taskId: "a" })], onOpenTask: () => {} };
    const { rerender } = render(<ThreadsBoard {...props} />);

    expect(screen.getByTestId("thread-session-list-error")).not.toBeNull();
    expect(screen.getByRole("button", { name: /retry/i })).not.toBeNull();
    expect(screen.queryByTestId("thread-conversation-session-a")).toBeNull();

    fireEvent.click(screen.getByRole("button", { name: /retry/i }));
    await act(async () => {
      await retry.mock.results[0]?.value;
    });
    rerender(<ThreadsBoard {...props} />);

    await waitFor(() => {
      expect(screen.queryByTestId("thread-session-list-error")).toBeNull();
      expect(screen.getByTestId("thread-conversation-session-a")).not.toBeNull();
    });
  });
});

describe("ThreadsBoard — session selection", () => {
  it("switches only the selected task column to another session", async () => {
    sessionMocks.sessionLists.set("a", [
      {
        id: PRIMARY_SESSION_A,
        task_id: TASK_A,
        name: "Planner",
        state: "RUNNING",
        is_primary: true,
        started_at: sessionMocks.startedAt,
        updated_at: sessionMocks.updatedAt,
      },
      {
        id: BUILDER_SESSION_A,
        task_id: TASK_A,
        name: "Builder",
        state: "COMPLETED",
        is_primary: false,
        started_at: "2026-08-27T11:00:00Z",
        updated_at: "2026-08-27T13:00:00Z",
      },
    ]);
    render(
      <ThreadsBoard
        threads={[thread({ taskId: TASK_A, sessionId: PRIMARY_SESSION_A })]}
        onOpenTask={() => {}}
      />,
    );

    await waitFor(() => {
      expect(screen.getByTestId(PRIMARY_CONVERSATION_A)).not.toBeNull();
    });
    fireEvent.mouseDown(screen.getByRole("tab", { name: /Builder/ }), { button: 0 });

    expect(screen.queryByTestId(PRIMARY_CONVERSATION_A)).toBeNull();
    expect(screen.getByTestId(BUILDER_CONVERSATION_A)).not.toBeNull();
  });

  it("applies a valid session deep link to the matching task column", async () => {
    sessionMocks.sessionLists.set("a", [
      {
        id: PRIMARY_SESSION_A,
        task_id: TASK_A,
        name: "Planner",
        state: "RUNNING",
        is_primary: true,
        started_at: sessionMocks.startedAt,
        updated_at: sessionMocks.updatedAt,
      },
      {
        id: BUILDER_SESSION_A,
        task_id: TASK_A,
        name: "Builder",
        state: "COMPLETED",
        is_primary: false,
        started_at: "2026-08-27T11:00:00Z",
        updated_at: "2026-08-27T13:00:00Z",
      },
    ]);
    render(
      <ThreadsBoard
        threads={[thread({ taskId: TASK_A, sessionId: PRIMARY_SESSION_A })]}
        focusedTaskId="a"
        focusedSessionId={BUILDER_SESSION_A}
        onOpenTask={() => {}}
      />,
    );

    await waitFor(() => {
      expect(screen.getByTestId(BUILDER_CONVERSATION_A)).not.toBeNull();
    });
    expect(screen.queryByTestId(PRIMARY_CONVERSATION_A)).toBeNull();
  });

  it("reports an invalid session deep link after membership loads and falls back locally", async () => {
    sessionMocks.sessionLists.set("a", [
      {
        id: PRIMARY_SESSION_A,
        task_id: TASK_A,
        state: "RUNNING",
        is_primary: true,
        started_at: sessionMocks.startedAt,
        updated_at: sessionMocks.updatedAt,
      },
    ]);
    const onInvalidRequestedSession = vi.fn();
    render(
      <ThreadsBoard
        threads={[thread({ taskId: TASK_A, sessionId: PRIMARY_SESSION_A })]}
        focusedTaskId="a"
        focusedSessionId="missing-session"
        onInvalidRequestedSession={onInvalidRequestedSession}
        onOpenTask={() => {}}
      />,
    );

    await waitFor(() => {
      expect(onInvalidRequestedSession).toHaveBeenCalledWith(TASK_A, "missing-session");
      expect(screen.getByTestId(PRIMARY_CONVERSATION_A)).not.toBeNull();
    });
  });
});

describe("ThreadsBoard — status, interaction and empty states", () => {
  it("shows plain waiting without presenting it as an agent question", () => {
    sessionMocks.sessionLists.set("a", [
      {
        id: "session-a",
        task_id: "a",
        state: "WAITING_FOR_INPUT",
        is_primary: true,
        started_at: sessionMocks.startedAt,
        updated_at: sessionMocks.updatedAt,
      },
    ]);
    render(
      <ThreadsBoard
        threads={[thread({ taskId: "a", sessionState: "WAITING_FOR_INPUT" })]}
        onOpenTask={() => {}}
      />,
    );

    expect(screen.getByText("Waiting")).not.toBeNull();
    expect(screen.queryByText("Working")).toBeNull();
    expect(screen.queryByTestId("thread-status-clarification")).toBeNull();
  });

  it("shows an explicit question while the session is parked", () => {
    render(
      <ThreadsBoard
        threads={[thread({ taskId: "a", sessionState: "IDLE", pendingAction: "clarification" })]}
        onOpenTask={() => {}}
      />,
    );

    expect(screen.getByText("Question from agent")).not.toBeNull();
  });

  it("counts subagents and queued prompts only when there are some", () => {
    render(
      <ThreadsBoard
        threads={[
          thread({ taskId: "a", activeSubagentCount: 2, queuedPromptCount: 1 }),
          thread({ taskId: "b" }),
        ]}
        onOpenTask={() => {}}
      />,
    );

    expect(screen.getByText("2 subagents")).not.toBeNull();
    expect(screen.getByText("1 queued prompt")).not.toBeNull();
    expect(screen.queryByText("0 subagents")).toBeNull();
  });

  it("opens the full task page from the column header", () => {
    const onOpenTask = vi.fn();
    render(<ThreadsBoard threads={[thread({ taskId: "a" })]} onOpenTask={onOpenTask} />);

    fireEvent.click(screen.getByRole("button", { name: "Open task" }));

    expect(onOpenTask).toHaveBeenCalledWith("a");
  });

  it("explains the empty board instead of showing a bare surface", () => {
    render(<ThreadsBoard threads={[]} onOpenTask={() => {}} />);

    expect(screen.getByTestId("threads-empty-state")).not.toBeNull();
    expect(screen.getByText("No agent is working right now")).not.toBeNull();
    expect(screen.queryByTestId("threads-board")).toBeNull();
  });

  it("shows a loading state before the first snapshot lands, not the empty state", () => {
    render(<ThreadsBoard threads={[]} isLoading onOpenTask={() => {}} />);

    expect(screen.getByText("Loading threads...")).not.toBeNull();
    expect(screen.queryByTestId("threads-empty-state")).toBeNull();
  });

  it("keeps a landed board visible while a background refresh runs", () => {
    render(<ThreadsBoard threads={[thread({ taskId: "a" })]} isLoading onOpenTask={() => {}} />);

    expect(screen.getByTestId(COLUMN_A)).not.toBeNull();
    expect(screen.queryByText("Loading threads...")).toBeNull();
  });
});

describe("ThreadsBoard — focusing a column from a deep link", () => {
  function scrollSpy() {
    const calls: Element[] = [];
    Element.prototype.scrollIntoView = function scrollIntoViewStub(this: Element) {
      calls.push(this);
    } as Element["scrollIntoView"];
    return calls;
  }

  it("marks the requested column and leaves the others alone", () => {
    scrollSpy();
    render(
      <ThreadsBoard
        threads={[thread({ taskId: "a" }), thread({ taskId: "b" })]}
        focusedTaskId="b"
        onOpenTask={() => {}}
      />,
    );

    expect(screen.getByTestId(COLUMN_B).getAttribute(FOCUSED_ATTR)).toBe("true");
    expect(screen.getByTestId(COLUMN_A).getAttribute(FOCUSED_ATTR)).toBeNull();
  });

  it("scrolls the requested column into view", () => {
    const calls = scrollSpy();
    render(
      <ThreadsBoard
        threads={[thread({ taskId: "a" }), thread({ taskId: "b" })]}
        focusedTaskId="b"
        onOpenTask={() => {}}
      />,
    );

    expect(calls).toEqual([screen.getByTestId(COLUMN_B)]);
  });

  it("scrolls nothing when no column was requested", () => {
    const calls = scrollSpy();
    render(<ThreadsBoard threads={[thread({ taskId: "a" })]} onOpenTask={() => {}} />);

    expect(calls).toEqual([]);
  });

  it("still scrolls when the column only arrives with a later snapshot", () => {
    const calls = scrollSpy();
    const { rerender } = render(
      <ThreadsBoard threads={[thread({ taskId: "a" })]} focusedTaskId="b" onOpenTask={() => {}} />,
    );
    expect(calls).toEqual([]);

    rerender(
      <ThreadsBoard
        threads={[thread({ taskId: "a" }), thread({ taskId: "b" })]}
        focusedTaskId="b"
        onOpenTask={() => {}}
      />,
    );

    expect(calls).toEqual([screen.getByTestId(COLUMN_B)]);
  });

  it("does not re-scroll a column that stays focused across updates", () => {
    const calls = scrollSpy();
    const { rerender } = render(
      <ThreadsBoard threads={[thread({ taskId: "b" })]} focusedTaskId="b" onOpenTask={() => {}} />,
    );
    rerender(
      <ThreadsBoard
        threads={[thread({ taskId: "b", queuedPromptCount: 3 })]}
        focusedTaskId="b"
        onOpenTask={() => {}}
      />,
    );

    expect(calls).toHaveLength(1);
  });
});

describe("ThreadsBoard — retiring the deep-link mark", () => {
  it("drops the mark once the reader touches the deck", () => {
    render(
      <ThreadsBoard
        threads={[thread({ taskId: "a" }), thread({ taskId: "b" })]}
        focusedTaskId="b"
        onOpenTask={() => {}}
      />,
    );
    expect(screen.getByTestId(COLUMN_B).getAttribute(FOCUSED_ATTR)).toBe("true");

    fireEvent.pointerDown(screen.getByTestId(COLUMN_A));

    expect(screen.getByTestId(COLUMN_B).getAttribute(FOCUSED_ATTR)).toBeNull();
  });

  it("drops the mark when focus lands anywhere in the deck", () => {
    render(
      <ThreadsBoard threads={[thread({ taskId: "b" })]} focusedTaskId="b" onOpenTask={() => {}} />,
    );

    fireEvent.focusIn(screen.getByTestId(COLUMN_B));

    expect(screen.getByTestId(COLUMN_B).getAttribute(FOCUSED_ATTR)).toBeNull();
  });

  it("marks again when a later deep link asks for another column", () => {
    const { rerender } = render(
      <ThreadsBoard
        threads={[thread({ taskId: "a" }), thread({ taskId: "b" })]}
        focusedTaskId="b"
        onOpenTask={() => {}}
      />,
    );
    fireEvent.pointerDown(screen.getByTestId(COLUMN_A));
    expect(screen.getByTestId(COLUMN_B).getAttribute(FOCUSED_ATTR)).toBeNull();

    rerender(
      <ThreadsBoard
        threads={[thread({ taskId: "a" }), thread({ taskId: "b" })]}
        focusedTaskId="a"
        onOpenTask={() => {}}
      />,
    );

    expect(screen.getByTestId(COLUMN_A).getAttribute(FOCUSED_ATTR)).toBe("true");
  });

  it("keeps the mark retired while the same deep link stays in the URL", () => {
    const { rerender } = render(
      <ThreadsBoard threads={[thread({ taskId: "b" })]} focusedTaskId="b" onOpenTask={() => {}} />,
    );
    fireEvent.pointerDown(screen.getByTestId(COLUMN_B));

    rerender(
      <ThreadsBoard
        threads={[thread({ taskId: "b", queuedPromptCount: 2 })]}
        focusedTaskId="b"
        onOpenTask={() => {}}
      />,
    );

    expect(screen.getByTestId(COLUMN_B).getAttribute(FOCUSED_ATTR)).toBeNull();
  });
});