import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
import { render, screen, fireEvent } from "@testing-library/react";
import { Header } from "./Header";

const noop = () => {};

// Helper to mock mobile/desktop viewport
function mockMatchMedia(matches: boolean) {
  Object.defineProperty(window, "matchMedia", {
    writable: true,
    value: vi.fn().mockImplementation((query: string) => ({
      matches: matches && query.includes("max-width: 768px"),
      media: query,
      onchange: null,
      addEventListener: vi.fn(),
      removeEventListener: vi.fn(),
      dispatchEvent: vi.fn(),
    })),
  });
}

function renderHeader(props = {}, isMobile = false) {
  mockMatchMedia(isMobile);
  return render(
    <Header
      onOpenSettings={noop}
      onOpenGitHubImport={noop}
      globalPaused={false}
      enginePaused={false}
      onToggleGlobalPause={noop}
      onToggleEnginePause={noop}
      {...props}
    />
  );
}

describe("Header", () => {
  it("renders the logo and brand", () => {
    renderHeader();
    expect(screen.getByText("Fusion")).toBeDefined();
    expect(screen.getByText("tasks")).toBeDefined();
  });

  it("renders action buttons", () => {
    renderHeader();
    expect(screen.getByTitle("Import from GitHub")).toBeDefined();
    expect(screen.getByTitle("Settings")).toBeDefined();
  });

  it("calls onOpenSettings when settings button is clicked", () => {
    const onOpenSettings = vi.fn();
    renderHeader({ onOpenSettings });
    fireEvent.click(screen.getByTitle("Settings"));
    expect(onOpenSettings).toHaveBeenCalled();
  });

  it("calls onOpenGitHubImport when import button is clicked", () => {
    const onOpenGitHubImport = vi.fn();
    renderHeader({ onOpenGitHubImport });
    fireEvent.click(screen.getByTitle("Import from GitHub"));
    expect(onOpenGitHubImport).toHaveBeenCalled();
  });

  describe("view toggle", () => {
    it("does not render view toggle when onChangeView is not provided", () => {
      renderHeader();
      expect(screen.queryByTitle("Board view")).toBeNull();
      expect(screen.queryByTitle("List view")).toBeNull();
    });

    it("renders view toggle when onChangeView is provided", () => {
      renderHeader({ onChangeView: noop });
      expect(screen.getByTitle("Board view")).toBeDefined();
      expect(screen.getByTitle("List view")).toBeDefined();
    });

    it("shows board view as active by default", () => {
      renderHeader({ onChangeView: noop });
      const boardBtn = screen.getByTitle("Board view");
      const listBtn = screen.getByTitle("List view");
      expect(boardBtn.className).toContain("active");
      expect(listBtn.className).not.toContain("active");
    });

    it("shows list view as active when view is 'list'", () => {
      renderHeader({ onChangeView: noop, view: "list" });
      const boardBtn = screen.getByTitle("Board view");
      const listBtn = screen.getByTitle("List view");
      expect(boardBtn.className).not.toContain("active");
      expect(listBtn.className).toContain("active");
    });

    it("calls onChangeView with 'board' when clicking board view button", () => {
      const onChangeView = vi.fn();
      renderHeader({ onChangeView, view: "list" });
      fireEvent.click(screen.getByTitle("Board view"));
      expect(onChangeView).toHaveBeenCalledWith("board");
    });

    it("calls onChangeView with 'list' when clicking list view button", () => {
      const onChangeView = vi.fn();
      renderHeader({ onChangeView, view: "board" });
      fireEvent.click(screen.getByTitle("List view"));
      expect(onChangeView).toHaveBeenCalledWith("list");
    });

    it("has correct aria attributes for accessibility", () => {
      renderHeader({ onChangeView: noop, view: "board" });
      const boardBtn = screen.getByTitle("Board view");
      const listBtn = screen.getByTitle("List view");
      expect(boardBtn.getAttribute("aria-pressed")).toBe("true");
      expect(listBtn.getAttribute("aria-pressed")).toBe("false");
    });
  });

  describe("terminal button", () => {
    it("renders terminal button with correct title on desktop", () => {
      renderHeader({ onToggleTerminal: noop }, false);
      expect(screen.getByTitle("Open Terminal")).toBeDefined();
    });

    it("does not render terminal button inline on mobile", () => {
      renderHeader({ onToggleTerminal: noop }, true);
      expect(screen.queryByTitle("Open Terminal")).toBeNull();
    });

    it("calls onToggleTerminal when terminal button is clicked", () => {
      const onToggleTerminal = vi.fn();
      renderHeader({ onToggleTerminal }, false);
      fireEvent.click(screen.getByTitle("Open Terminal"));
      expect(onToggleTerminal).toHaveBeenCalled();
    });

    it("is always enabled regardless of task state", () => {
      renderHeader({ onToggleTerminal: noop }, false);
      const btn = screen.getByTitle("Open Terminal");
      expect(btn.hasAttribute("disabled")).toBe(false);
    });
  });

  describe("files button", () => {
    it("renders files button on desktop when handler is provided", () => {
      renderHeader({ onOpenFiles: vi.fn() }, false);
      expect(screen.getByTitle("Browse files")).toBeDefined();
    });

    it("does not render files button on desktop when handler is omitted", () => {
      renderHeader({}, false);
      expect(screen.queryByTitle("Browse files")).toBeNull();
    });

    it("calls onOpenFiles when desktop files button is clicked", () => {
      const onOpenFiles = vi.fn();
      renderHeader({ onOpenFiles }, false);
      fireEvent.click(screen.getByTitle("Browse files"));
      expect(onOpenFiles).toHaveBeenCalled();
    });

    it("applies active class when files modal is open", () => {
      renderHeader({ onOpenFiles: vi.fn(), filesOpen: true }, false);
      expect(screen.getByTitle("Browse files").className).toContain("btn-icon--active");
    });

    it("shows files action in mobile overflow menu", () => {
      renderHeader({ onOpenFiles: vi.fn() }, true);
      fireEvent.click(screen.getByTitle("More header actions"));
      expect(screen.getByTestId("overflow-files-btn")).toBeDefined();
    });

    it("calls onOpenFiles from mobile overflow menu", () => {
      const onOpenFiles = vi.fn();
      renderHeader({ onOpenFiles }, true);
      fireEvent.click(screen.getByTitle("More header actions"));
      fireEvent.click(screen.getByTestId("overflow-files-btn"));
      expect(onOpenFiles).toHaveBeenCalled();
    });
  });

  describe("pause controls", () => {
    it("renders pause button for engine pause", () => {
      renderHeader();
      expect(screen.getByTitle("Pause scheduling")).toBeDefined();
    });

    it("renders stop button for global pause", () => {
      renderHeader();
      expect(screen.getByTitle("Stop AI engine")).toBeDefined();
    });

    it("calls onToggleEnginePause when pause button is clicked", () => {
      const onToggleEnginePause = vi.fn();
      renderHeader({ onToggleEnginePause });
      fireEvent.click(screen.getByTitle("Pause scheduling"));
      expect(onToggleEnginePause).toHaveBeenCalled();
    });

    it("calls onToggleGlobalPause when stop button is clicked", () => {
      const onToggleGlobalPause = vi.fn();
      renderHeader({ onToggleGlobalPause });
      fireEvent.click(screen.getByTitle("Stop AI engine"));
      expect(onToggleGlobalPause).toHaveBeenCalled();
    });

    it("shows resume text when engine is paused", () => {
      renderHeader({ enginePaused: true });
      expect(screen.getByTitle("Resume scheduling")).toBeDefined();
    });

    it("shows start text when global is paused", () => {
      renderHeader({ globalPaused: true });
      expect(screen.getByTitle("Start AI engine")).toBeDefined();
    });
  });

  describe("usage button", () => {
    it("does not render usage button when onOpenUsage is not provided", () => {
      renderHeader({}, false);
      expect(screen.queryByTitle("View usage")).toBeNull();
    });

    it("does not render usage button when onOpenUsage is not provided on mobile", () => {
      renderHeader({}, true);
      expect(screen.queryByTitle("View usage")).toBeNull();
    });

    it("renders usage button with correct title when onOpenUsage is provided on desktop", () => {
      renderHeader({ onOpenUsage: vi.fn() }, false);
      expect(screen.getByTitle("View usage")).toBeDefined();
    });

    it("does not render usage button inline on mobile when onOpenUsage is provided", () => {
      renderHeader({ onOpenUsage: vi.fn() }, true);
      // Button should NOT be inline on mobile (it's in overflow menu)
      expect(screen.queryByTitle("View usage")).toBeNull();
    });

    it("shows usage in overflow menu on mobile", () => {
      renderHeader({ onOpenUsage: vi.fn() }, true);
      fireEvent.click(screen.getByTitle("More header actions"));
      expect(screen.getByTestId("overflow-usage-btn")).toBeDefined();
    });

    it("calls onOpenUsage when usage button is clicked on desktop", () => {
      const onOpenUsage = vi.fn();
      renderHeader({ onOpenUsage }, false);
      fireEvent.click(screen.getByTitle("View usage"));
      expect(onOpenUsage).toHaveBeenCalled();
    });

    it("calls onOpenUsage when usage button in overflow menu is clicked", () => {
      const onOpenUsage = vi.fn();
      renderHeader({ onOpenUsage }, true);
      fireEvent.click(screen.getByTitle("More header actions"));
      fireEvent.click(screen.getByTestId("overflow-usage-btn"));
      expect(onOpenUsage).toHaveBeenCalled();
    });
  });

  describe("activity log button", () => {
    it("does not render activity log button when onOpenActivityLog is not provided", () => {
      renderHeader({}, false);
      expect(screen.queryByTitle("View Activity Log")).toBeNull();
    });

    it("does not render activity log button when onOpenActivityLog is not provided on mobile", () => {
      renderHeader({}, true);
      expect(screen.queryByTitle("View Activity Log")).toBeNull();
    });

    it("renders activity log button with correct title when onOpenActivityLog is provided on desktop", () => {
      renderHeader({ onOpenActivityLog: vi.fn() }, false);
      expect(screen.getByTitle("View Activity Log")).toBeDefined();
    });

    it("does not render activity log button inline on mobile when onOpenActivityLog is provided", () => {
      renderHeader({ onOpenActivityLog: vi.fn() }, true);
      // Button should NOT be inline on mobile (it's in overflow menu)
      expect(screen.queryByTitle("View Activity Log")).toBeNull();
    });

    it("shows activity log in overflow menu on mobile", () => {
      renderHeader({ onOpenActivityLog: vi.fn() }, true);
      fireEvent.click(screen.getByTitle("More header actions"));
      expect(screen.getByTestId("overflow-activity-log-btn")).toBeDefined();
    });

    it("calls onOpenActivityLog when activity log button is clicked on desktop", () => {
      const onOpenActivityLog = vi.fn();
      renderHeader({ onOpenActivityLog }, false);
      fireEvent.click(screen.getByTitle("View Activity Log"));
      expect(onOpenActivityLog).toHaveBeenCalled();
    });

    it("calls onOpenActivityLog when activity log button in overflow menu is clicked", () => {
      const onOpenActivityLog = vi.fn();
      renderHeader({ onOpenActivityLog }, true);
      fireEvent.click(screen.getByTitle("More header actions"));
      fireEvent.click(screen.getByTestId("overflow-activity-log-btn"));
      expect(onOpenActivityLog).toHaveBeenCalled();
    });
  });

  describe("planning button", () => {
    it("renders planning button with correct title on desktop", () => {
      renderHeader({ onOpenPlanning: vi.fn() }, false);
      expect(screen.getByTitle("Create a task with AI planning")).toBeDefined();
    });

    it("does not render planning button inline on mobile", () => {
      renderHeader({ onOpenPlanning: vi.fn() }, true);
      expect(screen.queryByTitle("Create a task with AI planning")).toBeNull();
    });

    it("calls onOpenPlanning when planning button is clicked", () => {
      const onOpenPlanning = vi.fn();
      renderHeader({ onOpenPlanning }, false);
      fireEvent.click(screen.getByTitle("Create a task with AI planning"));
      expect(onOpenPlanning).toHaveBeenCalled();
    });

    it("has correct data-testid for testing on desktop", () => {
      renderHeader({ onOpenPlanning: vi.fn() }, false);
      expect(screen.getByTestId("planning-btn")).toBeDefined();
    });
  });

  describe("mobile overflow menu", () => {
    it("renders overflow trigger on mobile", () => {
      renderHeader({}, true);
      expect(screen.getByTitle("More header actions")).toBeDefined();
    });

    it("does not render overflow trigger on desktop", () => {
      renderHeader({}, false);
      expect(screen.queryByTitle("More header actions")).toBeNull();
    });

    it("shows terminal in overflow menu on mobile", () => {
      renderHeader({ onToggleTerminal: noop }, true);
      fireEvent.click(screen.getByTitle("More header actions"));
      expect(screen.getByTestId("overflow-terminal-btn")).toBeDefined();
    });

    it("shows GitHub import in overflow menu on mobile", () => {
      renderHeader({}, true);
      fireEvent.click(screen.getByTitle("More header actions"));
      expect(screen.getByText("Import from GitHub")).toBeDefined();
    });

    it("shows planning in overflow menu on mobile", () => {
      renderHeader({ onOpenPlanning: noop }, true);
      fireEvent.click(screen.getByTitle("More header actions"));
      expect(screen.getByTestId("overflow-planning-btn")).toBeDefined();
    });

    it("shows settings in overflow menu on mobile", () => {
      renderHeader({}, true);
      fireEvent.click(screen.getByTitle("More header actions"));
      expect(screen.getByText("Settings")).toBeDefined();
    });

    it("calls onToggleTerminal when overflow terminal button is clicked", () => {
      const onToggleTerminal = vi.fn();
      renderHeader({ onToggleTerminal }, true);
      fireEvent.click(screen.getByTitle("More header actions"));
      fireEvent.click(screen.getByTestId("overflow-terminal-btn"));
      expect(onToggleTerminal).toHaveBeenCalled();
    });
  });

  describe("search functionality", () => {
    it("does not render search input when onSearchChange is not provided", () => {
      renderHeader({ view: "board" });
      expect(screen.queryByPlaceholderText("Search tasks...")).toBeNull();
    });

    it("renders search input when onSearchChange and view='board' are provided", () => {
      renderHeader({ onSearchChange: vi.fn(), view: "board" });
      expect(screen.getByPlaceholderText("Search tasks...")).toBeDefined();
    });

    it("does not render search input when view is 'list'", () => {
      renderHeader({ onSearchChange: vi.fn(), view: "list" });
      expect(screen.queryByPlaceholderText("Search tasks...")).toBeNull();
    });

    it("calls onSearchChange when typing in search input", () => {
      const onSearchChange = vi.fn();
      renderHeader({ onSearchChange, view: "board" });
      const input = screen.getByPlaceholderText("Search tasks...");
      fireEvent.change(input, { target: { value: "test query" } });
      expect(onSearchChange).toHaveBeenCalledWith("test query");
    });

    it("shows clear button when search query is not empty", () => {
      renderHeader({ onSearchChange: vi.fn(), view: "board", searchQuery: "test" });
      expect(screen.getByLabelText("Clear search")).toBeDefined();
    });

    it("does not show clear button when search query is empty", () => {
      renderHeader({ onSearchChange: vi.fn(), view: "board", searchQuery: "" });
      expect(screen.queryByLabelText("Clear search")).toBeNull();
    });

    it("calls onSearchChange with empty string when clear button is clicked", () => {
      const onSearchChange = vi.fn();
      renderHeader({ onSearchChange, view: "board", searchQuery: "test" });
      fireEvent.click(screen.getByLabelText("Clear search"));
      expect(onSearchChange).toHaveBeenCalledWith("");
    });

    it("search input has correct placeholder text", () => {
      renderHeader({ onSearchChange: vi.fn(), view: "board" });
      const input = screen.getByPlaceholderText("Search tasks...");
      expect(input).toBeDefined();
    });
  });

  describe("schedules button", () => {
    it("renders schedules button on desktop", () => {
      renderHeader({ onOpenSchedules: vi.fn() }, false);
      expect(screen.getByTitle("Scheduled tasks")).toBeDefined();
    });

    it("does not render schedules button inline on mobile", () => {
      renderHeader({ onOpenSchedules: vi.fn() }, true);
      expect(screen.queryByTitle("Scheduled tasks")).toBeNull();
    });

    it("calls onOpenSchedules when schedules button is clicked", () => {
      const onOpenSchedules = vi.fn();
      renderHeader({ onOpenSchedules }, false);
      fireEvent.click(screen.getByTitle("Scheduled tasks"));
      expect(onOpenSchedules).toHaveBeenCalled();
    });

    it("has correct data-testid for testing on desktop", () => {
      renderHeader({ onOpenSchedules: vi.fn() }, false);
      expect(screen.getByTestId("schedules-btn")).toBeDefined();
    });

    it("includes scheduled tasks in overflow menu on mobile", () => {
      renderHeader({ onOpenSchedules: vi.fn() }, true);
      fireEvent.click(screen.getByTitle("More header actions"));
      expect(screen.getByText("Scheduled Tasks")).toBeDefined();
    });

    it("calls onOpenSchedules from mobile overflow menu", () => {
      const onOpenSchedules = vi.fn();
      renderHeader({ onOpenSchedules }, true);
      fireEvent.click(screen.getByTitle("More header actions"));
      fireEvent.click(screen.getByTestId("overflow-schedules-btn"));
      expect(onOpenSchedules).toHaveBeenCalled();
    });
  });
});