import { describe, it, expect, vi, beforeEach } from 'vitest';
import { render, screen, waitFor, fireEvent } from '@testing-library/react';
import userEvent from '@testing-library/user-event';
import { SWRConfig } from 'swr';

const {
  mockListRegimens,
  mockCreateRegimen,
  mockUpdateRegimen,
  mockDeleteRegimen,
  mockGetBurnRates,
} = vi.hoisted(() => ({
  mockListRegimens: vi.fn(),
  mockCreateRegimen: vi.fn(),
  mockUpdateRegimen: vi.fn(),
  mockDeleteRegimen: vi.fn(),
  mockGetBurnRates: vi.fn(),
}));

const { mockListMedicines } = vi.hoisted(() => ({ mockListMedicines: vi.fn() }));

vi.mock('@/services/regimens', () => ({
  listRegimens: mockListRegimens,
  createRegimen: mockCreateRegimen,
  updateRegimen: mockUpdateRegimen,
  deleteRegimen: mockDeleteRegimen,
  getBurnRates: mockGetBurnRates,
}));

vi.mock('@/services/medicines', () => ({ listMedicines: mockListMedicines }));

import { RegimensTab } from '../../../../src/app/(dashboard)/medicines/RegimensTab';

const emptyMeds = { data: [], pagination: { cursor: null, hasMore: false } };
const emptyRegimens = { data: [], pagination: { cursor: null, hasMore: false } };

const regimen = {
  _id: 'reg-1',
  name: 'Morning Routine',
  isActive: true,
  medications: [
    {
      medicineId: 'med-1',
      medicineName: 'Metformin',
      medicineStrength: 500,
      medicineStrengthUnit: 'mg',
      medicineForm: 'tablet',
      dosage: 1,
      dosageUnit: 'tablet',
      frequency: 'once_daily',
    },
  ],
  createdAt: '2026-01-01T00:00:00.000Z',
};

beforeEach(() => {
  vi.clearAllMocks();
  mockListRegimens.mockResolvedValue(emptyRegimens);
  mockListMedicines.mockResolvedValue(emptyMeds);
  mockGetBurnRates.mockResolvedValue({ data: [] });
});

const wrapper = ({ children }: { children: React.ReactNode }) => (
  <SWRConfig value={{ provider: () => new Map(), dedupingInterval: 0 }}>{children}</SWRConfig>
);

describe('RegimensTab', () => {
  it('shows empty state when no regimens', async () => {
    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => expect(screen.getByText(/No regimens yet/)).toBeInTheDocument());
  });

  it('renders regimen list', async () => {
    mockListRegimens.mockResolvedValue({
      data: [regimen],
      pagination: { cursor: null, hasMore: false },
    });

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => expect(screen.getByText('Morning Routine')).toBeInTheDocument());
  });

  it('shows error when list fails', async () => {
    mockListRegimens.mockRejectedValue(new Error('Load failed'));

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => expect(screen.getByText('Load failed')).toBeInTheDocument());
  });

  it('dismisses error', async () => {
    mockListRegimens.mockRejectedValue(new Error('Load failed'));

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('Load failed'));
    await userEvent.click(screen.getByText('Dismiss'));
    expect(screen.queryByText('Load failed')).not.toBeInTheDocument();
  });

  it('toggles new regimen form', async () => {
    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('New Regimen'));
    await userEvent.click(screen.getByText('New Regimen'));
    expect(screen.getByText(/New Regimen/)).toBeInTheDocument();
    expect(screen.getByPlaceholderText('e.g. Morning routine')).toBeInTheDocument();

    await userEvent.click(screen.getAllByText('Cancel')[0]);
    expect(screen.queryByPlaceholderText('e.g. Morning routine')).not.toBeInTheDocument();
  });

  it('creates a regimen when form is submitted', async () => {
    mockCreateRegimen.mockResolvedValue(regimen);

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('New Regimen'));
    await userEvent.click(screen.getAllByText('New Regimen')[0]);

    await waitFor(() => screen.getByPlaceholderText('e.g. Morning routine'));
    fireEvent.change(screen.getByPlaceholderText('e.g. Morning routine'), {
      target: { value: 'Evening Routine' },
    });
    fireEvent.submit(screen.getByPlaceholderText('e.g. Morning routine').closest('form')!);

    await waitFor(() =>
      expect(mockCreateRegimen).toHaveBeenCalledWith(
        'hh1',
        expect.objectContaining({ name: 'Evening Routine' }),
      ),
    );
  });

  it('deletes regimen after confirmation', async () => {
    mockListRegimens.mockResolvedValue({
      data: [regimen],
      pagination: { cursor: null, hasMore: false },
    });
    mockDeleteRegimen.mockResolvedValue({});
    vi.spyOn(window, 'confirm').mockReturnValue(true);

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('Morning Routine'));
    await userEvent.click(screen.getByTitle('Delete'));

    expect(mockDeleteRegimen).toHaveBeenCalledWith('hh1', 'reg-1');
  });

  it('shows burn rate section when toggled', async () => {
    mockGetBurnRates.mockResolvedValue({ data: [] });

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('Burn rate'));
    await userEvent.click(screen.getByText('Burn rate'));

    await waitFor(() =>
      expect(screen.getByText('Burn Rate & Spending Projections')).toBeInTheDocument(),
    );
    expect(mockGetBurnRates).toHaveBeenCalledWith('hh1');
  });

  it('opens edit form for regimen', async () => {
    mockListRegimens.mockResolvedValue({
      data: [regimen],
      pagination: { cursor: null, hasMore: false },
    });

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('Morning Routine'));
    await userEvent.click(screen.getByTitle('Edit'));

    expect(screen.getByDisplayValue('Morning Routine')).toBeInTheDocument();
  });

  it('saves edited regimen', async () => {
    mockListRegimens.mockResolvedValue({
      data: [regimen],
      pagination: { cursor: null, hasMore: false },
    });
    mockUpdateRegimen.mockResolvedValue({ ...regimen, name: 'Evening Routine' });

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('Morning Routine'));
    await userEvent.click(screen.getByTitle('Edit'));

    await waitFor(() => screen.getByDisplayValue('Morning Routine'));
    fireEvent.change(screen.getByDisplayValue('Morning Routine'), {
      target: { value: 'Evening Routine' },
    });
    fireEvent.submit(screen.getByDisplayValue('Evening Routine').closest('form')!);

    await waitFor(() =>
      expect(mockUpdateRegimen).toHaveBeenCalledWith(
        'hh1',
        'reg-1',
        expect.objectContaining({ name: 'Evening Routine' }),
      ),
    );
  });

  it('shows validation error when submitting regimen form with no medications', async () => {
    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('New Regimen'));
    await userEvent.click(screen.getAllByText('New Regimen')[0]);

    await waitFor(() => screen.getByPlaceholderText('e.g. Morning routine'));
    fireEvent.change(screen.getByPlaceholderText('e.g. Morning routine'), {
      target: { value: 'My Regimen' },
    });
    // Remove the default medication
    await userEvent.click(screen.getByTitle('Remove medication'));
    // Submit with no medications
    fireEvent.submit(screen.getByPlaceholderText('e.g. Morning routine').closest('form')!);

    await waitFor(() =>
      expect(screen.getByText('At least one medication is required.')).toBeInTheDocument(),
    );
  });

  it('shows error when delete fails', async () => {
    mockListRegimens.mockResolvedValue({
      data: [regimen],
      pagination: { cursor: null, hasMore: false },
    });
    mockDeleteRegimen.mockRejectedValue(new Error('Delete failed'));
    vi.spyOn(window, 'confirm').mockReturnValue(true);

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('Morning Routine'));
    await userEvent.click(screen.getByTitle('Delete'));

    await waitFor(() => expect(screen.getByText('Delete failed')).toBeInTheDocument());
  });

  it('shows burn rate table with data', async () => {
    mockGetBurnRates.mockResolvedValue({
      data: [
        {
          medicineId: 'med-1',
          medicineName: 'Metformin',
          dailyConsumption: 2.0,
          totalInCabinet: 60,
          daysUntilEmpty: 30,
          earliestExpiry: null,
          avgUnitPrice: null,
          projectedDailyCost: null,
          projectedMonthlyCost: null,
          projectedYearlyCost: null,
          currency: null,
        },
      ],
    });

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('Burn rate'));
    await userEvent.click(screen.getByText('Burn rate'));

    await waitFor(() => expect(screen.getByText('Metformin')).toBeInTheDocument());
    expect(screen.getByText('2.00')).toBeInTheDocument();
  });

  it('cancels edit form and hides it', async () => {
    mockListRegimens.mockResolvedValue({
      data: [regimen],
      pagination: { cursor: null, hasMore: false },
    });

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('Morning Routine'));
    await userEvent.click(screen.getByTitle('Edit'));

    await waitFor(() => screen.getByDisplayValue('Morning Routine'));
    await userEvent.click(screen.getByRole('button', { name: 'Cancel' }));

    expect(screen.queryByDisplayValue('Morning Routine')).not.toBeInTheDocument();
  });

  it('filters regimens by active status', async () => {
    mockListRegimens.mockResolvedValue({
      data: [regimen],
      pagination: { cursor: null, hasMore: false },
    });

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('All regimens'));
    fireEvent.change(screen.getByDisplayValue('All regimens'), { target: { value: 'active' } });

    await waitFor(() => expect(mockListRegimens).toHaveBeenCalledTimes(2));
  });

  it('adds a medication in the regimen form', async () => {
    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('New Regimen'));
    await userEvent.click(screen.getAllByText('New Regimen')[0]);

    await waitFor(() => screen.getByText('+ Add medication'));
    await userEvent.click(screen.getByText('+ Add medication'));

    // Now 2 medications — verify the button still shows
    expect(screen.getByText('+ Add medication')).toBeInTheDocument();
  });

  it('toggles isActive checkbox in regimen form', async () => {
    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('New Regimen'));
    await userEvent.click(screen.getAllByText('New Regimen')[0]);

    await waitFor(() => screen.getByLabelText('Active'));
    expect(screen.getByLabelText('Active')).toBeChecked();
    fireEvent.click(screen.getByLabelText('Active'));
    expect(screen.getByLabelText('Active')).not.toBeChecked();
  });

  it('changes medicine, dosage, and unit in medication row', async () => {
    mockListMedicines.mockResolvedValue({
      data: [
        { _id: 'med-1', name: 'Metformin', strength: 500, strengthUnit: 'mg', form: 'tablet' },
      ],
      pagination: { cursor: null, hasMore: false },
    });

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('New Regimen'));
    await userEvent.click(screen.getAllByText('New Regimen')[0]);

    await waitFor(() => screen.getByText('Select medicine...'));

    // Select a medicine in the medication row
    const medicineSelect = screen
      .getAllByRole('combobox')
      .find(
        (s) => (s as HTMLSelectElement).options[0]?.text === 'Select medicine...',
      ) as HTMLSelectElement;
    expect(medicineSelect).toBeDefined();
    fireEvent.change(medicineSelect!, { target: { value: 'med-1' } });

    // Change dosage
    const dosageInput = document.querySelector('input[min="0.01"]') as HTMLElement;
    if (dosageInput) fireEvent.change(dosageInput, { target: { value: '2' } });

    // Change dosage unit
    const unitSelect = screen
      .getAllByRole('combobox')
      .find((s) => (s as HTMLSelectElement).value === 'tablet') as HTMLSelectElement;
    if (unitSelect) fireEvent.change(unitSelect!, { target: { value: 'capsule' } });

    expect(screen.getByPlaceholderText('e.g. Morning routine')).toBeInTheDocument();
  });

  it('changes instructions field in medication row', async () => {
    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('New Regimen'));
    await userEvent.click(screen.getAllByText('New Regimen')[0]);

    await waitFor(() => screen.getByPlaceholderText('e.g. Take with food'));
    fireEvent.change(screen.getByPlaceholderText('e.g. Take with food'), {
      target: { value: 'With meals' },
    });

    expect(screen.getByDisplayValue('With meals')).toBeInTheDocument();
  });

  it('changes frequency to custom and sets times per day', async () => {
    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('New Regimen'));
    await userEvent.click(screen.getAllByText('New Regimen')[0]);

    await waitFor(() => screen.getByPlaceholderText('e.g. Morning routine'));

    // The frequency select has 'daily' as its first option value
    const frequencySelect = screen
      .getAllByRole('combobox')
      .find((s) => (s as HTMLSelectElement).options[0]?.value === 'daily') as HTMLSelectElement;
    expect(frequencySelect).toBeDefined();
    fireEvent.change(frequencySelect!, { target: { value: 'custom' } });

    // customFrequencyPerDay input should appear
    await waitFor(() => expect(document.querySelector('input[min="1"][step="1"]')).not.toBeNull());
    const timesPerDayInput = document.querySelector('input[min="1"][step="1"]') as HTMLElement;
    fireEvent.change(timesPerDayInput, { target: { value: '3' } });

    // Change back to non-custom (covers the undefined branch)
    fireEvent.change(frequencySelect!, { target: { value: 'twice_daily' } });

    expect(screen.getByPlaceholderText('e.g. Morning routine')).toBeInTheDocument();
  });

  it('changes time of day in medication row', async () => {
    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('New Regimen'));
    await userEvent.click(screen.getAllByText('New Regimen')[0]);

    await waitFor(() => screen.getByPlaceholderText('e.g. Morning routine'));

    // The time-of-day select has 'Any time' as its first option text
    const timeOfDaySelect = screen
      .getAllByRole('combobox')
      .find((s) => (s as HTMLSelectElement).options[0]?.text === 'Any time') as HTMLSelectElement;
    expect(timeOfDaySelect).toBeDefined();
    fireEvent.change(timeOfDaySelect!, { target: { value: 'morning' } });

    expect(screen.getByPlaceholderText('e.g. Morning routine')).toBeInTheDocument();
  });

  it('shows error when burn rate fetch fails', async () => {
    mockGetBurnRates.mockRejectedValue(new Error('Burn rate failed'));

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('Burn rate'));
    await userEvent.click(screen.getByText('Burn rate'));

    await waitFor(() => expect(screen.getByText('Burn rate failed')).toBeInTheDocument());
  });

  it('shows error when update fails', async () => {
    mockListRegimens.mockResolvedValue({
      data: [regimen],
      pagination: { cursor: null, hasMore: false },
    });
    mockUpdateRegimen.mockRejectedValue(new Error('Update failed'));

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('Morning Routine'));
    await userEvent.click(screen.getByTitle('Deactivate'));

    await waitFor(() => expect(screen.getByText('Update failed')).toBeInTheDocument());
  });

  it('toggles active/inactive status', async () => {
    mockListRegimens.mockResolvedValue({
      data: [regimen],
      pagination: { cursor: null, hasMore: false },
    });
    mockUpdateRegimen.mockResolvedValue({ ...regimen, isActive: false });

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('Morning Routine'));
    await userEvent.click(screen.getByTitle('Deactivate'));

    expect(mockUpdateRegimen).toHaveBeenCalledWith('hh1', 'reg-1', { isActive: false });
  });

  it('cancels new regimen form using internal Cancel button', async () => {
    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('New Regimen'));
    await userEvent.click(screen.getAllByText('New Regimen')[0]);

    await waitFor(() => screen.getByPlaceholderText('e.g. Morning routine'));
    // The Cancel button inside the RegimenForm (not the toggle button)
    const cancelButtons = screen.getAllByRole('button', { name: 'Cancel' });
    await userEvent.click(cancelButtons[cancelButtons.length - 1]!);

    expect(screen.queryByPlaceholderText('e.g. Morning routine')).not.toBeInTheDocument();
  });

  it('filters regimens by inactive status', async () => {
    mockListRegimens.mockResolvedValue(emptyRegimens);

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => expect(mockListRegimens).toHaveBeenCalledTimes(1));

    const filterSelect = screen.getByDisplayValue('All regimens');
    fireEvent.change(filterSelect, { target: { value: 'inactive' } });

    await waitFor(() =>
      expect(mockListRegimens).toHaveBeenCalledWith(
        'hh1',
        expect.objectContaining({ isActive: false }),
      ),
    );
  });

  it('shows filtered empty state when filter is active and no results', async () => {
    mockListRegimens.mockResolvedValue(emptyRegimens);

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByDisplayValue('All regimens'));
    fireEvent.change(screen.getByDisplayValue('All regimens'), { target: { value: 'active' } });

    await waitFor(() => expect(screen.getByText('No active regimens found.')).toBeInTheDocument());
  });

  it('shows null when form is open and regimens list is empty', async () => {
    mockListRegimens.mockResolvedValue(emptyRegimens);

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('New Regimen'));
    await userEvent.click(screen.getAllByText('New Regimen')[0]);

    // Form is open with no regimens — empty state shows null (nothing visible in that spot)
    await waitFor(() => screen.getByPlaceholderText('e.g. Morning routine'));
    expect(screen.queryByText('No regimens yet.')).not.toBeInTheDocument();
  });

  it('shows plural medications label when regimen has multiple meds', async () => {
    const multiMedRegimen = {
      ...regimen,
      medications: [
        { ...regimen.medications[0] },
        { ...regimen.medications[0], medicineId: 'med-2', medicineName: 'Aspirin' },
      ],
    };
    mockListRegimens.mockResolvedValue({
      data: [multiMedRegimen],
      pagination: { cursor: null, hasMore: false },
    });

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => expect(screen.getByText(/2 medications/)).toBeInTheDocument());
  });

  it('shows fallback error when non-Error thrown on burn rates', async () => {
    mockGetBurnRates.mockRejectedValue('burn failed');
    mockListRegimens.mockResolvedValue(emptyRegimens);

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('Burn rate'));
    await userEvent.click(screen.getByText('Burn rate'));

    await waitFor(() => expect(screen.getByText('Failed to load data')).toBeInTheDocument());
  });

  it('shows fallback error when non-Error thrown on create regimen', async () => {
    mockCreateRegimen.mockRejectedValue('save failed');

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('New Regimen'));
    await userEvent.click(screen.getAllByText('New Regimen')[0]);

    await waitFor(() => screen.getByPlaceholderText('e.g. Morning routine'));
    await userEvent.type(screen.getByPlaceholderText('e.g. Morning routine'), 'Test');
    fireEvent.submit(screen.getByPlaceholderText('e.g. Morning routine').closest('form')!);

    await waitFor(() => expect(screen.getByText('Failed to save regimen')).toBeInTheDocument());
  });

  it('initializes edit form with existing medications', async () => {
    mockListRegimens.mockResolvedValue({
      data: [regimen],
      pagination: { cursor: null, hasMore: false },
    });

    render(<RegimensTab householdId="hh1" />, { wrapper });

    await waitFor(() => screen.getByText('Morning Routine'));
    await userEvent.click(screen.getByTitle('Edit'));

    await waitFor(() => screen.getByDisplayValue('Morning Routine'));
    // The medication row should be pre-filled — Remove button should be present
    expect(screen.getByTitle('Remove medication')).toBeInTheDocument();
  });
});