import { describe, it, expect, beforeEach, vi } from 'vitest'
import { renderHook, act } from '@testing-library/react'
import { useAnalytics } from './useAnalytics'
import * as api from '@/services/api'

vi.mock('@/services/api')

describe('useAnalytics', () => {
  beforeEach(() => {
    vi.clearAllMocks()
  })

  it('initializes with null data', () => {
    const { result } = renderHook(() => useAnalytics(null))
    expect(result.current.data).toBeNull()
    expect(result.current.isLoading).toBe(false)
  })

  it('fetches analytics data on mount', async () => {
    const mockData = {
      workspaceId: 'ws1',
      childId: 'child1',
      parentProjections: [],
      combinedDaysUsed: 10,
      combinedDaysLeft: 15,
      combinedExpiringAtB4: 50,
    }

    vi.mocked(api.getWorkspaceOverview).mockResolvedValue(mockData as any)

    renderHook(() => useAnalytics('ws1', 'child1'))

    await act(async () => {
      await new Promise((resolve) => setTimeout(resolve, 0))
    })

    expect(api.getWorkspaceOverview).toHaveBeenCalledWith('ws1', 'child1')
  })

  it('handles fetch errors', async () => {
    vi.mocked(api.getWorkspaceOverview).mockRejectedValue(new Error('API error'))

    const { result } = renderHook(() => useAnalytics('ws1', 'child1'))

    await act(async () => {
      await new Promise((resolve) => setTimeout(resolve, 0))
    })

    expect(result.current.error).toContain('API error')
  })

  it('falls back to a generic message when a non-Error value is thrown', async () => {
    vi.mocked(api.getWorkspaceOverview).mockRejectedValue('some string failure')

    const { result } = renderHook(() => useAnalytics('ws1', 'child1'))

    await act(async () => {
      await new Promise((resolve) => setTimeout(resolve, 0))
    })

    expect(result.current.error).toBe('Failed to fetch analytics')
    expect(result.current.data).toBeNull()
  })

  it('does not fetch when workspaceId is null', () => {
    vi.mocked(api.getWorkspaceOverview).mockResolvedValue({} as any)

    renderHook(() => useAnalytics(null))

    expect(api.getWorkspaceOverview).not.toHaveBeenCalled()
  })

  it('does not fetch when childId is missing', () => {
    vi.mocked(api.getWorkspaceOverview).mockResolvedValue({} as any)

    renderHook(() => useAnalytics('ws1'))

    expect(api.getWorkspaceOverview).not.toHaveBeenCalled()
  })

  it('provides refresh function', async () => {
    vi.mocked(api.getWorkspaceOverview).mockResolvedValue({} as any)

    const { result } = renderHook(() => useAnalytics('ws1', 'child1'))

    await act(async () => {
      await result.current.refresh()
    })

    expect(api.getWorkspaceOverview).toHaveBeenCalled()
  })

  it('clears stale data instead of leaving it rendered when the workspace/child identity is lost', async () => {
    const mockData = {
      workspaceId: 'ws1',
      childId: 'child1',
      parentProjections: [],
      combinedDaysUsed: 76,
      combinedDaysLeft: 164,
      combinedExpiringAtB4: 50,
    }
    vi.mocked(api.getWorkspaceOverview).mockResolvedValue(mockData as any)

    const { result, rerender } = renderHook(
      ({ workspaceId, childId }: { workspaceId: string | null; childId: string | undefined }) =>
        useAnalytics(workspaceId, childId),
      { initialProps: { workspaceId: 'ws1' as string | null, childId: 'child1' as string | undefined } },
    )

    await act(async () => {
      await new Promise((resolve) => setTimeout(resolve, 0))
    })
    expect(result.current.data).toEqual(mockData)

    // Simulate a logout clearing the workspace/child selection — this must
    // not leave the previous account's figures on screen.
    rerender({ workspaceId: null, childId: undefined })

    await act(async () => {
      await new Promise((resolve) => setTimeout(resolve, 0))
    })

    expect(result.current.data).toBeNull()
  })
})