import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest'
import { renderHook, waitFor, act } from '@testing-library/react'
import type { ReactNode } from 'react'
import { WorkspaceProvider, useWorkspace } from './WorkspaceContext'
import * as api from '@/services/api'
import { useAuth } from '@/context/AuthContext'
import type { Workspace } from '@/types'

vi.mock('@/services/api')
vi.mock('@/context/AuthContext', () => ({
  useAuth: vi.fn(),
}))

function wrapper({ children }: { children: ReactNode }) {
  return <WorkspaceProvider>{children}</WorkspaceProvider>
}

// Node's own experimental `localStorage` global (active in newer Node runtimes
// without a valid --localstorage-file) shadows jsdom's working implementation
// and throws on every call. Stub a real in-memory Storage for these tests.
function createLocalStorageMock(): Storage {
  let store: Record<string, string> = {}
  return {
    getItem: (key: string) => (key in store ? store[key]! : null),
    setItem: (key: string, value: string) => {
      store[key] = value
    },
    removeItem: (key: string) => {
      delete store[key]
    },
    clear: () => {
      store = {}
    },
    key: (index: number) => Object.keys(store)[index] ?? null,
    get length() {
      return Object.keys(store).length
    },
  }
}

const authenticated = {
  accessToken: 'tok',
  isAuthenticated: true,
  isLoading: false,
  login: vi.fn(),
  register: vi.fn(),
  logout: vi.fn(),
}

const unauthenticated = {
  accessToken: null,
  isAuthenticated: false,
  isLoading: false,
  login: vi.fn(),
  register: vi.fn(),
  logout: vi.fn(),
}

const workspace: Workspace = {
  id: 'ws1',
  name: 'Our workspace',
  createdAt: '2026-01-01T00:00:00Z',
}

const userContext: api.UserContext = {
  personal_data_uuid: 'pd1',
  workspace_id: 'ws1',
  parent_name: 'Anna',
  children: [
    { id: 'c1', name: 'Child One', birth_date: '2024-01-01' },
    { id: 'c2', name: 'Child Two', birth_date: '2025-01-01' },
  ],
  take_pl_on_red_days: false,
}

describe('WorkspaceContext', () => {
  beforeEach(() => {
    vi.clearAllMocks()
    vi.stubGlobal('localStorage', createLocalStorageMock())
  })

  afterEach(() => {
    vi.unstubAllGlobals()
  })

  it('does nothing when the user is not authenticated', async () => {
    vi.mocked(useAuth).mockReturnValue(unauthenticated)

    const { result } = renderHook(() => useWorkspace(), { wrapper })

    expect(api.getUserContext).not.toHaveBeenCalled()
    expect(result.current.workspace).toBeNull()
    expect(result.current.isLoading).toBe(false)
  })

  it('loads user context on mount when authenticated, with no follow-up workspace fetch', async () => {
    // H12 step 1: cold load used to be getUserContext() -> getWorkspace(id).
    // The workspace state this provider needs (id + takePlOnRedDays) now
    // comes straight from the context response, so getWorkspace must not
    // be called at all on this path.
    vi.mocked(useAuth).mockReturnValue(authenticated)
    vi.mocked(api.getUserContext).mockResolvedValue(userContext)

    const { result } = renderHook(() => useWorkspace(), { wrapper })

    await waitFor(() => expect(result.current.workspace).not.toBeNull())

    expect(api.getUserContext).toHaveBeenCalled()
    expect(api.getWorkspace).not.toHaveBeenCalled()
    expect(result.current.workspaceId).toBe('ws1')
    expect(result.current.personalDataUuid).toBe('pd1')
    expect(result.current.parentName).toBe('Anna')
    expect(result.current.children).toHaveLength(2)
    expect(result.current.selectedChildId).toBe('c1')
    expect(result.current.workspace).toEqual({ id: 'ws1', takePlOnRedDays: false })
    expect(localStorage.getItem('workspaceId')).toBe('ws1')
    expect(result.current.isLoading).toBe(false)
  })

  it('sets an error when loading the user context fails', async () => {
    vi.mocked(useAuth).mockReturnValue(authenticated)
    vi.mocked(api.getUserContext).mockRejectedValue(new Error('context boom'))

    const { result } = renderHook(() => useWorkspace(), { wrapper })

    await waitFor(() => expect(result.current.isLoading).toBe(false))

    expect(result.current.error).toBe('context boom')
    expect(result.current.workspace).toBeNull()
  })

  it('sets a non-Error rejection to a generic message when loading the user context fails', async () => {
    vi.mocked(useAuth).mockReturnValue(authenticated)
    vi.mocked(api.getUserContext).mockRejectedValue('nope')

    const { result } = renderHook(() => useWorkspace(), { wrapper })

    await waitFor(() => expect(result.current.isLoading).toBe(false))

    expect(result.current.error).toBe('Failed to load user context')
  })

  it('defaults to an empty children list when the context response omits children', async () => {
    vi.mocked(useAuth).mockReturnValue(authenticated)
    const contextWithoutChildren = {
      personal_data_uuid: userContext.personal_data_uuid,
      workspace_id: userContext.workspace_id,
      parent_name: userContext.parent_name,
      take_pl_on_red_days: false,
    } as unknown as api.UserContext
    vi.mocked(api.getUserContext).mockResolvedValue(contextWithoutChildren)

    const { result } = renderHook(() => useWorkspace(), { wrapper })

    await waitFor(() => expect(result.current.workspace).not.toBeNull())

    expect(result.current.children).toEqual([])
    expect(result.current.selectedChildId).toBeNull()
  })

  it('refetch sets a non-Error rejection to a generic message', async () => {
    vi.mocked(useAuth).mockReturnValue(authenticated)
    vi.mocked(api.getUserContext).mockResolvedValue(userContext)
    vi.mocked(api.getWorkspace).mockResolvedValue(workspace)

    const { result } = renderHook(() => useWorkspace(), { wrapper })
    await waitFor(() => expect(result.current.workspace).not.toBeNull())

    vi.mocked(api.getWorkspace).mockRejectedValue('nope')

    act(() => {
      result.current.refetch()
    })

    await waitFor(() => expect(result.current.error).toBe('Failed to load workspace'))
    expect(result.current.workspace).toBeNull()
  })

  it('selectChild updates the selected child id', async () => {
    vi.mocked(useAuth).mockReturnValue(authenticated)
    vi.mocked(api.getUserContext).mockResolvedValue(userContext)
    vi.mocked(api.getWorkspace).mockResolvedValue(workspace)

    const { result } = renderHook(() => useWorkspace(), { wrapper })
    await waitFor(() => expect(result.current.selectedChildId).toBe('c1'))

    act(() => {
      result.current.selectChild('c2')
    })

    expect(result.current.selectedChildId).toBe('c2')
  })

  it('setWorkspaceId stores the id, updates state, and fetches that workspace directly', async () => {
    // P2 in the frontend audit: this used to rely on a reactive effect that
    // only fired while `workspace` was still null, so switching workspaces
    // after the initial load silently never fetched the new one. Fetching
    // explicitly here fixes that without reintroducing the cold-load
    // duplicate GET /workspace the same effect used to cause.
    vi.mocked(useAuth).mockReturnValue(authenticated)
    vi.mocked(api.getUserContext).mockResolvedValue(userContext)
    vi.mocked(api.getWorkspace).mockResolvedValue(workspace)

    const { result } = renderHook(() => useWorkspace(), { wrapper })
    await waitFor(() => expect(result.current.workspace).not.toBeNull())

    const otherWorkspace: Workspace = { ...workspace, id: 'ws2', name: 'Other workspace' }
    vi.mocked(api.getWorkspace).mockResolvedValue(otherWorkspace)
    vi.mocked(api.getWorkspace).mockClear()

    act(() => {
      result.current.setWorkspaceId('ws2')
    })

    expect(result.current.workspaceId).toBe('ws2')
    expect(localStorage.getItem('workspaceId')).toBe('ws2')

    await waitFor(() => expect(api.getWorkspace).toHaveBeenCalledWith('ws2'))
    await waitFor(() => expect(result.current.workspace).toEqual(otherWorkspace))
  })

  it('refetch re-fetches the current workspace', async () => {
    vi.mocked(useAuth).mockReturnValue(authenticated)
    vi.mocked(api.getUserContext).mockResolvedValue(userContext)
    vi.mocked(api.getWorkspace).mockResolvedValue(workspace)

    const { result } = renderHook(() => useWorkspace(), { wrapper })
    await waitFor(() => expect(result.current.workspace).not.toBeNull())

    vi.mocked(api.getWorkspace).mockClear()

    act(() => {
      result.current.refetch()
    })

    await waitFor(() => expect(api.getWorkspace).toHaveBeenCalledWith('ws1'))
  })

  it('refetch is a no-op without a workspaceId', () => {
    vi.mocked(useAuth).mockReturnValue(unauthenticated)

    const { result } = renderHook(() => useWorkspace(), { wrapper })

    act(() => {
      result.current.refetch()
    })

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

  it('clears identity/workspace state on logout so it cannot leak into the next session', async () => {
    vi.mocked(useAuth).mockReturnValue(authenticated)
    vi.mocked(api.getUserContext).mockResolvedValue(userContext)
    vi.mocked(api.getWorkspace).mockResolvedValue(workspace)

    const { result, rerender } = renderHook(() => useWorkspace(), { wrapper })
    await waitFor(() => expect(result.current.workspace).not.toBeNull())
    expect(result.current.parentName).toBe('Anna')

    vi.mocked(useAuth).mockReturnValue(unauthenticated)
    rerender()

    await waitFor(() => expect(result.current.workspace).toBeNull())
    expect(result.current.workspaceId).toBeNull()
    expect(result.current.parentName).toBeNull()
    expect(result.current.personalDataUuid).toBeNull()
    expect(result.current.children).toEqual([])
    expect(result.current.selectedChildId).toBeNull()
    expect(localStorage.getItem('workspaceId')).toBeNull()
  })

  it('refetches on a fresh login even when stale data from a previous session is already present', async () => {
    // Regression for a login-swap bug: a previous guard only refetched when
    // workspaceId/children looked empty, so logging in as a *different*
    // user after a previous session's data was already cached here never
    // refetched at all, and the new session silently rendered the old
    // account's workspace/name/children.
    vi.mocked(useAuth).mockReturnValue(authenticated)
    vi.mocked(api.getUserContext).mockResolvedValue(userContext)
    vi.mocked(api.getWorkspace).mockResolvedValue(workspace)

    const { result, rerender } = renderHook(() => useWorkspace(), { wrapper })
    await waitFor(() => expect(result.current.parentName).toBe('Anna'))

    vi.mocked(useAuth).mockReturnValue(unauthenticated)
    rerender()
    await waitFor(() => expect(result.current.workspace).toBeNull())

    const otherUserContext: api.UserContext = {
      personal_data_uuid: 'pd2',
      workspace_id: 'ws2',
      parent_name: 'Alex',
      children: [{ id: 'c3', name: 'Child Three', birth_date: '2026-01-01' }],
      take_pl_on_red_days: true,
    }
    vi.mocked(api.getUserContext).mockResolvedValue(otherUserContext)
    vi.mocked(api.getUserContext).mockClear()

    vi.mocked(useAuth).mockReturnValue(authenticated)
    rerender()

    await waitFor(() => expect(result.current.parentName).toBe('Alex'))
    expect(api.getUserContext).toHaveBeenCalled()
    expect(result.current.workspaceId).toBe('ws2')
    expect(result.current.personalDataUuid).toBe('pd2')
    expect(result.current.selectedChildId).toBe('c3')
    expect(result.current.workspace).toEqual({ id: 'ws2', takePlOnRedDays: true })
  })

  it('discards a refreshContext response that resolves after logout (S4)', async () => {
    vi.mocked(useAuth).mockReturnValue(authenticated)
    let resolveContext: (value: api.UserContext) => void = () => {}
    const pending = new Promise<api.UserContext>((resolve) => {
      resolveContext = resolve
    })
    vi.mocked(api.getUserContext).mockReturnValue(pending)

    const { result, rerender } = renderHook(() => useWorkspace(), { wrapper })

    // Logout happens while the initial refreshContext() call is still
    // in flight (e.g. a slow /auth/context response).
    vi.mocked(useAuth).mockReturnValue(unauthenticated)
    rerender()

    await waitFor(() => expect(result.current.workspace).toBeNull())
    expect(result.current.workspaceId).toBeNull()

    // The stale response arrives after logout — it must be discarded
    // rather than repopulating this account's context.
    await act(async () => {
      resolveContext(userContext)
      await pending
    })

    expect(result.current.workspaceId).toBeNull()
    expect(result.current.parentName).toBeNull()
    expect(result.current.personalDataUuid).toBeNull()
    expect(result.current.children).toEqual([])
    expect(localStorage.getItem('workspaceId')).toBeNull()
  })

  it('throws when useWorkspace is used outside a WorkspaceProvider', () => {
    vi.mocked(useAuth).mockReturnValue(unauthenticated)

    expect(() => renderHook(() => useWorkspace())).toThrow(
      'useWorkspace must be used inside <WorkspaceProvider>',
    )
  })

  it('bumpPlanVersion increments planVersion, giving hooks watching it a reason to refetch', () => {
    vi.mocked(useAuth).mockReturnValue(unauthenticated)

    const { result } = renderHook(() => useWorkspace(), { wrapper })
    expect(result.current.planVersion).toBe(0)

    act(() => {
      result.current.bumpPlanVersion()
    })
    expect(result.current.planVersion).toBe(1)

    act(() => {
      result.current.bumpPlanVersion()
    })
    expect(result.current.planVersion).toBe(2)
  })
})