import { describe, it, expect, vi, beforeEach } from 'vitest'
import '../../../test/__mocks__/prisma'

import {
  hashToken,
  hashPassword,
  verifyPassword,
  validatePasswordStrength,
  createSession,
  getSessionToken,
  getSession,
  getCurrentUser,
  deleteSession,
  deleteAllUserSessions,
} from '@/lib/auth'
import { prisma } from '@/lib/prisma'
import { mockUser, mockSession } from '../../fixtures/users'
import { cookies } from 'next/headers'

// ─── hashToken ───────────────────────────────────────────────────────────────

describe('hashToken', () => {
  it('returns a 64-char hex string', () => {
    const hash = hashToken('sometoken')
    expect(hash).toMatch(/^[a-f0-9]{64}$/)
  })

  it('is deterministic for the same input', () => {
    expect(hashToken('abc')).toBe(hashToken('abc'))
  })

  it('produces different hashes for different inputs', () => {
    expect(hashToken('abc')).not.toBe(hashToken('xyz'))
  })
})

// ─── hashPassword / verifyPassword ───────────────────────────────────────────

describe('hashPassword / verifyPassword', () => {
  it('hashes a password and verifies it correctly', async () => {
    const hash = await hashPassword('MyPassword1!')
    expect(await verifyPassword('MyPassword1!', hash)).toBe(true)
  })

  it('returns false for wrong password', async () => {
    const hash = await hashPassword('MyPassword1!')
    expect(await verifyPassword('WrongPassword1!', hash)).toBe(false)
  })

  it('produces different hashes for the same password (bcrypt salt)', async () => {
    const h1 = await hashPassword('SamePass1!')
    const h2 = await hashPassword('SamePass1!')
    expect(h1).not.toBe(h2)
  })
})

// ─── validatePasswordStrength ─────────────────────────────────────────────────

describe('validatePasswordStrength', () => {
  it('returns null for a strong password', () => {
    expect(validatePasswordStrength('StrongPass1!')).toBeNull()
  })

  it('rejects password shorter than 12 chars', () => {
    expect(validatePasswordStrength('Short1!')).toMatch(/12 characters/)
  })

  it('rejects password without uppercase', () => {
    expect(validatePasswordStrength('nouppercase1!')).toMatch(/uppercase/)
  })

  it('rejects password without lowercase', () => {
    expect(validatePasswordStrength('NOLOWERCASE1!')).toMatch(/lowercase/)
  })

  it('rejects password without number', () => {
    expect(validatePasswordStrength('NoNumberHere!')).toMatch(/number/)
  })

  it('rejects password without symbol', () => {
    expect(validatePasswordStrength('NoSymbolHere12')).toMatch(/symbol/)
  })

  it('checks length first (shortest error message path)', () => {
    expect(validatePasswordStrength('short')).toMatch(/12 characters/)
  })
})

// ─── createSession ────────────────────────────────────────────────────────────

describe('createSession', () => {
  beforeEach(() => {
    vi.clearAllMocks()
    vi.mocked(prisma.session.create).mockResolvedValue(mockSession)
  })

  it('creates a session in DB and returns a token string', async () => {
    const token = await createSession(mockUser.id)
    expect(typeof token).toBe('string')
    expect(token.length).toBeGreaterThan(0)
  })

  it('calls prisma.session.create with userId and tokenHash', async () => {
    const token = await createSession(mockUser.id)
    expect(prisma.session.create).toHaveBeenCalledWith(
      expect.objectContaining({
        data: expect.objectContaining({ userId: mockUser.id }),
      })
    )
    const callArg = vi.mocked(prisma.session.create).mock.calls[0][0]
    const tokenHash = hashToken(token)
    expect(callArg.data.tokenHash).toBe(tokenHash)
  })

  it('sets expiry ~30 days from now', async () => {
    await createSession(mockUser.id)
    const callArg = vi.mocked(prisma.session.create).mock.calls[0][0]
    const expiresAt = callArg.data.expiresAt as Date
    const diffDays = (expiresAt.getTime() - Date.now()) / (1000 * 60 * 60 * 24)
    expect(diffDays).toBeCloseTo(30, 0)
  })
})

// ─── getSessionToken ──────────────────────────────────────────────────────────

describe('getSessionToken', () => {
  it('returns token from cookie', async () => {
    const mockCookieStore = { get: vi.fn().mockReturnValue({ value: 'mytoken' }), set: vi.fn(), delete: vi.fn() }
    vi.mocked(cookies).mockReturnValue(mockCookieStore as any)
    expect(await getSessionToken()).toBe('mytoken')
  })

  it('returns null when cookie is missing', async () => {
    const mockCookieStore = { get: vi.fn().mockReturnValue(undefined), set: vi.fn(), delete: vi.fn() }
    vi.mocked(cookies).mockReturnValue(mockCookieStore as any)
    expect(await getSessionToken()).toBeNull()
  })
})

// ─── getSession ───────────────────────────────────────────────────────────────

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

  it('returns null when no token cookie', async () => {
    const mockCookieStore = { get: vi.fn().mockReturnValue(undefined), set: vi.fn(), delete: vi.fn() }
    vi.mocked(cookies).mockReturnValue(mockCookieStore as any)
    expect(await getSession()).toBeNull()
  })

  it('returns session when token is valid and not expired', async () => {
    const mockCookieStore = { get: vi.fn().mockReturnValue({ value: 'validtoken' }), set: vi.fn(), delete: vi.fn() }
    vi.mocked(cookies).mockReturnValue(mockCookieStore as any)
    vi.mocked(prisma.session.findUnique).mockResolvedValue(mockSession as any)

    const session = await getSession()
    expect(session).not.toBeNull()
    expect(session?.user.id).toBe(mockUser.id)
  })

  it('returns null and deletes session when expired', async () => {
    const mockCookieStore = { get: vi.fn().mockReturnValue({ value: 'expiredtoken' }), set: vi.fn(), delete: vi.fn() }
    vi.mocked(cookies).mockReturnValue(mockCookieStore as any)
    const expiredSession = { ...mockSession, expiresAt: new Date(Date.now() - 1000) }
    vi.mocked(prisma.session.findUnique).mockResolvedValue(expiredSession as any)
    vi.mocked(prisma.session.delete).mockResolvedValue(expiredSession as any)

    const result = await getSession()
    expect(result).toBeNull()
    expect(prisma.session.delete).toHaveBeenCalledWith({ where: { id: expiredSession.id } })
  })

  it('returns null when session not found in DB', async () => {
    const mockCookieStore = { get: vi.fn().mockReturnValue({ value: 'unknowntoken' }), set: vi.fn(), delete: vi.fn() }
    vi.mocked(cookies).mockReturnValue(mockCookieStore as any)
    vi.mocked(prisma.session.findUnique).mockResolvedValue(null)

    expect(await getSession()).toBeNull()
  })
})

// ─── getCurrentUser ───────────────────────────────────────────────────────────

describe('getCurrentUser', () => {
  it('returns user from valid session', async () => {
    const mockCookieStore = { get: vi.fn().mockReturnValue({ value: 'validtoken' }), set: vi.fn(), delete: vi.fn() }
    vi.mocked(cookies).mockReturnValue(mockCookieStore as any)
    vi.mocked(prisma.session.findUnique).mockResolvedValue(mockSession as any)

    const user = await getCurrentUser()
    expect(user?.id).toBe(mockUser.id)
  })

  it('returns null when no session', async () => {
    const mockCookieStore = { get: vi.fn().mockReturnValue(undefined), set: vi.fn(), delete: vi.fn() }
    vi.mocked(cookies).mockReturnValue(mockCookieStore as any)

    expect(await getCurrentUser()).toBeNull()
  })
})

// ─── deleteSession / deleteAllUserSessions ────────────────────────────────────

describe('deleteSession', () => {
  it('calls prisma.session.deleteMany with the correct tokenHash', async () => {
    vi.mocked(prisma.session.deleteMany).mockResolvedValue({ count: 1 })
    await deleteSession('mytoken')
    expect(prisma.session.deleteMany).toHaveBeenCalledWith({
      where: { tokenHash: hashToken('mytoken') },
    })
  })
})

describe('deleteAllUserSessions', () => {
  it('calls prisma.session.deleteMany with the userId', async () => {
    vi.mocked(prisma.session.deleteMany).mockResolvedValue({ count: 3 })
    await deleteAllUserSessions('user-123')
    expect(prisma.session.deleteMany).toHaveBeenCalledWith({ where: { userId: 'user-123' } })
  })
})