import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest'
import { renderHook } from '@testing-library/react'
import { useTrialBanner } from './useTrialBanner'
import { useBillingStore } from '@/store/billingStore'
import type { SubscriptionState } from '@/types/billing'

const FROZEN_NOW = new Date('2026-05-06T00:00:00Z')

function makeSub(overrides: Partial<SubscriptionState>): SubscriptionState {
  return {
    status: 'trialing',
    plan: 'starter',
    current_period_start: '2026-05-01T00:00:00Z',
    current_period_end: null,
    cancel_at_period_end: false,
    seat_limit: null,
    has_pro_entitlement: false,
    is_paid: false,
    ...overrides,
  }
}

function setSubscription(overrides: Partial<SubscriptionState>) {
  useBillingStore.setState({ subscription: makeSub(overrides) })
}

describe('useTrialBanner', () => {
  beforeEach(() => {
    vi.useFakeTimers()
    vi.setSystemTime(FROZEN_NOW)
    useBillingStore.setState({
      subscription: null,
      planBilling: null,
      planLimits: {},
      enabledFeatures: {},
      isLoading: false,
      error: null,
    })
  })

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

  describe('stage matches subscription state matrix', () => {
    it('returns null when subscription is null (no flicker on initial load)', () => {
      const { result } = renderHook(() => useTrialBanner())
      expect(result.current.stage).toBe(null)
      expect(result.current.daysRemaining).toBe(null)
    })

    it('complimentary status -> complimentary stage', () => {
      setSubscription({ status: 'complimentary' })
      const { result } = renderHook(() => useTrialBanner())
      expect(result.current.stage).toBe('complimentary')
    })

    it('active status -> paid stage', () => {
      setSubscription({ status: 'active' })
      const { result } = renderHook(() => useTrialBanner())
      expect(result.current.stage).toBe('paid')
    })

    it('past_due status -> past_due stage', () => {
      setSubscription({ status: 'past_due' })
      const { result } = renderHook(() => useTrialBanner())
      expect(result.current.stage).toBe('past_due')
    })

    it('canceled status -> canceled stage', () => {
      setSubscription({ status: 'canceled' })
      const { result } = renderHook(() => useTrialBanner())
      expect(result.current.stage).toBe('canceled')
    })

    it('trialing >3 days remaining -> pristine', () => {
      // 7 days from frozen now.
      setSubscription({
        status: 'trialing',
        current_period_end: '2026-05-13T00:00:00Z',
      })
      const { result } = renderHook(() => useTrialBanner())
      expect(result.current.stage).toBe('pristine')
      expect(result.current.daysRemaining).toBe(7)
    })

    it('trialing 1-3 days remaining -> warning', () => {
      // 2 days from frozen now.
      setSubscription({
        status: 'trialing',
        current_period_end: '2026-05-08T00:00:00Z',
      })
      const { result } = renderHook(() => useTrialBanner())
      expect(result.current.stage).toBe('warning')
      expect(result.current.daysRemaining).toBe(2)
    })

    it('trialing exactly 24 hours remaining -> warning (boundary, not urgent)', () => {
      // Exactly 1.0 fractional day from frozen now — must sit on the warning
      // side per spec (1–3 days inclusive of 1).
      setSubscription({
        status: 'trialing',
        current_period_end: '2026-05-07T00:00:00Z',
      })
      const { result } = renderHook(() => useTrialBanner())
      expect(result.current.stage).toBe('warning')
      expect(result.current.daysRemaining).toBe(1)
    })

    it('trialing <1 day remaining -> urgent', () => {
      // 12 hours from frozen now -> Math.ceil(0.5) = 1 day.
      setSubscription({
        status: 'trialing',
        current_period_end: '2026-05-06T12:00:00Z',
      })
      const { result } = renderHook(() => useTrialBanner())
      expect(result.current.stage).toBe('urgent')
      expect(result.current.daysRemaining).toBe(1)
    })

    it('trialing past period_end -> expired', () => {
      setSubscription({
        status: 'trialing',
        current_period_end: '2026-05-01T00:00:00Z',
      })
      const { result } = renderHook(() => useTrialBanner())
      expect(result.current.stage).toBe('expired')
      expect(result.current.daysRemaining).toBe(0)
    })
  })
})