import { describe, it, expect, beforeAll } from 'vitest'
import * as db from '../src/database.js'

// Regression test for the "two rows created when turning email alerts back on" bug.
//
// Decoded production sequence (Sep 18 2026):
//   13:42:05 register  → row 1 (unconfirmed), confirm email #1
//   13:44:35 DELETE    → row 1 tombstoned (unsubscribed_at set)
//   13:44:36 register  → OLD BUG: a brand-new row 2 was inserted, confirm email #2
//   14:02:32 confirm   → row 2 finally confirmed
//
// Fix: when the same pubkey re-subscribes to the same email after being
// unsubscribed, reactivate the tombstoned row instead of inserting a new one,
// preserving the existing confirmed state and key.

const unique = (label: string) => `${label}-${Date.now()}-${Math.random().toString(36).slice(2)}`

describe('Re-subscribe after DELETE reactivates the same subscription (off/on cycle)', () => {
  const pubkey = unique('resub')
  const email = `${unique('resub')}@example.com`

  beforeAll(async () => {
    await db.migrate()
  })

  it('creates an unconfirmed subscription', async () => {
    const sub = await db.insertSubscription(pubkey, email, 'daily')
    expect(sub).toBeTruthy()
    expect(sub.confirmed_at).toBeFalsy()
    expect(sub.unsubscribed_at).toBeFalsy()
  })

  it('confirms it (user clicks the confirm link)', async () => {
    const active = await db.getSubscriptionByPubkey(pubkey)
    const result = await db.confirmSubscription(active!.key)
    expect(result).toBeTruthy()
    expect(result!.alreadyConfirmed).toBe(false)
    expect(result!.sub.confirmed_at).toBeTruthy()
  })

  it('unsubscribes it (the flotilla DELETE path)', async () => {
    const active = await db.getSubscriptionByPubkey(pubkey)
    const gone = await db.unsubscribeSubscription(active!.key)
    expect(gone).toBeTruthy()
    expect(gone!.unsubscribed_at).toBeTruthy()
    expect(await db.getSubscriptionByPubkey(pubkey)).toBeFalsy()
  })

  it('re-registers the SAME email — must reactivate row, NOT create a second row', async () => {
    const resigned = await db.insertSubscription(pubkey, email, 'daily')

    // Restores the very same row
    const active = await db.getSubscriptionByPubkey(pubkey)
    expect(active).toBeTruthy()
    expect(active!.key).toBe(resigned.key)
    expect(active!.unsubscribed_at).toBeFalsy()

    // Confirmed state is preserved — no second confirmation email needed
    expect(active!.confirmed_at).toBeTruthy()

    // Exhaustive: there exists exactly one row total for this pubkey
    const rows = await db.getAllSubscriptionsByPubkey(pubkey)
    expect(rows).toHaveLength(1)
    expect(rows[0].id).toBe(active!.id)
  })
})

describe('Re-subscribe after DELETE before ever confirming', () => {
  const pubkey = unique('resub-unconfirmed')
  const email = `${unique('resub-unconfirmed')}@example.com`

  beforeAll(async () => {
    await db.migrate()
  })

  it('registers then unsubscribes without confirming', async () => {
    const sub = await db.insertSubscription(pubkey, email, 'daily')
    await db.unsubscribeSubscription(sub.key)
    expect(await db.getSubscriptionByPubkey(pubkey)).toBeFalsy()
  })

  it('re-registers the same email — reactivates same row, still unconfirmed', async () => {
    const resigned = await db.insertSubscription(pubkey, email, 'daily')
    const active = await db.getSubscriptionByPubkey(pubkey)

    expect(active!.key).toBe(resigned.key)
    expect(active!.id).toBe(resigned.id)
    expect(active!.unsubscribed_at).toBeFalsy()
    // Was never confirmed, and re-subscribing does not skip confirmation
    expect(active!.confirmed_at).toBeFalsy()

    const rows = await db.getAllSubscriptionsByPubkey(pubkey)
    expect(rows).toHaveLength(1)
  })
})

describe('Re-subscribe with a DIFFERENT email after DELETE', () => {
  const pubkey = unique('resub-2')
  const email = `${unique('resub-2')}@example.com`

  beforeAll(async () => {
    await db.migrate()
  })

  it('registers, confirms, and unsubscribes', async () => {
    const sub = await db.insertSubscription(pubkey, email, 'daily')
    await db.confirmSubscription(sub.key)
    await db.unsubscribeSubscription(sub.key)
    expect(await db.getSubscriptionByPubkey(pubkey)).toBeFalsy()
  })

  it('a new email creates a new row, leaving the old one tombstoned', async () => {
    const newEmail = `${unique('resub-2-new')}@example.com`
    const resigned = await db.insertSubscription(pubkey, newEmail, 'daily')

    expect(resigned.email).toBe(newEmail)
    expect(resigned.confirmed_at).toBeFalsy() // new address must re-confirm

    const rows = await db.getAllSubscriptionsByPubkey(pubkey)
    expect(rows).toHaveLength(2)
    expect(rows[0].email).toBe(email) // old, tombstoned
    expect(rows[0].unsubscribed_at).toBeTruthy()
    expect(rows[1].email).toBe(newEmail) // new, active
    expect(rows[1].unsubscribed_at).toBeFalsy()
  })
})

describe('Re-subscribe with a changed frequency reactivates and updates cadence', () => {
  const pubkey = unique('resub-freq')
  const email = `${unique('resub-freq')}@example.com`

  beforeAll(async () => {
    await db.migrate()
  })

  it('registers confirm-free, unsubscribes', async () => {
    const sub = await db.insertSubscription(pubkey, email, 'daily')
    await db.unsubscribeSubscription(sub.key)
  })

  it('re-registers with weekly — reactivates the same row at the new cadence', async () => {
    const resigned = await db.insertSubscription(pubkey, email, 'weekly')
    const active = await db.getSubscriptionByPubkey(pubkey)

    expect(active!.key).toBe(resigned.key)
    expect(active!.frequency).toBe('weekly')
    expect(active!.unsubscribed_at).toBeFalsy()

    const rows = await db.getAllSubscriptionsByPubkey(pubkey)
    expect(rows).toHaveLength(1)
  })
})