import { describe, it, expect, beforeEach, vi } from 'vitest'
import { randomUUID } from 'node:crypto'

// Stub the social-identity verifiers so Google/Apple tests don't need real
// id_tokens. Each test passes the synthetic payload directly via the
// id_token string and the mock returns it parsed.
vi.mock('../../src/services/social-identity.service.js', () => ({
  verifyGoogleIdToken: vi.fn(async (idToken) => JSON.parse(idToken)),
  verifyAppleIdToken:  vi.fn(async (idToken) => JSON.parse(idToken)),
}))

const {
  completeCustomerPhoneSignIn,
  signInWithGoogle,
  signInWithApple,
} = await import('../../src/services/auth.service.js')
const { db, resetDb } = await import('../helpers/db.js')
const { createCustomer } = await import('../helpers/fixtures.js')

// Phase 4 §2.1 — Anonymous → existing-user merge breadcrumb.
//
// `resetDb` does NOT truncate the customers table (see helpers/db.js); each
// test must use a phone that's unique across runs to avoid colliding with rows
// left behind by prior runs.
const uniquePhone = () => {
  const digits = randomUUID().replace(/[^0-9]/g, '').slice(0, 11).padEnd(11, '0')
  return `+628${digits}`
}

describe('completeCustomerPhoneSignIn — Phase 4 §2.1 merge breadcrumb', () => {
  beforeEach(async () => {
    await resetDb()
  })

  // --- Case 4: no anon prefix, new phone ---
  it('creates a fresh identified customer with null display_name (no anon, new phone)', async () => {
    const phone = uniquePhone()

    const { profile } = await completeCustomerPhoneSignIn({
      phone,
      anonymousCustomerId: null,
      deviceInfo: {},
    })

    expect(profile.phone).toBe(phone)
    expect(profile.display_name).toBeNull()
    expect(profile.is_anonymous).toBe(false)
    expect(profile.account_belongs_to).toBeNull()
  })

  // --- Case 3: anon prefix, new phone → upgrade in place ---
  it('upgrades the anon row in place, preserving display_name (anon, new phone)', async () => {
    const phone = uniquePhone()
    const anon = await createCustomer({ callName: 'Bujak', isAnonymous: true })

    const { profile } = await completeCustomerPhoneSignIn({
      phone,
      anonymousCustomerId: anon.id,
      deviceInfo: {},
    })

    expect(profile.id).toBe(anon.id)               // same row, upgraded
    expect(profile.phone).toBe(phone)
    expect(profile.display_name).toBe('Bujak')     // preserved via COALESCE
    expect(profile.is_anonymous).toBe(false)
    expect(profile.account_belongs_to).toBeNull()  // no merge

    // No new customer row was created.
    const sql = db()
    const [{ count }] = await sql`SELECT COUNT(*)::int AS count FROM customers WHERE phone = ${phone}`
    expect(count).toBe(1)
  })

  // --- Case 1: anon prefix, existing phone → stamp breadcrumb, return existing ---
  it('stamps account_belongs_to on the anon row and returns the existing customer (anon, existing phone)', async () => {
    const phone = uniquePhone()
    const existing = await createCustomer({ callName: 'Wati', phone, isAnonymous: false })
    const anon = await createCustomer({ callName: 'Bujak', isAnonymous: true })

    const { profile, tokens } = await completeCustomerPhoneSignIn({
      phone,
      anonymousCustomerId: anon.id,
      deviceInfo: {},
    })

    // The session logs in AS the existing user.
    expect(profile.id).toBe(existing.id)
    expect(profile.display_name).toBe('Wati')      // existing's name, overwrites local
    expect(profile.phone).toBe(phone)
    expect(profile.account_belongs_to).toBeNull()  // existing row is the target, not stamped

    // Token claims point at the existing user (so subsequent requests act as them).
    expect(tokens.access_token).toBeDefined()

    // Anon row stays intact, now carries the merge breadcrumb.
    const sql = db()
    const [anonRow] = await sql`SELECT id, display_name, account_belongs_to, is_anonymous FROM customers WHERE id = ${anon.id}`
    expect(anonRow).toBeDefined()                           // not deleted
    expect(anonRow.display_name).toBe('Bujak')              // preserved
    expect(anonRow.account_belongs_to).toBe(existing.id)    // breadcrumb stamped
    expect(anonRow.is_anonymous).toBe(true)                 // still anon (for later reconciliation)
  })

  // --- Case 2a: no anon prefix, existing phone → return existing, no stamping ---
  it('returns the existing customer as-is when no anon prefix (existing phone, fresh app)', async () => {
    const phone = uniquePhone()
    const existing = await createCustomer({ callName: 'Wati', phone, isAnonymous: false })

    const { profile } = await completeCustomerPhoneSignIn({
      phone,
      anonymousCustomerId: null,
      deviceInfo: {},
    })

    expect(profile.id).toBe(existing.id)
    expect(profile.display_name).toBe('Wati')
    expect(profile.account_belongs_to).toBeNull()
  })

  // --- Case 2b: anon id === existing's id (user re-verifying own phone) ---
  // No-op merge. account_belongs_to stays null; no self-reference is created.
  it('does not self-stamp when the anon id equals the existing customer id (re-verify)', async () => {
    const phone = uniquePhone()
    const existing = await createCustomer({ callName: 'Wati', phone, isAnonymous: false })

    const { profile } = await completeCustomerPhoneSignIn({
      phone,
      anonymousCustomerId: existing.id,   // same id as the existing row
      deviceInfo: {},
    })

    expect(profile.id).toBe(existing.id)
    expect(profile.account_belongs_to).toBeNull()

    // Verify nothing self-referenced.
    const sql = db()
    const [row] = await sql`SELECT account_belongs_to FROM customers WHERE id = ${existing.id}`
    expect(row.account_belongs_to).toBeNull()
  })

  // --- Google: stamp breadcrumb on existing-different-id (parity with phone) ---
  it('Google: stamps account_belongs_to when existing google_sub differs from anon (Case 1)', async () => {
    const googleSub = `g-${randomUUID()}`
    const [existing] = await db()`
      INSERT INTO customers (display_name, is_anonymous, google_sub, email)
      VALUES ('Wati', false, ${googleSub}, 'wati@example.com')
      RETURNING ${db()`id, display_name, is_anonymous, phone, email, google_sub, apple_sub, usp_seen, account_belongs_to, created_at`}
    `
    const anon = await createCustomer({ callName: 'Bujak', isAnonymous: true })

    const { profile } = await signInWithGoogle({
      idToken: JSON.stringify({ sub: googleSub, email: 'wati@example.com' }),
      anonymousCustomerId: anon.id,
      deviceInfo: {},
    })

    expect(profile.id).toBe(existing.id)
    expect(profile.display_name).toBe('Wati')

    const [anonRow] = await db()`SELECT account_belongs_to FROM customers WHERE id = ${anon.id}`
    expect(anonRow.account_belongs_to).toBe(existing.id)
  })

  // --- Google: upgrade-in-place when google_sub is new ---
  it('Google: upgrades anon in place when google_sub is new, preserving display_name (Case 3)', async () => {
    const googleSub = `g-${randomUUID()}`
    const anon = await createCustomer({ callName: 'Bujak', isAnonymous: true })

    const { profile } = await signInWithGoogle({
      idToken: JSON.stringify({ sub: googleSub, email: 'bujak@example.com' }),
      anonymousCustomerId: anon.id,
      deviceInfo: {},
    })

    expect(profile.id).toBe(anon.id)
    expect(profile.google_sub).toBe(googleSub)
    expect(profile.email).toBe('bujak@example.com')
    expect(profile.display_name).toBe('Bujak')
    expect(profile.is_anonymous).toBe(false)
    expect(profile.account_belongs_to).toBeNull()
  })

  // --- Apple: stamp breadcrumb on existing-different-id (parity with phone) ---
  it('Apple: stamps account_belongs_to when existing apple_sub differs from anon (Case 1)', async () => {
    const appleSub = `a-${randomUUID()}`
    const [existing] = await db()`
      INSERT INTO customers (display_name, is_anonymous, apple_sub, email)
      VALUES ('Wati', false, ${appleSub}, 'wati@apple.example')
      RETURNING ${db()`id, display_name, is_anonymous, phone, email, google_sub, apple_sub, usp_seen, account_belongs_to, created_at`}
    `
    const anon = await createCustomer({ callName: 'Bujak', isAnonymous: true })

    const { profile } = await signInWithApple({
      idToken: JSON.stringify({ sub: appleSub, email: 'wati@apple.example' }),
      anonymousCustomerId: anon.id,
      deviceInfo: {},
    })

    expect(profile.id).toBe(existing.id)
    expect(profile.display_name).toBe('Wati')

    const [anonRow] = await db()`SELECT account_belongs_to FROM customers WHERE id = ${anon.id}`
    expect(anonRow.account_belongs_to).toBe(existing.id)
  })

  // --- Multi-merge: same anon path used twice for the same existing user accumulates without conflict ---
  it('handles multiple anon rows pointing at the same existing user (multi-merge accumulation)', async () => {
    const phone = uniquePhone()
    const existing = await createCustomer({ callName: 'Wati', phone, isAnonymous: false })
    const anon1 = await createCustomer({ callName: 'Bujak', isAnonymous: true })
    const anon2 = await createCustomer({ callName: 'Bendoyo', isAnonymous: true })

    await completeCustomerPhoneSignIn({ phone, anonymousCustomerId: anon1.id, deviceInfo: {} })
    await completeCustomerPhoneSignIn({ phone, anonymousCustomerId: anon2.id, deviceInfo: {} })

    const sql = db()
    const rows = await sql`SELECT id, account_belongs_to FROM customers WHERE id IN (${anon1.id}, ${anon2.id}) ORDER BY display_name`
    expect(rows).toHaveLength(2)
    for (const row of rows) {
      expect(row.account_belongs_to).toBe(existing.id)
    }
  })
})