/**
 * Auth: upsertUser color round-robin + identity stability
 *
 * Tests for apps/api/src/auth/user.ts (Plan 02)
 */

import { describe, it, expect, vi, beforeEach } from 'vitest'

// Mock the db singleton at module level (Vitest hoisting — must be top-level)
vi.mock('../../src/db/client.js', () => ({
  db: {
    select: vi.fn(),
    insert: vi.fn(),
  },
}))

// Import after mock is set up
import { db } from '../../src/db/client.js'
import { upsertUser, COLOR_PALETTE } from '../../src/auth/user.js'

const mockDb = db as {
  select: ReturnType<typeof vi.fn>
  insert: ReturnType<typeof vi.fn>
}

// Chainable builder factory used in multiple tests
function makeSelectChain(resolvedValue: unknown[]) {
  const chain = {
    from: vi.fn(),
    where: vi.fn(),
    limit: vi.fn().mockResolvedValue(resolvedValue),
  }
  chain.from.mockReturnValue(chain)
  chain.where.mockReturnValue(chain)
  return chain
}

function makeInsertChain(returningIdValue: { id: number }[]) {
  const chain = {
    values: vi.fn(),
    $returningId: vi.fn().mockResolvedValue(returningIdValue),
  }
  chain.values.mockReturnValue(chain)
  return chain
}

describe('COLOR_PALETTE', () => {
  it('exports at least 4 distinct hex colors', () => {
    expect(COLOR_PALETTE).toBeDefined()
    expect(COLOR_PALETTE.length).toBeGreaterThanOrEqual(4)
    for (const c of COLOR_PALETTE) {
      // Each entry must be a 7-char hex string like #4A90D9
      expect(c).toMatch(/^#[0-9A-Fa-f]{6}$/)
    }
    // All colors must be distinct
    const unique = new Set(COLOR_PALETTE)
    expect(unique.size).toBe(COLOR_PALETTE.length)
  })
})

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

  it('assigns palette[0] to the first user inserted', async () => {
    const iss = 'https://auth.example.com'
    const sub = 'user-sub-001'

    // First select: no existing user
    // Second select (count): count = 0
    // Third select (re-fetch after insert): return the inserted row
    let selectCallCount = 0
    mockDb.select.mockImplementation(() => {
      selectCallCount++
      if (selectCallCount === 1) {
        // Lookup by iss+sub — not found
        return makeSelectChain([])
      }
      if (selectCallCount === 2) {
        // COUNT(*) query — 0 users
        return {
          from: vi.fn().mockResolvedValue([{ count: 0 }]),
        }
      }
      // Re-fetch after insert
      return makeSelectChain([
        { id: 1, oidcIss: iss, oidcSub: sub, displayName: null, color: COLOR_PALETTE[0], createdAt: new Date() },
      ])
    })

    mockDb.insert.mockReturnValue(makeInsertChain([{ id: 1 }]))

    const user = await upsertUser(iss, sub)

    expect(user).toBeDefined()
    expect(user!.color).toBe(COLOR_PALETTE[0])
    expect(user!.id).toBe(1)
  })

  it('assigns palette[1] to the second distinct user', async () => {
    const iss = 'https://auth.example.com'
    const sub2 = 'user-sub-002'

    let selectCallCount = 0
    mockDb.select.mockImplementation(() => {
      selectCallCount++
      if (selectCallCount === 1) {
        return makeSelectChain([]) // not found
      }
      if (selectCallCount === 2) {
        // COUNT(*) — 1 existing user
        return {
          from: vi.fn().mockResolvedValue([{ count: 1 }]),
        }
      }
      return makeSelectChain([
        { id: 2, oidcIss: iss, oidcSub: sub2, displayName: null, color: COLOR_PALETTE[1], createdAt: new Date() },
      ])
    })

    mockDb.insert.mockReturnValue(makeInsertChain([{ id: 2 }]))

    const user = await upsertUser(iss, sub2)

    expect(user!.color).toBe(COLOR_PALETTE[1])
  })

  it('returns the same user row on re-upsert (idempotent — no duplicate insert)', async () => {
    const iss = 'https://auth.example.com'
    const sub = 'user-sub-001'
    const existingRow = {
      id: 1,
      oidcIss: iss,
      oidcSub: sub,
      displayName: 'Lucas',
      color: COLOR_PALETTE[0],
      createdAt: new Date(),
    }

    // select returns existing row immediately
    mockDb.select.mockImplementation(() => makeSelectChain([existingRow]))

    const user = await upsertUser(iss, sub, 'Lucas')

    // Must NOT call insert (idempotent path)
    expect(mockDb.insert).not.toHaveBeenCalled()
    expect(user!.id).toBe(1)
    expect(user!.color).toBe(COLOR_PALETTE[0])
  })

  it('uses oidc_iss + oidc_sub as identity key, never email', async () => {
    const iss = 'https://auth.example.com'
    const sub = 'user-sub-003'

    let selectCallCount = 0
    mockDb.select.mockImplementation(() => {
      selectCallCount++
      if (selectCallCount === 1) return makeSelectChain([])
      if (selectCallCount === 2) {
        return { from: vi.fn().mockResolvedValue([{ count: 0 }]) }
      }
      return makeSelectChain([
        { id: 3, oidcIss: iss, oidcSub: sub, displayName: null, color: COLOR_PALETTE[0], createdAt: new Date() },
      ])
    })
    mockDb.insert.mockReturnValue(makeInsertChain([{ id: 3 }]))

    // Pass a displayName (e.g. email) — identity still keyed on iss+sub
    await upsertUser(iss, sub, 'lucas@example.com')

    // The insert values must include oidcIss and oidcSub, not email as key
    const insertValues = mockDb.insert.mock.results[0]?.value?.values.mock.calls[0]?.[0]
    expect(insertValues).toBeDefined()
    expect(insertValues.oidcIss).toBe(iss)
    expect(insertValues.oidcSub).toBe(sub)
    // No 'email' property should be used as an identity field
    expect(insertValues).not.toHaveProperty('email')
  })

  it('returns the full user row including id, color, displayName', async () => {
    const iss = 'https://auth.example.com'
    const sub = 'user-sub-004'
    const existingRow = {
      id: 42,
      oidcIss: iss,
      oidcSub: sub,
      displayName: 'Alice',
      color: '#9B6DC5',
      createdAt: new Date(),
    }

    mockDb.select.mockImplementation(() => makeSelectChain([existingRow]))

    const user = await upsertUser(iss, sub, 'Alice')

    expect(user).toBeDefined()
    expect(user!.id).toBe(42)
    expect(user!.color).toBe('#9B6DC5')
    expect(user!.displayName).toBe('Alice')
  })
})