import { afterAll, beforeAll, describe, expect, it, vi } from 'vitest'
import { clear, load, save } from './restoreVerificationKeyCache'

const STORAGE_KEY = 'pdsmoover:restore-verification-key:v1'
const DID = 'did:plc:alice'
const OTHER_DID = 'did:plc:bob'
const PRIVATE_KEY = 'z3u2Yy8jVqExamplePrivateKey'
const PUBLIC_KEY = 'did:key:zQ3shExamplePublicKey'

class MemoryStorage {
  #store = new Map<string, string>()

  getItem(key: string): string | null {
    return this.#store.get(key) ?? null
  }

  setItem(key: string, value: string): void {
    this.#store.set(key, value)
  }

  removeItem(key: string): void {
    this.#store.delete(key)
  }
}

describe('restoreVerificationKeyCache', () => {
  let storage: MemoryStorage

  beforeAll(() => {
    storage = new MemoryStorage()
    vi.stubGlobal('localStorage', storage)
  })

  afterAll(() => {
    vi.unstubAllGlobals()
  })

  it('round-trips a saved key for its own DID', () => {
    save(DID, PRIVATE_KEY, PUBLIC_KEY)
    const loaded = load(DID)
    expect(loaded).not.toBeNull()
    expect(loaded?.did).toBe(DID)
    expect(loaded?.privateKey).toBe(PRIVATE_KEY)
    expect(loaded?.publicKey).toBe(PUBLIC_KEY)
    expect(typeof loaded?.savedAt).toBe('number')
  })

  it('ignores a saved key belonging to a different DID', () => {
    save(DID, PRIVATE_KEY, PUBLIC_KEY)
    expect(load(OTHER_DID)).toBeNull()
  })

  it('replaces the previous entry when saving for another DID', () => {
    save(DID, PRIVATE_KEY, PUBLIC_KEY)
    save(OTHER_DID, PRIVATE_KEY, PUBLIC_KEY)
    expect(load(DID)).toBeNull()
    expect(load(OTHER_DID)?.did).toBe(OTHER_DID)
  })

  it('clears the saved key', () => {
    save(DID, PRIVATE_KEY, PUBLIC_KEY)
    clear()
    expect(load(DID)).toBeNull()
    expect(storage.getItem(STORAGE_KEY)).toBeNull()
  })

  it('drops a corrupt entry', () => {
    storage.setItem(STORAGE_KEY, 'not json')
    expect(load(DID)).toBeNull()
    expect(storage.getItem(STORAGE_KEY)).toBeNull()
  })

  it('drops an entry with an unexpected shape', () => {
    storage.setItem(STORAGE_KEY, JSON.stringify({ did: DID, publicKey: PUBLIC_KEY }))
    expect(load(DID)).toBeNull()
    expect(storage.getItem(STORAGE_KEY)).toBeNull()
  })

  it('drops an entry whose private key is not a multikey', () => {
    storage.setItem(
      STORAGE_KEY,
      JSON.stringify({ did: DID, privateKey: 'not-a-multikey', publicKey: PUBLIC_KEY }),
    )
    expect(load(DID)).toBeNull()
    expect(storage.getItem(STORAGE_KEY)).toBeNull()
  })
})