import { describe, it, expect } from 'vitest'
import { toBip122WireAccount } from './BridgeParent'

/**
 * Regression guard for the bip122 account wire shape.
 *
 * Framed bip122 connect failed for every wallet until `toBip122WireAccount`
 * existed: Comlink marshals with the structured clone algorithm, which copies
 * only OWN ENUMERABLE properties, and MetaMask's bitcoin account is a class
 * instance whose `address`/`publicKey` live as accessors on the prototype. The
 * child therefore received `{}` and the adapter's first
 * `bytesToHex(account.publicKey)` threw "bytes is not iterable" — before the
 * request ever reached the wallet.
 *
 * `structuredClone` is used directly rather than a real MessageChannel: it IS
 * the algorithm `postMessage` applies, and isolating it keeps the failing
 * mechanism visible instead of buried in transport setup.
 */

/**
 * Stand-in for a wallet-native account.
 *
 * The `#` private fields are load-bearing — they are what makes
 * `Object.getOwnPropertyNames(account)` empty, exactly as observed on
 * MetaMask's real account object. A fixture using ordinary properties would
 * survive a structured clone and would therefore pass against the very bug
 * this file exists to catch.
 */
class WalletNativeAccount {
  readonly #address: string
  readonly #publicKey: Uint8Array
  readonly #purpose?: string

  constructor(address: string, publicKey: Uint8Array, purpose?: string) {
    this.#address = address
    this.#publicKey = publicKey
    this.#purpose = purpose
  }

  get address(): string {
    return this.#address
  }
  get publicKey(): Uint8Array {
    return this.#publicKey
  }
  get purpose(): string | undefined {
    return this.#purpose
  }
}

const ADDRESS = 'bc1qjxztncefrl5czfyfxd449t8tht634g9cnaz5ka'
const PUBLIC_KEY = Uint8Array.from([3, 65, 234, 69, 78, 93, 165, 185, 148])

describe('toBip122WireAccount', () => {
  it('confirms the flattening this transform exists to prevent', () => {
    const account = new WalletNativeAccount(ADDRESS, PUBLIC_KEY, 'payment')

    // The accessors are on the prototype, so the instance owns nothing...
    expect(Object.getOwnPropertyNames(account)).toEqual([])

    // ...and a structured clone consequently carries no data at all.
    const cloned = structuredClone(account) as Record<string, unknown>
    expect(Object.keys(cloned)).toEqual([])
    expect(cloned.address).toBeUndefined()
    expect(cloned.publicKey).toBeUndefined()
  })

  it('survives a structured clone with every field the adapter reads', () => {
    const account = new WalletNativeAccount(ADDRESS, PUBLIC_KEY, 'payment')

    const cloned = structuredClone(toBip122WireAccount(account))

    // These three are exactly what wallet-standard.ts `getAccounts` consumes.
    expect(cloned.address).toBe(ADDRESS)
    expect(cloned.publicKey).toEqual([3, 65, 234, 69, 78, 93, 165, 185, 148])
    expect(cloned.purpose).toBe('payment')
  })

  it('sends publicKey as a plain array so the wire carries no typed-array assumption', () => {
    const wire = toBip122WireAccount(
      new WalletNativeAccount(ADDRESS, PUBLIC_KEY)
    )

    expect(Array.isArray(wire.publicKey)).toBe(true)
    expect(wire.publicKey).not.toBeInstanceOf(Uint8Array)
  })

  it('omits purpose when the wallet does not report one', () => {
    const wire = toBip122WireAccount(
      new WalletNativeAccount(ADDRESS, PUBLIC_KEY)
    )

    expect('purpose' in wire).toBe(false)
  })

  it('marshals a wallet that already hands back plain data identically', () => {
    // Not every bip122 wallet uses accessor-backed classes; a plain object with
    // a number-array publicKey must produce the same wire shape.
    const wire = toBip122WireAccount({
      address: ADDRESS,
      publicKey: [3, 65, 234],
      purpose: 'ordinal'
    })

    expect(wire).toEqual({
      address: ADDRESS,
      publicKey: [3, 65, 234],
      purpose: 'ordinal'
    })
  })

  it('tolerates a missing publicKey rather than throwing mid-discovery', () => {
    // Discovery maps EVERY account; one malformed entry must not take down the
    // whole wallet list.
    const wire = toBip122WireAccount({ address: ADDRESS })

    expect(wire.publicKey).toEqual([])
  })
})