import type { Client } from '../../clients/createClient.js'
import type { Transport } from '../../clients/transports/createTransport.js'
import { AccountNotFoundError } from '../../errors/account.js'
import type { ErrorType } from '../../errors/utils.js'
import type {
  GetAccountParameter,
  JsonRpcAccount,
} from '../../types/account.js'
import type { Chain } from '../../types/chain.js'
import type {
  WalletCapabilities,
  WalletCapabilitiesRecord,
} from '../../types/eip1193.js'
import type { Prettify } from '../../types/utils.js'
import { parseAccount } from '../../utils/accounts.js'
import type { RequestErrorType } from '../../utils/buildRequest.js'

export type GetCapabilitiesParameters<
  account extends JsonRpcAccount | undefined = JsonRpcAccount | undefined,
> = GetAccountParameter<account>

export type GetCapabilitiesReturnType = Prettify<
  WalletCapabilitiesRecord<WalletCapabilities, number>
>

export type GetCapabilitiesErrorType = RequestErrorType | ErrorType

/**
 * Extract capabilities that a connected wallet supports (e.g. paymasters, session keys, etc).
 *
 * - Docs: https://viem.sh/experimental/actions/getCapabilities
 * - JSON-RPC Methods: [`wallet_getCapabilities`](https://eips.ethereum.org/EIPS/eip-5792)
 *
 * @param client - Client to use
 * @returns The wallet's capabilities. {@link GetCapabilitiesReturnType}
 *
 * @example
 * import { createWalletClient, custom } from 'viem'
 * import { mainnet } from 'viem/chains'
 * import { getCapabilities } from 'viem/wallet'
 *
 * const client = createWalletClient({
 *   chain: mainnet,
 *   transport: custom(window.ethereum),
 * })
 * const capabilities = await getCapabilities(client)
 */
export async function getCapabilities<
  chain extends Chain | undefined,
  account extends JsonRpcAccount | undefined = undefined,
>(
  ...parameters: account extends JsonRpcAccount
    ?
        | [client: Client<Transport, chain, account>]
        | [
            client: Client<Transport, chain, account>,
            parameters: GetCapabilitiesParameters<account>,
          ]
    : [
        client: Client<Transport, chain, account>,
        parameters: GetCapabilitiesParameters<account>,
      ]
): Promise<GetCapabilitiesReturnType> {
  const [client, args] = parameters
  const account_raw = args?.account ?? client.account

  if (!account_raw) throw new AccountNotFoundError()
  const account = parseAccount(account_raw)

  const capabilities_raw = await client.request({
    method: 'wallet_getCapabilities',
    params: [account.address],
  })

  const capabilities = {} as WalletCapabilitiesRecord<
    WalletCapabilities,
    number
  >
  for (const [key, value] of Object.entries(capabilities_raw))
    capabilities[Number(key)] = value
  return capabilities
}