import type { Address } from 'abitype'
import type { Hash } from '../../../types/misc.js'
import { encodeAbiParameters } from '../../../utils/abi/encodeAbiParameters.js'
import { concat } from '../../../utils/data/concat.js'
import { pad } from '../../../utils/data/pad.js'
import { numberToHex } from '../../../utils/encoding/toHex.js'
import { keccak256 } from '../../../utils/hash/keccak256.js'
import type { EntryPointVersion } from '../../types/entryPointVersion.js'
import type { UserOperation } from '../../types/userOperation.js'

export type GetUserOperationHashParameters<
  entryPointVersion extends EntryPointVersion = EntryPointVersion,
> = {
  chainId: number
  entryPointAddress: Address
  entryPointVersion: entryPointVersion | EntryPointVersion
  userOperation: UserOperation<entryPointVersion>
}

export type GetUserOperationHashReturnType = Hash

export function getUserOperationHash<
  entryPointVersion extends EntryPointVersion,
>(
  parameters: GetUserOperationHashParameters<entryPointVersion>,
): GetUserOperationHashReturnType {
  const { chainId, entryPointAddress, entryPointVersion } = parameters
  const userOperation = parameters.userOperation as UserOperation
  const {
    callData,
    callGasLimit,
    initCode,
    maxFeePerGas,
    maxPriorityFeePerGas,
    nonce,
    paymasterAndData,
    preVerificationGas,
    sender,
    verificationGasLimit,
  } = userOperation

  const packedUserOp = (() => {
    if (entryPointVersion === '0.6') {
      return encodeAbiParameters(
        [
          { type: 'address' },
          { type: 'uint256' },
          { type: 'bytes32' },
          { type: 'bytes32' },
          { type: 'uint256' },
          { type: 'uint256' },
          { type: 'uint256' },
          { type: 'uint256' },
          { type: 'uint256' },
          { type: 'bytes32' },
        ],
        [
          sender,
          nonce,
          keccak256(initCode ?? '0x'),
          keccak256(callData ?? '0x'),
          callGasLimit,
          verificationGasLimit,
          preVerificationGas,
          maxFeePerGas,
          maxPriorityFeePerGas,
          keccak256(paymasterAndData ?? '0x'),
        ],
      )
    }

    if (entryPointVersion === '0.7') {
      const accountGasLimits = concat([
        pad(numberToHex(userOperation.verificationGasLimit), { size: 16 }),
        pad(numberToHex(userOperation.callGasLimit), { size: 16 }),
      ])
      const callData_hashed = keccak256(callData)
      const gasFees = concat([
        pad(numberToHex(userOperation.maxPriorityFeePerGas), { size: 16 }),
        pad(numberToHex(userOperation.maxFeePerGas), { size: 16 }),
      ])
      const initCode_hashed = keccak256(
        userOperation.factory && userOperation.factoryData
          ? concat([userOperation.factory, userOperation.factoryData])
          : '0x',
      )
      const paymasterAndData_hashed = keccak256(
        userOperation.paymaster
          ? concat([
              userOperation.paymaster,
              pad(
                numberToHex(userOperation.paymasterVerificationGasLimit || 0),
                {
                  size: 16,
                },
              ),
              pad(numberToHex(userOperation.paymasterPostOpGasLimit || 0), {
                size: 16,
              }),
              userOperation.paymasterData || '0x',
            ])
          : '0x',
      )

      return encodeAbiParameters(
        [
          { type: 'address' },
          { type: 'uint256' },
          { type: 'bytes32' },
          { type: 'bytes32' },
          { type: 'bytes32' },
          { type: 'uint256' },
          { type: 'bytes32' },
          { type: 'bytes32' },
        ],
        [
          sender,
          nonce,
          initCode_hashed,
          callData_hashed,
          accountGasLimits,
          preVerificationGas,
          gasFees,
          paymasterAndData_hashed,
        ],
      )
    }

    throw new Error(`entryPointVersion "${entryPointVersion}" not supported.`)
  })()

  return keccak256(
    encodeAbiParameters(
      [{ type: 'bytes32' }, { type: 'address' }, { type: 'uint256' }],
      [keccak256(packedUserOp), entryPointAddress, BigInt(chainId)],
    ),
  )
}