import { gql } from 'graphql-request'
import { type Address } from 'viem'
import type { ClientWithPns } from '../../contracts/consts.js'
import { createSubgraphClient } from './client.js'

export type GetReferralStatsParameters = {
  /** The referral address for */
  address: Address
}

export type GetReferralStatsReturnType = {
  id: string,
  count: number,
  commission: string
}

const query = gql`
  query getReferralStats($address: ID!) {
    referrer(id: $address) {
      id
      count
      commission
    }
  }
`

type SubgraphResult = {
  referrer?: {
    id: string,
    count: number,
    commission: string
  }
}

/**
 * Gets referral statistics of an address from the subgraph.
 * @param client - {@link ClientWithPns}
 * @param parameters - {@link GetReferralStatsParameters}
 * @returns Referral statistics detail. {@link GetReferralStatsReturnType}
 *
 * @example
 * import { createPublicClient, http } from 'viem'
 * import { mainnet } from 'viem/chains'
 * import { addPnsContracts } from '@pnsdomains/pnsjs'
 * import { getReferralStats } from '@pnsdomains/pnsjs/subgraph'
 *
 * const client = createPublicClient({
 *   chain: addPnsContracts(mainnet),
 *   transport: http(),
 * })
 * const result = await getReferralStats(client, { address: '0xb6E040C9ECAaE172a89bD561c5F73e1C48d28cd9' })
 * // { id: '0xb6E040C9ECAaE172a89bD561c5F73e1C48d28cd9', commission: '0', count: 0}
 */
const getReferralStats = async (
  client: ClientWithPns,
  { address }: GetReferralStatsParameters,
): Promise<GetReferralStatsReturnType> => {
  const subgraphClient = createSubgraphClient({ client })

  const result = await subgraphClient.request<SubgraphResult>(query, {
    address,
  })

  return result?.referrer || {
    id: address,
    commission: '0',
    count: 0
  }
}

export default getReferralStats