/**
 * RWATransferAdapterClient — permissioned RWA → USDC.e redemption.
 * Contract: aerenew/contracts/contracts/lending/RWATransferAdapter.sol
 */

export interface RpcProvider {
  request(args: { method: string; params: unknown[] }): Promise<unknown>;
}

const pad32 = (h: string) => h.toLowerCase().replace(/^0x/, '').padStart(64, '0');
const encUint = (n: bigint) => pad32(n.toString(16));
const encAddr = (a: string) => pad32(a.replace(/^0x/, ''));

async function ethCall(p: RpcProvider, to: string, data: string): Promise<string> {
  return await p.request({ method: 'eth_call', params: [{ to, data }, 'latest'] }) as string;
}
async function ethSend(p: RpcProvider, from: string, to: string, data: string): Promise<string> {
  return await p.request({ method: 'eth_sendTransaction', params: [{ from, to, data, value: '0x0' }] }) as string;
}

const SEL = {
  PAYOUT_TOKEN:     '0x935ca8e6',  // PAYOUT_TOKEN()
  ORACLE:           '0x7dc0d1d0',  // ORACLE()
  FOUNDATION:       '0x4d09f93e',  // FOUNDATION()
  configs:          '0x1d12be96',  // configs(address)
  states:           '0xb95da3ec',  // states(address)
  periodRemaining:  '0x3aff0d34',  // periodRemaining(address)
  payoutLiquidity:  '0x8b8a55be',  // payoutLiquidity()
  redeem:           '0x1e9a6950',  // redeem(address,uint256)
} as const;

export class RWATransferAdapterClient {
  constructor(public readonly provider: RpcProvider, public readonly address: string) {}

  async getPayoutToken(): Promise<string> {
    return '0x' + (await ethCall(this.provider, this.address, SEL.PAYOUT_TOKEN)).slice(-40);
  }
  async getFoundation(): Promise<string> {
    return '0x' + (await ethCall(this.provider, this.address, SEL.FOUNDATION)).slice(-40);
  }
  async periodRemaining(asset: string): Promise<bigint> {
    return BigInt(await ethCall(this.provider, this.address, SEL.periodRemaining + encAddr(asset)));
  }
  async payoutLiquidity(): Promise<bigint> {
    return BigInt(await ethCall(this.provider, this.address, SEL.payoutLiquidity));
  }

  /** Permissionless redeem. Caller must approve `asset` for `rwaAmount` on this contract first. */
  async redeem(from: string, asset: string, rwaAmount: bigint): Promise<string> {
    return ethSend(this.provider, from, this.address, SEL.redeem + encAddr(asset) + encUint(rwaAmount));
  }
}