import { RequestArguments } from './providers/base-provider';
import { PrexClient } from './prex-client';
import { ApprovalRequestFunction, PrexClientOptions } from './types';

export class WalletMessageReceiver extends PrexClient {
  allowedOrigins: string[];
  approvalRequestFn?: ApprovalRequestFunction;

  approvedOrigins: string[] = [];

  constructor(
    chainId: number,
    policyId: string,
    options: PrexClientOptions & {
      allowedOrigins?: string[];
      approvalRequestFn?: ApprovalRequestFunction;
    }
  ) {
    super(chainId, policyId, options);
    this.allowedOrigins = options.allowedOrigins || [];
    this.approvalRequestFn = options.approvalRequestFn;
  }

  async startHandler() {
    window.addEventListener('message', async (event) => {
      if (!this.allowedOrigins.includes(event.origin)) return;

      if (this.approvalRequestFn) {
        if (!this.approvedOrigins.includes(event.origin)) {
          const approval = await this.approvalRequestFn(event.origin);
          if (!approval) {
            throw new Error('Approval denied');
          }
          this.approvedOrigins.push(event.origin);
        }
      }

      if (!!event.data.data.method) {
        const approval = await this.checkApproval(event.data.data);

        if (!approval) {
          throw new Error('Approval denied');
        }

        const response = await this.signer?.provider?.request(event.data.data);

        event.source?.postMessage(
          {
            id: event.data.id,
            requestId: event.data.id,
            data: response,
          },
          {
            targetOrigin: event.origin,
          }
        );
      }
    });

    window.opener.postMessage(
      {
        event: 'PopupLoaded',
      },
      this.allowedOrigins[0]
    );
  }

  async checkApproval(request: RequestArguments) {
    if (!this.approvalRequestFn) {
      return true;
    }

    const { method, params } = request;

    switch (method) {
      case 'eth_requestAccounts':
        return true;
      case 'eth_sign':
        if (Array.isArray(params)) {
          return this.approvalRequestFn({
            contractAddress: params[0],
            hash: params[1],
          });
        } else {
          throw new Error('invalid params');
        }
      case 'eth_signTypedData_v4':
        if (Array.isArray(params)) {
          return this.approvalRequestFn(params[1]);
        } else {
          throw new Error('invalid params');
        }
      default:
        return true;
    }
  }
}