import { pick } from 'ramda';
import { APIGatewayProxyHandler } from 'aws-lambda';

export type Params = {
    [name: string]: string;
};

export type Usecase = ({}: { args?: {}, params?: Params | null, tenant?: string, email?: string }) => Promise<any>;

const toLambda = (usecase: Usecase, fields: string[], parameters: string[]) => {
    const callback: APIGatewayProxyHandler = (event) => {
        // @ts-ignore - hmmm probably shouldn't, but we pass custom fields in here normally...
        const { tenant, email } = event.requestContext.authorizer;
        let args = JSON.parse(event.body as string);
        let params = event.pathParameters;
        if (parameters[0] !== '*') {
            params = pick(parameters, params);
        }

        if (fields[0] !== '*') {
            args = pick(fields, args);
        }

        return usecase({ args, params, tenant, email });
    };

    return callback;
}

export default toLambda;