Odi-ts/odi

import { Request } from "../aliases";
import * as keys from "../definitions";
import { metadata } from "../utils/metadata.utils";
import { FunctionParam } from "../utils/reflection/function.reflection";

export function buildParamsFunc(rawParams: FunctionParam[]): (req: Request) => any[] {
    const fncDef = `req => [${extractParamsAliases(rawParams).join(", ")}];`;

    return eval(fncDef);
}

function extractParamsAliases(rawParams: FunctionParam[]) {
    const params = [];

    for (const { name, type } of rawParams) {
        const md = metadata(type);

        if ([ Number, String, Boolean ].includes(type)) {
            params.push(`(req.params["${name}"] ? ${type.name}(req.params["${name}"]) : undefined)`);
        }

        else if (typeof type === "function" && md.hasMetadata(keys.DATA_CLASS)) {
            params.push(md.getMetadata(keys.DATA_CLASS) === keys.BODY_DTO ? "req.body" : "req.query");
             }

        else {
            params.push(undefined);
             }
    }

    return params;
}