"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var tslib_1 = require("tslib");
var helper_1 = require("../helper");
function lookup(rows, options) {
    var opts = helper_1.mergeOptions(options, { default: null, as: [] });
    var as = opts.as, values = opts.values, field = opts.field, from = opts.from, key = opts.key;
    return rows.map(function (row) {
        var item = tslib_1.__assign({}, row);
        var target = from.find(function (item) { return item[key] === row[field]; });
        if (!values) {
            if (!Array.isArray(as) || !as[0])
                throw new Error('as is required when values is unspecified');
            if (!target)
                item[as[0]] = opts.default;
            else
                item[as[0]] = target;
        }
        else {
            values.map(function (key, index) {
                item[as[index] || key] = target ? target[key] : opts.default;
            });
        }
        return item;
    });
}
exports.lookup = lookup;