Changeset View

Standalone View

				const Query = require("./query.js");
				const QueryStep = require("./query-step.js");

				module.exports = class extends Query {
				constructor(...queries) {
				super();
				this.lookup_steps = [];
				for (let query of queries) {
				this.addQuery(query);
				}
				}
				addQuery(query) {
				const steps = query.dump();
				this.lookup_steps.push(
				...steps.filter(step => step instanceof QueryStep.Lookup)
				);
				const match_stage_bodies = [];
				steps
				.filter(step => step instanceof QueryStep.Match)
				.forEach(step => step.pushDump(match_stage_bodies));

				const match_stage =
				match_stage_bodies.length > 1
				? { $and: match_stage_bodies }
				: match_stage_bodies[0];
				this.steps.push(new QueryStep.Match(match_stage));
				}
				dump() {
				return this.lookup_steps.concat(
				new QueryStep.Match({ $or: this._getMatchExpressions() })
				);
				}
				toPipeline() {
				const lookups = this.lookup_steps.reduce(
				(acc, step) => step.pushStage(acc),
				[]
				);

				return lookups.concat({ $match: { $or: this._getMatchExpressions() } });
				}
				_getMatchExpressions() {
				return this.steps.reduce((acc, step) => step.pushDump(acc), []);
				}
				};