import chai from "chai";
import AWSMock from "aws-sdk-mock";
import _ from "lodash";
import promClient from "prom-client";
import { mockDynamoCampaigns } from "../../mocks/dynamo.mock";

chai.should();
const expect = chai.expect;

describe("DDBConnector", () => {
  describe("batchGet", () => {
    afterEach(() => {
      AWSMock.restore();
    });

    it("should send parameters to Dynamo and format response", async () => {
      const campaigns = {
        "cm:1": { data: 1 },
        "cm:2": { data: 2 },
        "cm:3": { data: 3 },
        "cm:4": { data: 4 },
      };

      const fakes = await mockDynamoCampaigns(campaigns);

      const { DDBConnector } = require("../../../src/models/connector/DDBConnector");
      const connector = new DDBConnector();

      const result = await connector.batchGet(["cm:1", "cm:4", "cm:2"]);

      expect(result).to.deep.equal({
        "cm:1": { data: 1 },
        "cm:2": { data: 2 },
        "cm:4": { data: 4 },
      });
      expect(fakes.batchGetItem.callCount).to.equal(1);
    });

    it("should limit queries to max 50 items", async () => {
      const campaigns: any = {};
      for (let i = 0; i < 230; ++i) {
        campaigns[`cm:${i}`] = { data: i };
      }

      const fakes = await mockDynamoCampaigns(campaigns);

      const { DDBConnector } = require("../../../src/models/connector/DDBConnector");
      const connector = new DDBConnector();

      // mix of existing and missing keys, total of 3 batches
      const query: any[] = [];
      for (let i = 0; i < 230; ++i) {
        query.push(`cm:${i * 2}`);
      }

      const result = await connector.batchGet(query);

      const expected = query.reduce((acc, val) => {
        acc[val] = campaigns[val] ?? null;
        return acc;
      }, {});
      expect(result).to.deep.equal(expected);
      expect(fakes.batchGetItem.callCount).to.equal(5);
    });
  });

  describe("monitoring", () => {
    it("should not fail when collecting metrics", async () => {
      const { DDBConnector } = require("../../../src/models/connector/DDBConnector");
      const connector = new DDBConnector();

      await promClient.register.metrics();
    });
  });
});