//
//  ClientMetricsCollectorTests.swift
//  AmazonChimeSDK
//
//  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
//  SPDX-License-Identifier: Apache-2.0
//

import Foundation

@testable import AmazonChimeSDK
import XCTest

class ClientMetricsCollectorTests: XCTestCase, MetricsObserver {
    // Replicated here as to confirm values don't change and to avoid exposing in actual code
    private let clientMicDeviceFramesLostPercent = 0
    private let clientPostJbSpk1sPacketsLostPercent = 7
    private let serverPostJbMic1sPacketsLostPercent = 3
    private var receivedMetrics: [AnyHashable: Any] = [:]

    private let metricsReceivedExpectation = XCTestExpectation(
        description: "Is fulfilled after metrics were received")
    private let metricsReceivedTimeoutMs = 10.0

    private var clientMetricsCollector: DefaultClientMetricsCollector?

    override func setUp() {
        super.setUp()
        clientMetricsCollector = DefaultClientMetricsCollector()
        clientMetricsCollector?.subscribeToMetrics(observer: self)
    }

    func testOnMetricsReceiveShouldNotBeCalledBeforeInterval() {
        let audioClientMetrics = [
            serverPostJbMic1sPacketsLostPercent: 1,
            clientPostJbSpk1sPacketsLostPercent: 2
        ]
        clientMetricsCollector?.processAudioClientMetrics(metrics: audioClientMetrics)

        // No callback should have occurred
        XCTAssertEqual(receivedMetrics.count, 0)
    }

    func testOnMetricsReceiveShouldBeCalledAfterInterval() {
        let audioClientMetrics = [
            serverPostJbMic1sPacketsLostPercent: 1,
            clientPostJbSpk1sPacketsLostPercent: 2
        ]

        // Wait at least a second and next time we process metrics we should receive the callback
        Thread.sleep(forTimeInterval: 1)
        clientMetricsCollector?.processAudioClientMetrics(metrics: audioClientMetrics)
        wait(for: [metricsReceivedExpectation], timeout: metricsReceivedTimeoutMs)

        XCTAssertEqual(receivedMetrics.count, 2)
        XCTAssertEqual(receivedMetrics[ObservableMetric.audioSendPacketLossPercent] as? Int, 1)
        XCTAssertEqual(receivedMetrics[ObservableMetric.audioReceivePacketLossPercent] as? Int, 2)
    }

    func testNonObservableMetricShouldNotBeEmitted() {
        let audioClientMetrics = [
            clientMicDeviceFramesLostPercent: 1
        ]

        // Wait at least a second and next time we process metrics we should receive the callback
        Thread.sleep(forTimeInterval: 1)
        clientMetricsCollector?.processAudioClientMetrics(metrics: audioClientMetrics)

        XCTAssertEqual(receivedMetrics.count, 0)
    }

    func testInvalidMetricShouldNotBeEmitted() {
        let audioClientMetrics = [
            999: 1
        ]

        // Wait at least a second and next time we process metrics we should receive the callback
        Thread.sleep(forTimeInterval: 1)
        clientMetricsCollector?.processAudioClientMetrics(metrics: audioClientMetrics)

        XCTAssertEqual(receivedMetrics.count, 0)
    }

    func metricsDidReceive(metrics: [AnyHashable: Any]) {
        metricsReceivedExpectation.fulfill()
        receivedMetrics = metrics
    }
}