/**
 * Tests that FTDC collects information about the change collection, including its purging job.
 * @tags: [ requires_fcv_62 ]
 */
(function() {
'use strict';

// For verifyGetDiagnosticData.
load('jstests/libs/ftdc.js');
// For ChangeStreamMultitenantReplicaSetTest.
load("jstests/serverless/libs/change_collection_util.js");

const kExpiredChangeRemovalJobSleepSeconds = 1;
const kExpireAfterSeconds = 1;

const replicaSet = new ChangeStreamMultitenantReplicaSetTest({
    nodes: 1,
    changeCollectionExpiredDocumentsRemoverJobSleepSeconds: kExpiredChangeRemovalJobSleepSeconds
});

const primary = replicaSet.getPrimary();
const adminDb = primary.getDB('admin');

// Hard code the tenant id such that the tenant can be identified deterministically.
const tenantId = ObjectId("6303b6bb84305d2266d0b779");

// Connection to the replica set primary that are stamped with their respective tenant ids.
const tenantConn =
    ChangeStreamMultitenantReplicaSetTest.getTenantConnection(primary.host, tenantId);

const testDb = tenantConn.getDB(jsTestName());

// Enable change streams to ensure the creation of change collections if run in serverless mode.
assert.commandWorked(
    tenantConn.getDB("admin").runCommand({setChangeStreamState: 1, enabled: true}));

const changeCollection = tenantConn.getDB("config").system.change_collection;

assert.soon(() => {
    // Ensure that server status diagnostics is collecting change collection statistics.
    const serverStatusDiagnostics = verifyGetDiagnosticData(adminDb).serverStatus;
    return serverStatusDiagnostics.hasOwnProperty('changeCollections') &&
        serverStatusDiagnostics.changeCollections.hasOwnProperty('purgingJob');
});

const diagnosticsBeforeTestCollInsertions =
    verifyGetDiagnosticData(adminDb).serverStatus.changeCollections.purgingJob;

// Create collection and insert sample data.
assert.commandWorked(testDb.createCollection("testColl"));
const numberOfDocuments = 1000;
for (let i = 0; i < numberOfDocuments; i++) {
    assert.commandWorked(testDb.testColl.insert({x: i}));
}
const wallTimeOfTheFirstOplogEntry =
    new NumberLong(changeCollection.find().sort({wall: 1}).limit(1).next().wall.getTime());
const estimatedToBeRemovedDocsSize = changeCollection.find()
                                         .sort({wall: -1})
                                         .skip(1)
                                         .toArray()
                                         .map(doc => Object.bsonsize(doc))
                                         .reduce((acc, size) => acc + size, 0);
assert.gt(estimatedToBeRemovedDocsSize, 0);

// Set the 'expireAfterSeconds' to 'kExpireAfterSeconds'.
assert.commandWorked(tenantConn.adminCommand(
    {setClusterParameter: {changeStreams: {expireAfterSeconds: kExpireAfterSeconds}}}));

// Ensure purging job deletes the expired oplog entries about insertion into test collection.
assert.soon(() => {
    // All change collection entries are removed but one.
    return changeCollection.count() === 1;
});

// Ensure that FTDC collected the purging job information of the change collection.
assert.soon(() => {
    const diagnosticsAfterTestCollInsertions =
        verifyGetDiagnosticData(adminDb).serverStatus.changeCollections.purgingJob;

    return diagnosticsAfterTestCollInsertions.totalPass >
        diagnosticsBeforeTestCollInsertions.totalPass &&
        diagnosticsAfterTestCollInsertions.scannedCollections >
        diagnosticsBeforeTestCollInsertions.scannedCollections &&
        diagnosticsAfterTestCollInsertions.bytesDeleted >=
        diagnosticsBeforeTestCollInsertions.bytesDeleted + estimatedToBeRemovedDocsSize &&
        diagnosticsAfterTestCollInsertions.docsDeleted >
        diagnosticsBeforeTestCollInsertions.docsDeleted + numberOfDocuments - 1 &&
        diagnosticsAfterTestCollInsertions.maxStartWallTimeMillis.tojson() >=
        wallTimeOfTheFirstOplogEntry.tojson() &&
        diagnosticsAfterTestCollInsertions.timeElapsedMillis >=
        diagnosticsBeforeTestCollInsertions.timeElapsedMillis;
});

replicaSet.stopSet();
}());