// Test the populating lastOpVisible field of the ReplSetMetadata.
// First we do a writeConcern-free write and ensure that a local read will return the same
// lastOpVisible, and that majority read with afterOpTime of lastOpVisible will return it as well.
// We then confirm that a writeConcern majority write will be seen as the lastVisibleOp by a
// majority read.

(function() {
    "use strict";

    var name = 'lastOpVisible';
    var replTest =
        new ReplSetTest({name: name, nodes: 3, nodeOptions: {enableMajorityReadConcern: ''}});

    try {
        replTest.startSet();
    } catch (e) {
        var conn = MongoRunner.runMongod();
        if (!conn.getDB('admin').serverStatus().storageEngine.supportsCommittedReads) {
            print("Skipping read_majority.js since storageEngine doesn't support it.");
            MongoRunner.stopMongod(conn);
            return;
        }
        throw e;
    }

    replTest.initiate();

    var primary = replTest.getPrimary();

    // Do an insert without writeConcern.
    var res = primary.getDB(name).runCommandWithMetadata({insert: name, documents: [{x: 1}]},
                                                         {"$replData": 1});
    assert.commandWorked(res.commandReply);
    var last_op_visible = res.metadata["$replData"].lastOpVisible;

    // A find should return the same lastVisibleOp.
    res = primary.getDB(name).runCommandWithMetadata({find: name, readConcern: {level: "local"}},
                                                     {"$replData": 1});
    assert.commandWorked(res.commandReply);
    assert.eq(last_op_visible, res.metadata["$replData"].lastOpVisible);

    // A majority readConcern with afterOpTime: lastOpVisible should also return the same
    // lastVisibleOp.
    res = primary.getDB(name).runCommandWithMetadata(
        {find: name, readConcern: {level: "majority", afterOpTime: last_op_visible}},
        {"$replData": 1});
    assert.commandWorked(res.commandReply);
    assert.eq(last_op_visible, res.metadata["$replData"].lastOpVisible);

    // Do an insert without writeConcern.
    res = primary.getDB(name).runCommandWithMetadata(
        {insert: name, documents: [{x: 1}], writeConcern: {w: "majority"}}, {"$replData": 1});
    assert.commandWorked(res.commandReply);
    last_op_visible = res.metadata["$replData"].lastOpVisible;

    // A majority readConcern should return the same lastVisibleOp.
    res = primary.getDB(name).runCommandWithMetadata({find: name, readConcern: {level: "majority"}},
                                                     {"$replData": 1});
    assert.commandWorked(res.commandReply);
    assert.eq(last_op_visible, res.metadata["$replData"].lastOpVisible);

}());
