// Test parsing of readConcern level 'snapshot' on mongos.
// @tags: [requires_replication,requires_sharding, uses_transactions, uses_atclustertime]
(function() {
"use strict";

load("jstests/sharding/libs/sharded_transactions_helpers.js");

// Runs the command as the first in a multi statement txn that is aborted right after, expecting
// success.
function expectSuccessInTxnThenAbort(session, sessionConn, cmdObj) {
    session.startTransaction();
    assert.commandWorked(sessionConn.runCommand(cmdObj));
    assert.commandWorked(session.abortTransaction_forTesting());
}

// Runs the command as the first in a multi statement txn that is aborted right after, expecting
// failure with the given error code.
function expectFailInTxnThenAbort(session, sessionConn, expectedErrorCode, cmdObj) {
    session.startTransaction();
    assert.commandFailedWithCode(sessionConn.runCommand(cmdObj), expectedErrorCode);
    assert.commandFailedWithCode(session.abortTransaction_forTesting(),
                                 ErrorCodes.NoSuchTransaction);
}

const dbName = "test";
const collName = "coll";

let st = new ShardingTest({shards: 1, rs: {nodes: 2}, config: 2, mongos: 1});
let testDB = st.getDB(dbName);
let coll = testDB.coll;

// Insert data to create the collection.
assert.writeOK(testDB[collName].insert({x: 1}));

flushRoutersAndRefreshShardMetadata(st, {ns: dbName + "." + collName, dbNames: [dbName]});

// noPassthrough tests

// readConcern 'snapshot' is not allowed outside session context.
assert.commandFailedWithCode(testDB.runCommand({find: collName, readConcern: {level: "snapshot"}}),
                             ErrorCodes.InvalidOptions);

let session = testDB.getMongo().startSession({causalConsistency: false});
let sessionDb = session.getDatabase(dbName);

// readConcern 'snapshot' is not allowed outside transaction context.
assert.commandFailedWithCode(sessionDb.runCommand({
    find: collName,
    readConcern: {level: "snapshot"},
}),
                             ErrorCodes.InvalidOptions);

// readConcern 'snapshot' is not allowed with 'atClusterTime'.
let pingRes = assert.commandWorked(st.s0.adminCommand({ping: 1}));
assert(pingRes.hasOwnProperty("$clusterTime"), tojson(pingRes));
assert(pingRes.$clusterTime.hasOwnProperty("clusterTime"), tojson(pingRes));
const clusterTime = pingRes.$clusterTime.clusterTime;

expectFailInTxnThenAbort(session, sessionDb, ErrorCodes.InvalidOptions, {
    find: collName,
    readConcern: {level: "snapshot", atClusterTime: clusterTime},
});

// Passthrough tests. There are parts not implemented on mongod and mongos, they are tracked by
// separate jiras

// readConcern 'snapshot' is supported by insert on mongos in a transaction.
expectSuccessInTxnThenAbort(session, sessionDb, {
    insert: collName,
    documents: [{_id: "single-insert"}],
    readConcern: {level: "snapshot"},
});

// readConcern 'snapshot' is supported by update on mongos in a transaction.
expectSuccessInTxnThenAbort(session, sessionDb, {
    update: collName,
    updates: [{q: {_id: 0}, u: {$inc: {a: 1}}}],
    readConcern: {level: "snapshot"},
});

// readConcern 'snapshot' is supported by delete on mongos in a transaction.
expectSuccessInTxnThenAbort(session, sessionDb, {
    delete: collName,
    deletes: [{q: {}, limit: 1}],
    readConcern: {level: "snapshot"},
});

// readConcern 'snapshot' is supported by findAndModify on mongos in a transaction.
expectSuccessInTxnThenAbort(session, sessionDb, {
    findAndModify: collName,
    query: {},
    update: {$set: {a: 1}},
    readConcern: {level: "snapshot"},
});

expectSuccessInTxnThenAbort(session, sessionDb, {
    aggregate: collName,
    pipeline: [],
    cursor: {},
    readConcern: {level: "snapshot"},
});

// readConcern 'snapshot' is supported by find on mongos.
expectSuccessInTxnThenAbort(session, sessionDb, {
    find: collName,
    readConcern: {level: "snapshot"},
});

// readConcern 'snapshot' is supported by distinct on mongos.
expectSuccessInTxnThenAbort(session, sessionDb, {
    distinct: collName,
    key: "x",
    readConcern: {level: "snapshot"},
});

// readConcern 'snapshot' is allowed with 'afterClusterTime'.
expectSuccessInTxnThenAbort(session, sessionDb, {
    find: collName,
    readConcern: {level: "snapshot", afterClusterTime: clusterTime},
});

expectSuccessInTxnThenAbort(session, sessionDb, {
    aggregate: collName,
    pipeline: [],
    cursor: {},
    readConcern: {level: "snapshot", afterClusterTime: clusterTime},
});

st.stop();
}());