// Test the creation of views with various options.
// @tags: [
//   assumes_superuser_permissions,
// ]

(function() {
"use strict";

// For arrayEq.
load("jstests/aggregation/extras/utils.js");

const viewsDBName = "views_creation";

let viewsDB = db.getSiblingDB(viewsDBName);
assert.commandWorked(viewsDB.dropDatabase());

let collNames = viewsDB.getCollectionNames();
assert.eq(0, collNames.length, tojson(collNames));

// You cannot create a view that starts with 'system.'.
assert.commandFailedWithCode(viewsDB.runCommand({create: "system.special", viewOn: "collection"}),
                             ErrorCodes.InvalidNamespace,
                             "Created an illegal view named 'system.views'");

// Collections that start with 'system.' that are not special to MongoDB fail with a different
// error code.
assert.commandFailedWithCode(viewsDB.runCommand({create: "system.foo", viewOn: "collection"}),
                             ErrorCodes.InvalidNamespace,
                             "Created an illegal view named 'system.foo'");

// Create a collection for test purposes.
assert.commandWorked(viewsDB.runCommand({create: "collection"}));

let pipe = [{$match: {}}];

// Create a "regular" view on a collection.
assert.commandWorked(viewsDB.runCommand({create: "view", viewOn: "collection", pipeline: pipe}));

collNames = viewsDB.getCollectionNames().filter((function(coll) {
    return !coll.startsWith("system.");
}));
assert.eq(2, collNames.length, tojson(collNames));
let res = viewsDB.runCommand({listCollections: 1, filter: {type: "view"}});
assert.commandWorked(res);

// Ensure that the output of listCollections has all the expected options for a view.
let expectedListCollectionsOutput = [{
    name: "view",
    type: "view",
    options: {viewOn: "collection", pipeline: pipe},
    info: {readOnly: true}
}];
assert(arrayEq(res.cursor.firstBatch, expectedListCollectionsOutput), tojson({
           expectedListCollectionsOutput: expectedListCollectionsOutput,
           got: res.cursor.firstBatch
       }));

// Create a view on a non-existent collection.
assert.commandWorked(
    viewsDB.runCommand({create: "viewOnNonexistent", viewOn: "nonexistent", pipeline: pipe}));

// Create a view but don't specify a pipeline; this should default to something sane.
assert.commandWorked(viewsDB.runCommand({create: "viewWithDefaultPipeline", viewOn: "collection"}));

// Specifying a pipeline but no view namespace must fail.
assert.commandFailed(viewsDB.runCommand({create: "viewNoViewNamespace", pipeline: pipe}));

// Create a view on another view.
assert.commandWorked(viewsDB.runCommand({create: "viewOnView", viewOn: "view", pipeline: pipe}));

// View names are constrained to the same limitations as collection names.
assert.commandFailed(viewsDB.runCommand({create: "", viewOn: "collection", pipeline: pipe}));
assert.commandFailedWithCode(
    viewsDB.runCommand({create: "system.local.new", viewOn: "collection", pipeline: pipe}),
    ErrorCodes.InvalidNamespace);
assert.commandFailedWithCode(
    viewsDB.runCommand({create: "dollar$", viewOn: "collection", pipeline: pipe}),
    ErrorCodes.InvalidNamespace);

// You cannot create a view with a $out stage, by itself or nested inside of a different stage.
const ERROR_CODE_OUT_BANNED_IN_LOOKUP = 51047;
const outStage = {
    $out: "nonExistentCollection"
};
assert.commandFailedWithCode(
    viewsDB.runCommand({create: "viewWithOut", viewOn: "collection", pipeline: [outStage]}),
    ErrorCodes.OptionNotSupportedOnView);
assert.commandFailedWithCode(viewsDB.runCommand({
    create: "viewWithOutInLookup",
    viewOn: "collection",
    pipeline: [{$lookup: {from: "other", pipeline: [outStage], as: "result"}}]
}),
                             ERROR_CODE_OUT_BANNED_IN_LOOKUP);
assert.commandFailedWithCode(viewsDB.runCommand({
    create: "viewWithOutInFacet",
    viewOn: "collection",
    pipeline: [{$facet: {output: [outStage]}}]
}),
                             40600);

// These test that, when an existing view in system.views is invalid because of a $out in the
// pipeline, the database errors on creation of a new view.
assert.commandWorked(viewsDB.system.views.insert({
    _id: `${viewsDBName}.invalidView`,
    viewOn: "collection",
    pipeline: [{$project: {_id: false}}, {$out: "notExistingCollection"}]
}));
assert.commandFailedWithCode(
    viewsDB.runCommand({create: "viewWithBadViewCatalog", viewOn: "collection", pipeline: []}),
    ErrorCodes.OptionNotSupportedOnView);
assert.commandWorked(
    viewsDB.system.views.remove({_id: `${viewsDBName}.invalidView`}, {justOne: true}));
}());