/**
 *    Copyright (C) 2018-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#include "mongo/db/auth/privilege_parser.h"

#include <string>

#include "mongo/db/auth/privilege.h"
#include "mongo/db/field_parser.h"
#include "mongo/db/namespace_string.h"
#include "mongo/util/str.h"

namespace mongo {

using std::string;
using std::vector;

using str::stream;

const BSONField<bool> ParsedResource::anyResource("anyResource");
const BSONField<bool> ParsedResource::cluster("cluster");
const BSONField<string> ParsedResource::systemBuckets("system_buckets");
const BSONField<string> ParsedResource::db("db");
const BSONField<string> ParsedResource::collection("collection");

ParsedResource::ParsedResource() {
    clear();
}

ParsedResource::~ParsedResource() {}

bool ParsedResource::isValid(std::string* errMsg) const {
    std::string dummy;
    if (errMsg == nullptr) {
        errMsg = &dummy;
    }

    int numCandidateTypes = 0;
    if (isAnyResourceSet())
        ++numCandidateTypes;
    if (isClusterSet())
        ++numCandidateTypes;
    if (isDbSet() || isCollectionSet() || isSystemBucketsSet())
        ++numCandidateTypes;

    if (!isSystemBucketsSet() && isDbSet() != isCollectionSet()) {
        *errMsg = stream() << "resource must set both " << db.name() << " and " << collection.name()
                           << " or neither, but not exactly one.";
        return false;
    } else if (isSystemBucketsSet()) {
        if (isCollectionSet()) {
            *errMsg = stream() << "system_buckets and collection cannot both be set";
            return false;
        }
    }

    if (numCandidateTypes != 1) {
        *errMsg = stream() << "resource must have exactly " << db.name() << " and "
                           << collection.name() << " set, or have only " << cluster.name()
                           << " set "
                           << " or have only " << anyResource.name() << " set";
        return false;
    }

    if (isAnyResourceSet() && !getAnyResource()) {
        *errMsg = stream() << anyResource.name() << " must be true when specified";
        return false;
    }

    if (isClusterSet() && !getCluster()) {
        *errMsg = stream() << cluster.name() << " must be true when specified";
        return false;
    }

    if (isDbSet() &&
        (!NamespaceString::validDBName(getDb(), NamespaceString::DollarInDbNameBehavior::Allow) &&
         !getDb().empty())) {
        *errMsg = stream() << getDb() << " is not a valid database name";
        return false;
    }

    if (isCollectionSet() &&
        (!NamespaceString::validCollectionName(getCollection()) && !getCollection().empty())) {
        // local.oplog.$main is a real collection that the server will create. But, collection
        // names with a '$' character are illegal. We must make an exception for this collection
        // here so we can grant users access to it.
        if (!(getDb() == DatabaseName::kLocal.db() && getCollection() == "oplog.$main")) {
            *errMsg = stream() << getCollection() << " is not a valid collection name";
            return false;
        }
    }

    return true;
}

BSONObj ParsedResource::toBSON() const {
    BSONObjBuilder builder;

    if (_isAnyResourceSet)
        builder.append(anyResource(), _anyResource);

    if (_isClusterSet)
        builder.append(cluster(), _cluster);

    if (_isSystemBucketsSet)
        builder.append(systemBuckets(), _systemBuckets);

    if (_isDbSet)
        builder.append(db(), _db);

    if (_isCollectionSet)
        builder.append(collection(), _collection);

    return builder.obj();
}

bool ParsedResource::parseBSON(const BSONObj& source, string* errMsg) {
    clear();

    std::string dummy;
    if (!errMsg)
        errMsg = &dummy;

    FieldParser::FieldState fieldState;
    fieldState = FieldParser::extract(source, anyResource, &_anyResource, errMsg);
    if (fieldState == FieldParser::FIELD_INVALID)
        return false;
    _isAnyResourceSet = fieldState == FieldParser::FIELD_SET;

    fieldState = FieldParser::extract(source, cluster, &_cluster, errMsg);
    if (fieldState == FieldParser::FIELD_INVALID)
        return false;
    _isClusterSet = fieldState == FieldParser::FIELD_SET;

    fieldState = FieldParser::extract(source, systemBuckets, &_systemBuckets, errMsg);
    if (fieldState == FieldParser::FIELD_INVALID)
        return false;
    _isSystemBucketsSet = fieldState == FieldParser::FIELD_SET;

    fieldState = FieldParser::extract(source, db, &_db, errMsg);
    if (fieldState == FieldParser::FIELD_INVALID)
        return false;
    _isDbSet = fieldState == FieldParser::FIELD_SET;

    fieldState = FieldParser::extract(source, collection, &_collection, errMsg);
    if (fieldState == FieldParser::FIELD_INVALID)
        return false;
    _isCollectionSet = fieldState == FieldParser::FIELD_SET;

    return true;
}

void ParsedResource::clear() {
    _anyResource = false;
    _isAnyResourceSet = false;

    _cluster = false;
    _isClusterSet = false;

    _systemBuckets.clear();
    _isSystemBucketsSet = false;

    _db.clear();
    _isDbSet = false;

    _collection.clear();
    _isCollectionSet = false;
}

void ParsedResource::cloneTo(ParsedResource* other) const {
    other->clear();

    other->_anyResource = _anyResource;
    other->_isAnyResourceSet = _isAnyResourceSet;

    other->_cluster = _cluster;
    other->_isClusterSet = _isClusterSet;

    other->_systemBuckets = _systemBuckets;
    other->_isSystemBucketsSet = _isSystemBucketsSet;

    other->_db = _db;
    other->_isDbSet = _isDbSet;

    other->_collection = _collection;
    other->_isCollectionSet = _isCollectionSet;
}

std::string ParsedResource::toString() const {
    return toBSON().toString();
}

void ParsedResource::setAnyResource(bool anyResource) {
    _anyResource = anyResource;
    _isAnyResourceSet = true;
}

void ParsedResource::unsetAnyResource() {
    _isAnyResourceSet = false;
}

bool ParsedResource::isAnyResourceSet() const {
    return _isAnyResourceSet;
}

bool ParsedResource::getAnyResource() const {
    dassert(_isAnyResourceSet);
    return _anyResource;
}

void ParsedResource::setCluster(bool cluster) {
    _cluster = cluster;
    _isClusterSet = true;
}

void ParsedResource::unsetCluster() {
    _isClusterSet = false;
}

bool ParsedResource::isClusterSet() const {
    return _isClusterSet;
}

bool ParsedResource::getCluster() const {
    dassert(_isClusterSet);
    return _cluster;
}

void ParsedResource::setSystemBuckets(StringData collection) {
    _systemBuckets = collection.toString();
    _isSystemBucketsSet = true;
}

void ParsedResource::unsetSystemBuckets() {
    _isSystemBucketsSet = false;
}

bool ParsedResource::isSystemBucketsSet() const {
    return _isSystemBucketsSet;
}

const std::string& ParsedResource::getSystemBuckets() const {
    dassert(_isSystemBucketsSet);
    return _systemBuckets;
}

void ParsedResource::setDb(StringData db) {
    _db = db.toString();
    _isDbSet = true;
}

void ParsedResource::unsetDb() {
    _isDbSet = false;
}

bool ParsedResource::isDbSet() const {
    return _isDbSet;
}

const std::string& ParsedResource::getDb() const {
    dassert(_isDbSet);
    return _db;
}

void ParsedResource::setCollection(StringData collection) {
    _collection = collection.toString();
    _isCollectionSet = true;
}

void ParsedResource::unsetCollection() {
    _isCollectionSet = false;
}

bool ParsedResource::isCollectionSet() const {
    return _isCollectionSet;
}

const std::string& ParsedResource::getCollection() const {
    dassert(_isCollectionSet);
    return _collection;
}

const BSONField<std::vector<string>> ParsedPrivilege::actions("actions");
const BSONField<ParsedResource> ParsedPrivilege::resource("resource");

ParsedPrivilege::ParsedPrivilege() {
    clear();
}

ParsedPrivilege::~ParsedPrivilege() {}

bool ParsedPrivilege::isValid(std::string* errMsg) const {
    std::string dummy;
    if (errMsg == nullptr) {
        errMsg = &dummy;
    }

    // All the mandatory fields must be present.
    if (!_isActionsSet || !_actions.size()) {
        *errMsg = stream() << "missing " << actions.name() << " field";
        return false;
    }

    if (!_isResourceSet) {
        *errMsg = stream() << "missing " << resource.name() << " field";
        return false;
    }

    return getResource().isValid(errMsg);
}

BSONObj ParsedPrivilege::toBSON() const {
    BSONObjBuilder builder;

    if (_isResourceSet)
        builder.append(resource(), _resource.toBSON());

    if (_isActionsSet) {
        BSONArrayBuilder actionsBuilder(builder.subarrayStart(actions()));
        for (std::vector<string>::const_iterator it = _actions.begin(); it != _actions.end();
             ++it) {
            actionsBuilder.append(*it);
        }
        actionsBuilder.doneFast();
    }

    return builder.obj().getOwned();
}

bool ParsedPrivilege::parseBSON(const BSONObj& source, string* errMsg) {
    clear();

    std::string dummy;
    if (!errMsg)
        errMsg = &dummy;

    FieldParser::FieldState fieldState;
    fieldState = FieldParser::extract(source, actions, &_actions, errMsg);
    if (fieldState == FieldParser::FIELD_INVALID)
        return false;
    _isActionsSet = fieldState == FieldParser::FIELD_SET;

    fieldState = FieldParser::extract(source, resource, &_resource, errMsg);
    if (fieldState == FieldParser::FIELD_INVALID)
        return false;
    _isResourceSet = fieldState == FieldParser::FIELD_SET;

    return true;
}

void ParsedPrivilege::clear() {
    _actions.clear();
    _isActionsSet = false;
    _resource.clear();
    _isResourceSet = false;
}

std::string ParsedPrivilege::toString() const {
    return toBSON().toString();
}

void ParsedPrivilege::setActions(const std::vector<string>& actions) {
    for (std::vector<string>::const_iterator it = actions.begin(); it != actions.end(); ++it) {
        addToActions((*it));
    }
    _isActionsSet = actions.size() > 0;
}

void ParsedPrivilege::addToActions(const string& actions) {
    _actions.push_back(actions);
    _isActionsSet = true;
}

void ParsedPrivilege::unsetActions() {
    _actions.clear();
    _isActionsSet = false;
}

bool ParsedPrivilege::isActionsSet() const {
    return _isActionsSet;
}

size_t ParsedPrivilege::sizeActions() const {
    return _actions.size();
}

const std::vector<string>& ParsedPrivilege::getActions() const {
    dassert(_isActionsSet);
    return _actions;
}

const string& ParsedPrivilege::getActionsAt(size_t pos) const {
    dassert(_isActionsSet);
    dassert(_actions.size() > pos);
    return _actions.at(pos);
}

void ParsedPrivilege::setResource(const ParsedResource& resource) {
    resource.cloneTo(&_resource);
    _isResourceSet = true;
}

void ParsedPrivilege::unsetResource() {
    _isResourceSet = false;
}

bool ParsedPrivilege::isResourceSet() const {
    return _isResourceSet;
}

const ParsedResource& ParsedPrivilege::getResource() const {
    dassert(_isResourceSet);
    return _resource;
}

Status ParsedPrivilege::parsedPrivilegeToPrivilege(const ParsedPrivilege& parsedPrivilege,
                                                   Privilege* result,
                                                   std::vector<std::string>* unrecognizedActions) {
    std::string errmsg;
    if (!parsedPrivilege.isValid(&errmsg)) {
        return Status(ErrorCodes::FailedToParse, errmsg);
    }

    // Build actions
    ActionSet actions;
    const vector<std::string>& parsedActions = parsedPrivilege.getActions();
    Status status =
        ActionSet::parseActionSetFromStringVector(parsedActions, &actions, unrecognizedActions);
    if (!status.isOK()) {
        return status;
    }

    // Build resource
    ResourcePattern resource;
    const ParsedResource& parsedResource = parsedPrivilege.getResource();
    if (parsedResource.isAnyResourceSet() && parsedResource.getAnyResource()) {
        resource = ResourcePattern::forAnyResource();
    } else if (parsedResource.isClusterSet() && parsedResource.getCluster()) {
        resource = ResourcePattern::forClusterResource();
    } else if (parsedResource.isSystemBucketsSet()) {
        if (parsedResource.isDbSet()) {
            if (parsedResource.getDb().empty()) {
                if (parsedResource.getSystemBuckets().empty()) {
                    // {db: "", system_buckets: ""} - match any system buckets in any db
                    resource = ResourcePattern::forAnySystemBuckets();
                } else {
                    // {db: "", system_buckets: "<coll>"} - match any system.buckets.<coll> in
                    // any db
                    resource = ResourcePattern::forAnySystemBucketsInAnyDatabase(
                        parsedResource.getSystemBuckets());
                }
            } else {
                if (parsedResource.getSystemBuckets().empty()) {
                    // {db: "<db>", system_buckets: ""} - match any system buckets in db <db>
                    resource =
                        ResourcePattern::forAnySystemBucketsInDatabase(parsedResource.getDb());
                } else {
                    // {db: "<db>", system_buckets: "<coll>"} - match <db>.system.buckets.<coll>
                    resource = ResourcePattern::forExactSystemBucketsCollection(
                        parsedResource.getDb(), parsedResource.getSystemBuckets());
                }
            }
        } else {
            if (parsedResource.getSystemBuckets().empty()) {
                // {system_buckets: ""} - match any system buckets in any db
                resource = ResourcePattern::forAnySystemBuckets();
            } else {
                // {system_buckets: "<coll>"} - match any system.buckets.<coll> in any db
                resource = ResourcePattern::forAnySystemBucketsInAnyDatabase(
                    parsedResource.getSystemBuckets());
            }
        }

    } else {
        if (parsedResource.isDbSet() && !parsedResource.getDb().empty()) {
            if (parsedResource.isCollectionSet() && !parsedResource.getCollection().empty()) {
                resource = ResourcePattern::forExactNamespace(
                    NamespaceString::createNamespaceStringForAuth(
                        boost::none, parsedResource.getDb(), parsedResource.getCollection()));
            } else {
                resource = ResourcePattern::forDatabaseName(parsedResource.getDb());
            }
        } else {
            if (parsedResource.isCollectionSet() && !parsedResource.getCollection().empty()) {
                resource = ResourcePattern::forCollectionName(parsedResource.getCollection());
            } else {
                resource = ResourcePattern::forAnyNormalResource();
            }
        }
    }

    *result = Privilege(resource, actions);
    return Status::OK();
}

bool ParsedPrivilege::privilegeToParsedPrivilege(const Privilege& privilege,
                                                 ParsedPrivilege* result,
                                                 std::string* errmsg) {
    ParsedResource parsedResource;
    if (privilege.getResourcePattern().isExactNamespacePattern()) {
        parsedResource.setDb(privilege.getResourcePattern().databaseToMatch());
        parsedResource.setCollection(privilege.getResourcePattern().collectionToMatch());
    } else if (privilege.getResourcePattern().isDatabasePattern()) {
        parsedResource.setDb(privilege.getResourcePattern().databaseToMatch());
        parsedResource.setCollection("");
    } else if (privilege.getResourcePattern().isCollectionPattern()) {
        parsedResource.setDb("");
        parsedResource.setCollection(privilege.getResourcePattern().collectionToMatch());
    } else if (privilege.getResourcePattern().isAnyNormalResourcePattern()) {
        parsedResource.setDb("");
        parsedResource.setCollection("");
    } else if (privilege.getResourcePattern().isClusterResourcePattern()) {
        parsedResource.setCluster(true);
    } else if (privilege.getResourcePattern().isAnySystemBucketsCollection()) {
        parsedResource.setSystemBuckets("");
    } else if (privilege.getResourcePattern().isAnySystemBucketsCollectionInDB()) {
        parsedResource.setSystemBuckets("");
        parsedResource.setDb(privilege.getResourcePattern().databaseToMatch());
    } else if (privilege.getResourcePattern().isAnySystemBucketsCollectionInAnyDB()) {
        parsedResource.setSystemBuckets(privilege.getResourcePattern().collectionToMatch());
    } else if (privilege.getResourcePattern().isExactSystemBucketsCollection()) {
        parsedResource.setDb(privilege.getResourcePattern().databaseToMatch());
        parsedResource.setSystemBuckets(privilege.getResourcePattern().collectionToMatch());
    } else if (privilege.getResourcePattern().isAnyResourcePattern()) {
        parsedResource.setAnyResource(true);
    } else {
        *errmsg = stream() << privilege.getResourcePattern().toString()
                           << " is not a valid user-grantable resource pattern";
        return false;
    }

    result->clear();
    result->setResource(parsedResource);
    result->setActions(privilege.getActions().getActionsAsStrings());
    return result->isValid(errmsg);
}
}  // namespace mongo