/*    Copyright 2012 10gen Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    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
 *    GNU Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *    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 GNU Affero General 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/bson/util/bson_extract.h"

#include "mongo/db/jsobj.h"
#include "mongo/util/mongoutils/str.h"

namespace mongo {

namespace {

Status bsonExtractFieldImpl(const BSONObj& object,
                            StringData fieldName,
                            BSONElement* outElement,
                            bool withDefault) {
    BSONElement element = object.getField(fieldName);

    if (!element.eoo()) {
        *outElement = element;
        return Status::OK();
    }
    if (withDefault) {
        static const Status kDefaultCase(ErrorCodes::NoSuchKey,
                                         "bsonExtractFieldImpl default case no such key error");
        return kDefaultCase;
    }
    return Status(ErrorCodes::NoSuchKey,
                  mongoutils::str::stream() << "Missing expected field \"" << fieldName.toString()
                                            << "\"");
}

Status bsonExtractTypedFieldImpl(const BSONObj& object,
                                 StringData fieldName,
                                 BSONType type,
                                 BSONElement* outElement,
                                 bool withDefault) {
    Status status = bsonExtractFieldImpl(object, fieldName, outElement, withDefault);
    if (!status.isOK())
        return status;
    if (type != outElement->type()) {
        return Status(ErrorCodes::TypeMismatch,
                      mongoutils::str::stream() << "\"" << fieldName
                                                << "\" had the wrong type. Expected "
                                                << typeName(type)
                                                << ", found "
                                                << typeName(outElement->type()));
    }
    return status;
}

Status bsonExtractIntegerFieldImpl(const BSONObj& object,
                                   StringData fieldName,
                                   long long* out,
                                   bool withDefault) {
    BSONElement element;
    Status status = bsonExtractFieldImpl(object, fieldName, &element, withDefault);
    if (!status.isOK())
        return status;
    if (!element.isNumber()) {
        return Status(ErrorCodes::TypeMismatch,
                      mongoutils::str::stream() << "Expected field \"" << fieldName
                                                << "\" to have numeric type, but found "
                                                << typeName(element.type()));
    }
    long long result = element.safeNumberLong();
    if (result != element.numberDouble()) {
        return Status(
            ErrorCodes::BadValue,
            mongoutils::str::stream() << "Expected field \"" << fieldName
                                      << "\" to have a value "
                                         "exactly representable as a 64-bit integer, but found "
                                      << element);
    }
    *out = result;
    return status;
}

Status bsonExtractDoubleFieldImpl(const BSONObj& object,
                                  StringData fieldName,
                                  double* out,
                                  bool withDefault) {
    BSONElement element;
    Status status = bsonExtractField(object, fieldName, &element);
    if (!status.isOK())
        return status;
    if (!element.isNumber()) {
        return Status(ErrorCodes::TypeMismatch,
                      mongoutils::str::stream() << "Expected field \"" << fieldName
                                                << "\" to have numeric type, but found "
                                                << typeName(element.type()));
    }
    *out = element.numberDouble();
    return status;
}
}  // namespace


Status bsonExtractField(const BSONObj& object, StringData fieldName, BSONElement* outElement) {
    return bsonExtractFieldImpl(object, fieldName, outElement, false);
}

Status bsonExtractTypedField(const BSONObj& object,
                             StringData fieldName,
                             BSONType type,
                             BSONElement* outElement) {
    return bsonExtractTypedFieldImpl(object, fieldName, type, outElement, false);
}

Status bsonExtractBooleanField(const BSONObj& object, StringData fieldName, bool* out) {
    BSONElement element;
    Status status = bsonExtractTypedField(object, fieldName, Bool, &element);
    if (status.isOK())
        *out = element.boolean();
    return status;
}

Status bsonExtractBooleanFieldWithDefault(const BSONObj& object,
                                          StringData fieldName,
                                          bool defaultValue,
                                          bool* out) {
    BSONElement element;
    Status status = bsonExtractFieldImpl(object, fieldName, &element, true);
    if (status == ErrorCodes::NoSuchKey) {
        *out = defaultValue;
        return Status::OK();
    }

    if (!status.isOK())
        return status;

    if (!element.isNumber() && !element.isBoolean()) {
        return Status(ErrorCodes::TypeMismatch,
                      mongoutils::str::stream() << "Expected boolean or number type for field \""
                                                << fieldName
                                                << "\", found "
                                                << typeName(element.type()));
    }
    *out = element.trueValue();
    return status;
}

Status bsonExtractStringField(const BSONObj& object, StringData fieldName, std::string* out) {
    BSONElement element;
    Status status = bsonExtractTypedField(object, fieldName, String, &element);
    if (status.isOK())
        *out = element.str();
    return status;
}

Status bsonExtractTimestampField(const BSONObj& object, StringData fieldName, Timestamp* out) {
    BSONElement element;
    Status status = bsonExtractTypedField(object, fieldName, bsonTimestamp, &element);
    if (status.isOK())
        *out = element.timestamp();
    return status;
}

Status bsonExtractOIDField(const BSONObj& object, StringData fieldName, OID* out) {
    BSONElement element;
    Status status = bsonExtractTypedField(object, fieldName, jstOID, &element);
    if (status.isOK())
        *out = element.OID();
    return status;
}

Status bsonExtractOIDFieldWithDefault(const BSONObj& object,
                                      StringData fieldName,
                                      const OID& defaultValue,
                                      OID* out) {
    BSONElement element;
    Status status = bsonExtractTypedFieldImpl(object, fieldName, jstOID, &element, true);
    if (status == ErrorCodes::NoSuchKey) {
        *out = defaultValue;
        return Status::OK();
    }
    if (status.isOK())
        *out = element.OID();
    return status;
}

Status bsonExtractStringFieldWithDefault(const BSONObj& object,
                                         StringData fieldName,
                                         StringData defaultValue,
                                         std::string* out) {
    BSONElement element;
    Status status = bsonExtractTypedFieldImpl(object, fieldName, String, &element, true);
    if (status == ErrorCodes::NoSuchKey) {
        *out = defaultValue.toString();
        return Status::OK();
    }
    if (status.isOK())
        *out = element.str();
    return status;
}

Status bsonExtractIntegerField(const BSONObj& object, StringData fieldName, long long* out) {
    return bsonExtractIntegerFieldImpl(object, fieldName, out, false);
}

Status bsonExtractDoubleField(const BSONObj& object, StringData fieldName, double* out) {
    return bsonExtractDoubleFieldImpl(object, fieldName, out, false);
}

Status bsonExtractDoubleFieldWithDefault(const BSONObj& object,
                                         StringData fieldName,
                                         double defaultValue,
                                         double* out) {
    Status status = bsonExtractDoubleFieldImpl(object, fieldName, out, true);
    if (status == ErrorCodes::NoSuchKey) {
        *out = defaultValue;
        return Status::OK();
    }
    return status;
}

Status bsonExtractIntegerFieldWithDefault(const BSONObj& object,
                                          StringData fieldName,
                                          long long defaultValue,
                                          long long* out) {
    Status status = bsonExtractIntegerFieldImpl(object, fieldName, out, true);
    if (status == ErrorCodes::NoSuchKey) {
        *out = defaultValue;
        return Status::OK();
    }
    return status;
}

Status bsonExtractIntegerFieldWithDefaultIf(const BSONObj& object,
                                            StringData fieldName,
                                            long long defaultValue,
                                            stdx::function<bool(long long)> pred,
                                            const std::string& predDescription,
                                            long long* out) {
    Status status = bsonExtractIntegerFieldWithDefault(object, fieldName, defaultValue, out);
    if (!status.isOK()) {
        return status;
    }
    if (!pred(*out)) {
        return Status(
            ErrorCodes::BadValue,
            mongoutils::str::stream() << "Invalid value in field \"" << fieldName << "\": " << *out
                                      << ": "
                                      << predDescription);
    }
    return status;
}

Status bsonExtractIntegerFieldWithDefaultIf(const BSONObj& object,
                                            StringData fieldName,
                                            long long defaultValue,
                                            stdx::function<bool(long long)> pred,
                                            long long* out) {
    return bsonExtractIntegerFieldWithDefaultIf(
        object, fieldName, defaultValue, pred, "constraint failed", out);
}

}  // namespace mongo