client.go

// Copyright 2014-2022 Aerospike, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package aerospike

import (
	"bytes"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"os"
	"runtime"
	"strconv"
	"strings"
	"time"

	"github.com/aerospike/aerospike-client-go/v7/logger"
	"github.com/aerospike/aerospike-client-go/v7/types"
)

const unreachable = "UNREACHABLE"

// Client encapsulates an Aerospike cluster.
// All database operations are available against this object.
type Client struct {
	cluster *Cluster

	// DefaultPolicy is used for all read commands without a specific policy.
	DefaultPolicy *BasePolicy
	// DefaultBatchPolicy is the default parent policy used in batch read commands. Base policy fields
	// include socketTimeout, totalTimeout, maxRetries, etc...
	DefaultBatchPolicy *BatchPolicy
	// DefaultBatchReadPolicy is the default read policy used in batch operate commands.
	DefaultBatchReadPolicy *BatchReadPolicy
	// DefaultBatchWritePolicy is the default write policy used in batch operate commands.
	// Write policy fields include generation, expiration, durableDelete, etc...
	DefaultBatchWritePolicy *BatchWritePolicy
	// DefaultBatchDeletePolicy is the default delete policy used in batch delete commands.
	DefaultBatchDeletePolicy *BatchDeletePolicy
	// DefaultBatchUDFPolicy is the default user defined function policy used in batch UDF execute commands.
	DefaultBatchUDFPolicy *BatchUDFPolicy
	// DefaultWritePolicy is used for all write commands without a specific policy.
	DefaultWritePolicy *WritePolicy
	// DefaultScanPolicy is used for all scan commands without a specific policy.
	DefaultScanPolicy *ScanPolicy
	// DefaultQueryPolicy is used for all query commands without a specific policy.
	DefaultQueryPolicy *QueryPolicy
	// DefaultAdminPolicy is used for all security commands without a specific policy.
	DefaultAdminPolicy *AdminPolicy
	// DefaultInfoPolicy is used for all info commands without a specific policy.
	DefaultInfoPolicy *InfoPolicy
}

func clientFinalizer(f *Client) {
	f.Close()
}

//-------------------------------------------------------
// Constructors
//-------------------------------------------------------

// NewClient generates a new Client instance.
func NewClient(hostname string, port int) (*Client, Error) {
	return NewClientWithPolicyAndHost(NewClientPolicy(), NewHost(hostname, port))
}

// NewClientWithPolicy generates a new Client using the specified ClientPolicy.
// If the policy is nil, the default relevant policy will be used.
func NewClientWithPolicy(policy *ClientPolicy, hostname string, port int) (*Client, Error) {
	return NewClientWithPolicyAndHost(policy, NewHost(hostname, port))
}

// NewClientWithPolicyAndHost generates a new Client with the specified ClientPolicy and
// sets up the cluster using the provided hosts.
// If the policy is nil, the default relevant policy will be used.
func NewClientWithPolicyAndHost(policy *ClientPolicy, hosts ...*Host) (*Client, Error) {
	if policy == nil {
		policy = NewClientPolicy()
	}

	cluster, err := NewCluster(policy, hosts)
	if err != nil && policy.FailIfNotConnected {
		logger.Logger.Debug("Failed to connect to host(s): %v; error: %s", hosts, err)
		return nil, err
	}

	client := &Client{
		cluster:                  cluster,
		DefaultPolicy:            NewPolicy(),
		DefaultBatchPolicy:       NewBatchPolicy(),
		DefaultBatchReadPolicy:   NewBatchReadPolicy(),
		DefaultBatchWritePolicy:  NewBatchWritePolicy(),
		DefaultBatchDeletePolicy: NewBatchDeletePolicy(),
		DefaultBatchUDFPolicy:    NewBatchUDFPolicy(),
		DefaultWritePolicy:       NewWritePolicy(0, 0),
		DefaultScanPolicy:        NewScanPolicy(),
		DefaultQueryPolicy:       NewQueryPolicy(),
		DefaultAdminPolicy:       NewAdminPolicy(),
		DefaultInfoPolicy:        NewInfoPolicy(),
	}

	// back reference especially used in batch commands
	cluster.client = client

	runtime.SetFinalizer(client, clientFinalizer)
	return client, err

}

//-------------------------------------------------------
// Policy methods
//-------------------------------------------------------

// DefaultPolicy returns corresponding default policy from the client
func (clnt *Client) GetDefaultPolicy() *BasePolicy {
	return clnt.DefaultPolicy
}

// DefaultBatchPolicy returns corresponding default policy from the client
func (clnt *Client) GetDefaultBatchPolicy() *BatchPolicy {
	return clnt.DefaultBatchPolicy
}

// DefaultBatchWritePolicy returns corresponding default policy from the client
func (clnt *Client) GetDefaultBatchWritePolicy() *BatchWritePolicy {
	return clnt.DefaultBatchWritePolicy
}

// DefaultBatchDeletePolicy returns corresponding default policy from the client
func (clnt *Client) GetDefaultBatchDeletePolicy() *BatchDeletePolicy {
	return clnt.DefaultBatchDeletePolicy
}

// DefaultBatchUDFPolicy returns corresponding default policy from the client
func (clnt *Client) GetDefaultBatchUDFPolicy() *BatchUDFPolicy {
	return clnt.DefaultBatchUDFPolicy
}

// DefaultWritePolicy returns corresponding default policy from the client
func (clnt *Client) GetDefaultWritePolicy() *WritePolicy {
	return clnt.DefaultWritePolicy
}

// DefaultScanPolicy returns corresponding default policy from the client
func (clnt *Client) GetDefaultScanPolicy() *ScanPolicy {
	return clnt.DefaultScanPolicy
}

// DefaultQueryPolicy returns corresponding default policy from the client
func (clnt *Client) GetDefaultQueryPolicy() *QueryPolicy {
	return clnt.DefaultQueryPolicy
}

// DefaultAdminPolicy returns corresponding default policy from the client
func (clnt *Client) GetDefaultAdminPolicy() *AdminPolicy {
	return clnt.DefaultAdminPolicy
}

// DefaultInfoPolicy returns corresponding default policy from the client
func (clnt *Client) GetDefaultInfoPolicy() *InfoPolicy {
	return clnt.DefaultInfoPolicy
}

// DefaultPolicy returns corresponding default policy from the client
func (clnt *Client) SetDefaultPolicy(policy *BasePolicy) {
	clnt.DefaultPolicy = policy
}

// DefaultBatchPolicy returns corresponding default policy from the client
func (clnt *Client) SetDefaultBatchPolicy(policy *BatchPolicy) {
	clnt.DefaultBatchPolicy = policy
}

// DefaultBatchWritePolicy returns corresponding default policy from the client
func (clnt *Client) SetDefaultBatchWritePolicy(policy *BatchWritePolicy) {
	clnt.DefaultBatchWritePolicy = policy
}

// DefaultBatchDeletePolicy returns corresponding default policy from the client
func (clnt *Client) SetDefaultBatchDeletePolicy(policy *BatchDeletePolicy) {
	clnt.DefaultBatchDeletePolicy = policy
}

// DefaultBatchUDFPolicy returns corresponding default policy from the client
func (clnt *Client) SetDefaultBatchUDFPolicy(policy *BatchUDFPolicy) {
	clnt.DefaultBatchUDFPolicy = policy
}

// DefaultWritePolicy returns corresponding default policy from the client
func (clnt *Client) SetDefaultWritePolicy(policy *WritePolicy) {
	clnt.DefaultWritePolicy = policy
}

// DefaultScanPolicy returns corresponding default policy from the client
func (clnt *Client) SetDefaultScanPolicy(policy *ScanPolicy) {
	clnt.DefaultScanPolicy = policy
}

// DefaultQueryPolicy returns corresponding default policy from the client
func (clnt *Client) SetDefaultQueryPolicy(policy *QueryPolicy) {
	clnt.DefaultQueryPolicy = policy
}

// DefaultAdminPolicy returns corresponding default policy from the client
func (clnt *Client) SetDefaultAdminPolicy(policy *AdminPolicy) {
	clnt.DefaultAdminPolicy = policy
}

// DefaultInfoPolicy returns corresponding default policy from the client
func (clnt *Client) SetDefaultInfoPolicy(policy *InfoPolicy) {
	clnt.DefaultInfoPolicy = policy
}

//-------------------------------------------------------
// Cluster Connection Management
//-------------------------------------------------------

// Close closes all client connections to database server nodes.
func (clnt *Client) Close() {
	clnt.cluster.Close()
}

// IsConnected determines if the client is ready to talk to the database server cluster.
func (clnt *Client) IsConnected() bool {
	return clnt.cluster.IsConnected()
}

// GetNodes returns an array of active server nodes in the cluster.
func (clnt *Client) GetNodes() []*Node {
	return clnt.cluster.GetNodes()
}

// GetNodeNames returns a list of active server node names in the cluster.
func (clnt *Client) GetNodeNames() []string {
	nodes := clnt.cluster.GetNodes()
	names := make([]string, 0, len(nodes))

	for _, node := range nodes {
		names = append(names, node.GetName())
	}
	return names
}

//-------------------------------------------------------
// Write Record Operations
//-------------------------------------------------------

// Put writes record bin(s) to the server.
// The policy specifies the transaction timeout, record expiration and how the transaction is
// handled when the record already exists.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) Put(policy *WritePolicy, key *Key, binMap BinMap) Error {
	policy = clnt.getUsableWritePolicy(policy)
	command, err := newWriteCommand(clnt.cluster, policy, key, nil, binMap, _WRITE)
	if err != nil {
		return err
	}

	return command.Execute()
}

// PutBins writes record bin(s) to the server.
// The policy specifies the transaction timeout, record expiration and how the transaction is
// handled when the record already exists.
// This method avoids using the BinMap allocation and iteration and is lighter on GC.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) PutBins(policy *WritePolicy, key *Key, bins ...*Bin) Error {
	policy = clnt.getUsableWritePolicy(policy)
	command, err := newWriteCommand(clnt.cluster, policy, key, bins, nil, _WRITE)
	if err != nil {
		return err
	}

	return command.Execute()
}

//-------------------------------------------------------
// Operations string
//-------------------------------------------------------

// Append appends bin value's string to existing record bin values.
// The policy specifies the transaction timeout, record expiration and how the transaction is
// handled when the record already exists.
// This call only works for string and []byte values.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) Append(policy *WritePolicy, key *Key, binMap BinMap) Error {
	policy = clnt.getUsableWritePolicy(policy)
	command, err := newWriteCommand(clnt.cluster, policy, key, nil, binMap, _APPEND)
	if err != nil {
		return err
	}

	return command.Execute()
}

// AppendBins works the same as Append, but avoids BinMap allocation and iteration.
func (clnt *Client) AppendBins(policy *WritePolicy, key *Key, bins ...*Bin) Error {
	policy = clnt.getUsableWritePolicy(policy)
	command, err := newWriteCommand(clnt.cluster, policy, key, bins, nil, _APPEND)
	if err != nil {
		return err
	}

	return command.Execute()
}

// Prepend prepends bin value's string to existing record bin values.
// The policy specifies the transaction timeout, record expiration and how the transaction is
// handled when the record already exists.
// This call works only for string and []byte values.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) Prepend(policy *WritePolicy, key *Key, binMap BinMap) Error {
	policy = clnt.getUsableWritePolicy(policy)
	command, err := newWriteCommand(clnt.cluster, policy, key, nil, binMap, _PREPEND)
	if err != nil {
		return err
	}

	return command.Execute()
}

// PrependBins works the same as Prepend, but avoids BinMap allocation and iteration.
func (clnt *Client) PrependBins(policy *WritePolicy, key *Key, bins ...*Bin) Error {
	policy = clnt.getUsableWritePolicy(policy)
	command, err := newWriteCommand(clnt.cluster, policy, key, bins, nil, _PREPEND)
	if err != nil {
		return err
	}

	return command.Execute()
}

//-------------------------------------------------------
// Arithmetic Operations
//-------------------------------------------------------

// Add adds integer bin values to existing record bin values.
// The policy specifies the transaction timeout, record expiration and how the transaction is
// handled when the record already exists.
// This call only works for integer values.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) Add(policy *WritePolicy, key *Key, binMap BinMap) Error {
	policy = clnt.getUsableWritePolicy(policy)
	command, err := newWriteCommand(clnt.cluster, policy, key, nil, binMap, _ADD)
	if err != nil {
		return err
	}

	return command.Execute()
}

// AddBins works the same as Add, but avoids BinMap allocation and iteration.
func (clnt *Client) AddBins(policy *WritePolicy, key *Key, bins ...*Bin) Error {
	policy = clnt.getUsableWritePolicy(policy)
	command, err := newWriteCommand(clnt.cluster, policy, key, bins, nil, _ADD)
	if err != nil {
		return err
	}

	return command.Execute()
}

//-------------------------------------------------------
// Delete Operations
//-------------------------------------------------------

// Delete deletes a record for specified key.
// The policy specifies the transaction timeout.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) Delete(policy *WritePolicy, key *Key) (bool, Error) {
	policy = clnt.getUsableWritePolicy(policy)
	command, err := newDeleteCommand(clnt.cluster, policy, key)
	if err != nil {
		return false, err
	}

	err = command.Execute()
	return command.Existed(), err
}

//-------------------------------------------------------
// Touch Operations
//-------------------------------------------------------

// Touch updates a record's metadata.
// If the record exists, the record's TTL will be reset to the
// policy's expiration.
// If the record doesn't exist, it will return an error.
func (clnt *Client) Touch(policy *WritePolicy, key *Key) Error {
	policy = clnt.getUsableWritePolicy(policy)
	command, err := newTouchCommand(clnt.cluster, policy, key)
	if err != nil {
		return err
	}

	return command.Execute()
}

//-------------------------------------------------------
// Existence-Check Operations
//-------------------------------------------------------

// Exists determine if a record key exists.
// The policy can be used to specify timeouts.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) Exists(policy *BasePolicy, key *Key) (bool, Error) {
	policy = clnt.getUsablePolicy(policy)
	command, err := newExistsCommand(clnt.cluster, policy, key)
	if err != nil {
		return false, err
	}

	err = command.Execute()
	return command.Exists(), err
}

// BatchExists determines if multiple record keys exist in one batch request.
// The returned boolean array is in positional order with the original key array order.
// The policy can be used to specify timeouts.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) BatchExists(policy *BatchPolicy, keys []*Key) ([]bool, Error) {
	policy = clnt.getUsableBatchPolicy(policy)

	// same array can be used without synchronization;
	// when a key exists, the corresponding index will be marked true
	existsArray := make([]bool, len(keys))

	batchNodes, err := newBatchNodeList(clnt.cluster, policy, keys, nil, false)
	if err != nil {
		return nil, err
	}

	// pass nil to make sure it will be cloned and prepared
	cmd := newBatchCommandExists(nil, nil, policy, keys, existsArray)
	filteredOut, err := clnt.batchExecute(policy, batchNodes, cmd)
	if filteredOut > 0 {
		err = chainErrors(ErrFilteredOut.err(), err)
	}

	if err != nil {
		return nil, err
	}

	return existsArray, err
}

//-------------------------------------------------------
// Read Record Operations
//-------------------------------------------------------

// Get reads a record header and bins for specified key.
// The policy can be used to specify timeouts.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) Get(policy *BasePolicy, key *Key, binNames ...string) (*Record, Error) {
	policy = clnt.getUsablePolicy(policy)

	command, err := newReadCommand(clnt.cluster, policy, key, binNames, nil)
	if err != nil {
		return nil, err
	}

	if err := command.Execute(); err != nil {
		return nil, err
	}
	return command.GetRecord(), nil
}

// GetHeader reads a record generation and expiration only for specified key.
// Bins are not read.
// The policy can be used to specify timeouts.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) GetHeader(policy *BasePolicy, key *Key) (*Record, Error) {
	policy = clnt.getUsablePolicy(policy)

	command, err := newReadHeaderCommand(clnt.cluster, policy, key)
	if err != nil {
		return nil, err
	}

	if err := command.Execute(); err != nil {
		return nil, err
	}
	return command.GetRecord(), nil
}

//-------------------------------------------------------
// Batch Read Operations
//-------------------------------------------------------

// BatchGet reads multiple record headers and bins for specified keys in one batch request.
// The returned records are in positional order with the original key array order.
// If a key is not found, the positional record will be nil.
// The policy can be used to specify timeouts.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) BatchGet(policy *BatchPolicy, keys []*Key, binNames ...string) ([]*Record, Error) {
	policy = clnt.getUsableBatchPolicy(policy)

	// same array can be used without synchronization;
	// when a key exists, the corresponding index will be set to record
	records := make([]*Record, len(keys))

	batchNodes, err := newBatchNodeList(clnt.cluster, policy, keys, nil, false)
	if err != nil {
		return nil, err
	}

	cmd := newBatchCommandGet(nil, nil, policy, keys, binNames, nil, records, _INFO1_READ, false)
	filteredOut, err := clnt.batchExecute(policy, batchNodes, cmd)
	if err != nil && !policy.AllowPartialResults {
		return nil, err
	}

	if filteredOut > 0 {
		err = chainErrors(ErrFilteredOut.err(), err)
	}

	return records, err
}

// BatchGetOperate reads multiple records for specified keys using read operations in one batch call.
// The returned records are in positional order with the original key array order.
// If a key is not found, the positional record will be nil.
//
// If a batch request to a node fails, the entire batch is cancelled.
func (clnt *Client) BatchGetOperate(policy *BatchPolicy, keys []*Key, ops ...*Operation) ([]*Record, Error) {
	policy = clnt.getUsableBatchPolicy(policy)

	// same array can be used without synchronization;
	// when a key exists, the corresponding index will be set to record
	records := make([]*Record, len(keys))

	batchNodes, err := newBatchNodeList(clnt.cluster, policy, keys, nil, false)
	if err != nil {
		return nil, err
	}

	cmd := newBatchCommandGet(nil, nil, policy, keys, nil, ops, records, _INFO1_READ, true)
	filteredOut, err := clnt.batchExecute(policy, batchNodes, cmd)
	if err != nil && !policy.AllowPartialResults {
		return nil, err
	}

	if filteredOut > 0 {
		err = chainErrors(ErrFilteredOut.err(), err)
	}

	return records, err
}

// BatchGetComplex reads multiple records for specified batch keys in one batch call.
// This method allows different namespaces/bins to be requested for each key in the batch.
// The returned records are located in the same list.
// If the BatchRead key field is not found, the corresponding record field will be nil.
// The policy can be used to specify timeouts and maximum concurrent goroutines.
// This method requires Aerospike Server version >= 3.6.0.
func (clnt *Client) BatchGetComplex(policy *BatchPolicy, records []*BatchRead) Error {
	policy = clnt.getUsableBatchPolicy(policy)

	cmd := newBatchIndexCommandGet(nil, policy, records, true)

	batchNodes, err := newBatchIndexNodeList(clnt.cluster, policy, records)
	if err != nil {
		return err
	}

	filteredOut, err := clnt.batchExecute(policy, batchNodes, cmd)
	if err != nil && !policy.AllowPartialResults {
		return err
	}

	if filteredOut > 0 {
		err = chainErrors(ErrFilteredOut.err(), err)
	}

	return err
}

// BatchGetHeader reads multiple record header data for specified keys in one batch request.
// The returned records are in positional order with the original key array order.
// If a key is not found, the positional record will be nil.
// The policy can be used to specify timeouts.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) BatchGetHeader(policy *BatchPolicy, keys []*Key) ([]*Record, Error) {
	policy = clnt.getUsableBatchPolicy(policy)

	// same array can be used without synchronization;
	// when a key exists, the corresponding index will be set to record
	records := make([]*Record, len(keys))

	batchNodes, err := newBatchNodeList(clnt.cluster, policy, keys, nil, false)
	if err != nil {
		return nil, err
	}

	cmd := newBatchCommandGet(nil, nil, policy, keys, nil, nil, records, _INFO1_READ|_INFO1_NOBINDATA, false)
	filteredOut, err := clnt.batchExecute(policy, batchNodes, cmd)
	if err != nil && !policy.AllowPartialResults {
		return nil, err
	}

	if filteredOut > 0 {
		err = chainErrors(ErrFilteredOut.err(), err)
	}

	return records, err
}

// BatchDelete deletes records for specified keys. If a key is not found, the corresponding result
// BatchRecord.ResultCode will be types.KEY_NOT_FOUND_ERROR.
//
// Requires server version 6.0+
func (clnt *Client) BatchDelete(policy *BatchPolicy, deletePolicy *BatchDeletePolicy, keys []*Key) ([]*BatchRecord, Error) {
	policy = clnt.getUsableBatchPolicy(policy)
	deletePolicy = clnt.getUsableBatchDeletePolicy(deletePolicy)

	attr := &batchAttr{}
	attr.setBatchDelete(deletePolicy)

	// same array can be used without synchronization;
	// when a key exists, the corresponding index will be set to record
	records := make([]*BatchRecord, len(keys))
	for i := range records {
		records[i] = newSimpleBatchRecord(keys[i], true)
	}

	batchNodes, err := newBatchNodeList(clnt.cluster, policy, keys, records, true)
	if err != nil {
		return nil, err
	}

	cmd := newBatchCommandDelete(nil, nil, policy, deletePolicy, keys, records, attr)
	_, err = clnt.batchExecute(policy, batchNodes, cmd)
	return records, err
}

// BatchOperate will read/write multiple records for specified batch keys in one batch call.
// This method allows different namespaces/bins for each key in the batch.
// The returned records are located in the same list.
//
// BatchRecord can be *BatchRead, *BatchWrite, *BatchDelete or *BatchUDF.
//
// Requires server version 6.0+
func (clnt *Client) BatchOperate(policy *BatchPolicy, records []BatchRecordIfc) Error {
	policy = clnt.getUsableBatchPolicy(policy)

	batchNodes, err := newBatchOperateNodeListIfc(clnt.cluster, policy, records)
	if err != nil && policy.RespondAllKeys {
		return err
	}

	cmd := newBatchCommandOperate(clnt, nil, nil, policy, records)
	_, err = clnt.batchExecute(policy, batchNodes, cmd)
	return err
}

// BatchExecute will read/write multiple records for specified batch keys in one batch call.
// This method allows different namespaces/bins for each key in the batch.
// The returned records are located in the same list.
//
// BatchRecord can be *BatchRead, *BatchWrite, *BatchDelete or *BatchUDF.
//
// Requires server version 6.0+
func (clnt *Client) BatchExecute(policy *BatchPolicy, udfPolicy *BatchUDFPolicy, keys []*Key, packageName string, functionName string, args ...Value) ([]*BatchRecord, Error) {
	policy = clnt.getUsableBatchPolicy(policy)
	udfPolicy = clnt.getUsableBatchUDFPolicy(udfPolicy)

	attr := &batchAttr{}
	attr.setBatchUDF(udfPolicy)

	// same array can be used without synchronization;
	// when a key exists, the corresponding index will be set to record
	records := make([]*BatchRecord, len(keys))
	for i := range records {
		records[i] = newSimpleBatchRecord(keys[i], attr.hasWrite)
	}

	batchNodes, err := newBatchNodeList(clnt.cluster, policy, keys, records, attr.hasWrite)
	if err != nil {
		return nil, err
	}

	cmd := newBatchCommandUDF(nil, nil, policy, udfPolicy, keys, packageName, functionName, args, records, attr)
	_, err = clnt.batchExecute(policy, batchNodes, cmd)
	return records, err
}

//-------------------------------------------------------
// Generic Database Operations
//-------------------------------------------------------

// Operate performs multiple read/write operations on a single key in one batch request.
// An example would be to add an integer value to an existing record and then
// read the result, all in one database call.
//
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) Operate(policy *WritePolicy, key *Key, operations ...*Operation) (*Record, Error) {
	policy = clnt.getUsableWritePolicy(policy)
	args, err := newOperateArgs(clnt.cluster, policy, key, operations)
	if err != nil {
		return nil, err
	}
	command, err := newOperateCommand(clnt.cluster, policy, key, args)
	if err != nil {
		return nil, err
	}

	if err := command.Execute(); err != nil {
		return nil, err
	}
	return command.GetRecord(), nil
}

//-------------------------------------------------------
// Scan Operations
//-------------------------------------------------------

// ScanPartitions Read records in specified namespace, set and partition filter.
// If the policy's concurrentNodes is specified, each server node will be read in
// parallel. Otherwise, server nodes are read sequentially.
// If partitionFilter is nil, all partitions will be scanned.
// If the policy is nil, the default relevant policy will be used.
// This method is only supported by Aerospike 4.9+ servers.
func (clnt *Client) ScanPartitions(apolicy *ScanPolicy, partitionFilter *PartitionFilter, namespace string, setName string, binNames ...string) (*Recordset, Error) {
	policy := *clnt.getUsableScanPolicy(apolicy)

	nodes := clnt.cluster.GetNodes()
	if len(nodes) == 0 {
		return nil, ErrClusterIsEmpty.err()
	}

	var tracker *partitionTracker
	if partitionFilter == nil {
		tracker = newPartitionTrackerForNodes(&policy.MultiPolicy, nodes)
	} else {
		tracker = newPartitionTracker(&policy.MultiPolicy, partitionFilter, nodes)
	}

	// result recordset
	res := newRecordset(policy.RecordQueueSize, 1)
	go clnt.scanPartitions(&policy, tracker, namespace, setName, res, binNames...)

	return res, nil
}

// ScanAll reads all records in specified namespace and set from all nodes.
// If the policy's concurrentNodes is specified, each server node will be read in
// parallel. Otherwise, server nodes are read sequentially.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) ScanAll(apolicy *ScanPolicy, namespace string, setName string, binNames ...string) (*Recordset, Error) {
	return clnt.ScanPartitions(apolicy, nil, namespace, setName, binNames...)
}

// scanNodePartitions reads all records in specified namespace and set for one node only.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) scanNodePartitions(apolicy *ScanPolicy, node *Node, namespace string, setName string, binNames ...string) (*Recordset, Error) {
	policy := *clnt.getUsableScanPolicy(apolicy)
	tracker := newPartitionTrackerForNode(&policy.MultiPolicy, node)

	// result recordset
	res := newRecordset(policy.RecordQueueSize, 1)
	go clnt.scanPartitions(&policy, tracker, namespace, setName, res, binNames...)

	return res, nil
}

// ScanNode reads all records in specified namespace and set for one node only.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) ScanNode(apolicy *ScanPolicy, node *Node, namespace string, setName string, binNames ...string) (*Recordset, Error) {
	return clnt.scanNodePartitions(apolicy, node, namespace, setName, binNames...)
}

//---------------------------------------------------------------
// User defined functions (Supported by Aerospike 3+ servers only)
//---------------------------------------------------------------

// RegisterUDFFromFile reads a file from file system and registers
// the containing a package user defined functions with the server.
// This asynchronous server call will return before command is complete.
// The user can optionally wait for command completion by using the returned
// RegisterTask instance.
//
// This method is only supported by Aerospike 3+ servers.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) RegisterUDFFromFile(policy *WritePolicy, clientPath string, serverPath string, language Language) (*RegisterTask, Error) {
	policy = clnt.getUsableWritePolicy(policy)
	udfBody, err := os.ReadFile(clientPath)
	if err != nil {
		return nil, newCommonError(err)
	}

	return clnt.RegisterUDF(policy, udfBody, serverPath, language)
}

// RegisterUDF registers a package containing user defined functions with server.
// This asynchronous server call will return before command is complete.
// The user can optionally wait for command completion by using the returned
// RegisterTask instance.
//
// This method is only supported by Aerospike 3+ servers.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) RegisterUDF(policy *WritePolicy, udfBody []byte, serverPath string, language Language) (*RegisterTask, Error) {
	policy = clnt.getUsableWritePolicy(policy)
	content := base64.StdEncoding.EncodeToString(udfBody)

	var strCmd bytes.Buffer
	// errors are to remove errcheck warnings
	// they will always be nil as stated in golang docs
	strCmd.WriteString("udf-put:filename=")
	strCmd.WriteString(serverPath)
	strCmd.WriteString(";content=")
	strCmd.WriteString(content)
	strCmd.WriteString(";content-len=")
	strCmd.WriteString(strconv.Itoa(len(content)))
	strCmd.WriteString(";udf-type=")
	strCmd.WriteString(string(language))
	strCmd.WriteString(";")

	// Send UDF to one node. That node will distribute the UDF to other nodes.
	responseMap, err := clnt.sendInfoCommand(policy.TotalTimeout, strCmd.String())
	if err != nil {
		return nil, err
	}

	response := responseMap[strCmd.String()]
	res := make(map[string]string)
	vals := strings.Split(response, ";")
	for _, pair := range vals {
		t := strings.SplitN(pair, "=", 2)
		if len(t) == 2 {
			res[t[0]] = t[1]
		} else if len(t) == 1 {
			res[t[0]] = ""
		}
	}

	if _, exists := res["error"]; exists {
		msg, _ := base64.StdEncoding.DecodeString(res["message"])
		return nil, newError(types.COMMAND_REJECTED, fmt.Sprintf("Registration failed: %s\nFile: %s\nLine: %s\nMessage: %s",
			res["error"], res["file"], res["line"], msg))
	}
	return NewRegisterTask(clnt.cluster, serverPath), nil
}

// RemoveUDF removes a package containing user defined functions in the server.
// This asynchronous server call will return before command is complete.
// The user can optionally wait for command completion by using the returned
// RemoveTask instance.
//
// This method is only supported by Aerospike 3+ servers.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) RemoveUDF(policy *WritePolicy, udfName string) (*RemoveTask, Error) {
	policy = clnt.getUsableWritePolicy(policy)
	var strCmd bytes.Buffer
	// errors are to remove errcheck warnings
	// they will always be nil as stated in golang docs
	strCmd.WriteString("udf-remove:filename=")
	strCmd.WriteString(udfName)
	strCmd.WriteString(";")

	// Send command to one node. That node will distribute it to other nodes.
	responseMap, err := clnt.sendInfoCommand(policy.TotalTimeout, strCmd.String())
	if err != nil {
		return nil, err
	}

	response := responseMap[strCmd.String()]
	if response == "ok" {
		return NewRemoveTask(clnt.cluster, udfName), nil
	}
	return nil, newError(types.SERVER_ERROR, response)
}

// ListUDF lists all packages containing user defined functions in the server.
// This method is only supported by Aerospike 3+ servers.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) ListUDF(policy *BasePolicy) ([]*UDF, Error) {
	policy = clnt.getUsablePolicy(policy)

	var strCmd bytes.Buffer
	// errors are to remove errcheck warnings
	// they will always be nil as stated in golang docs
	strCmd.WriteString("udf-list")

	// Send command to one node. That node will distribute it to other nodes.
	responseMap, err := clnt.sendInfoCommand(policy.TotalTimeout, strCmd.String())
	if err != nil {
		return nil, err
	}

	response := responseMap[strCmd.String()]
	vals := strings.Split(response, ";")
	res := make([]*UDF, 0, len(vals))

	for _, udfInfo := range vals {
		if strings.Trim(udfInfo, " ") == "" {
			continue
		}
		udfParts := strings.Split(udfInfo, ",")

		udf := &UDF{}
		for _, values := range udfParts {
			valueParts := strings.Split(values, "=")
			if len(valueParts) == 2 {
				switch valueParts[0] {
				case "filename":
					udf.Filename = valueParts[1]
				case "hash":
					udf.Hash = valueParts[1]
				case "type":
					udf.Language = Language(valueParts[1])
				}
			}
		}
		res = append(res, udf)
	}

	return res, nil
}

// Execute executes a user defined function on server and return results.
// The function operates on a single record.
// The package name is used to locate the udf file location:
//
// udf file = <server udf dir>/<package name>.lua
//
// This method is only supported by Aerospike 3+ servers.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) Execute(policy *WritePolicy, key *Key, packageName string, functionName string, args ...Value) (interface{}, Error) {
	record, err := clnt.execute(policy, key, packageName, functionName, args...)
	if err != nil {
		return nil, err
	}

	if record == nil || len(record.Bins) == 0 {
		return nil, nil
	}

	for k, v := range record.Bins {
		if strings.Contains(k, "SUCCESS") {
			return v, nil
		} else if strings.Contains(k, "FAILURE") {
			return nil, newError(ErrUDFBadResponse.ResultCode, fmt.Sprintf("%v", v))
		}
	}

	return nil, ErrUDFBadResponse.err()
}

func (clnt *Client) execute(policy *WritePolicy, key *Key, packageName string, functionName string, args ...Value) (*Record, Error) {
	policy = clnt.getUsableWritePolicy(policy)
	command, err := newExecuteCommand(clnt.cluster, policy, key, packageName, functionName, NewValueArray(args))
	if err != nil {
		return nil, err
	}

	if err := command.Execute(); err != nil {
		return nil, err
	}

	return command.GetRecord(), nil
}

//----------------------------------------------------------
// Query/Execute (Supported by Aerospike 3+ servers only)
//----------------------------------------------------------

// QueryExecute applies operations on records that match the statement filter.
// Records are not returned to the client.
// This asynchronous server call will return before the command is complete.
// The user can optionally wait for command completion by using the returned
// ExecuteTask instance.
//
// This method is only supported by Aerospike 3+ servers.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) QueryExecute(policy *QueryPolicy,
	writePolicy *WritePolicy,
	statement *Statement,
	ops ...*Operation,
) (*ExecuteTask, Error) {

	if len(statement.BinNames) > 0 {
		return nil, ErrNoBinNamesAllowedInQueryExecute.err()
	}

	policy = clnt.getUsableQueryPolicy(policy)
	writePolicy = clnt.getUsableWritePolicy(writePolicy)

	nodes := clnt.cluster.GetNodes()
	if len(nodes) == 0 {
		return nil, ErrClusterIsEmpty.err()
	}

	statement.prepare(false)

	var errs Error
	for i := range nodes {
		command := newServerCommand(nodes[i], policy, writePolicy, statement, statement.TaskId, ops)
		if err := command.Execute(); err != nil {
			errs = chainErrors(err, errs)
		}
	}

	return NewExecuteTask(clnt.cluster, statement), errs
}

// ExecuteUDF applies user defined function on records that match the statement filter.
// Records are not returned to the client.
// This asynchronous server call will return before command is complete.
// The user can optionally wait for command completion by using the returned
// ExecuteTask instance.
//
// This method is only supported by Aerospike 3+ servers.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) ExecuteUDF(policy *QueryPolicy,
	statement *Statement,
	packageName string,
	functionName string,
	functionArgs ...Value,
) (*ExecuteTask, Error) {
	policy = clnt.getUsableQueryPolicy(policy)

	nodes := clnt.cluster.GetNodes()
	if len(nodes) == 0 {
		return nil, ErrClusterIsEmpty.err()
	}

	statement.SetAggregateFunction(packageName, functionName, functionArgs, false)

	var errs Error
	for i := range nodes {
		command := newServerCommand(nodes[i], policy, nil, statement, statement.TaskId, nil)
		if err := command.Execute(); err != nil {
			errs = chainErrors(err, errs)
		}
	}

	return NewExecuteTask(clnt.cluster, statement), errs
}

// ExecuteUDFNode applies user defined function on records that match the statement filter on the specified node.
// Records are not returned to the client.
// This asynchronous server call will return before command is complete.
// The user can optionally wait for command completion by using the returned
// ExecuteTask instance.
//
// This method is only supported by Aerospike 3+ servers.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) ExecuteUDFNode(policy *QueryPolicy,
	node *Node,
	statement *Statement,
	packageName string,
	functionName string,
	functionArgs ...Value,
) (*ExecuteTask, Error) {
	policy = clnt.getUsableQueryPolicy(policy)

	if node == nil {
		return nil, ErrClusterIsEmpty.err()
	}

	statement.SetAggregateFunction(packageName, functionName, functionArgs, false)

	command := newServerCommand(node, policy, nil, statement, statement.TaskId, nil)
	err := command.Execute()

	return NewExecuteTask(clnt.cluster, statement), err
}

// SetXDRFilter sets XDR filter for given datacenter name and namespace. The expression filter indicates
// which records XDR should ship to the datacenter.
// Pass nil as filter to remove the currentl filter on the server.
func (clnt *Client) SetXDRFilter(policy *InfoPolicy, datacenter string, namespace string, filter *Expression) Error {
	policy = clnt.getUsableInfoPolicy(policy)

	var strCmd string
	if filter == nil {
		strCmd = "xdr-set-filter:dc=" + datacenter + ";namespace=" + namespace + ";exp=null"
	} else {
		b64, err := filter.Base64()
		if err != nil {
			return newError(types.SERIALIZE_ERROR, "FilterExpression could not be serialized to Base64")
		}

		strCmd = "xdr-set-filter:dc=" + datacenter + ";namespace=" + namespace + ";exp=" + b64
	}

	// Send command to one node. That node will distribute it to other nodes.
	responseMap, err := clnt.sendInfoCommand(policy.Timeout, strCmd)
	if err != nil {
		return err
	}

	response := responseMap[strCmd]
	if strings.EqualFold(response, "ok") {
		return nil
	}

	code := parseIndexErrorCode(response)
	return newError(code, response)
}

func parseIndexErrorCode(response string) types.ResultCode {
	var code = types.OK

	list := strings.Split(response, ":")
	if len(list) >= 2 && list[0] == "FAIL" {
		i, err := strconv.ParseInt(list[1], 10, 64)
		if err == nil {
			code = types.ResultCode(i)
		}
	}

	if code == 0 {
		code = types.SERVER_ERROR
	}

	return code
}

//--------------------------------------------------------
// Query functions (Supported by Aerospike 3+ servers only)
//--------------------------------------------------------

// QueryPartitions executes a query for specified partitions and returns a recordset.
// The query executor puts records on the channel from separate goroutines.
// The caller can concurrently pop records off the channel through the
// Recordset.Records channel.
//
// This method is only supported by Aerospike 4.9+ servers.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) QueryPartitions(policy *QueryPolicy, statement *Statement, partitionFilter *PartitionFilter) (*Recordset, Error) {
	policy = clnt.getUsableQueryPolicy(policy)
	nodes := clnt.cluster.GetNodes()
	if len(nodes) == 0 {
		return nil, ErrClusterIsEmpty.err()
	}

	var tracker *partitionTracker
	if partitionFilter == nil {
		tracker = newPartitionTrackerForNodes(&policy.MultiPolicy, nodes)
	} else {
		tracker = newPartitionTracker(&policy.MultiPolicy, partitionFilter, nodes)
	}

	// result recordset
	res := newRecordset(policy.RecordQueueSize, 1)
	go clnt.queryPartitions(policy, tracker, statement, res)

	return res, nil
}

// Query executes a query and returns a Recordset.
// The query executor puts records on the channel from separate goroutines.
// The caller can concurrently pop records off the channel through the
// Recordset.Records channel.
//
// This method is only supported by Aerospike 3+ servers.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) Query(policy *QueryPolicy, statement *Statement) (*Recordset, Error) {
	return clnt.QueryPartitions(policy, statement, nil)
}

// QueryNode executes a query on a specific node and returns a recordset.
// The caller can concurrently pop records off the channel through the
// record channel.
//
// This method is only supported by Aerospike 3+ servers.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) QueryNode(policy *QueryPolicy, node *Node, statement *Statement) (*Recordset, Error) {
	return clnt.queryNodePartitions(policy, node, statement)
}

func (clnt *Client) queryNodePartitions(policy *QueryPolicy, node *Node, statement *Statement) (*Recordset, Error) {
	policy = clnt.getUsableQueryPolicy(policy)
	tracker := newPartitionTrackerForNode(&policy.MultiPolicy, node)

	// result recordset
	res := newRecordset(policy.RecordQueueSize, 1)
	go clnt.queryPartitions(policy, tracker, statement, res)

	return res, nil
}

//--------------------------------------------------------
// Index functions (Supported by Aerospike 3+ servers only)
//--------------------------------------------------------

// CreateIndex creates a secondary index.
// This asynchronous server call will return before the command is complete.
// The user can optionally wait for command completion by using the returned
// IndexTask instance.
// This method is only supported by Aerospike 3+ servers.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) CreateIndex(
	policy *WritePolicy,
	namespace string,
	setName string,
	indexName string,
	binName string,
	indexType IndexType,
) (*IndexTask, Error) {
	policy = clnt.getUsableWritePolicy(policy)
	return clnt.CreateComplexIndex(policy, namespace, setName, indexName, binName, indexType, ICT_DEFAULT)
}

// CreateComplexIndex creates a secondary index, with the ability to put indexes
// on bin containing complex data types, e.g: Maps and Lists.
// This asynchronous server call will return before the command is complete.
// The user can optionally wait for command completion by using the returned
// IndexTask instance.
// This method is only supported by Aerospike 3+ servers.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) CreateComplexIndex(
	policy *WritePolicy,
	namespace string,
	setName string,
	indexName string,
	binName string,
	indexType IndexType,
	indexCollectionType IndexCollectionType,
	ctx ...*CDTContext,
) (*IndexTask, Error) {
	policy = clnt.getUsableWritePolicy(policy)

	var strCmd bytes.Buffer
	strCmd.WriteString("sindex-create:ns=")
	strCmd.WriteString(namespace)

	if len(setName) > 0 {
		strCmd.WriteString(";set=")
		strCmd.WriteString(setName)
	}

	strCmd.WriteString(";indexname=")
	strCmd.WriteString(indexName)

	var bufEx *bufferEx
	if len(ctx) > 0 {
		sz, err := cdtContextList(ctx).packArray(nil)
		if err != nil {
			return nil, err
		}

		bufEx = newBuffer(sz)

		_, err = cdtContextList(ctx).packArray(bufEx)
		if err != nil {
			return nil, err
		}

		strCmd.WriteString(";context=")
		s := base64.StdEncoding.EncodeToString(bufEx.Bytes())
		strCmd.WriteString(s)
	}

	if indexCollectionType != ICT_DEFAULT {
		strCmd.WriteString(";indextype=")
		strCmd.WriteString(ictToString(indexCollectionType))
	}

	strCmd.WriteString(";indexdata=")
	strCmd.WriteString(binName)
	strCmd.WriteString(",")
	strCmd.WriteString(string(indexType))

	// Send index command to one node. That node will distribute the command to other nodes.
	responseMap, err := clnt.sendInfoCommand(policy.TotalTimeout, strCmd.String())
	if err != nil {
		return nil, err
	}

	response := responseMap[strCmd.String()]
	if strings.EqualFold(response, "OK") {
		// Return task that could optionally be polled for completion.
		return NewIndexTask(clnt.cluster, namespace, indexName), nil
	}

	if strings.HasPrefix(response, "FAIL:200") {
		// Index has already been created.  Do not need to poll for completion.
		return nil, newError(types.INDEX_FOUND)
	}

	return nil, newError(types.INDEX_GENERIC, "Create index failed: "+response)
}

// DropIndex deletes a secondary index. It will block until index is dropped on all nodes.
// This method is only supported by Aerospike 3+ servers.
// If the policy is nil, the default relevant policy will be used.
func (clnt *Client) DropIndex(
	policy *WritePolicy,
	namespace string,
	setName string,
	indexName string,
) Error {
	policy = clnt.getUsableWritePolicy(policy)
	var strCmd bytes.Buffer
	strCmd.WriteString("sindex-delete:ns=")
	strCmd.WriteString(namespace)

	if len(setName) > 0 {
		strCmd.WriteString(";set=")
		strCmd.WriteString(setName)
	}
	strCmd.WriteString(";indexname=")
	strCmd.WriteString(indexName)

	// Send index command to one node. That node will distribute the command to other nodes.
	responseMap, err := clnt.sendInfoCommand(policy.TotalTimeout, strCmd.String())
	if err != nil {
		return err
	}

	response := responseMap[strCmd.String()]

	if strings.EqualFold(response, "OK") {
		// Return task that could optionally be polled for completion.
		task := NewDropIndexTask(clnt.cluster, namespace, indexName)
		return <-task.OnComplete()
	}

	if strings.HasPrefix(response, "FAIL:201") {
		// Index did not previously exist. Return without error.
		return nil
	}

	return newError(types.INDEX_GENERIC, "Drop index failed: "+response)
}

// Truncate removes records in specified namespace/set efficiently.  This method is many orders of magnitude
// faster than deleting records one at a time.  Works with Aerospike Server versions >= 3.12.
// This asynchronous server call may return before the truncation is complete.  The user can still
// write new records after the server call returns because new records will have last update times
// greater than the truncate cutoff (set at the time of truncate call).
// For more information, See https://www.aerospike.com/docs/reference/info#truncate
func (clnt *Client) Truncate(policy *InfoPolicy, namespace, set string, beforeLastUpdate *time.Time) Error {
	policy = clnt.getUsableInfoPolicy(policy)

	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return err
	}

	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err = node.initTendConn(policy.Timeout); err != nil {
		return err
	}

	var strCmd bytes.Buffer
	if len(set) > 0 {
		strCmd.WriteString("truncate:namespace=")
		strCmd.WriteString(namespace)
		strCmd.WriteString(";set=")
		strCmd.WriteString(set)
	} else {
		strCmd.WriteString("truncate-namespace:namespace=")
		strCmd.WriteString(namespace)
	}
	if beforeLastUpdate != nil {
		strCmd.WriteString(";lut=")
		strCmd.WriteString(strconv.FormatInt(beforeLastUpdate.UnixNano(), 10))
	}

	responseMap, err := node.tendConn.RequestInfo(strCmd.String())
	if err != nil {
		node.tendConn.Close()
		return err
	}

	response := responseMap[strCmd.String()]
	if strings.EqualFold(response, "OK") {
		return nil
	}

	return newError(types.SERVER_ERROR, "Truncate failed: "+response)
}

//-------------------------------------------------------
// User administration
//-------------------------------------------------------

// CreateUser creates a new user with password and roles. Clear-text password will be hashed using bcrypt
// before sending to server.
func (clnt *Client) CreateUser(policy *AdminPolicy, user string, password string, roles []string) Error {
	policy = clnt.getUsableAdminPolicy(policy)

	hash, err := hashPassword(password)
	if err != nil {
		return err
	}

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return err
	}

	command := NewAdminCommand(nil)
	return command.createUser(node.tendConn, policy, user, hash, roles)
}

// DropUser removes a user from the cluster.
func (clnt *Client) DropUser(policy *AdminPolicy, user string) Error {
	policy = clnt.getUsableAdminPolicy(policy)

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return err
	}

	command := NewAdminCommand(nil)
	return command.dropUser(node.tendConn, policy, user)
}

// ChangePassword changes a user's password. Clear-text password will be hashed using bcrypt before sending to server.
func (clnt *Client) ChangePassword(policy *AdminPolicy, user string, password string) Error {
	policy = clnt.getUsableAdminPolicy(policy)

	if clnt.cluster.user == "" {
		return ErrInvalidUser.err()
	}

	hash, err := hashPassword(password)
	if err != nil {
		return err
	}

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return err
	}

	command := NewAdminCommand(nil)

	if user == clnt.cluster.user {
		// Change own password.
		if err := command.changePassword(node.tendConn, policy, user, clnt.cluster.Password(), hash); err != nil {
			return err
		}
	} else {
		// Change other user's password by user admin.
		if err := command.setPassword(node.tendConn, policy, user, hash); err != nil {
			return err
		}
	}

	clnt.cluster.changePassword(user, password, hash)

	return nil
}

// GrantRoles adds roles to user's list of roles.
func (clnt *Client) GrantRoles(policy *AdminPolicy, user string, roles []string) Error {
	policy = clnt.getUsableAdminPolicy(policy)

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return err
	}

	command := NewAdminCommand(nil)
	return command.grantRoles(node.tendConn, policy, user, roles)
}

// RevokeRoles removes roles from user's list of roles.
func (clnt *Client) RevokeRoles(policy *AdminPolicy, user string, roles []string) Error {
	policy = clnt.getUsableAdminPolicy(policy)

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return err
	}

	command := NewAdminCommand(nil)
	return command.revokeRoles(node.tendConn, policy, user, roles)
}

// QueryUser retrieves roles for a given user.
func (clnt *Client) QueryUser(policy *AdminPolicy, user string) (*UserRoles, Error) {
	policy = clnt.getUsableAdminPolicy(policy)

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return nil, err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return nil, err
	}

	command := NewAdminCommand(nil)
	return command.QueryUser(node.tendConn, policy, user)
}

// QueryUsers retrieves all users and their roles.
func (clnt *Client) QueryUsers(policy *AdminPolicy) ([]*UserRoles, Error) {
	policy = clnt.getUsableAdminPolicy(policy)

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return nil, err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return nil, err
	}

	command := NewAdminCommand(nil)
	return command.QueryUsers(node.tendConn, policy)
}

// QueryRole retrieves privileges for a given role.
func (clnt *Client) QueryRole(policy *AdminPolicy, role string) (*Role, Error) {
	policy = clnt.getUsableAdminPolicy(policy)

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return nil, err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return nil, err
	}

	command := NewAdminCommand(nil)
	return command.QueryRole(node.tendConn, policy, role)
}

// QueryRoles retrieves all roles and their privileges.
func (clnt *Client) QueryRoles(policy *AdminPolicy) ([]*Role, Error) {
	policy = clnt.getUsableAdminPolicy(policy)

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return nil, err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return nil, err
	}

	command := NewAdminCommand(nil)
	return command.QueryRoles(node.tendConn, policy)
}

// CreateRole creates a user-defined role.
// Quotas require server security configuration "enable-quotas" to be set to true.
// Pass 0 for quota values for no limit.
func (clnt *Client) CreateRole(policy *AdminPolicy, roleName string, privileges []Privilege, whitelist []string, readQuota, writeQuota uint32) Error {
	policy = clnt.getUsableAdminPolicy(policy)

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return err
	}

	command := NewAdminCommand(nil)
	return command.createRole(node.tendConn, policy, roleName, privileges, whitelist, readQuota, writeQuota)
}

// DropRole removes a user-defined role.
func (clnt *Client) DropRole(policy *AdminPolicy, roleName string) Error {
	policy = clnt.getUsableAdminPolicy(policy)

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return err
	}

	command := NewAdminCommand(nil)
	return command.dropRole(node.tendConn, policy, roleName)
}

// GrantPrivileges grant privileges to a user-defined role.
func (clnt *Client) GrantPrivileges(policy *AdminPolicy, roleName string, privileges []Privilege) Error {
	policy = clnt.getUsableAdminPolicy(policy)

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return err
	}

	command := NewAdminCommand(nil)
	return command.grantPrivileges(node.tendConn, policy, roleName, privileges)
}

// RevokePrivileges revokes privileges from a user-defined role.
func (clnt *Client) RevokePrivileges(policy *AdminPolicy, roleName string, privileges []Privilege) Error {
	policy = clnt.getUsableAdminPolicy(policy)

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return err
	}

	command := NewAdminCommand(nil)
	return command.revokePrivileges(node.tendConn, policy, roleName, privileges)
}

// SetWhitelist sets IP address whitelist for a role. If whitelist is nil or empty, it removes existing whitelist from role.
func (clnt *Client) SetWhitelist(policy *AdminPolicy, roleName string, whitelist []string) Error {
	policy = clnt.getUsableAdminPolicy(policy)

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return err
	}

	command := NewAdminCommand(nil)
	return command.setWhitelist(node.tendConn, policy, roleName, whitelist)
}

// SetQuotas sets maximum reads/writes per second limits for a role.  If a quota is zero, the limit is removed.
// Quotas require server security configuration "enable-quotas" to be set to true.
// Pass 0 for quota values for no limit.
func (clnt *Client) SetQuotas(policy *AdminPolicy, roleName string, readQuota, writeQuota uint32) Error {
	policy = clnt.getUsableAdminPolicy(policy)

	// prepare the node.tendConn
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return err
	}
	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err := node.initTendConn(time.Second); err != nil {
		return err
	}

	command := NewAdminCommand(nil)
	return command.setQuotas(node.tendConn, policy, roleName, readQuota, writeQuota)
}

//-------------------------------------------------------
// Access Methods
//-------------------------------------------------------

// Cluster exposes the cluster object to the user
func (clnt *Client) Cluster() *Cluster {
	return clnt.cluster
}

// String implements the Stringer interface for client
func (clnt *Client) String() string {
	if clnt.cluster != nil {
		return clnt.cluster.String()
	}
	return ""
}

// MetricsEnabled returns true if metrics are enabled for the cluster.
func (clnt *Client) MetricsEnabled() bool {
	return clnt.cluster.MetricsEnabled()
}

// EnableMetrics enables the cluster transaction metrics gathering.
// If the parameters for the histogram in the policy are the different from the one already
// on the cluster, the metrics will be reset.
func (clnt *Client) EnableMetrics(policy *MetricsPolicy) {
	clnt.cluster.EnableMetrics(policy)
}

// DisableMetrics disables the cluster transaction metrics gathering.
func (clnt *Client) DisableMetrics() {
	clnt.cluster.DisableMetrics()
}

// Stats returns internal statistics regarding the inner state of the client and the cluster.
func (clnt *Client) Stats() (map[string]interface{}, Error) {
	resStats := clnt.cluster.statsCopy()

	clusterStats := *newNodeStats(clnt.cluster.MetricsPolicy())
	for _, stats := range resStats {
		clusterStats.aggregate(&stats)
	}

	resStats["cluster-aggregated-stats"] = clusterStats

	b, err := json.Marshal(resStats)
	if err != nil {
		return nil, newCommonError(err)
	}

	res := map[string]interface{}{}
	err = json.Unmarshal(b, &res)
	if err != nil {
		return nil, newCommonError(err)
	}

	res["open-connections"] = clusterStats.ConnectionsOpen.Get()
	res["total-nodes"] = len(clnt.cluster.GetNodes())

	aggstats := res["cluster-aggregated-stats"].(map[string]interface{})
	aggstats["exceeded-max-retries"] = clnt.cluster.maxRetriesExceededCount.Get()
	aggstats["exceeded-total-timeout"] = clnt.cluster.totalTimeoutExceededCount.Get()

	return res, nil
}

// WarmUp fills the connection pool with connections for all nodes.
// This is necessary on startup for high traffic programs.
// If the count is <= 0, the connection queue will be filled.
// If the count is more than the size of the pool, the pool will be filled.
// Note: One connection per node is reserved for tend operations and is not used for transactions.
func (clnt *Client) WarmUp(count int) (int, Error) {
	return clnt.cluster.WarmUp(count)
}

//-------------------------------------------------------
// Internal Methods
//-------------------------------------------------------

func (clnt *Client) sendInfoCommand(timeout time.Duration, command string) (map[string]string, Error) {
	node, err := clnt.cluster.GetRandomNode()
	if err != nil {
		return nil, err
	}

	node.tendConnLock.Lock()
	defer node.tendConnLock.Unlock()

	if err = node.initTendConn(timeout); err != nil {
		return nil, err
	}

	results, err := node.tendConn.RequestInfo(command)
	if err != nil {
		node.tendConn.Close()
		return nil, err
	}

	return results, nil
}

//-------------------------------------------------------
// Policy Methods
//-------------------------------------------------------

func (clnt *Client) getUsablePolicy(policy *BasePolicy) *BasePolicy {
	if policy == nil {
		if clnt.DefaultPolicy != nil {
			return clnt.DefaultPolicy
		}
		return NewPolicy()
	}
	return policy
}

func (clnt *Client) getUsableBatchPolicy(policy *BatchPolicy) *BatchPolicy {
	if policy == nil {
		if clnt.DefaultBatchPolicy != nil {
			return clnt.DefaultBatchPolicy
		}
		return NewBatchPolicy()
	}
	return policy
}

func (clnt *Client) getUsableBaseBatchWritePolicy(policy *BatchPolicy) *BatchPolicy {
	if policy == nil {
		if clnt.DefaultBatchPolicy != nil {
			return clnt.DefaultBatchPolicy
		}
		return NewBatchPolicy()
	}
	return policy
}

func (clnt *Client) getUsableBatchReadPolicy(policy *BatchReadPolicy) *BatchReadPolicy {
	if policy == nil {
		if clnt.DefaultBatchReadPolicy != nil {
			return clnt.DefaultBatchReadPolicy
		}
		return NewBatchReadPolicy()
	}
	return policy
}

func (clnt *Client) getUsableBatchWritePolicy(policy *BatchWritePolicy) *BatchWritePolicy {
	if policy == nil {
		if clnt.DefaultBatchWritePolicy != nil {
			return clnt.DefaultBatchWritePolicy
		}
		return NewBatchWritePolicy()
	}
	return policy
}

func (clnt *Client) getUsableBatchDeletePolicy(policy *BatchDeletePolicy) *BatchDeletePolicy {
	if policy == nil {
		if clnt.DefaultBatchDeletePolicy != nil {
			return clnt.DefaultBatchDeletePolicy
		}
		return NewBatchDeletePolicy()
	}
	return policy
}

func (clnt *Client) getUsableBatchUDFPolicy(policy *BatchUDFPolicy) *BatchUDFPolicy {
	if policy == nil {
		if clnt.DefaultBatchUDFPolicy != nil {
			return clnt.DefaultBatchUDFPolicy
		}
		return NewBatchUDFPolicy()
	}
	return policy
}

func (clnt *Client) getUsableWritePolicy(policy *WritePolicy) *WritePolicy {
	if policy == nil {
		if clnt.DefaultWritePolicy != nil {
			return clnt.DefaultWritePolicy
		}
		return NewWritePolicy(0, 0)
	}
	return policy
}

func (clnt *Client) getUsableScanPolicy(policy *ScanPolicy) *ScanPolicy {
	if policy == nil {
		if clnt.DefaultScanPolicy != nil {
			return clnt.DefaultScanPolicy
		}
		return NewScanPolicy()
	}
	return policy
}

func (clnt *Client) getUsableQueryPolicy(policy *QueryPolicy) *QueryPolicy {
	if policy == nil {
		if clnt.DefaultQueryPolicy != nil {
			return clnt.DefaultQueryPolicy
		}
		return NewQueryPolicy()
	}
	return policy
}

func (clnt *Client) getUsableAdminPolicy(policy *AdminPolicy) *AdminPolicy {
	if policy == nil {
		if clnt.DefaultAdminPolicy != nil {
			return clnt.DefaultAdminPolicy
		}
		return NewAdminPolicy()
	}
	return policy
}

func (clnt *Client) getUsableInfoPolicy(policy *InfoPolicy) *InfoPolicy {
	if policy == nil {
		if clnt.DefaultInfoPolicy != nil {
			return clnt.DefaultInfoPolicy
		}
		return NewInfoPolicy()
	}
	return policy
}

//-------------------------------------------------------
// Utility Functions
//-------------------------------------------------------