package sarama

import (
	"time"
)

type CreateTopicsRequest struct {
	// Version defines the protocol version to use for encode and decode
	Version int16
	// TopicDetails contains the topics to create.
	TopicDetails map[string]*TopicDetail
	// Timeout contains how long to wait before timing out the request.
	Timeout time.Duration
	// ValidateOnly if true, check that the topics can be created as specified,
	// but don't create anything.
	ValidateOnly bool
}

func NewCreateTopicsRequest(version KafkaVersion, topicDetails map[string]*TopicDetail, timeout time.Duration) *CreateTopicsRequest {
	r := &CreateTopicsRequest{
		TopicDetails: topicDetails,
		Timeout:      timeout,
	}
	if version.IsAtLeast(V2_0_0_0) {
		r.Version = 3
	} else if version.IsAtLeast(V0_11_0_0) {
		r.Version = 2
	} else if version.IsAtLeast(V0_10_2_0) {
		r.Version = 1
	}
	return r
}

func (c *CreateTopicsRequest) encode(pe packetEncoder) error {
	if err := pe.putArrayLength(len(c.TopicDetails)); err != nil {
		return err
	}
	for topic, detail := range c.TopicDetails {
		if err := pe.putString(topic); err != nil {
			return err
		}
		if err := detail.encode(pe); err != nil {
			return err
		}
	}

	pe.putInt32(int32(c.Timeout / time.Millisecond))

	if c.Version >= 1 {
		pe.putBool(c.ValidateOnly)
	}

	return nil
}

func (c *CreateTopicsRequest) decode(pd packetDecoder, version int16) (err error) {
	n, err := pd.getArrayLength()
	if err != nil {
		return err
	}

	c.TopicDetails = make(map[string]*TopicDetail, n)

	for i := 0; i < n; i++ {
		topic, err := pd.getString()
		if err != nil {
			return err
		}
		c.TopicDetails[topic] = new(TopicDetail)
		if err = c.TopicDetails[topic].decode(pd, version); err != nil {
			return err
		}
	}

	timeout, err := pd.getInt32()
	if err != nil {
		return err
	}
	c.Timeout = time.Duration(timeout) * time.Millisecond

	if version >= 1 {
		c.ValidateOnly, err = pd.getBool()
		if err != nil {
			return err
		}

		c.Version = version
	}

	return nil
}

func (c *CreateTopicsRequest) key() int16 {
	return 19
}

func (c *CreateTopicsRequest) version() int16 {
	return c.Version
}

func (r *CreateTopicsRequest) headerVersion() int16 {
	return 1
}

func (c *CreateTopicsRequest) isValidVersion() bool {
	return c.Version >= 0 && c.Version <= 3
}

func (c *CreateTopicsRequest) requiredVersion() KafkaVersion {
	switch c.Version {
	case 3:
		return V2_0_0_0
	case 2:
		return V0_11_0_0
	case 1:
		return V0_10_2_0
	case 0:
		return V0_10_1_0
	default:
		return V2_8_0_0
	}
}

type TopicDetail struct {
	// NumPartitions contains the number of partitions to create in the topic, or
	// -1 if we are either specifying a manual partition assignment or using the
	// default partitions.
	NumPartitions int32
	// ReplicationFactor contains the number of replicas to create for each
	// partition in the topic, or -1 if we are either specifying a manual
	// partition assignment or using the default replication factor.
	ReplicationFactor int16
	// ReplicaAssignment contains the manual partition assignment, or the empty
	// array if we are using automatic assignment.
	ReplicaAssignment map[int32][]int32
	// ConfigEntries contains the custom topic configurations to set.
	ConfigEntries map[string]*string
}

func (t *TopicDetail) encode(pe packetEncoder) error {
	pe.putInt32(t.NumPartitions)
	pe.putInt16(t.ReplicationFactor)

	if err := pe.putArrayLength(len(t.ReplicaAssignment)); err != nil {
		return err
	}
	for partition, assignment := range t.ReplicaAssignment {
		pe.putInt32(partition)
		if err := pe.putInt32Array(assignment); err != nil {
			return err
		}
	}

	if err := pe.putArrayLength(len(t.ConfigEntries)); err != nil {
		return err
	}
	for configKey, configValue := range t.ConfigEntries {
		if err := pe.putString(configKey); err != nil {
			return err
		}
		if err := pe.putNullableString(configValue); err != nil {
			return err
		}
	}

	return nil
}

func (t *TopicDetail) decode(pd packetDecoder, version int16) (err error) {
	if t.NumPartitions, err = pd.getInt32(); err != nil {
		return err
	}
	if t.ReplicationFactor, err = pd.getInt16(); err != nil {
		return err
	}

	n, err := pd.getArrayLength()
	if err != nil {
		return err
	}

	if n > 0 {
		t.ReplicaAssignment = make(map[int32][]int32, n)
		for i := 0; i < n; i++ {
			replica, err := pd.getInt32()
			if err != nil {
				return err
			}
			if t.ReplicaAssignment[replica], err = pd.getInt32Array(); err != nil {
				return err
			}
		}
	}

	n, err = pd.getArrayLength()
	if err != nil {
		return err
	}

	if n > 0 {
		t.ConfigEntries = make(map[string]*string, n)
		for i := 0; i < n; i++ {
			configKey, err := pd.getString()
			if err != nil {
				return err
			}
			if t.ConfigEntries[configKey], err = pd.getNullableString(); err != nil {
				return err
			}
		}
	}

	return nil
}