package ipvlan

import (
	"encoding/json"
	"fmt"
	"net"

	"github.com/docker/libnetwork/datastore"
	"github.com/docker/libnetwork/discoverapi"
	"github.com/docker/libnetwork/netlabel"
	"github.com/docker/libnetwork/types"
	"github.com/sirupsen/logrus"
)

const (
	ipvlanPrefix         = "ipvlan"
	ipvlanNetworkPrefix  = ipvlanPrefix + "/network"
	ipvlanEndpointPrefix = ipvlanPrefix + "/endpoint"
)

// networkConfiguration for this driver's network specific configuration
type configuration struct {
	ID               string
	Mtu              int
	dbIndex          uint64
	dbExists         bool
	Internal         bool
	Parent           string
	IpvlanMode       string
	CreatedSlaveLink bool
	Ipv4Subnets      []*ipv4Subnet
	Ipv6Subnets      []*ipv6Subnet
}

type ipv4Subnet struct {
	SubnetIP string
	GwIP     string
}

type ipv6Subnet struct {
	SubnetIP string
	GwIP     string
}

// initStore drivers are responsible for caching their own persistent state
func (d *driver) initStore(option map[string]interface{}) error {
	if data, ok := option[netlabel.LocalKVClient]; ok {
		var err error
		dsc, ok := data.(discoverapi.DatastoreConfigData)
		if !ok {
			return types.InternalErrorf("incorrect data in datastore configuration: %v", data)
		}
		d.store, err = datastore.NewDataStoreFromConfig(dsc)
		if err != nil {
			return types.InternalErrorf("ipvlan driver failed to initialize data store: %v", err)
		}

		err = d.populateNetworks()
		if err != nil {
			return err
		}
		err = d.populateEndpoints()
		if err != nil {
			return err
		}
	}

	return nil
}

// populateNetworks is invoked at driver init to recreate persistently stored networks
func (d *driver) populateNetworks() error {
	kvol, err := d.store.List(datastore.Key(ipvlanNetworkPrefix), &configuration{})
	if err != nil && err != datastore.ErrKeyNotFound {
		return fmt.Errorf("failed to get ipvlan network configurations from store: %v", err)
	}
	// If empty it simply means no ipvlan networks have been created yet
	if err == datastore.ErrKeyNotFound {
		return nil
	}
	for _, kvo := range kvol {
		config := kvo.(*configuration)
		if _, err = d.createNetwork(config); err != nil {
			logrus.Warnf("could not create ipvlan network for id %s from persistent state", config.ID)
		}
	}

	return nil
}

func (d *driver) populateEndpoints() error {
	kvol, err := d.store.List(datastore.Key(ipvlanEndpointPrefix), &endpoint{})
	if err != nil && err != datastore.ErrKeyNotFound {
		return fmt.Errorf("failed to get ipvlan endpoints from store: %v", err)
	}

	if err == datastore.ErrKeyNotFound {
		return nil
	}

	for _, kvo := range kvol {
		ep := kvo.(*endpoint)
		n, ok := d.networks[ep.nid]
		if !ok {
			logrus.Debugf("Network (%.7s) not found for restored ipvlan endpoint (%.7s)", ep.nid, ep.id)
			logrus.Debugf("Deleting stale ipvlan endpoint (%.7s) from store", ep.id)
			if err := d.storeDelete(ep); err != nil {
				logrus.Debugf("Failed to delete stale ipvlan endpoint (%.7s) from store", ep.id)
			}
			continue
		}
		n.endpoints[ep.id] = ep
		logrus.Debugf("Endpoint (%.7s) restored to network (%.7s)", ep.id, ep.nid)
	}

	return nil
}

// storeUpdate used to update persistent ipvlan network records as they are created
func (d *driver) storeUpdate(kvObject datastore.KVObject) error {
	if d.store == nil {
		logrus.Warnf("ipvlan store not initialized. kv object %s is not added to the store", datastore.Key(kvObject.Key()...))
		return nil
	}
	if err := d.store.PutObjectAtomic(kvObject); err != nil {
		return fmt.Errorf("failed to update ipvlan store for object type %T: %v", kvObject, err)
	}

	return nil
}

// storeDelete used to delete ipvlan network records from persistent cache as they are deleted
func (d *driver) storeDelete(kvObject datastore.KVObject) error {
	if d.store == nil {
		logrus.Debugf("ipvlan store not initialized. kv object %s is not deleted from store", datastore.Key(kvObject.Key()...))
		return nil
	}
retry:
	if err := d.store.DeleteObjectAtomic(kvObject); err != nil {
		if err == datastore.ErrKeyModified {
			if err := d.store.GetObject(datastore.Key(kvObject.Key()...), kvObject); err != nil {
				return fmt.Errorf("could not update the kvobject to latest when trying to delete: %v", err)
			}
			goto retry
		}
		return err
	}

	return nil
}

func (config *configuration) MarshalJSON() ([]byte, error) {
	nMap := make(map[string]interface{})
	nMap["ID"] = config.ID
	nMap["Mtu"] = config.Mtu
	nMap["Parent"] = config.Parent
	nMap["IpvlanMode"] = config.IpvlanMode
	nMap["Internal"] = config.Internal
	nMap["CreatedSubIface"] = config.CreatedSlaveLink
	if len(config.Ipv4Subnets) > 0 {
		iis, err := json.Marshal(config.Ipv4Subnets)
		if err != nil {
			return nil, err
		}
		nMap["Ipv4Subnets"] = string(iis)
	}
	if len(config.Ipv6Subnets) > 0 {
		iis, err := json.Marshal(config.Ipv6Subnets)
		if err != nil {
			return nil, err
		}
		nMap["Ipv6Subnets"] = string(iis)
	}

	return json.Marshal(nMap)
}

func (config *configuration) UnmarshalJSON(b []byte) error {
	var (
		err  error
		nMap map[string]interface{}
	)

	if err = json.Unmarshal(b, &nMap); err != nil {
		return err
	}
	config.ID = nMap["ID"].(string)
	config.Mtu = int(nMap["Mtu"].(float64))
	config.Parent = nMap["Parent"].(string)
	config.IpvlanMode = nMap["IpvlanMode"].(string)
	config.Internal = nMap["Internal"].(bool)
	config.CreatedSlaveLink = nMap["CreatedSubIface"].(bool)
	if v, ok := nMap["Ipv4Subnets"]; ok {
		if err := json.Unmarshal([]byte(v.(string)), &config.Ipv4Subnets); err != nil {
			return err
		}
	}
	if v, ok := nMap["Ipv6Subnets"]; ok {
		if err := json.Unmarshal([]byte(v.(string)), &config.Ipv6Subnets); err != nil {
			return err
		}
	}

	return nil
}

func (config *configuration) Key() []string {
	return []string{ipvlanNetworkPrefix, config.ID}
}

func (config *configuration) KeyPrefix() []string {
	return []string{ipvlanNetworkPrefix}
}

func (config *configuration) Value() []byte {
	b, err := json.Marshal(config)
	if err != nil {
		return nil
	}
	return b
}

func (config *configuration) SetValue(value []byte) error {
	return json.Unmarshal(value, config)
}

func (config *configuration) Index() uint64 {
	return config.dbIndex
}

func (config *configuration) SetIndex(index uint64) {
	config.dbIndex = index
	config.dbExists = true
}

func (config *configuration) Exists() bool {
	return config.dbExists
}

func (config *configuration) Skip() bool {
	return false
}

func (config *configuration) New() datastore.KVObject {
	return &configuration{}
}

func (config *configuration) CopyTo(o datastore.KVObject) error {
	dstNcfg := o.(*configuration)
	*dstNcfg = *config
	return nil
}

func (config *configuration) DataScope() string {
	return datastore.LocalScope
}

func (ep *endpoint) MarshalJSON() ([]byte, error) {
	epMap := make(map[string]interface{})
	epMap["id"] = ep.id
	epMap["nid"] = ep.nid
	epMap["SrcName"] = ep.srcName
	if len(ep.mac) != 0 {
		epMap["MacAddress"] = ep.mac.String()
	}
	if ep.addr != nil {
		epMap["Addr"] = ep.addr.String()
	}
	if ep.addrv6 != nil {
		epMap["Addrv6"] = ep.addrv6.String()
	}
	return json.Marshal(epMap)
}

func (ep *endpoint) UnmarshalJSON(b []byte) error {
	var (
		err   error
		epMap map[string]interface{}
	)

	if err = json.Unmarshal(b, &epMap); err != nil {
		return fmt.Errorf("Failed to unmarshal to ipvlan endpoint: %v", err)
	}

	if v, ok := epMap["MacAddress"]; ok {
		if ep.mac, err = net.ParseMAC(v.(string)); err != nil {
			return types.InternalErrorf("failed to decode ipvlan endpoint MAC address (%s) after json unmarshal: %v", v.(string), err)
		}
	}
	if v, ok := epMap["Addr"]; ok {
		if ep.addr, err = types.ParseCIDR(v.(string)); err != nil {
			return types.InternalErrorf("failed to decode ipvlan endpoint IPv4 address (%s) after json unmarshal: %v", v.(string), err)
		}
	}
	if v, ok := epMap["Addrv6"]; ok {
		if ep.addrv6, err = types.ParseCIDR(v.(string)); err != nil {
			return types.InternalErrorf("failed to decode ipvlan endpoint IPv6 address (%s) after json unmarshal: %v", v.(string), err)
		}
	}
	ep.id = epMap["id"].(string)
	ep.nid = epMap["nid"].(string)
	ep.srcName = epMap["SrcName"].(string)

	return nil
}

func (ep *endpoint) Key() []string {
	return []string{ipvlanEndpointPrefix, ep.id}
}

func (ep *endpoint) KeyPrefix() []string {
	return []string{ipvlanEndpointPrefix}
}

func (ep *endpoint) Value() []byte {
	b, err := json.Marshal(ep)
	if err != nil {
		return nil
	}
	return b
}

func (ep *endpoint) SetValue(value []byte) error {
	return json.Unmarshal(value, ep)
}

func (ep *endpoint) Index() uint64 {
	return ep.dbIndex
}

func (ep *endpoint) SetIndex(index uint64) {
	ep.dbIndex = index
	ep.dbExists = true
}

func (ep *endpoint) Exists() bool {
	return ep.dbExists
}

func (ep *endpoint) Skip() bool {
	return false
}

func (ep *endpoint) New() datastore.KVObject {
	return &endpoint{}
}

func (ep *endpoint) CopyTo(o datastore.KVObject) error {
	dstEp := o.(*endpoint)
	*dstEp = *ep
	return nil
}

func (ep *endpoint) DataScope() string {
	return datastore.LocalScope
}
