/*
// Copyright (c) 2016 Intel Corporation
//
// 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 types

import (
	"encoding/json"
	"errors"
	"strconv"
	"strings"
	"sync"
	"time"

	"github.com/ciao-project/ciao/ciao-storage"
	"github.com/ciao-project/ciao/payloads"
	"github.com/ciao-project/ciao/ssntp"
	"github.com/golang/glog"
)

// SourceType contains the valid values of the storage source.
type SourceType string

const (
	// ImageService indicates the source comes from the image service.
	ImageService SourceType = "image"

	// VolumeService indicates the source comes from the volume service.
	VolumeService SourceType = "volume"

	// Empty indicates that there is no source for the storage source
	Empty SourceType = "empty"
)

// StorageResource defines a storage resource for a workload.
// TBD: should the workload support multiple of these?
type StorageResource struct {
	// ID indicates a volumeID. If ID is blank, then it needs to be created.
	ID string `json:"id"`

	// Bootable indicates whether should the resource be used for booting
	Bootable bool `json:"bootable"`

	// Ephemeral indicates whether the storage is temporary
	// TBD: do we bother to save info about temp storage?
	//      does it count against quota?
	Ephemeral bool `json:"ephemeral"`

	// Size is the size of the storage to be created if new.
	Size int `json:"size"`

	// ImageType indicates whether we are making a new resource
	// based on an image or existing volume.
	// Needed only for new storage.
	SourceType SourceType `json:"source_type"`

	// Source represents the ID or name of either the image or the volume
	// that the storage resource is based on.
	Source string `json:"source_id"`

	// Tag is a piece of abitrary search/sort identifier text
	Tag string

	// Internal indicates whether this storage should be shown to the user
	Internal bool
}

// Workload contains resource and configuration information for a user
// workload.
type Workload struct {
	ID           string                        `json:"id"`
	TenantID     string                        `json:"-"`
	Description  string                        `json:"description"`
	FWType       string                        `json:"fw_type"`
	VMType       payloads.Hypervisor           `json:"vm_type"`
	ImageName    string                        `json:"image_name"`
	Config       string                        `json:"config"`
	Storage      []StorageResource             `json:"storage"`
	Visibility   Visibility                    `json:"visibility"`
	Requirements payloads.WorkloadRequirements `json:"workload_requirements"`
}

// WorkloadResponse will be returned from /workloads apis
// It provides details on the workload, and references for the client.
type WorkloadResponse struct {
	Workload Workload `json:"workload"`
	Link     Link     `json:"link"`
}

// WorkloadRequest contains resource and configuration for a user
// workload.
type WorkloadRequest struct {
	WorkloadID string
	TenantID   string
	Instances  int
	TraceLabel string
	Name       string
	Subnet     string
}

// Instance contains information about an instance of a workload.
type Instance struct {
	ID          string       `json:"instance_id"`
	TenantID    string       `json:"tenant_id"`
	State       string       `json:"instance_state"`
	WorkloadID  string       `json:"workload_id"`
	NodeID      string       `json:"node_id"`
	MACAddress  string       `json:"mac_address"`
	VnicUUID    string       `json:"vnic_uuid"`
	Subnet      string       `json:"subnet"`
	IPAddress   string       `json:"ip_address"`
	SSHIP       string       `json:"ssh_ip"`
	SSHPort     int          `json:"ssh_port"`
	CNCI        bool         `json:"-"`
	CreateTime  time.Time    `json:"-"`
	Name        string       `json:"name"`
	StateLock   sync.RWMutex `json:"-"`
	StateChange *sync.Cond   `json:"-"`
}

// SortedInstancesByID implements sort.Interface for Instance by ID string
type SortedInstancesByID []*Instance

func (s SortedInstancesByID) Len() int           { return len(s) }
func (s SortedInstancesByID) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
func (s SortedInstancesByID) Less(i, j int) bool { return s[i].ID < s[j].ID }

// SortedNodesByID implements sort.Interface for Node by ID string
type SortedNodesByID []CiaoNode

func (s SortedNodesByID) Len() int           { return len(s) }
func (s SortedNodesByID) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
func (s SortedNodesByID) Less(i, j int) bool { return s[i].ID < s[j].ID }

// TenantConfig stores the configurable attributes of a tenant.
type TenantConfig struct {
	Name        string `json:"name"`
	SubnetBits  int    `json:"subnet_bits"`
	Permissions struct {
		PrivilegedContainers bool `json:"privileged_containers"`
	} `json:"permissions"`
}

// Tenant contains information about a tenant or project.
type Tenant struct {
	TenantConfig
	ID       string
	CNCIctrl CNCIController
}

// TenantSummary is a short form of Tenant
type TenantSummary struct {
	ID    string `json:"id"`
	Name  string `json:"name"`
	Links []Link `json:"links,omitempty"`
}

// TenantsListResponse stores a list of tenants retrieved by listTenants
type TenantsListResponse struct {
	Tenants []TenantSummary `json:"tenants"`
}

// TenantRequest contains information for creating a new tenant.
type TenantRequest struct {
	ID     string       `json:"id"`
	Config TenantConfig `json:"config"`
}

// LogEntry stores information about events.
type LogEntry struct {
	Timestamp time.Time `json:"time_stamp"`
	TenantID  string    `json:"tenant_id"`
	NodeID    string    `json:"node_id"`
	EventType string    `json:"type"`
	Message   string    `json:"message"`
}

// NodeStats stores statistics for individual nodes in the cluster.
type NodeStats struct {
	NodeID          string    `json:"node_id"`
	Timestamp       time.Time `json:"time_stamp"`
	Load            int       `json:"load"`
	MemTotalMB      int       `json:"mem_total_mb"`
	MemAvailableMB  int       `json:"mem_available_mb"`
	DiskTotalMB     int       `json:"disk_total_mb"`
	DiskAvailableMB int       `json:"disk_available_mb"`
	CpusOnline      int       `json:"cpus_online"`
}

// NodeSummary contains summary information for all nodes in the cluster.
type NodeSummary struct {
	NodeID                string `json:"node_id"`
	TotalInstances        int    `json:"total_instances"`
	TotalRunningInstances int    `json:"total_running_instances"`
	TotalPendingInstances int    `json:"total_pending_instances"`
	TotalPausedInstances  int    `json:"total_paused_instances"`
	TotalFailures         int    `json:"total_failures"`
}

// TenantCNCI contains information about the CNCI instance for a tenant.
type TenantCNCI struct {
	TenantID   string   `json:"tenant_id"`
	IPAddress  string   `json:"ip_address"`
	MACAddress string   `json:"mac_address"`
	InstanceID string   `json:"instance_id"`
	Subnets    []string `json:"subnets"`
}

// FrameStat contains tracing information per node.
type FrameStat struct {
	ID               string  `json:"node_id"`
	TotalElapsedTime float64 `json:"total_elapsed_time"`
	ControllerTime   float64 `json:"total_controller_time"`
	LauncherTime     float64 `json:"total_launcher_time"`
	SchedulerTime    float64 `json:"total_scheduler_time"`
}

// BatchFrameStat contains tracing information for a group of start requests
// by label.
type BatchFrameStat struct {
	NumInstances             int     `json:"num_instances"`
	TotalElapsed             float64 `json:"total_elapsed"`
	AverageElapsed           float64 `json:"average_elapsed"`
	AverageControllerElapsed float64 `json:"average_controller_elapsed"`
	AverageLauncherElapsed   float64 `json:"average_launcher_elapsed"`
	AverageSchedulerElapsed  float64 `json:"average_scheduler_elapsed"`
	VarianceController       float64 `json:"controller_variance"`
	VarianceLauncher         float64 `json:"launcher_variance"`
	VarianceScheduler        float64 `json:"scheduler_variance"`
}

// BatchFrameSummary provides summary information on tracing per label.
type BatchFrameSummary struct {
	BatchID      string `json:"batch_id"`
	NumInstances int    `json:"num_instances"`
}

// Node contains information about a physical node in the cluster.
type Node struct {
	ID                   string     `json:"node_id"`
	IPAddr               string     `json:"ip_address"`
	Hostname             string     `json:"hostname"`
	TotalFailures        int        `json:"total_failures"`
	StartFailures        int        `json:"start_failures"`
	AttachVolumeFailures int        `json:"attach_failures"`
	DeleteFailures       int        `json:"delete_failures"`
	NodeRole             ssntp.Role `json:"role"`
}

// BlockState represents the state of the block device in the controller
// datastore. This is a subset of the openstack status type.
type BlockState string

const (
	// Available means that the volume is ok for attaching.
	Available BlockState = "available"

	// Attaching means that the volume is in the process
	// of attaching to an instance.
	Attaching BlockState = "attaching"

	// InUse means that the volume has been successfully
	// attached to an instance.
	InUse BlockState = "in-use"

	// Detaching means that the volume is in process
	// of detaching.
	Detaching BlockState = "detaching"
)

// Volume respresents the attributes of this block device.
// TBD - do we really need to store this as actual data,
// or can we use a set of interfaces to get the info?
type Volume struct {
	storage.BlockDevice
	TenantID    string     `json:"tenant_id"`   // the tenant who owns this volume
	State       BlockState `json:"state"`       // status of
	CreateTime  time.Time  `json:"created"`     // when we created the volume
	Name        string     `json:"name"`        // a human readable name for this volume
	Description string     `json:"description"` // some text to describe this volume.
	Internal    bool       `json:"internal"`    // whether this storage should be shown to the user
}

// StorageAttachment represents a link between a block device and
// an instance.
type StorageAttachment struct {
	ID         string // a uuid
	InstanceID string // the instance this volume is attached to
	BlockID    string // the ID of the block device
	Ephemeral  bool   // whether the storage should be deleted on Cleanup
	Boot       bool   // whether this is a boot device
}

// CiaoNode contains status and statistic information for an individual
// node.
type CiaoNode struct {
	ID                    string    `json:"id"`
	Hostname              string    `json:"hostname"`
	Timestamp             time.Time `json:"updated"`
	Status                string    `json:"status"`
	MemTotal              int       `json:"ram_total"`
	MemAvailable          int       `json:"ram_available"`
	DiskTotal             int       `json:"disk_total"`
	DiskAvailable         int       `json:"disk_available"`
	Load                  int       `json:"load"`
	OnlineCPUs            int       `json:"online_cpus"`
	TotalInstances        int       `json:"total_instances"`
	TotalRunningInstances int       `json:"total_running_instances"`
	TotalPendingInstances int       `json:"total_pending_instances"`
	TotalPausedInstances  int       `json:"total_paused_instances"`
	TotalFailures         int       `json:"total_failures"`
	StartFailures         int       `json:"start_failures"`
	AttachVolumeFailures  int       `json:"attach_failures"`
	DeleteFailures        int       `json:"delete_failures"`
}

// NodeStatusType contains the valid values of a node's status
type NodeStatusType string

const (
	// NodeStatusReady indicates that a node is ready to receive start
	// requests.
	NodeStatusReady NodeStatusType = "READY"

	// NodeStatusFull indicates that a node is full and cannot satisfy
	// start requests.
	NodeStatusFull NodeStatusType = "FULL"

	// NodeStatusMaintenance indicates that a node is in maintenance mode
	// and cannot satisfy start requests.
	NodeStatusMaintenance NodeStatusType = "MAINTENANCE"
)

// CiaoNodeStatus contains status information for an individual node.
type CiaoNodeStatus struct {
	Status NodeStatusType `json:"status"`
}

// CiaoNodes represents the unmarshalled version of the contents of a
// /v2.1/nodes response.  It contains status and statistics information
// for a set of nodes.
type CiaoNodes struct {
	Nodes []CiaoNode `json:"nodes"`
}

// NewCiaoNodes allocates a CiaoNodes structure.
// It allocates the Nodes slice as well so that the marshalled
// JSON is an empty array and not a nil pointer, as specified by the
// OpenStack APIs.
func NewCiaoNodes() (nodes CiaoNodes) {
	nodes.Nodes = []CiaoNode{}
	return
}

// CiaoTenantResources represents the unmarshalled version of the contents of a
// /v2.1/{tenant}/quotas response.  It contains the current resource usage
// information for a tenant.
type CiaoTenantResources struct {
	ID            string    `json:"id"`
	Timestamp     time.Time `json:"updated"`
	InstanceLimit int       `json:"instances_limit"`
	InstanceUsage int       `json:"instances_usage"`
	VCPULimit     int       `json:"cpus_limit"`
	VCPUUsage     int       `json:"cpus_usage"`
	MemLimit      int       `json:"ram_limit"`
	MemUsage      int       `json:"ram_usage"`
	DiskLimit     int       `json:"disk_limit"`
	DiskUsage     int       `json:"disk_usage"`
}

// CiaoUsage contains a snapshot of resource consumption for a tenant.
type CiaoUsage struct {
	VCPU      int       `json:"cpus_usage"`
	Memory    int       `json:"ram_usage"`
	Disk      int       `json:"disk_usage"`
	Timestamp time.Time `json:"timestamp"`
}

// CiaoUsageHistory represents the unmarshalled version of the contents of a
// /v2.1/{tenant}/resources response.  It contains snapshots of usage information
// for a given tenant over a given period of time.
type CiaoUsageHistory struct {
	Usages []CiaoUsage `json:"usage"`
}

// CiaoCNCISubnet contains subnet information for a CNCI.
type CiaoCNCISubnet struct {
	Subnet string `json:"subnet_cidr"`
}

// CiaoCNCI contains information about an individual CNCI.
type CiaoCNCI struct {
	ID        string           `json:"id"`
	TenantID  string           `json:"tenant_id"`
	IPv4      string           `json:"IPv4"`
	Geography string           `json:"geography"`
	Subnets   []CiaoCNCISubnet `json:"subnets"`
}

// CiaoCNCIDetail represents the unmarshalled version of the contents of a
// v2.1/cncis/{cnci}/detail response.  It contains information about a CNCI.
type CiaoCNCIDetail struct {
	CiaoCNCI `json:"cnci"`
}

// CiaoCNCIs represents the unmarshalled version of the contents of a
// v2.1/cncis response.  It contains information about all the CNCIs
// in the ciao cluster.
type CiaoCNCIs struct {
	CNCIs []CiaoCNCI `json:"cncis"`
}

// NewCiaoCNCIs allocates a CiaoCNCIs structure.
// It allocates the CNCIs slice as well so that the marshalled
// JSON is an empty array and not a nil pointer, as specified by the
// OpenStack APIs.
func NewCiaoCNCIs() (cncis CiaoCNCIs) {
	cncis.CNCIs = []CiaoCNCI{}
	return
}

// CiaoServerStats contains status information about a CN or a NN.
type CiaoServerStats struct {
	ID        string    `json:"id"`
	NodeID    string    `json:"node_id"`
	Timestamp time.Time `json:"updated"`
	Status    string    `json:"status"`
	TenantID  string    `json:"tenant_id"`
	IPv4      string    `json:"IPv4"`
	VCPUUsage int       `json:"cpus_usage"`
	MemUsage  int       `json:"ram_usage"`
	DiskUsage int       `json:"disk_usage"`
}

// CiaoServersStats represents the unmarshalled version of the contents of a
// v2.1/nodes/{node}/servers/detail response.  It contains general information
// about a group of instances.
type CiaoServersStats struct {
	TotalServers int               `json:"total_servers"`
	Servers      []CiaoServerStats `json:"servers"`
}

// NewCiaoServersStats allocates a CiaoServersStats structure.
// It allocates the Servers slice as well so that the marshalled
// JSON is an empty array and not a nil pointer, as specified by the
// OpenStack APIs.
func NewCiaoServersStats() (servers CiaoServersStats) {
	servers.Servers = []CiaoServerStats{}
	return
}

// CNCIDetail stores the IPv4 for a CNCI Agent.
type CNCIDetail struct {
	IPv4 string `json:"IPv4"`
}

// CiaoServersAction represents the unmarshalled version of the contents of a
// v2.1/servers/action request.  It contains an action to be performed on
// one or more instances.
type CiaoServersAction struct {
	Action    string   `json:"action"`
	ServerIDs []string `json:"servers"`
}

// CiaoTraceSummary contains information about a specific SSNTP Trace label.
type CiaoTraceSummary struct {
	Label     string `json:"label"`
	Instances int    `json:"instances"`
}

// CiaoTracesSummary represents the unmarshalled version of the response to a
// v2.1/traces request.  It contains a list of all trace labels and the
// number of instances associated with them.
type CiaoTracesSummary struct {
	Summaries []CiaoTraceSummary `json:"summaries"`
}

// CiaoFrameStat contains the elapsed time statistics for a frame.
type CiaoFrameStat struct {
	ID               string  `json:"node_id"`
	TotalElapsedTime float64 `json:"total_elapsed_time"`
	ControllerTime   float64 `json:"total_controller_time"`
	LauncherTime     float64 `json:"total_launcher_time"`
	SchedulerTime    float64 `json:"total_scheduler_time"`
}

// CiaoBatchFrameStat contains frame statisitics for a ciao cluster.
type CiaoBatchFrameStat struct {
	NumInstances             int     `json:"num_instances"`
	TotalElapsed             float64 `json:"total_elapsed"`
	AverageElapsed           float64 `json:"average_elapsed"`
	AverageControllerElapsed float64 `json:"average_controller_elapsed"`
	AverageLauncherElapsed   float64 `json:"average_launcher_elapsed"`
	AverageSchedulerElapsed  float64 `json:"average_scheduler_elapsed"`
	VarianceController       float64 `json:"controller_variance"`
	VarianceLauncher         float64 `json:"launcher_variance"`
	VarianceScheduler        float64 `json:"scheduler_variance"`
}

// CiaoTraceData represents the unmarshalled version of the response to a
// v2.1/traces/{label} request.  It contains statistics computed from the trace
// information of SSNTP commands sent within a ciao cluster.
type CiaoTraceData struct {
	Summary    CiaoBatchFrameStat `json:"summary"`
	FramesStat []CiaoFrameStat    `json:"frames"`
}

// CiaoEvent contains information about an individual event generated
// in a ciao cluster.
type CiaoEvent struct {
	Timestamp time.Time `json:"time_stamp"`
	TenantID  string    `json:"tenant_id"`
	EventType string    `json:"type"`
	Message   string    `json:"message"`
}

// CiaoEvents represents the unmarshalled version of the response to a
// v2.1/{tenant}/event or v2.1/event request.
type CiaoEvents struct {
	Events []CiaoEvent `json:"events"`
}

// NewCiaoEvents allocates a CiaoEvents structure.
// It allocates the Events slice as well so that the marshalled
// JSON is an empty array and not a nil pointer, as specified by the
// OpenStack APIs.
func NewCiaoEvents() (events CiaoEvents) {
	events.Events = []CiaoEvent{}
	return
}

var (
	// ErrQuota is returned when a resource limit is exceeded.
	ErrQuota = errors.New("Over Quota")

	// ErrTenantNotFound is returned when a tenant ID is unknown.
	ErrTenantNotFound = errors.New("Tenant not found")

	// ErrInstanceNotFound is returned when an instance is not found.
	ErrInstanceNotFound = errors.New("Instance not found")

	// ErrInstanceNotAssigned is returned when an instance is not assigned to a node.
	ErrInstanceNotAssigned = errors.New("Cannot perform operation: instance not assigned to Node")

	// ErrDuplicateSubnet is returned when a subnet already exists
	ErrDuplicateSubnet = errors.New("Cannot add overlapping subnet")

	// ErrDuplicateIP is returned when a duplicate external IP is added
	ErrDuplicateIP = errors.New("Cannot add duplicated external IP")

	// ErrInvalidIP is returned when an IP cannot be parsed
	ErrInvalidIP = errors.New("The IP Address is not valid")

	// ErrSubnetTooSmall is returned when an invalid subnet is used
	ErrSubnetTooSmall = errors.New("Requested subnet is too small to be usable")

	// ErrPoolNotFound is returned when an external IP pool is not found
	ErrPoolNotFound = errors.New("Pool not found")

	// ErrPoolNotEmpty is returned when a pool is still in use
	ErrPoolNotEmpty = errors.New("Pool has mapped IPs")

	// ErrAddressNotFound is returned when an address isn't found.
	ErrAddressNotFound = errors.New("Address Not Found")

	// ErrInvalidPoolAddress is returned when an address isn't part of a pool
	ErrInvalidPoolAddress = errors.New("The Address is not found in this pool")

	// ErrBadRequest is returned when we have a malformed request
	ErrBadRequest = errors.New("Invalid Request")

	// ErrPoolEmpty is returned when a pool has no free IPs
	ErrPoolEmpty = errors.New("Pool has no Free IPs")

	// ErrDuplicatePoolName is returned when a duplicate pool name is used
	ErrDuplicatePoolName = errors.New("Pool by that name already exists")

	// ErrInstanceMapped is returned when an instance cannot be deleted
	// due to having an external IP assigned to it.
	ErrInstanceMapped = errors.New("Unmap the external IP prior to deletion")

	// ErrWorkloadNotFound is returned when a workload ID cannot be found
	ErrWorkloadNotFound = errors.New("Workload not found")

	// ErrWorkloadInUse is returned by DeleteWorkload when an instance of a workload is still active.
	ErrWorkloadInUse = errors.New("Workload definition still in use")

	// ErrBadName is returned when a name doesn't match the requirements
	ErrBadName = errors.New("Requested name doesn't match requirements")
)

// Link provides a url and relationship for a resource.
type Link struct {
	Rel  string `json:"rel"`
	Href string `json:"href"`
}

// APILink provides information and links about a supported resource.
type APILink struct {
	Rel        string `json:"rel"`
	Href       string `json:"href"`
	Version    string `json:"version"`
	MinVersion string `json:"minimum_version"`
}

// ExternalSubnet represents a subnet for External IPs.
type ExternalSubnet struct {
	ID    string `json:"id"`
	CIDR  string `json:"subnet"`
	Links []Link `json:"links"`
}

// ExternalIP represents an External IP individual address.
type ExternalIP struct {
	ID      string `json:"id"`
	Address string `json:"address"`
	Links   []Link `json:"links"`
}

// Pool represents a pool of external IPs.
type Pool struct {
	ID       string           `json:"id"`
	Name     string           `json:"name"`
	Free     int              `json:"free"`
	TotalIPs int              `json:"total_ips"`
	Links    []Link           `json:"links"`
	Subnets  []ExternalSubnet `json:"subnets"`
	IPs      []ExternalIP     `json:"ips"`
}

// NewPoolRequest is used to create a new pool.
type NewPoolRequest struct {
	Name   string  `json:"name"`
	Subnet *string `json:"subnet"`
	IPs    []struct {
		IP string `json:"ip"`
	} `json:"ips"`
}

// PoolSummary is a short form of Pool.
type PoolSummary struct {
	ID       string `json:"id"`
	Name     string `json:"name"`
	Free     *int   `json:"free,omitempty"`
	TotalIPs *int   `json:"total_ips,omitempty"`
	Links    []Link `json:"links,omitempty"`
}

// ListPoolsResponse respresents a summary list of all pools.
type ListPoolsResponse struct {
	Pools []PoolSummary `json:"pools"`
}

// NewIPAddressRequest is used to add a new external IP to a pool.
type NewIPAddressRequest struct {
	IP string `json:"ip"`
}

// NewAddressRequest is used to add a new IP or new subnet to a pool.
type NewAddressRequest struct {
	Subnet *string               `json:"subnet"`
	IPs    []NewIPAddressRequest `json:"ips"`
}

// MappedIP represents a mapping of external IP -> instance IP.
type MappedIP struct {
	ID         string `json:"mapping_id"`
	ExternalIP string `json:"external_ip"`
	InternalIP string `json:"internal_ip"`
	InstanceID string `json:"instance_id"`
	TenantID   string `json:"tenant_id"`
	PoolID     string `json:"pool_id"`
	PoolName   string `json:"pool_name"`
	Links      []Link `json:"links"`
}

// MappedIPShort is a summary version of a MappedIP.
type MappedIPShort struct {
	ID         string `json:"mapping_id"`
	ExternalIP string `json:"external_ip"`
	InternalIP string `json:"internal_ip"`
	InstanceID string `json:"instance_id"`
	Links      []Link `json:"links"`
}

// MapIPRequest is used to request that an external IP be assigned from a pool
// to a particular instance.
type MapIPRequest struct {
	PoolName   *string `json:"pool_name"`
	InstanceID string  `json:"instance_id"`
}

// QuotaDetails holds information for updating and querying quotas
type QuotaDetails struct {
	Name  string
	Value int
	Usage int
}

// MarshalJSON provides a custom marshaller for quota API
func (qd *QuotaDetails) MarshalJSON() ([]byte, error) {
	var v string
	if qd.Value == -1 {
		v = "unlimited"
	} else {
		v = strconv.Itoa(qd.Value)
	}

	if strings.Contains(qd.Name, "limit") {
		return json.Marshal(&struct {
			Name  string `json:"name"`
			Value string `json:"value"`
		}{
			Name:  qd.Name,
			Value: v,
		})
	}

	return json.Marshal(&struct {
		Name  string `json:"name"`
		Value string `json:"value"`
		Usage string `json:"usage"`
	}{
		Name:  qd.Name,
		Value: v,
		Usage: strconv.Itoa(qd.Usage),
	})
}

// UnmarshalJSON provides a custom demarshaller for quota API
func (qd *QuotaDetails) UnmarshalJSON(data []byte) error {
	tmp := struct {
		Name  string `json:"name"`
		Value string `json:"value"`
		Usage string `json:"usage"`
	}{}

	err := json.Unmarshal(data, &tmp)
	if err != nil {
		return err
	}

	qd.Name = tmp.Name
	if tmp.Value == "unlimited" {
		qd.Value = -1
	} else {
		qd.Value, _ = strconv.Atoi(tmp.Value)
	}
	qd.Usage, _ = strconv.Atoi(tmp.Usage)
	return nil
}

// QuotaUpdateRequest holds the layout for updating quota API
type QuotaUpdateRequest struct {
	Quotas []QuotaDetails `json:"quotas"`
}

// QuotaListResponse holds the layout for returning quotas in the API
type QuotaListResponse struct {
	Quotas []QuotaDetails `json:"quotas"`
}

// CNCIController is the interface for the cnci controller associated with each tenant
type CNCIController interface {
	CNCIAdded(ID string) error
	CNCIRemoved(ID string) error
	CNCIStopped(id string) error
	StartFailure(ID string) error
	Active(ID string) bool
	ScheduleRemoveSubnet(subnet string) error
	RemoveSubnet(subnet string) error
	WaitForActive(subnet string) error
	GetInstanceCNCI(InstanceID string) (*Instance, error)
	GetSubnetCNCI(subnet string) (*Instance, error)
	Shutdown()
}

// ImageState represents the state of the image.
type ImageState string

const (
	// Created means that an empty image has been created
	Created ImageState = "created"

	// Saving means the image is being saved
	Saving ImageState = "saving"

	// Active means that the image is created, uploaded and ready to use.
	Active ImageState = "active"

	// Killed means that an image data upload error occurred.
	Killed ImageState = "killed"
)

// Visibility defines whether an image is per tenant or public.
type Visibility string

const (
	// Public indicates that the image can be used by anyone.
	Public Visibility = "public"

	// Private indicates that the image is only available to a tenant.
	Private Visibility = "private"

	// Internal indicates that an image is only for Ciao internal usage.
	Internal Visibility = "internal"
)

// Image contains the information that ciao will store about the image
type Image struct {
	ID         string     `json:"id"`
	State      ImageState `json:"state"`
	TenantID   string     `json:"tenant_id"`
	Name       string     `json:"name"`
	CreateTime time.Time  `json:"create_time"`
	Size       uint64     `json:"size"`
	Visibility Visibility `json:"visibility"`
}

// TransitionInstanceState safely sets thes state on an instance
func (i *Instance) TransitionInstanceState(to string) error {
	i.StateLock.Lock()
	defer i.StateLock.Unlock()

	glog.V(2).Infof("Instance %s: %s -> %s", i.ID, i.State, to)

	switch to {
	case payloads.Stopping:
		if i.State != payloads.Running {
			return errors.New("Stop operation not allowed")
		}
	case payloads.Running:
		if i.State != payloads.Pending {
			return errors.New("Set active without pending")
		}
	}

	i.StateChange.L.Lock()
	i.State = to
	i.StateChange.L.Unlock()
	i.StateChange.Signal()

	return nil
}
