package taskenv

import (
	"fmt"
	"net"
	"os"
	"strconv"
	"strings"
	"sync"

	"github.com/hashicorp/nomad/helper"
	hargs "github.com/hashicorp/nomad/helper/args"
	"github.com/hashicorp/nomad/nomad/structs"
	"github.com/hashicorp/nomad/plugins/drivers"
	"github.com/zclconf/go-cty/cty"
)

// A set of environment variables that are exported by each driver.
const (
	// AllocDir is the environment variable with the path to the alloc directory
	// that is shared across tasks within a task group.
	AllocDir = "NOMAD_ALLOC_DIR"

	// TaskLocalDir is the environment variable with the path to the tasks local
	// directory where it can store data that is persisted to the alloc is
	// removed.
	TaskLocalDir = "NOMAD_TASK_DIR"

	// SecretsDir is the environment variable with the path to the tasks secret
	// directory where it can store sensitive data.
	SecretsDir = "NOMAD_SECRETS_DIR"

	// MemLimit is the environment variable with the tasks memory limit in MBs.
	MemLimit = "NOMAD_MEMORY_LIMIT"

	// CpuLimit is the environment variable with the tasks CPU limit in MHz.
	CpuLimit = "NOMAD_CPU_LIMIT"

	// AllocID is the environment variable for passing the allocation ID.
	AllocID = "NOMAD_ALLOC_ID"

	// AllocName is the environment variable for passing the allocation name.
	AllocName = "NOMAD_ALLOC_NAME"

	// TaskName is the environment variable for passing the task name.
	TaskName = "NOMAD_TASK_NAME"

	// GroupName is the environment variable for passing the task group name.
	GroupName = "NOMAD_GROUP_NAME"

	// JobName is the environment variable for passing the job name.
	JobName = "NOMAD_JOB_NAME"

	// AllocIndex is the environment variable for passing the allocation index.
	AllocIndex = "NOMAD_ALLOC_INDEX"

	// Datacenter is the environment variable for passing the datacenter in which the alloc is running.
	Datacenter = "NOMAD_DC"

	// Namespace is the environment variable for passing the namespace in which the alloc is running.
	Namespace = "NOMAD_NAMESPACE"

	// Region is the environment variable for passing the region in which the alloc is running.
	Region = "NOMAD_REGION"

	// AddrPrefix is the prefix for passing both dynamic and static port
	// allocations to tasks.
	// E.g $NOMAD_ADDR_http=127.0.0.1:80
	//
	// The ip:port are always the host's.
	AddrPrefix = "NOMAD_ADDR_"

	// IpPrefix is the prefix for passing the host IP of a port allocation
	// to a task.
	IpPrefix = "NOMAD_IP_"

	// PortPrefix is the prefix for passing the port allocation to a task.
	// It will be the task's port if a port map is specified. Task's should
	// bind to this port.
	PortPrefix = "NOMAD_PORT_"

	// HostPortPrefix is the prefix for passing the host port when a port
	// map is specified.
	HostPortPrefix = "NOMAD_HOST_PORT_"

	// MetaPrefix is the prefix for passing task meta data.
	MetaPrefix = "NOMAD_META_"

	// UpstreamPrefix is the prefix for passing upstream IP and ports to the alloc
	UpstreamPrefix = "NOMAD_UPSTREAM_"

	// VaultToken is the environment variable for passing the Vault token
	VaultToken = "VAULT_TOKEN"

	// VaultNamespace is the environment variable for passing the Vault namespace, if applicable
	VaultNamespace = "VAULT_NAMESPACE"
)

// The node values that can be interpreted.
const (
	nodeIdKey     = "node.unique.id"
	nodeDcKey     = "node.datacenter"
	nodeRegionKey = "node.region"
	nodeNameKey   = "node.unique.name"
	nodeClassKey  = "node.class"

	// Prefixes used for lookups.
	nodeAttributePrefix = "attr."
	nodeMetaPrefix      = "meta."
)

// TaskEnv is a task's environment as well as node attribute's for
// interpolation.
type TaskEnv struct {
	// NodeAttrs is the map of node attributes for interpolation
	NodeAttrs map[string]string

	// EnvMap is the map of environment variables
	EnvMap map[string]string

	// deviceEnv is the environment variables populated from the device hooks.
	deviceEnv map[string]string

	// envList is a memoized list created by List()
	envList []string
}

// NewTaskEnv creates a new task environment with the given environment, device
// environment and node attribute maps.
func NewTaskEnv(env, deviceEnv, node map[string]string) *TaskEnv {
	return &TaskEnv{
		NodeAttrs: node,
		deviceEnv: deviceEnv,
		EnvMap:    env,
	}
}

// NewEmptyTaskEnv creates a new empty task environment.
func NewEmptyTaskEnv() *TaskEnv {
	return &TaskEnv{
		NodeAttrs: make(map[string]string),
		deviceEnv: make(map[string]string),
		EnvMap:    make(map[string]string),
	}
}

// List returns the task's environment as a slice of NAME=value pair strings.
func (t *TaskEnv) List() []string {
	if t.envList != nil {
		return t.envList
	}

	env := []string{}
	for k, v := range t.EnvMap {
		env = append(env, fmt.Sprintf("%s=%s", k, v))
	}

	return env
}

// DeviceEnv returns the task's environment variables set by device hooks.
func (t *TaskEnv) DeviceEnv() map[string]string {
	m := make(map[string]string, len(t.deviceEnv))
	for k, v := range t.deviceEnv {
		m[k] = v
	}

	return m
}

// Map of the task's environment variables.
func (t *TaskEnv) Map() map[string]string {
	m := make(map[string]string, len(t.EnvMap))
	for k, v := range t.EnvMap {
		m[k] = v
	}

	return m
}

// All of the task's environment variables and the node's attributes in a
// single map.
func (t *TaskEnv) All() map[string]string {
	m := make(map[string]string, len(t.EnvMap)+len(t.NodeAttrs))
	for k, v := range t.EnvMap {
		m[k] = v
	}
	for k, v := range t.NodeAttrs {
		m[k] = v
	}

	return m
}

// AllValues is a map of the task's environment variables and the node's
// attributes with cty.Value (String) values. Errors including keys are
// returned in a map by key name.
//
// In the rare case of a fatal error, only an error value is returned. This is
// likely a programming error as user input should not be able to cause a fatal
// error.
func (t *TaskEnv) AllValues() (map[string]cty.Value, map[string]error, error) {
	errs := make(map[string]error)

	// Intermediate map for building up nested go types
	allMap := make(map[string]interface{}, len(t.EnvMap)+len(t.NodeAttrs))

	// Intermediate map for all env vars including those whose keys that
	// cannot be nested (eg foo...bar)
	envMap := make(map[string]cty.Value, len(t.EnvMap))

	// Prepare job-based variables (eg job.meta, job.group.task.env, etc)
	for k, v := range t.EnvMap {
		if err := addNestedKey(allMap, k, v); err != nil {
			errs[k] = err
		}
		envMap[k] = cty.StringVal(v)
	}

	// Prepare node-based variables (eg node.*, attr.*, meta.*)
	for k, v := range t.NodeAttrs {
		if err := addNestedKey(allMap, k, v); err != nil {
			errs[k] = err
		}
	}

	// Add flat envMap as a Map to allMap so users can access any key via
	// HCL2's indexing syntax: ${env["foo...bar"]}
	allMap["env"] = cty.MapVal(envMap)

	// Add meta and attr to node if they exist to properly namespace things
	// a bit.
	nodeMapI, ok := allMap["node"]
	if !ok {
		return nil, nil, fmt.Errorf("missing node variable")
	}
	nodeMap, ok := nodeMapI.(map[string]interface{})
	if !ok {
		return nil, nil, fmt.Errorf("invalid type for node variable: %T", nodeMapI)
	}
	if attrMap, ok := allMap["attr"]; ok {
		nodeMap["attr"] = attrMap
	}
	if metaMap, ok := allMap["meta"]; ok {
		nodeMap["meta"] = metaMap
	}

	// ctyify the entire tree of strings and maps
	tree, err := ctyify(allMap)
	if err != nil {
		// This should not be possible and is likely a programming
		// error. Invalid user input should be cleaned earlier.
		return nil, nil, err
	}

	return tree, errs, nil
}

// ParseAndReplace takes the user supplied args replaces any instance of an
// environment variable or Nomad variable in the args with the actual value.
func (t *TaskEnv) ParseAndReplace(args []string) []string {
	if args == nil {
		return nil
	}

	replaced := make([]string, len(args))
	for i, arg := range args {
		replaced[i] = hargs.ReplaceEnv(arg, t.EnvMap, t.NodeAttrs)
	}

	return replaced
}

// ReplaceEnv takes an arg and replaces all occurrences of environment variables
// and Nomad variables.  If the variable is found in the passed map it is
// replaced, otherwise the original string is returned.
func (t *TaskEnv) ReplaceEnv(arg string) string {
	return hargs.ReplaceEnv(arg, t.EnvMap, t.NodeAttrs)
}

// Builder is used to build task environment's and is safe for concurrent use.
type Builder struct {
	// envvars are custom set environment variables
	envvars map[string]string

	// templateEnv are env vars set from templates
	templateEnv map[string]string

	// hostEnv are environment variables filtered from the host
	hostEnv map[string]string

	// nodeAttrs are Node attributes and metadata
	nodeAttrs map[string]string

	// taskMeta are the meta attributes on the task
	taskMeta map[string]string

	// allocDir from task's perspective; eg /alloc
	allocDir string

	// localDir from task's perspective; eg /local
	localDir string

	// secretsDir from task's perspective; eg /secrets
	secretsDir string

	cpuLimit         int64
	memLimit         int64
	taskName         string
	allocIndex       int
	datacenter       string
	namespace        string
	region           string
	allocId          string
	allocName        string
	groupName        string
	vaultToken       string
	vaultNamespace   string
	injectVaultToken bool
	jobName          string

	// otherPorts for tasks in the same alloc
	otherPorts map[string]string

	// driverNetwork is the network defined by the driver (or nil if none
	// was defined).
	driverNetwork *drivers.DriverNetwork

	// network resources from the task; must be lazily turned into env vars
	// because portMaps and advertiseIP can change after builder creation
	// and affect network env vars.
	networks []*structs.NetworkResource

	// hookEnvs are env vars set by hooks and stored by hook name to
	// support adding/removing vars from multiple hooks (eg HookA adds A:1,
	// HookB adds A:2, HookA removes A, A should equal 2)
	hookEnvs map[string]map[string]string

	// hookNames is a slice of hooks in hookEnvs to apply hookEnvs in the
	// order the hooks are run.
	hookNames []string

	// deviceHookName is the device hook name. It is set only if device hooks
	// are set. While a bit round about, this enables us to return device hook
	// environment variables without having to hardcode the name of the hook.
	deviceHookName string

	// upstreams from the group connect enabled services
	upstreams []structs.ConsulUpstream

	mu *sync.RWMutex
}

// NewBuilder creates a new task environment builder.
func NewBuilder(node *structs.Node, alloc *structs.Allocation, task *structs.Task, region string) *Builder {
	b := NewEmptyBuilder()
	b.region = region
	return b.setTask(task).setAlloc(alloc).setNode(node)
}

// NewEmptyBuilder creates a new environment builder.
func NewEmptyBuilder() *Builder {
	return &Builder{
		mu:       &sync.RWMutex{},
		hookEnvs: map[string]map[string]string{},
		envvars:  make(map[string]string),
	}
}

// Build must be called after all the tasks environment values have been set.
func (b *Builder) Build() *TaskEnv {
	nodeAttrs := make(map[string]string)
	envMap := make(map[string]string)
	var deviceEnvs map[string]string

	b.mu.RLock()
	defer b.mu.RUnlock()

	// Add the directories
	if b.allocDir != "" {
		envMap[AllocDir] = b.allocDir
	}
	if b.localDir != "" {
		envMap[TaskLocalDir] = b.localDir
	}
	if b.secretsDir != "" {
		envMap[SecretsDir] = b.secretsDir
	}

	// Add the resource limits
	if b.memLimit != 0 {
		envMap[MemLimit] = strconv.FormatInt(b.memLimit, 10)
	}
	if b.cpuLimit != 0 {
		envMap[CpuLimit] = strconv.FormatInt(b.cpuLimit, 10)
	}

	// Add the task metadata
	if b.allocId != "" {
		envMap[AllocID] = b.allocId
	}
	if b.allocName != "" {
		envMap[AllocName] = b.allocName
	}
	if b.groupName != "" {
		envMap[GroupName] = b.groupName
	}
	if b.allocIndex != -1 {
		envMap[AllocIndex] = strconv.Itoa(b.allocIndex)
	}
	if b.taskName != "" {
		envMap[TaskName] = b.taskName
	}
	if b.jobName != "" {
		envMap[JobName] = b.jobName
	}
	if b.datacenter != "" {
		envMap[Datacenter] = b.datacenter
	}
	if b.namespace != "" {
		envMap[Namespace] = b.namespace
	}
	if b.region != "" {
		envMap[Region] = b.region

		// Copy region over to node attrs
		nodeAttrs[nodeRegionKey] = b.region
	}

	// Build the network related env vars
	buildNetworkEnv(envMap, b.networks, b.driverNetwork)

	// Build the addr of the other tasks
	for k, v := range b.otherPorts {
		envMap[k] = v
	}

	// Build the Consul Connect upstream env vars
	buildUpstreamsEnv(envMap, b.upstreams)

	// Build the Vault Token
	if b.injectVaultToken && b.vaultToken != "" {
		envMap[VaultToken] = b.vaultToken
	}

	// Build the Vault Namespace
	if b.injectVaultToken && b.vaultNamespace != "" {
		envMap[VaultNamespace] = b.vaultNamespace
	}

	// Copy task meta
	for k, v := range b.taskMeta {
		envMap[k] = v
	}

	// Copy node attributes
	for k, v := range b.nodeAttrs {
		nodeAttrs[k] = v
	}

	// Interpolate and add environment variables
	for k, v := range b.hostEnv {
		envMap[k] = hargs.ReplaceEnv(v, nodeAttrs, envMap)
	}

	// Copy interpolated task env vars second as they override host env vars
	for k, v := range b.envvars {
		envMap[k] = hargs.ReplaceEnv(v, nodeAttrs, envMap)
	}

	// Copy hook env vars in the order the hooks were run
	for _, h := range b.hookNames {
		for k, v := range b.hookEnvs[h] {
			e := hargs.ReplaceEnv(v, nodeAttrs, envMap)
			envMap[k] = e

			if h == b.deviceHookName {
				if deviceEnvs == nil {
					deviceEnvs = make(map[string]string, len(b.hookEnvs[h]))
				}

				deviceEnvs[k] = e
			}
		}
	}

	// Copy template env vars as they override task env vars
	for k, v := range b.templateEnv {
		envMap[k] = v
	}

	// Clean keys (see #2405)
	prefixesToClean := [...]string{AddrPrefix, IpPrefix, PortPrefix, HostPortPrefix, MetaPrefix}
	cleanedEnv := make(map[string]string, len(envMap))
	for k, v := range envMap {
		cleanedK := k
		for i := range prefixesToClean {
			if strings.HasPrefix(k, prefixesToClean[i]) {
				cleanedK = helper.CleanEnvVar(k, '_')
			}
		}
		cleanedEnv[cleanedK] = v
	}

	return NewTaskEnv(cleanedEnv, deviceEnvs, nodeAttrs)
}

// Update task updates the environment based on a new alloc and task.
func (b *Builder) UpdateTask(alloc *structs.Allocation, task *structs.Task) *Builder {
	b.mu.Lock()
	defer b.mu.Unlock()
	return b.setTask(task).setAlloc(alloc)
}

// SetHookEnv sets environment variables from a hook. Variables are
// Last-Write-Wins, so if a hook writes a variable that's also written by a
// later hook, the later hooks value always gets used.
func (b *Builder) SetHookEnv(hook string, envs map[string]string) *Builder {
	b.mu.Lock()
	defer b.mu.Unlock()
	return b.setHookEnvLocked(hook, envs)
}

// setHookEnvLocked is the implementation of setting hook environment variables
// and should be called with the lock held
func (b *Builder) setHookEnvLocked(hook string, envs map[string]string) *Builder {
	if _, exists := b.hookEnvs[hook]; !exists {
		b.hookNames = append(b.hookNames, hook)
	}
	b.hookEnvs[hook] = envs

	return b
}

// SetDeviceHookEnv sets environment variables from a device hook. Variables are
// Last-Write-Wins, so if a hook writes a variable that's also written by a
// later hook, the later hooks value always gets used.
func (b *Builder) SetDeviceHookEnv(hookName string, envs map[string]string) *Builder {
	b.mu.Lock()
	defer b.mu.Unlock()

	// Store the device hook name
	b.deviceHookName = hookName
	return b.setHookEnvLocked(hookName, envs)
}

// setTask is called from NewBuilder to populate task related environment
// variables.
func (b *Builder) setTask(task *structs.Task) *Builder {
	b.taskName = task.Name
	b.envvars = make(map[string]string, len(task.Env))
	for k, v := range task.Env {
		b.envvars[k] = v
	}

	// COMPAT(0.11): Remove in 0.11
	if task.Resources == nil {
		b.memLimit = 0
		b.cpuLimit = 0
	} else {
		b.memLimit = int64(task.Resources.MemoryMB)
		b.cpuLimit = int64(task.Resources.CPU)
	}
	return b
}

// setAlloc is called from NewBuilder to populate alloc related environment
// variables.
func (b *Builder) setAlloc(alloc *structs.Allocation) *Builder {
	b.allocId = alloc.ID
	b.allocName = alloc.Name
	b.groupName = alloc.TaskGroup
	b.allocIndex = int(alloc.Index())
	b.jobName = alloc.Job.Name
	b.namespace = alloc.Namespace

	// Set meta
	combined := alloc.Job.CombinedTaskMeta(alloc.TaskGroup, b.taskName)
	// taskMetaSize is double to total meta keys to account for given and upper
	// cased values
	taskMetaSize := len(combined) * 2

	// if job is parameterized initialize optional meta to empty strings
	if alloc.Job.Dispatched {
		optionalMetaCount := len(alloc.Job.ParameterizedJob.MetaOptional)
		b.taskMeta = make(map[string]string, taskMetaSize+optionalMetaCount*2)

		for _, k := range alloc.Job.ParameterizedJob.MetaOptional {
			b.taskMeta[fmt.Sprintf("%s%s", MetaPrefix, strings.ToUpper(k))] = ""
			b.taskMeta[fmt.Sprintf("%s%s", MetaPrefix, k)] = ""
		}
	} else {
		b.taskMeta = make(map[string]string, taskMetaSize)
	}

	for k, v := range combined {
		b.taskMeta[fmt.Sprintf("%s%s", MetaPrefix, strings.ToUpper(k))] = v
		b.taskMeta[fmt.Sprintf("%s%s", MetaPrefix, k)] = v
	}

	tg := alloc.Job.LookupTaskGroup(alloc.TaskGroup)

	// COMPAT(0.11): Remove in 0.11
	b.otherPorts = make(map[string]string, len(tg.Tasks)*2)
	if alloc.AllocatedResources != nil {
		// Populate task resources
		if tr, ok := alloc.AllocatedResources.Tasks[b.taskName]; ok {
			b.cpuLimit = tr.Cpu.CpuShares
			b.memLimit = tr.Memory.MemoryMB

			// Copy networks to prevent sharing
			b.networks = make([]*structs.NetworkResource, len(tr.Networks))
			for i, n := range tr.Networks {
				b.networks[i] = n.Copy()
			}
		}

		// Add ports from other tasks
		for taskName, resources := range alloc.AllocatedResources.Tasks {
			// Add ports from other tasks
			if taskName == b.taskName {
				continue
			}

			for _, nw := range resources.Networks {
				for _, p := range nw.ReservedPorts {
					addPort(b.otherPorts, taskName, nw.IP, p.Label, p.Value)
				}
				for _, p := range nw.DynamicPorts {
					addPort(b.otherPorts, taskName, nw.IP, p.Label, p.Value)
				}
			}
		}

		// Add ports from group networks
		//TODO Expose IPs but possibly only via variable interpolation
		for _, nw := range alloc.AllocatedResources.Shared.Networks {
			for _, p := range nw.ReservedPorts {
				addGroupPort(b.otherPorts, p)
			}
			for _, p := range nw.DynamicPorts {
				addGroupPort(b.otherPorts, p)
			}
		}
	} else if alloc.TaskResources != nil {
		if tr, ok := alloc.TaskResources[b.taskName]; ok {
			// Copy networks to prevent sharing
			b.networks = make([]*structs.NetworkResource, len(tr.Networks))
			for i, n := range tr.Networks {
				b.networks[i] = n.Copy()
			}

		}

		for taskName, resources := range alloc.TaskResources {
			// Add ports from other tasks
			if taskName == b.taskName {
				continue
			}
			for _, nw := range resources.Networks {
				for _, p := range nw.ReservedPorts {
					addPort(b.otherPorts, taskName, nw.IP, p.Label, p.Value)
				}
				for _, p := range nw.DynamicPorts {
					addPort(b.otherPorts, taskName, nw.IP, p.Label, p.Value)
				}
			}
		}
	}

	upstreams := []structs.ConsulUpstream{}
	for _, svc := range tg.Services {
		if svc.Connect.HasSidecar() && svc.Connect.SidecarService.HasUpstreams() {
			upstreams = append(upstreams, svc.Connect.SidecarService.Proxy.Upstreams...)
		}
	}
	if len(upstreams) > 0 {
		b.SetUpstreams(upstreams)
	}

	return b
}

// setNode is called from NewBuilder to populate node attributes.
func (b *Builder) setNode(n *structs.Node) *Builder {
	b.nodeAttrs = make(map[string]string, 4+len(n.Attributes)+len(n.Meta))
	b.nodeAttrs[nodeIdKey] = n.ID
	b.nodeAttrs[nodeNameKey] = n.Name
	b.nodeAttrs[nodeClassKey] = n.NodeClass
	b.nodeAttrs[nodeDcKey] = n.Datacenter
	b.datacenter = n.Datacenter

	// Set up the attributes.
	for k, v := range n.Attributes {
		b.nodeAttrs[fmt.Sprintf("%s%s", nodeAttributePrefix, k)] = v
	}

	// Set up the meta.
	for k, v := range n.Meta {
		b.nodeAttrs[fmt.Sprintf("%s%s", nodeMetaPrefix, k)] = v
	}
	return b
}

func (b *Builder) SetAllocDir(dir string) *Builder {
	b.mu.Lock()
	b.allocDir = dir
	b.mu.Unlock()
	return b
}

func (b *Builder) SetTaskLocalDir(dir string) *Builder {
	b.mu.Lock()
	b.localDir = dir
	b.mu.Unlock()
	return b
}

func (b *Builder) SetSecretsDir(dir string) *Builder {
	b.mu.Lock()
	b.secretsDir = dir
	b.mu.Unlock()
	return b
}

// SetDriverNetwork defined by the driver.
func (b *Builder) SetDriverNetwork(n *drivers.DriverNetwork) *Builder {
	ncopy := n.Copy()
	b.mu.Lock()
	b.driverNetwork = ncopy
	b.mu.Unlock()
	return b
}

// buildNetworkEnv env vars in the given map.
//
//	Auto:   NOMAD_PORT_<label>
//	Host:   NOMAD_IP_<label>, NOMAD_ADDR_<label>, NOMAD_HOST_PORT_<label>
//
// Handled by setAlloc -> otherPorts:
//
//	Task:   NOMAD_TASK_{IP,PORT,ADDR}_<task>_<label> # Always host values
//
func buildNetworkEnv(envMap map[string]string, nets structs.Networks, driverNet *drivers.DriverNetwork) {
	for _, n := range nets {
		for _, p := range n.ReservedPorts {
			buildPortEnv(envMap, p, n.IP, driverNet)
		}
		for _, p := range n.DynamicPorts {
			buildPortEnv(envMap, p, n.IP, driverNet)
		}
	}
}

func buildPortEnv(envMap map[string]string, p structs.Port, ip string, driverNet *drivers.DriverNetwork) {
	// Host IP, port, and address
	portStr := strconv.Itoa(p.Value)
	envMap[IpPrefix+p.Label] = ip
	envMap[HostPortPrefix+p.Label] = portStr
	envMap[AddrPrefix+p.Label] = net.JoinHostPort(ip, portStr)

	// Set Port to task's value if there's a port map
	if driverNet != nil && driverNet.PortMap[p.Label] != 0 {
		envMap[PortPrefix+p.Label] = strconv.Itoa(driverNet.PortMap[p.Label])
	} else {
		// Default to host's
		envMap[PortPrefix+p.Label] = portStr
	}
}

// SetUpstreams defined by connect enabled group services
func (b *Builder) SetUpstreams(upstreams []structs.ConsulUpstream) *Builder {
	b.mu.Lock()
	b.upstreams = upstreams
	b.mu.Unlock()
	return b
}

// buildUpstreamsEnv builds NOMAD_UPSTREAM_{IP,PORT,ADDR}_{destination} vars
func buildUpstreamsEnv(envMap map[string]string, upstreams []structs.ConsulUpstream) {
	// Proxy sidecars always bind to localhost
	const ip = "127.0.0.1"
	for _, u := range upstreams {
		port := strconv.Itoa(u.LocalBindPort)
		envMap[UpstreamPrefix+"IP_"+u.DestinationName] = ip
		envMap[UpstreamPrefix+"PORT_"+u.DestinationName] = port
		envMap[UpstreamPrefix+"ADDR_"+u.DestinationName] = net.JoinHostPort(ip, port)

		// Also add cleaned version
		cleanName := helper.CleanEnvVar(u.DestinationName, '_')
		envMap[UpstreamPrefix+"ADDR_"+cleanName] = net.JoinHostPort(ip, port)
		envMap[UpstreamPrefix+"IP_"+cleanName] = ip
		envMap[UpstreamPrefix+"PORT_"+cleanName] = port
	}
}

// SetPortMapEnvs sets the PortMap related environment variables on the map
func SetPortMapEnvs(envs map[string]string, ports map[string]int) map[string]string {
	if envs == nil {
		envs = map[string]string{}
	}

	for portLabel, port := range ports {
		portEnv := helper.CleanEnvVar(PortPrefix+portLabel, '_')
		envs[portEnv] = strconv.Itoa(port)
	}
	return envs
}

// SetHostEnvvars adds the host environment variables to the tasks. The filter
// parameter can be use to filter host environment from entering the tasks.
func (b *Builder) SetHostEnvvars(filter []string) *Builder {
	filterMap := make(map[string]struct{}, len(filter))
	for _, f := range filter {
		filterMap[f] = struct{}{}
	}

	fullHostEnv := os.Environ()
	filteredHostEnv := make(map[string]string, len(fullHostEnv))
	for _, e := range fullHostEnv {
		parts := strings.SplitN(e, "=", 2)
		key, value := parts[0], parts[1]

		// Skip filtered environment variables
		if _, filtered := filterMap[key]; filtered {
			continue
		}

		filteredHostEnv[key] = value
	}

	b.mu.Lock()
	b.hostEnv = filteredHostEnv
	b.mu.Unlock()
	return b
}

func (b *Builder) SetTemplateEnv(m map[string]string) *Builder {
	b.mu.Lock()
	b.templateEnv = m
	b.mu.Unlock()
	return b
}

func (b *Builder) SetVaultToken(token, namespace string, inject bool) *Builder {
	b.mu.Lock()
	b.vaultToken = token
	b.vaultNamespace = namespace
	b.injectVaultToken = inject
	b.mu.Unlock()
	return b
}

// addPort keys and values for other tasks to an env var map
func addPort(m map[string]string, taskName, ip, portLabel string, port int) {
	key := fmt.Sprintf("%s%s_%s", AddrPrefix, taskName, portLabel)
	m[key] = fmt.Sprintf("%s:%d", ip, port)
	key = fmt.Sprintf("%s%s_%s", IpPrefix, taskName, portLabel)
	m[key] = ip
	key = fmt.Sprintf("%s%s_%s", PortPrefix, taskName, portLabel)
	m[key] = strconv.Itoa(port)
}

// addGroupPort adds a group network port. The To value is used if one is
// specified.
func addGroupPort(m map[string]string, port structs.Port) {
	if port.To > 0 {
		m[PortPrefix+port.Label] = strconv.Itoa(port.To)
	} else {
		m[PortPrefix+port.Label] = strconv.Itoa(port.Value)
	}

	m[HostPortPrefix+port.Label] = strconv.Itoa(port.Value)
}