package api

import (
	"fmt"
	"net/url"
	"sort"
	"strconv"
	"time"

	"github.com/gorhill/cronexpr"
	"github.com/hashicorp/nomad/helper"
	"github.com/hashicorp/nomad/nomad/structs"
)

const (
	// JobTypeService indicates a long-running processes
	JobTypeService = "service"

	// JobTypeBatch indicates a short-lived process
	JobTypeBatch = "batch"

	// PeriodicSpecCron is used for a cron spec.
	PeriodicSpecCron = "cron"

	// DefaultNamespace is the default namespace.
	DefaultNamespace = "default"
)

const (
	// RegisterEnforceIndexErrPrefix is the prefix to use in errors caused by
	// enforcing the job modify index during registers.
	RegisterEnforceIndexErrPrefix = "Enforcing job modify index"
)

// Jobs is used to access the job-specific endpoints.
type Jobs struct {
	client *Client
}

// JobsParseRequest is used for arguments of the /vi/jobs/parse endpoint
type JobsParseRequest struct {
	// JobHCL is an hcl jobspec
	JobHCL string

	// Canonicalize is a flag as to if the server should return default values
	// for unset fields
	Canonicalize bool
}

// Jobs returns a handle on the jobs endpoints.
func (c *Client) Jobs() *Jobs {
	return &Jobs{client: c}
}

// Parse is used to convert the HCL repesentation of a Job to JSON server side.
// To parse the HCL client side see package github.com/hashicorp/nomad/jobspec
func (j *Jobs) ParseHCL(jobHCL string, canonicalize bool) (*Job, error) {
	var job Job
	req := &JobsParseRequest{
		JobHCL:       jobHCL,
		Canonicalize: canonicalize,
	}
	_, err := j.client.write("/v1/jobs/parse", req, &job, nil)
	return &job, err
}

func (j *Jobs) Validate(job *Job, q *WriteOptions) (*JobValidateResponse, *WriteMeta, error) {
	var resp JobValidateResponse
	req := &JobValidateRequest{Job: job}
	if q != nil {
		req.WriteRequest = WriteRequest{Region: q.Region}
	}
	wm, err := j.client.write("/v1/validate/job", req, &resp, q)
	return &resp, wm, err
}

// RegisterOptions is used to pass through job registration parameters
type RegisterOptions struct {
	EnforceIndex   bool
	ModifyIndex    uint64
	PolicyOverride bool
}

// Register is used to register a new job. It returns the ID
// of the evaluation, along with any errors encountered.
func (j *Jobs) Register(job *Job, q *WriteOptions) (*JobRegisterResponse, *WriteMeta, error) {
	return j.RegisterOpts(job, nil, q)
}

// EnforceRegister is used to register a job enforcing its job modify index.
func (j *Jobs) EnforceRegister(job *Job, modifyIndex uint64, q *WriteOptions) (*JobRegisterResponse, *WriteMeta, error) {
	opts := RegisterOptions{EnforceIndex: true, ModifyIndex: modifyIndex}
	return j.RegisterOpts(job, &opts, q)
}

// Register is used to register a new job. It returns the ID
// of the evaluation, along with any errors encountered.
func (j *Jobs) RegisterOpts(job *Job, opts *RegisterOptions, q *WriteOptions) (*JobRegisterResponse, *WriteMeta, error) {
	// Format the request
	req := &RegisterJobRequest{
		Job: job,
	}
	if opts != nil {
		if opts.EnforceIndex {
			req.EnforceIndex = true
			req.JobModifyIndex = opts.ModifyIndex
		}
		if opts.PolicyOverride {
			req.PolicyOverride = true
		}
	}

	var resp JobRegisterResponse
	wm, err := j.client.write("/v1/jobs", req, &resp, q)
	if err != nil {
		return nil, nil, err
	}
	return &resp, wm, nil
}

// List is used to list all of the existing jobs.
func (j *Jobs) List(q *QueryOptions) ([]*JobListStub, *QueryMeta, error) {
	var resp []*JobListStub
	qm, err := j.client.query("/v1/jobs", &resp, q)
	if err != nil {
		return nil, qm, err
	}
	sort.Sort(JobIDSort(resp))
	return resp, qm, nil
}

// PrefixList is used to list all existing jobs that match the prefix.
func (j *Jobs) PrefixList(prefix string) ([]*JobListStub, *QueryMeta, error) {
	return j.List(&QueryOptions{Prefix: prefix})
}

// Info is used to retrieve information about a particular
// job given its unique ID.
func (j *Jobs) Info(jobID string, q *QueryOptions) (*Job, *QueryMeta, error) {
	var resp Job
	qm, err := j.client.query("/v1/job/"+jobID, &resp, q)
	if err != nil {
		return nil, nil, err
	}
	return &resp, qm, nil
}

// Versions is used to retrieve all versions of a particular job given its
// unique ID.
func (j *Jobs) Versions(jobID string, diffs bool, q *QueryOptions) ([]*Job, []*JobDiff, *QueryMeta, error) {
	var resp JobVersionsResponse
	qm, err := j.client.query(fmt.Sprintf("/v1/job/%s/versions?diffs=%v", jobID, diffs), &resp, q)
	if err != nil {
		return nil, nil, nil, err
	}
	return resp.Versions, resp.Diffs, qm, nil
}

// Allocations is used to return the allocs for a given job ID.
func (j *Jobs) Allocations(jobID string, allAllocs bool, q *QueryOptions) ([]*AllocationListStub, *QueryMeta, error) {
	var resp []*AllocationListStub
	u, err := url.Parse("/v1/job/" + jobID + "/allocations")
	if err != nil {
		return nil, nil, err
	}

	v := u.Query()
	v.Add("all", strconv.FormatBool(allAllocs))
	u.RawQuery = v.Encode()

	qm, err := j.client.query(u.String(), &resp, q)
	if err != nil {
		return nil, nil, err
	}
	sort.Sort(AllocIndexSort(resp))
	return resp, qm, nil
}

// Deployments is used to query the deployments associated with the given job
// ID.
func (j *Jobs) Deployments(jobID string, q *QueryOptions) ([]*Deployment, *QueryMeta, error) {
	var resp []*Deployment
	qm, err := j.client.query("/v1/job/"+jobID+"/deployments", &resp, q)
	if err != nil {
		return nil, nil, err
	}
	sort.Sort(DeploymentIndexSort(resp))
	return resp, qm, nil
}

// LatestDeployment is used to query for the latest deployment associated with
// the given job ID.
func (j *Jobs) LatestDeployment(jobID string, q *QueryOptions) (*Deployment, *QueryMeta, error) {
	var resp *Deployment
	qm, err := j.client.query("/v1/job/"+jobID+"/deployment", &resp, q)
	if err != nil {
		return nil, nil, err
	}
	return resp, qm, nil
}

// Evaluations is used to query the evaluations associated with the given job
// ID.
func (j *Jobs) Evaluations(jobID string, q *QueryOptions) ([]*Evaluation, *QueryMeta, error) {
	var resp []*Evaluation
	qm, err := j.client.query("/v1/job/"+jobID+"/evaluations", &resp, q)
	if err != nil {
		return nil, nil, err
	}
	sort.Sort(EvalIndexSort(resp))
	return resp, qm, nil
}

// Deregister is used to remove an existing job. If purge is set to true, the job
// is deregistered and purged from the system versus still being queryable and
// eventually GC'ed from the system. Most callers should not specify purge.
func (j *Jobs) Deregister(jobID string, purge bool, q *WriteOptions) (string, *WriteMeta, error) {
	var resp JobDeregisterResponse
	wm, err := j.client.delete(fmt.Sprintf("/v1/job/%v?purge=%t", jobID, purge), &resp, q)
	if err != nil {
		return "", nil, err
	}
	return resp.EvalID, wm, nil
}

// ForceEvaluate is used to force-evaluate an existing job.
func (j *Jobs) ForceEvaluate(jobID string, q *WriteOptions) (string, *WriteMeta, error) {
	var resp JobRegisterResponse
	wm, err := j.client.write("/v1/job/"+jobID+"/evaluate", nil, &resp, q)
	if err != nil {
		return "", nil, err
	}
	return resp.EvalID, wm, nil
}

// PeriodicForce spawns a new instance of the periodic job and returns the eval ID
func (j *Jobs) PeriodicForce(jobID string, q *WriteOptions) (string, *WriteMeta, error) {
	var resp periodicForceResponse
	wm, err := j.client.write("/v1/job/"+jobID+"/periodic/force", nil, &resp, q)
	if err != nil {
		return "", nil, err
	}
	return resp.EvalID, wm, nil
}

// PlanOptions is used to pass through job planning parameters
type PlanOptions struct {
	Diff           bool
	PolicyOverride bool
}

func (j *Jobs) Plan(job *Job, diff bool, q *WriteOptions) (*JobPlanResponse, *WriteMeta, error) {
	opts := PlanOptions{Diff: diff}
	return j.PlanOpts(job, &opts, q)
}

func (j *Jobs) PlanOpts(job *Job, opts *PlanOptions, q *WriteOptions) (*JobPlanResponse, *WriteMeta, error) {
	if job == nil {
		return nil, nil, fmt.Errorf("must pass non-nil job")
	}

	// Setup the request
	req := &JobPlanRequest{
		Job: job,
	}
	if opts != nil {
		req.Diff = opts.Diff
		req.PolicyOverride = opts.PolicyOverride
	}

	var resp JobPlanResponse
	wm, err := j.client.write("/v1/job/"+*job.ID+"/plan", req, &resp, q)
	if err != nil {
		return nil, nil, err
	}
	return &resp, wm, nil
}

func (j *Jobs) Summary(jobID string, q *QueryOptions) (*JobSummary, *QueryMeta, error) {
	var resp JobSummary
	qm, err := j.client.query("/v1/job/"+jobID+"/summary", &resp, q)
	if err != nil {
		return nil, nil, err
	}
	return &resp, qm, nil
}

func (j *Jobs) Dispatch(jobID string, meta map[string]string,
	payload []byte, q *WriteOptions) (*JobDispatchResponse, *WriteMeta, error) {
	var resp JobDispatchResponse
	req := &JobDispatchRequest{
		JobID:   jobID,
		Meta:    meta,
		Payload: payload,
	}
	wm, err := j.client.write("/v1/job/"+jobID+"/dispatch", req, &resp, q)
	if err != nil {
		return nil, nil, err
	}
	return &resp, wm, nil
}

// Revert is used to revert the given job to the passed version. If
// enforceVersion is set, the job is only reverted if the current version is at
// the passed version.
func (j *Jobs) Revert(jobID string, version uint64, enforcePriorVersion *uint64,
	q *WriteOptions) (*JobRegisterResponse, *WriteMeta, error) {

	var resp JobRegisterResponse
	req := &JobRevertRequest{
		JobID:               jobID,
		JobVersion:          version,
		EnforcePriorVersion: enforcePriorVersion,
	}
	wm, err := j.client.write("/v1/job/"+jobID+"/revert", req, &resp, q)
	if err != nil {
		return nil, nil, err
	}
	return &resp, wm, nil
}

// Stable is used to mark a job version's stability.
func (j *Jobs) Stable(jobID string, version uint64, stable bool,
	q *WriteOptions) (*JobStabilityResponse, *WriteMeta, error) {

	var resp JobStabilityResponse
	req := &JobStabilityRequest{
		JobID:      jobID,
		JobVersion: version,
		Stable:     stable,
	}
	wm, err := j.client.write("/v1/job/"+jobID+"/stable", req, &resp, q)
	if err != nil {
		return nil, nil, err
	}
	return &resp, wm, nil
}

// periodicForceResponse is used to deserialize a force response
type periodicForceResponse struct {
	EvalID string
}

// UpdateStrategy defines a task groups update strategy.
type UpdateStrategy struct {
	Stagger          *time.Duration `mapstructure:"stagger"`
	MaxParallel      *int           `mapstructure:"max_parallel"`
	HealthCheck      *string        `mapstructure:"health_check"`
	MinHealthyTime   *time.Duration `mapstructure:"min_healthy_time"`
	HealthyDeadline  *time.Duration `mapstructure:"healthy_deadline"`
	ProgressDeadline *time.Duration `mapstructure:"progress_deadline"`
	AutoRevert       *bool          `mapstructure:"auto_revert"`
	Canary           *int           `mapstructure:"canary"`
}

// DefaultUpdateStrategy provides a baseline that can be used to upgrade
// jobs with the old policy or for populating field defaults.
func DefaultUpdateStrategy() *UpdateStrategy {
	return &UpdateStrategy{
		Stagger:          helper.TimeToPtr(30 * time.Second),
		MaxParallel:      helper.IntToPtr(1),
		HealthCheck:      helper.StringToPtr("checks"),
		MinHealthyTime:   helper.TimeToPtr(10 * time.Second),
		HealthyDeadline:  helper.TimeToPtr(5 * time.Minute),
		ProgressDeadline: helper.TimeToPtr(10 * time.Minute),
		AutoRevert:       helper.BoolToPtr(false),
		Canary:           helper.IntToPtr(0),
	}
}

func (u *UpdateStrategy) Copy() *UpdateStrategy {
	if u == nil {
		return nil
	}

	copy := new(UpdateStrategy)

	if u.Stagger != nil {
		copy.Stagger = helper.TimeToPtr(*u.Stagger)
	}

	if u.MaxParallel != nil {
		copy.MaxParallel = helper.IntToPtr(*u.MaxParallel)
	}

	if u.HealthCheck != nil {
		copy.HealthCheck = helper.StringToPtr(*u.HealthCheck)
	}

	if u.MinHealthyTime != nil {
		copy.MinHealthyTime = helper.TimeToPtr(*u.MinHealthyTime)
	}

	if u.HealthyDeadline != nil {
		copy.HealthyDeadline = helper.TimeToPtr(*u.HealthyDeadline)
	}

	if u.ProgressDeadline != nil {
		copy.ProgressDeadline = helper.TimeToPtr(*u.ProgressDeadline)
	}

	if u.AutoRevert != nil {
		copy.AutoRevert = helper.BoolToPtr(*u.AutoRevert)
	}

	if u.Canary != nil {
		copy.Canary = helper.IntToPtr(*u.Canary)
	}

	return copy
}

func (u *UpdateStrategy) Merge(o *UpdateStrategy) {
	if o == nil {
		return
	}

	if o.Stagger != nil {
		u.Stagger = helper.TimeToPtr(*o.Stagger)
	}

	if o.MaxParallel != nil {
		u.MaxParallel = helper.IntToPtr(*o.MaxParallel)
	}

	if o.HealthCheck != nil {
		u.HealthCheck = helper.StringToPtr(*o.HealthCheck)
	}

	if o.MinHealthyTime != nil {
		u.MinHealthyTime = helper.TimeToPtr(*o.MinHealthyTime)
	}

	if o.HealthyDeadline != nil {
		u.HealthyDeadline = helper.TimeToPtr(*o.HealthyDeadline)
	}

	if o.ProgressDeadline != nil {
		u.ProgressDeadline = helper.TimeToPtr(*o.ProgressDeadline)
	}

	if o.AutoRevert != nil {
		u.AutoRevert = helper.BoolToPtr(*o.AutoRevert)
	}

	if o.Canary != nil {
		u.Canary = helper.IntToPtr(*o.Canary)
	}
}

func (u *UpdateStrategy) Canonicalize() {
	d := DefaultUpdateStrategy()

	if u.MaxParallel == nil {
		u.MaxParallel = d.MaxParallel
	}

	if u.Stagger == nil {
		u.Stagger = d.Stagger
	}

	if u.HealthCheck == nil {
		u.HealthCheck = d.HealthCheck
	}

	if u.HealthyDeadline == nil {
		u.HealthyDeadline = d.HealthyDeadline
	}

	if u.ProgressDeadline == nil {
		u.ProgressDeadline = d.ProgressDeadline
	}

	if u.MinHealthyTime == nil {
		u.MinHealthyTime = d.MinHealthyTime
	}

	if u.AutoRevert == nil {
		u.AutoRevert = d.AutoRevert
	}

	if u.Canary == nil {
		u.Canary = d.Canary
	}
}

// Empty returns whether the UpdateStrategy is empty or has user defined values.
func (u *UpdateStrategy) Empty() bool {
	if u == nil {
		return true
	}

	if u.Stagger != nil && *u.Stagger != 0 {
		return false
	}

	if u.MaxParallel != nil && *u.MaxParallel != 0 {
		return false
	}

	if u.HealthCheck != nil && *u.HealthCheck != "" {
		return false
	}

	if u.MinHealthyTime != nil && *u.MinHealthyTime != 0 {
		return false
	}

	if u.HealthyDeadline != nil && *u.HealthyDeadline != 0 {
		return false
	}

	if u.ProgressDeadline != nil && *u.ProgressDeadline != 0 {
		return false
	}

	if u.AutoRevert != nil && *u.AutoRevert {
		return false
	}

	if u.Canary != nil && *u.Canary != 0 {
		return false
	}

	return true
}

// PeriodicConfig is for serializing periodic config for a job.
type PeriodicConfig struct {
	Enabled         *bool
	Spec            *string
	SpecType        *string
	ProhibitOverlap *bool   `mapstructure:"prohibit_overlap"`
	TimeZone        *string `mapstructure:"time_zone"`
}

func (p *PeriodicConfig) Canonicalize() {
	if p.Enabled == nil {
		p.Enabled = helper.BoolToPtr(true)
	}
	if p.Spec == nil {
		p.Spec = helper.StringToPtr("")
	}
	if p.SpecType == nil {
		p.SpecType = helper.StringToPtr(PeriodicSpecCron)
	}
	if p.ProhibitOverlap == nil {
		p.ProhibitOverlap = helper.BoolToPtr(false)
	}
	if p.TimeZone == nil || *p.TimeZone == "" {
		p.TimeZone = helper.StringToPtr("UTC")
	}
}

// Next returns the closest time instant matching the spec that is after the
// passed time. If no matching instance exists, the zero value of time.Time is
// returned. The `time.Location` of the returned value matches that of the
// passed time.
func (p *PeriodicConfig) Next(fromTime time.Time) (time.Time, error) {
	if *p.SpecType == PeriodicSpecCron {
		if e, err := cronexpr.Parse(*p.Spec); err == nil {
			return structs.CronParseNext(e, fromTime, *p.Spec)
		}
	}

	return time.Time{}, nil
}

func (p *PeriodicConfig) GetLocation() (*time.Location, error) {
	if p.TimeZone == nil || *p.TimeZone == "" {
		return time.UTC, nil
	}

	return time.LoadLocation(*p.TimeZone)
}

// ParameterizedJobConfig is used to configure the parameterized job.
type ParameterizedJobConfig struct {
	Payload      string
	MetaRequired []string `mapstructure:"meta_required"`
	MetaOptional []string `mapstructure:"meta_optional"`
}

// Job is used to serialize a job.
type Job struct {
	Stop              *bool
	Region            *string
	Namespace         *string
	ID                *string
	ParentID          *string
	Name              *string
	Type              *string
	Priority          *int
	AllAtOnce         *bool `mapstructure:"all_at_once"`
	Datacenters       []string
	Constraints       []*Constraint
	TaskGroups        []*TaskGroup
	Update            *UpdateStrategy
	Periodic          *PeriodicConfig
	ParameterizedJob  *ParameterizedJobConfig
	Payload           []byte
	Reschedule        *ReschedulePolicy
	Migrate           *MigrateStrategy
	Meta              map[string]string
	VaultToken        *string `mapstructure:"vault_token"`
	Status            *string
	StatusDescription *string
	Stable            *bool
	Version           *uint64
	SubmitTime        *int64
	CreateIndex       *uint64
	ModifyIndex       *uint64
	JobModifyIndex    *uint64
}

// IsPeriodic returns whether a job is periodic.
func (j *Job) IsPeriodic() bool {
	return j.Periodic != nil
}

// IsParameterized returns whether a job is parameterized job.
func (j *Job) IsParameterized() bool {
	return j.ParameterizedJob != nil
}

func (j *Job) Canonicalize() {
	if j.ID == nil {
		j.ID = helper.StringToPtr("")
	}
	if j.Name == nil {
		j.Name = helper.StringToPtr(*j.ID)
	}
	if j.ParentID == nil {
		j.ParentID = helper.StringToPtr("")
	}
	if j.Namespace == nil {
		j.Namespace = helper.StringToPtr(DefaultNamespace)
	}
	if j.Priority == nil {
		j.Priority = helper.IntToPtr(50)
	}
	if j.Stop == nil {
		j.Stop = helper.BoolToPtr(false)
	}
	if j.Region == nil {
		j.Region = helper.StringToPtr("global")
	}
	if j.Namespace == nil {
		j.Namespace = helper.StringToPtr("default")
	}
	if j.Type == nil {
		j.Type = helper.StringToPtr("service")
	}
	if j.AllAtOnce == nil {
		j.AllAtOnce = helper.BoolToPtr(false)
	}
	if j.VaultToken == nil {
		j.VaultToken = helper.StringToPtr("")
	}
	if j.Status == nil {
		j.Status = helper.StringToPtr("")
	}
	if j.StatusDescription == nil {
		j.StatusDescription = helper.StringToPtr("")
	}
	if j.Stable == nil {
		j.Stable = helper.BoolToPtr(false)
	}
	if j.Version == nil {
		j.Version = helper.Uint64ToPtr(0)
	}
	if j.CreateIndex == nil {
		j.CreateIndex = helper.Uint64ToPtr(0)
	}
	if j.ModifyIndex == nil {
		j.ModifyIndex = helper.Uint64ToPtr(0)
	}
	if j.JobModifyIndex == nil {
		j.JobModifyIndex = helper.Uint64ToPtr(0)
	}
	if j.Periodic != nil {
		j.Periodic.Canonicalize()
	}
	if j.Update != nil {
		j.Update.Canonicalize()
	}

	for _, tg := range j.TaskGroups {
		tg.Canonicalize(j)
	}
}

// LookupTaskGroup finds a task group by name
func (j *Job) LookupTaskGroup(name string) *TaskGroup {
	for _, tg := range j.TaskGroups {
		if *tg.Name == name {
			return tg
		}
	}
	return nil
}

// JobSummary summarizes the state of the allocations of a job
type JobSummary struct {
	JobID     string
	Namespace string
	Summary   map[string]TaskGroupSummary
	Children  *JobChildrenSummary

	// Raft Indexes
	CreateIndex uint64
	ModifyIndex uint64
}

// JobChildrenSummary contains the summary of children job status
type JobChildrenSummary struct {
	Pending int64
	Running int64
	Dead    int64
}

func (jc *JobChildrenSummary) Sum() int {
	if jc == nil {
		return 0
	}

	return int(jc.Pending + jc.Running + jc.Dead)
}

// TaskGroup summarizes the state of all the allocations of a particular
// TaskGroup
type TaskGroupSummary struct {
	Queued   int
	Complete int
	Failed   int
	Running  int
	Starting int
	Lost     int
}

// JobListStub is used to return a subset of information about
// jobs during list operations.
type JobListStub struct {
	ID                string
	ParentID          string
	Name              string
	Type              string
	Priority          int
	Periodic          bool
	ParameterizedJob  bool
	Stop              bool
	Status            string
	StatusDescription string
	JobSummary        *JobSummary
	CreateIndex       uint64
	ModifyIndex       uint64
	JobModifyIndex    uint64
	SubmitTime        int64
}

// JobIDSort is used to sort jobs by their job ID's.
type JobIDSort []*JobListStub

func (j JobIDSort) Len() int {
	return len(j)
}

func (j JobIDSort) Less(a, b int) bool {
	return j[a].ID < j[b].ID
}

func (j JobIDSort) Swap(a, b int) {
	j[a], j[b] = j[b], j[a]
}

// NewServiceJob creates and returns a new service-style job
// for long-lived processes using the provided name, ID, and
// relative job priority.
func NewServiceJob(id, name, region string, pri int) *Job {
	return newJob(id, name, region, JobTypeService, pri)
}

// NewBatchJob creates and returns a new batch-style job for
// short-lived processes using the provided name and ID along
// with the relative job priority.
func NewBatchJob(id, name, region string, pri int) *Job {
	return newJob(id, name, region, JobTypeBatch, pri)
}

// newJob is used to create a new Job struct.
func newJob(id, name, region, typ string, pri int) *Job {
	return &Job{
		Region:   &region,
		ID:       &id,
		Name:     &name,
		Type:     &typ,
		Priority: &pri,
	}
}

// SetMeta is used to set arbitrary k/v pairs of metadata on a job.
func (j *Job) SetMeta(key, val string) *Job {
	if j.Meta == nil {
		j.Meta = make(map[string]string)
	}
	j.Meta[key] = val
	return j
}

// AddDatacenter is used to add a datacenter to a job.
func (j *Job) AddDatacenter(dc string) *Job {
	j.Datacenters = append(j.Datacenters, dc)
	return j
}

// Constrain is used to add a constraint to a job.
func (j *Job) Constrain(c *Constraint) *Job {
	j.Constraints = append(j.Constraints, c)
	return j
}

// AddTaskGroup adds a task group to an existing job.
func (j *Job) AddTaskGroup(grp *TaskGroup) *Job {
	j.TaskGroups = append(j.TaskGroups, grp)
	return j
}

// AddPeriodicConfig adds a periodic config to an existing job.
func (j *Job) AddPeriodicConfig(cfg *PeriodicConfig) *Job {
	j.Periodic = cfg
	return j
}

type WriteRequest struct {
	// The target region for this write
	Region string

	// Namespace is the target namespace for this write
	Namespace string

	// SecretID is the secret ID of an ACL token
	SecretID string
}

// JobValidateRequest is used to validate a job
type JobValidateRequest struct {
	Job *Job
	WriteRequest
}

// JobValidateResponse is the response from validate request
type JobValidateResponse struct {
	// DriverConfigValidated indicates whether the agent validated the driver
	// config
	DriverConfigValidated bool

	// ValidationErrors is a list of validation errors
	ValidationErrors []string

	// Error is a string version of any error that may have occurred
	Error string

	// Warnings contains any warnings about the given job. These may include
	// deprecation warnings.
	Warnings string
}

// JobRevertRequest is used to revert a job to a prior version.
type JobRevertRequest struct {
	// JobID is the ID of the job  being reverted
	JobID string

	// JobVersion the version to revert to.
	JobVersion uint64

	// EnforcePriorVersion if set will enforce that the job is at the given
	// version before reverting.
	EnforcePriorVersion *uint64

	WriteRequest
}

// JobUpdateRequest is used to update a job
type JobRegisterRequest struct {
	Job *Job
	// If EnforceIndex is set then the job will only be registered if the passed
	// JobModifyIndex matches the current Jobs index. If the index is zero, the
	// register only occurs if the job is new.
	EnforceIndex   bool
	JobModifyIndex uint64
	PolicyOverride bool

	WriteRequest
}

// RegisterJobRequest is used to serialize a job registration
type RegisterJobRequest struct {
	Job            *Job
	EnforceIndex   bool   `json:",omitempty"`
	JobModifyIndex uint64 `json:",omitempty"`
	PolicyOverride bool   `json:",omitempty"`
}

// JobRegisterResponse is used to respond to a job registration
type JobRegisterResponse struct {
	EvalID          string
	EvalCreateIndex uint64
	JobModifyIndex  uint64

	// Warnings contains any warnings about the given job. These may include
	// deprecation warnings.
	Warnings string

	QueryMeta
}

// JobDeregisterResponse is used to respond to a job deregistration
type JobDeregisterResponse struct {
	EvalID          string
	EvalCreateIndex uint64
	JobModifyIndex  uint64
	QueryMeta
}

type JobPlanRequest struct {
	Job            *Job
	Diff           bool
	PolicyOverride bool
	WriteRequest
}

type JobPlanResponse struct {
	JobModifyIndex     uint64
	CreatedEvals       []*Evaluation
	Diff               *JobDiff
	Annotations        *PlanAnnotations
	FailedTGAllocs     map[string]*AllocationMetric
	NextPeriodicLaunch time.Time

	// Warnings contains any warnings about the given job. These may include
	// deprecation warnings.
	Warnings string
}

type JobDiff struct {
	Type       string
	ID         string
	Fields     []*FieldDiff
	Objects    []*ObjectDiff
	TaskGroups []*TaskGroupDiff
}

type TaskGroupDiff struct {
	Type    string
	Name    string
	Fields  []*FieldDiff
	Objects []*ObjectDiff
	Tasks   []*TaskDiff
	Updates map[string]uint64
}

type TaskDiff struct {
	Type        string
	Name        string
	Fields      []*FieldDiff
	Objects     []*ObjectDiff
	Annotations []string
}

type FieldDiff struct {
	Type        string
	Name        string
	Old, New    string
	Annotations []string
}

type ObjectDiff struct {
	Type    string
	Name    string
	Fields  []*FieldDiff
	Objects []*ObjectDiff
}

type PlanAnnotations struct {
	DesiredTGUpdates map[string]*DesiredUpdates
}

type DesiredUpdates struct {
	Ignore            uint64
	Place             uint64
	Migrate           uint64
	Stop              uint64
	InPlaceUpdate     uint64
	DestructiveUpdate uint64
	Canary            uint64
}

type JobDispatchRequest struct {
	JobID   string
	Payload []byte
	Meta    map[string]string
}

type JobDispatchResponse struct {
	DispatchedJobID string
	EvalID          string
	EvalCreateIndex uint64
	JobCreateIndex  uint64
	WriteMeta
}

// JobVersionsResponse is used for a job get versions request
type JobVersionsResponse struct {
	Versions []*Job
	Diffs    []*JobDiff
	QueryMeta
}

// JobStabilityRequest is used to marked a job as stable.
type JobStabilityRequest struct {
	// Job to set the stability on
	JobID      string
	JobVersion uint64

	// Set the stability
	Stable bool
	WriteRequest
}

// JobStabilityResponse is the response when marking a job as stable.
type JobStabilityResponse struct {
	JobModifyIndex uint64
	WriteMeta
}