/**
 * 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 realis

import (
	"strconv"

	"github.com/paypal/gorealis/gen-go/apache/aurora"
)

// Job inteface is used to define a set of functions an Aurora Job object
// must implemement.
// TODO(rdelvalle): Consider getting rid of the Job interface
type Job interface {
	// Set Job Key environment.
	Environment(env string) Job
	Role(role string) Job
	Name(name string) Job
	CronSchedule(cron string) Job
	CronCollisionPolicy(policy aurora.CronCollisionPolicy) Job
	CPU(cpus float64) Job
	Disk(disk int64) Job
	RAM(ram int64) Job
	GPU(gpu int64) Job
	ExecutorName(name string) Job
	ExecutorData(data string) Job
	AddPorts(num int) Job
	AddLabel(key string, value string) Job
	AddNamedPorts(names ...string) Job
	AddLimitConstraint(name string, limit int32) Job
	AddValueConstraint(name string, negated bool, values ...string) Job

	// From Aurora Docs:
	// dedicated attribute. Aurora treats this specially, and only allows matching jobs
	// to run on these machines, and will only schedule matching jobs on these machines.
	// When a job is created, the scheduler requires that the $role component matches
	// the role field in the job configuration, and will reject the job creation otherwise.
	// A wildcard (*) may be used for the role portion of the dedicated attribute, which
	// will allow any owner to elect for a job to run on the host(s)
	AddDedicatedConstraint(role, name string) Job
	AddURIs(extract bool, cache bool, values ...string) Job
	JobKey() *aurora.JobKey
	JobConfig() *aurora.JobConfiguration
	TaskConfig() *aurora.TaskConfig
	IsService(isService bool) Job
	InstanceCount(instCount int32) Job
	GetInstanceCount() int32
	MaxFailure(maxFail int32) Job
	Container(container Container) Job
	PartitionPolicy(policy *aurora.PartitionPolicy) Job
	Tier(tier string) Job
	SlaPolicy(policy *aurora.SlaPolicy) Job
	Priority(priority int32) Job
}

type resourceType int

const (
	CPU resourceType = iota
	RAM
	DISK
	GPU
)

const portNamePrefix = "org.apache.aurora.port."

// AuroraJob is a structure to collect all information pertaining to an Aurora job.
type AuroraJob struct {
	jobConfig   *aurora.JobConfiguration
	resources   map[resourceType]*aurora.Resource
	metadata    map[string]*aurora.Metadata
	constraints map[string]*aurora.Constraint
	portCount   int
}

// NewJob is used to create a Job object with everything initialized.
func NewJob() Job {
	jobConfig := aurora.NewJobConfiguration()
	taskConfig := aurora.NewTaskConfig()
	jobKey := aurora.NewJobKey()

	// Job Config
	jobConfig.Key = jobKey
	jobConfig.TaskConfig = taskConfig

	// Task Config
	taskConfig.Job = jobKey
	taskConfig.Container = aurora.NewContainer()
	taskConfig.Container.Mesos = aurora.NewMesosContainer()

	// Resources
	numCpus := aurora.NewResource()
	ramMb := aurora.NewResource()
	diskMb := aurora.NewResource()

	resources := map[resourceType]*aurora.Resource{CPU: numCpus, RAM: ramMb, DISK: diskMb}
	taskConfig.Resources = []*aurora.Resource{numCpus, ramMb, diskMb}

	numCpus.NumCpus = new(float64)
	ramMb.RamMb = new(int64)
	diskMb.DiskMb = new(int64)

	return &AuroraJob{
		jobConfig:   jobConfig,
		resources:   resources,
		metadata:    make(map[string]*aurora.Metadata),
		constraints: make(map[string]*aurora.Constraint),
		portCount:   0,
	}
}

// Environment sets the Job Key environment.
func (j *AuroraJob) Environment(env string) Job {
	j.jobConfig.Key.Environment = env
	return j
}

// Role sets the Job Key role.
func (j *AuroraJob) Role(role string) Job {
	j.jobConfig.Key.Role = role

	// Will be deprecated
	identity := &aurora.Identity{User: role}
	j.jobConfig.Owner = identity
	j.jobConfig.TaskConfig.Owner = identity
	return j
}

// Name sets the Job Key Name.
func (j *AuroraJob) Name(name string) Job {
	j.jobConfig.Key.Name = name
	return j
}

// ExecutorName sets the name of the executor that will the task will be configured to.
func (j *AuroraJob) ExecutorName(name string) Job {

	if j.jobConfig.TaskConfig.ExecutorConfig == nil {
		j.jobConfig.TaskConfig.ExecutorConfig = aurora.NewExecutorConfig()
	}

	j.jobConfig.TaskConfig.ExecutorConfig.Name = name
	return j
}

// ExecutorData sets the data blob that will be passed to the Mesos executor.
func (j *AuroraJob) ExecutorData(data string) Job {

	if j.jobConfig.TaskConfig.ExecutorConfig == nil {
		j.jobConfig.TaskConfig.ExecutorConfig = aurora.NewExecutorConfig()
	}

	j.jobConfig.TaskConfig.ExecutorConfig.Data = data
	return j
}

// CPU sets the amount of CPU each task will use in an Aurora Job.
func (j *AuroraJob) CPU(cpus float64) Job {
	*j.resources[CPU].NumCpus = cpus
	return j
}

// RAM sets the amount of RAM each task will use in an Aurora Job.
func (j *AuroraJob) RAM(ram int64) Job {
	*j.resources[RAM].RamMb = ram
	return j
}

// Disk sets the amount of Disk each task will use in an Aurora Job.
func (j *AuroraJob) Disk(disk int64) Job {
	*j.resources[DISK].DiskMb = disk
	return j
}

// GPU sets the amount of GPU each task will use in an Aurora Job.
func (j *AuroraJob) GPU(gpu int64) Job {
	// GPU resource must be set explicitly since the scheduler by default
	// rejects jobs with GPU resources attached to it.
	if _, ok := j.resources[GPU]; !ok {
		j.resources[GPU] = &aurora.Resource{}
		j.JobConfig().GetTaskConfig().Resources = append(
			j.JobConfig().GetTaskConfig().Resources,
			j.resources[GPU])
	}

	j.resources[GPU].NumGpus = &gpu
	return j
}

// MaxFailure sets how many failures to tolerate before giving up per Job.
func (j *AuroraJob) MaxFailure(maxFail int32) Job {
	j.jobConfig.TaskConfig.MaxTaskFailures = maxFail
	return j
}

// InstanceCount sets how many instances of the task to run for this Job.
func (j *AuroraJob) InstanceCount(instCount int32) Job {
	j.jobConfig.InstanceCount = instCount
	return j
}

// CronSchedule allows the user to configure a cron schedule for this job to run in.
func (j *AuroraJob) CronSchedule(cron string) Job {
	j.jobConfig.CronSchedule = &cron
	return j
}

// CronCollisionPolicy allows the user to decide what happens if two or more instances
// of the same Cron job need to run.
func (j *AuroraJob) CronCollisionPolicy(policy aurora.CronCollisionPolicy) Job {
	j.jobConfig.CronCollisionPolicy = policy
	return j
}

// GetInstanceCount returns how many tasks this Job contains.
func (j *AuroraJob) GetInstanceCount() int32 {
	return j.jobConfig.InstanceCount
}

// IsService returns true if the job is a long term running job or false if it is an ad-hoc job.
func (j *AuroraJob) IsService(isService bool) Job {
	j.jobConfig.TaskConfig.IsService = isService
	return j
}

// JobKey returns the job's configuration key.
func (j *AuroraJob) JobKey() *aurora.JobKey {
	return j.jobConfig.Key
}

// JobConfig returns the job's configuration.
func (j *AuroraJob) JobConfig() *aurora.JobConfiguration {
	return j.jobConfig
}

// TaskConfig returns the job's task(shard) configuration.
func (j *AuroraJob) TaskConfig() *aurora.TaskConfig {
	return j.jobConfig.TaskConfig
}

// AddURIs adds a list of URIs with the same extract and cache configuration. Scheduler must have
// --enable_mesos_fetcher flag enabled. Currently there is no duplicate detection.
func (j *AuroraJob) AddURIs(extract bool, cache bool, values ...string) Job {
	for _, value := range values {
		j.jobConfig.TaskConfig.MesosFetcherUris = append(j.jobConfig.TaskConfig.MesosFetcherUris,
			&aurora.MesosFetcherURI{Value: value, Extract: &extract, Cache: &cache})
	}
	return j
}

// AddLabel adds a Mesos label to the job. Note that Aurora will add the
// prefix "org.apache.aurora.metadata." to the beginning of each key.
func (j *AuroraJob) AddLabel(key string, value string) Job {
	if _, ok := j.metadata[key]; !ok {
		j.metadata[key] = &aurora.Metadata{Key: key}
		j.jobConfig.TaskConfig.Metadata = append(j.jobConfig.TaskConfig.Metadata, j.metadata[key])
	}

	j.metadata[key].Value = value
	return j
}

// AddNamedPorts adds a named port to the job configuration  These are random ports as it's
// not currently possible to request specific ports using Aurora.
func (j *AuroraJob) AddNamedPorts(names ...string) Job {
	j.portCount += len(names)
	for _, name := range names {
		j.jobConfig.TaskConfig.Resources = append(
			j.jobConfig.TaskConfig.Resources,
			&aurora.Resource{NamedPort: &name})
	}

	return j
}

// AddPorts adds a request for a number of ports to the job configuration. The names chosen for these ports
// will be org.apache.aurora.port.X, where X is the current port count for the job configuration
// starting at 0. These are random ports as it's not currently possible to request
// specific ports using Aurora.
func (j *AuroraJob) AddPorts(num int) Job {
	start := j.portCount
	j.portCount += num
	for i := start; i < j.portCount; i++ {
		portName := portNamePrefix + strconv.Itoa(i)
		j.jobConfig.TaskConfig.Resources = append(
			j.jobConfig.TaskConfig.Resources,
			&aurora.Resource{NamedPort: &portName})
	}

	return j
}

// AddValueConstraint allows the user to add a value constrain to the job to limit which agents the job's
// tasks can be run on. If the name matches a constraint that was previously set, the previous value will be
// overwritten. In case the previous constraint attached to the name was of type limit, the constraint will be clobbered
// by this new Value constraint.
// From Aurora Docs:
// Add a Value constraint
// name - Mesos slave attribute that the constraint is matched against.
// If negated = true , treat this as a 'not' - to avoid specific values.
// Values - list of values we look for in attribute name
func (j *AuroraJob) AddValueConstraint(name string, negated bool, values ...string) Job {
	if _, ok := j.constraints[name]; !ok {
		j.constraints[name] = &aurora.Constraint{Name: name}
		j.jobConfig.TaskConfig.Constraints = append(j.jobConfig.TaskConfig.Constraints, j.constraints[name])
	}

	j.constraints[name].Constraint = &aurora.TaskConstraint{
		Value: &aurora.ValueConstraint{
			Negated: negated,
			Values:  values,
		},
		Limit: nil,
	}

	return j
}

// AddLimitConstraint allows the user to limit how many tasks form the same Job are run on a single host.
// If the name matches a constraint that was previously set, the previous value will be
// overwritten. In case the previous constraint attached to the name was of type Value, the constraint will be clobbered
// by this new Limit constraint.
// From Aurora Docs:
// A constraint that specifies the maximum number of active tasks on a host with
// a matching attribute that may be scheduled simultaneously.
func (j *AuroraJob) AddLimitConstraint(name string, limit int32) Job {
	if _, ok := j.constraints[name]; !ok {
		j.constraints[name] = &aurora.Constraint{Name: name}
		j.jobConfig.TaskConfig.Constraints = append(j.jobConfig.TaskConfig.Constraints, j.constraints[name])
	}

	j.constraints[name].Constraint = &aurora.TaskConstraint{
		Value: nil,
		Limit: &aurora.LimitConstraint{Limit: limit},
	}

	return j
}

// AddDedicatedConstraint is a convenience function that allows the user to
// add a dedicated constraint to a Job configuration.
// In case a previous dedicated constraint was set, it will be clobbered by this new value.
func (j *AuroraJob) AddDedicatedConstraint(role, name string) Job {
	j.AddValueConstraint("dedicated", false, role+"/"+name)

	return j
}

// Container sets a container to run for the job configuration to run.
func (j *AuroraJob) Container(container Container) Job {
	j.jobConfig.TaskConfig.Container = container.Build()

	return j
}

// PartitionPolicy sets a partition policy for the job configuration to implement.
func (j *AuroraJob) PartitionPolicy(policy *aurora.PartitionPolicy) Job {
	j.jobConfig.TaskConfig.PartitionPolicy = policy
	return j
}

// Tier sets the Tier for the Job.
func (j *AuroraJob) Tier(tier string) Job {
	j.jobConfig.TaskConfig.Tier = &tier

	return j
}

// SlaPolicy sets an SlaPolicy for the Job.
func (j *AuroraJob) SlaPolicy(policy *aurora.SlaPolicy) Job {
	j.jobConfig.TaskConfig.SlaPolicy = policy

	return j
}

func (j *AuroraJob) Priority(priority int32) Job {
	j.jobConfig.TaskConfig.Priority = priority
	return j
}