// Copyright (C) 2022 NHR@FAU, University Erlangen-Nuremberg.
// All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package schema

import (
	"errors"
	"fmt"
	"io"
	"time"
)

// Common subset of Job and JobMeta. Use one of those, not
// this type directly.
type BaseJob struct {
	JobID            int64             `json:"jobId" db:"job_id"`
	User             string            `json:"user" db:"user"`
	Project          string            `json:"project" db:"project"`
	Cluster          string            `json:"cluster" db:"cluster"`
	SubCluster       string            `json:"subCluster" db:"subcluster"`
	Partition        string            `json:"partition" db:"partition"`
	ArrayJobId       int32             `json:"arrayJobId" db:"array_job_id"`
	NumNodes         int32             `json:"numNodes" db:"num_nodes"`
	NumHWThreads     int32             `json:"numHwthreads" db:"num_hwthreads"`
	NumAcc           int32             `json:"numAcc" db:"num_acc"`
	Exclusive        int32             `json:"exclusive" db:"exclusive"`
	MonitoringStatus int32             `json:"monitoringStatus" db:"monitoring_status"`
	SMT              int32             `json:"smt" db:"smt"`
	State            JobState          `json:"jobState" db:"job_state"`
	Duration         int32             `json:"duration" db:"duration"`
	Walltime         int64             `json:"walltime" db:"walltime"`
	Tags             []*Tag            `json:"tags"`
	RawResources     []byte            `json:"-" db:"resources"`
	Resources        []*Resource       `json:"resources"`
	RawMetaData      []byte            `json:"-" db:"meta_data"`
	MetaData         map[string]string `json:"metaData"`
}

// This type is used as the GraphQL interface and using sqlx as a table row.
type Job struct {
	ID int64 `json:"id" db:"id"`
	BaseJob
	StartTimeUnix    int64     `json:"-" db:"start_time"`
	StartTime        time.Time `json:"startTime"`
	MemUsedMax       float64   `json:"-" db:"mem_used_max"`
	FlopsAnyAvg      float64   `json:"-" db:"flops_any_avg"`
	MemBwAvg         float64   `json:"-" db:"mem_bw_avg"`
	LoadAvg          float64   `json:"-" db:"load_avg"`
	NetBwAvg         float64   `json:"-" db:"net_bw_avg"`
	NetDataVolTotal  float64   `json:"-" db:"net_data_vol_total"`
	FileBwAvg        float64   `json:"-" db:"file_bw_avg"`
	FileDataVolTotal float64   `json:"-" db:"file_data_vol_total"`
}

// When reading from the database or sending data via GraphQL, the start time can be in the much more
// convenient time.Time type. In the `meta.json` files, the start time is encoded as a unix epoch timestamp.
// This is why there is this struct, which contains all fields from the regular job struct, but "overwrites"
// the StartTime field with one of type int64.
type JobMeta struct {
	ID *int64 `json:"id,omitempty"` // never used in the job-archive, only available via REST-API
	BaseJob
	StartTime  int64                    `json:"startTime" db:"start_time"`
	Statistics map[string]JobStatistics `json:"statistics,omitempty"`
}

const (
	MonitoringStatusDisabled            int32 = 0
	MonitoringStatusRunningOrArchiving  int32 = 1
	MonitoringStatusArchivingFailed     int32 = 2
	MonitoringStatusArchivingSuccessful int32 = 3
)

var JobDefaults BaseJob = BaseJob{
	Exclusive:        1,
	MonitoringStatus: MonitoringStatusRunningOrArchiving,
}

type JobStatistics struct {
	Unit string  `json:"unit"`
	Avg  float64 `json:"avg"`
	Min  float64 `json:"min"`
	Max  float64 `json:"max"`
}

type Tag struct {
	ID   int64  `json:"id" db:"id"`
	Type string `json:"type" db:"tag_type"`
	Name string `json:"name" db:"tag_name"`
}

type Resource struct {
	Hostname      string   `json:"hostname"`
	HWThreads     []int    `json:"hwthreads,omitempty"`
	Accelerators  []string `json:"accelerators,omitempty"`
	Configuration string   `json:"configuration,omitempty"`
}

type JobState string

const (
	JobStateRunning     JobState = "running"
	JobStateCompleted   JobState = "completed"
	JobStateFailed      JobState = "failed"
	JobStateCancelled   JobState = "cancelled"
	JobStateStopped     JobState = "stopped"
	JobStateTimeout     JobState = "timeout"
	JobStatePreempted   JobState = "preempted"
	JobStateOutOfMemory JobState = "out_of_memory"
)

func (e *JobState) UnmarshalGQL(v interface{}) error {
	str, ok := v.(string)
	if !ok {
		return fmt.Errorf("enums must be strings")
	}

	*e = JobState(str)
	if !e.Valid() {
		return errors.New("invalid job state")
	}

	return nil
}

func (e JobState) MarshalGQL(w io.Writer) {
	fmt.Fprintf(w, "\"%s\"", e)
}

func (e JobState) Valid() bool {
	return e == JobStateRunning ||
		e == JobStateCompleted ||
		e == JobStateFailed ||
		e == JobStateCancelled ||
		e == JobStateStopped ||
		e == JobStateTimeout ||
		e == JobStatePreempted ||
		e == JobStateOutOfMemory
}