package jobs

import (
	"context"
	"sync"
	"sync/atomic"
	"time"
)

type Status string

const (
	StatusQueued      Status = "queued"
	StatusDownloading Status = "downloading"
	StatusExtracting  Status = "extracting"
	StatusReady       Status = "ready"
	StatusMoving      Status = "moving"
	StatusCompleted   Status = "completed"
	StatusFailed      Status = "failed"
	StatusCancelled   Status = "cancelled"
)

type Snapshot struct {
	ID         string    `json:"id"`
	SourceURL  string    `json:"sourceUrl"`
	FileName   string    `json:"fileName"`
	Status     Status    `json:"status"`
	Message    string    `json:"message"`
	BytesDone  int64     `json:"bytesDone"`
	BytesTotal int64     `json:"bytesTotal"`
	CreatedAt  time.Time `json:"createdAt"`
}

type Job struct {
	id          string
	sourceURL   string
	displayURL  string
	directory   string
	autoExtract bool
	createdAt   time.Time
	jobContext  context.Context
	cancel      context.CancelFunc
	workers     sync.WaitGroup

	mutex    sync.Mutex
	status   Status
	message  string
	fileName string
	deleted  bool

	bytesDone  atomic.Int64
	bytesTotal atomic.Int64
}

func (job *Job) SetTotal(total int64) {
	job.bytesTotal.Store(total)
}

func (job *Job) Add(delta int64) {
	job.bytesDone.Add(delta)
}

func (job *Job) SetFileName(name string) {
	job.mutex.Lock()
	defer job.mutex.Unlock()
	job.fileName = name
}

func (job *Job) resetProgress() {
	job.bytesDone.Store(0)
	job.bytesTotal.Store(0)
}

func (job *Job) setStatus(status Status, message string) {
	job.mutex.Lock()
	defer job.mutex.Unlock()
	if job.deleted {
		return
	}
	job.status = status
	job.message = message
}

func (job *Job) currentStatus() Status {
	job.mutex.Lock()
	defer job.mutex.Unlock()
	return job.status
}

func (job *Job) begin(from, to Status) bool {
	job.mutex.Lock()
	defer job.mutex.Unlock()
	if job.deleted || job.status != from {
		return false
	}
	job.status = to
	job.message = ""
	job.workers.Add(1)
	return true
}

func (job *Job) markDeleted() bool {
	job.mutex.Lock()
	defer job.mutex.Unlock()
	if job.status == StatusMoving {
		return false
	}
	job.deleted = true
	job.status = StatusCancelled
	return true
}

func (job *Job) snapshot() Snapshot {
	job.mutex.Lock()
	defer job.mutex.Unlock()
	return Snapshot{
		ID:         job.id,
		SourceURL:  job.displayURL,
		FileName:   job.fileName,
		Status:     job.status,
		Message:    job.message,
		BytesDone:  job.bytesDone.Load(),
		BytesTotal: job.bytesTotal.Load(),
		CreatedAt:  job.createdAt,
	}
}