package tasksch

import (
	"sync"
	"time"
)

const (
	TaskStatusBegin     = 0
	TaskStatusWorking   = 0
	TaskStatusCanceling = 1

	TaskStatusEndBegin = 2
	TaskStatusFinished = 2
	TaskStatusCanceled = 3
	TaskStatusFailed   = 4
	TaskStatusEnd      = 4
)

type ITask interface {
	Run() *ITask
	GetResult(duration time.Duration) (retVal []interface{}, err error)
	Cancel()
	GetTotalItemCount() int
	GetFinishedItemCount() int
	GetTotalJobCount() int
	GetFinishedJobCount() int
	GetStatus() int
}

type BaseTask struct {
	Name                string    `json:"name"`
	ID                  string    `json:"id"`
	ParallelCount       int       `json:"parallelCount"`
	BatchSize           int       `json:"batchSize"`
	IsContinueWhenError bool      `json:"isContinueWhenError"`
	CreatedBy           string    `json:"createdBy"`
	CreatedAt           time.Time `json:"createdAt"`
	UpdatedAt           time.Time `json:"updatedAt"`
	TerminatedAt        time.Time `json:"terminatedAt"`
	TotalItemCount      int       `json:"totalItemCount"`
	TotalJobCount       int       `json:"totalJobCount"`
	FinishedItemCount   int       `json:"finishedItemCount"`
	FinishedJobCount    int       `json:"finishedJobCount"`
	FailedItemCount     int       `json:"failedItemCount"`
	FailedJobCount      int       `json:"failedJobCount"`
	Status              int       `json:"status"`

	finishChan chan int
	C          <-chan int `json:"-"`
	params     []interface{}
	quitChan   chan int

	locker sync.RWMutex
	result interface{}
	err    error
}

type TaskList []*Task

func (s TaskList) Len() int {
	return len(s)
}

func (s TaskList) Less(i, j int) bool {
	return s[i].CreatedAt.Sub(s[j].CreatedAt) < 0
}

func (s TaskList) Swap(i, j int) {
	tmp := s[i]
	s[i] = s[j]
	s[j] = tmp
}

func (t *BaseTask) GetResult(duration time.Duration) (retVal []interface{}, err error) {
	if t.GetStatus() >= TaskStatusEndBegin {
		retVal, _ = t.result.([]interface{})
		return retVal, t.err
	}
	if duration == 0 {
		duration = time.Hour * 10000 // duration为0表示无限等待
	}
	timer := time.NewTimer(duration)
	select {
	case <-t.finishChan:
		timer.Stop()
		t.locker.RLock()
		defer t.locker.RUnlock()

		retVal, _ = t.result.([]interface{})
		return retVal, t.err
	case <-timer.C:
	}
	return nil, ErrTaskNotFinished
}

func (t *BaseTask) Cancel() {
	t.locker.Lock()
	defer t.locker.Unlock()
	if t.Status < TaskStatusEndBegin && t.Status != TaskStatusCanceling {
		t.Status = TaskStatusCanceling
		for i := 0; i < t.ParallelCount; i++ {
			t.quitChan <- 0
		}
	}
}

func (t *BaseTask) GetTotalItemCount() int {
	return t.TotalItemCount
}

func (t *BaseTask) GetFinishedItemCount() int {
	t.locker.RLock()
	defer t.locker.RUnlock()

	return t.FinishedItemCount
}

func (t *BaseTask) GetTotalJobCount() int {
	return t.TotalJobCount
}

func (t *BaseTask) GetFinishedJobCount() int {
	t.locker.RLock()
	defer t.locker.RUnlock()

	return t.FinishedJobCount
}

func (t *BaseTask) GetStatus() int {
	t.locker.RLock()
	defer t.locker.RUnlock()

	return t.Status
}

/////////
func (t *BaseTask) finishedOneJob(itemCount int, err error) {
	t.locker.Lock()
	defer t.locker.Unlock()

	t.UpdatedAt = time.Now()
	if err == nil {
		t.FinishedItemCount += itemCount
		t.FinishedJobCount++
	} else {
		t.FailedItemCount += itemCount
		t.FailedJobCount++
	}
}

func (t *BaseTask) setStatus(status int) {
	t.locker.Lock()
	defer t.locker.Unlock()

	t.Status = status
}