Lithium/pipelines/step.go

package pipelines

import (
	"encoding/json"
	"errors"
)

type StepType int

const (
	TypeResizeImageStep StepType = iota
	TypeRotateImageStep
	TypeFlipImageStep
	TypeGrayscaleImageStep
	TypeFitImageStep
)

type Step struct {
	Name    string          `json:"name" faker:"name"`
	Type    StepType        `json:"type" faker:"-"`
	Options json.RawMessage `json:"options"`
}

func (s Step) GetExecutable() (IExecutableStep, error) {
	switch s.GetType() {

	case TypeResizeImageStep:
		step := ResizeImageStep{}
		if err := json.Unmarshal(s.Options, &step.Options); err != nil {
			return nil, err
		}
		return step, nil

	case TypeRotateImageStep:
		step := RotateImageStep{}
		if err := json.Unmarshal(s.Options, &step.Options); err != nil {
			return nil, err
		}
		return step, nil

	case TypeFlipImageStep:
		step := FlipImageStep{}
		if err := json.Unmarshal(s.Options, &step.Options); err != nil {
			return nil, err
		}
		return step, nil

	case TypeFitImageStep:
		step := FitImageStep{}
		if err := json.Unmarshal(s.Options, &step.Options); err != nil {
			return nil, err
		}
		return step, nil

	case TypeGrayscaleImageStep:
		return GrayscaleImageStep{}, nil
	}

	return nil, errors.New("invalid type")
}

func (s Step) GetType() StepType {
	return s.Type
}

func (s Step) GetName() string {
	return s.Name
}