Revive the right block of the program

Moved the right part of the program from the old version. Slightly reworked the structure.

internal/application/convertor/queue.go

@@ -0,0 +1,148 @@
+package convertor
+
+import "errors"
+
+type Queue struct {
+	Setting *ConvertSetting
+	Status  StatusContract
+	Error   error
+}
+
+type StatusContract interface {
+	Name() string
+	Ordinal() int
+}
+
+const (
+	Waiting = iota
+	InProgress
+	Completed
+	Error
+)
+
+type StatusType uint
+
+var statusTypeStrings = []string{
+	"waiting",
+	"inProgress",
+	"completed",
+	"error",
+}
+
+func (status StatusType) Name() string {
+	return statusTypeStrings[status]
+}
+
+func (status StatusType) Ordinal() int {
+	return int(status)
+}
+
+type QueueListenerContract interface {
+	AddQueue(key int, queue *Queue)
+	ChangeQueue(key int, queue *Queue)
+	RemoveQueue(key int, status StatusContract)
+}
+
+type QueueListContract interface {
+	AddListener(queueListener QueueListenerContract)
+	GetItems() map[int]*Queue
+	Add(setting *ConvertSetting)
+	EventChangeQueue(key int, queue *Queue)
+	Remove(key int)
+	GetItem(key int) (*Queue, error)
+	Next() (key int, queue *Queue)
+}
+
+type queueList struct {
+	currentKey    int
+	items         map[int]*Queue
+	queue         map[int]int
+	queueListener map[int]QueueListenerContract
+}
+
+func NewQueueList() QueueListContract {
+	return &queueList{
+		currentKey:    0,
+		items:         map[int]*Queue{},
+		queueListener: map[int]QueueListenerContract{},
+	}
+}
+
+func (l *queueList) GetItems() map[int]*Queue {
+	return l.items
+}
+
+func (l *queueList) Add(setting *ConvertSetting) {
+	queue := Queue{
+		Setting: setting,
+		Status:  StatusType(Waiting),
+	}
+
+	l.currentKey += 1
+	l.items[l.currentKey] = &queue
+	l.queue[l.currentKey] = l.currentKey
+
+	l.eventAdd(l.currentKey, &queue)
+}
+
+func (l *queueList) EventChangeQueue(key int, queue *Queue) {
+	l.eventChange(key, queue)
+}
+
+func (l *queueList) Remove(key int) {
+	if _, ok := l.queue[key]; ok {
+		delete(l.queue, key)
+	}
+
+	if _, ok := l.items[key]; ok {
+		status := l.items[key].Status
+		l.eventRemove(key, status)
+		delete(l.items, key)
+	}
+}
+
+func (l *queueList) GetItem(key int) (*Queue, error) {
+	if item, ok := l.items[key]; ok {
+		return item, nil
+	}
+
+	return nil, errors.New("key not found")
+}
+
+func (l *queueList) AddListener(queueListener QueueListenerContract) {
+	l.queueListener[len(l.queueListener)] = queueListener
+}
+
+func (l *queueList) Next() (key int, queue *Queue) {
+	statusWaiting := StatusType(Waiting)
+	for key, queueId := range l.queue {
+		if queue, ok := l.items[queueId]; ok {
+			if queue.Status == statusWaiting {
+				return queueId, queue
+			}
+		}
+
+		if _, ok := l.queue[key]; ok {
+			delete(l.queue, key)
+		}
+	}
+	return -1, nil
+}
+
+func (l *queueList) eventAdd(key int, queue *Queue) {
+	for _, listener := range l.queueListener {
+		listener.AddQueue(key, queue)
+	}
+}
+
+func (l *queueList) eventChange(key int, queue *Queue) {
+	for _, listener := range l.queueListener {
+		listener.ChangeQueue(key, queue)
+	}
+}
+
+func (l *queueList) eventRemove(key int, status StatusContract) {
+	for _, listener := range l.queueListener {
+		listener.RemoveQueue(key, status)
+	}
+}