package util

import “sync”

// EventType is the type for fzf events type EventType int

// Events is a type that associates EventType to any data type Events mapinterface{}

// EventBox is used for coordinating events type EventBox struct {

events Events
cond   *sync.Cond
ignore map[EventType]bool

}

// NewEventBox returns a new EventBox func NewEventBox() *EventBox {

return &EventBox{
        events: make(Events),
        cond:   sync.NewCond(&sync.Mutex{}),
        ignore: make(map[EventType]bool)}

}

// Wait blocks the goroutine until signaled func (b *EventBox) Wait(callback func(*Events)) {

b.cond.L.Lock()

if len(b.events) == 0 {
        b.cond.Wait()
}

callback(&b.events)
b.cond.L.Unlock()

}

// Set turns on the event type on the box func (b *EventBox) Set(event EventType, value interface{}) {

b.cond.L.Lock()
b.events[event] = value
if _, found := b.ignore[event]; !found {
        b.cond.Broadcast()
}
b.cond.L.Unlock()

}

// Clear clears the events // Unsynchronized; should be called within Wait routine func (events *Events) Clear() {

for event := range *events {
        delete(*events, event)
}

}

// Peek peeks at the event box if the given event is set func (b *EventBox) Peek(event EventType) bool {

b.cond.L.Lock()
_, ok := b.events[event]
b.cond.L.Unlock()
return ok

}

// Watch deletes the events from the ignore list func (b *EventBox) Watch(events …EventType) {

b.cond.L.Lock()
for _, event := range events {
        delete(b.ignore, event)
}
b.cond.L.Unlock()

}

// Unwatch adds the events to the ignore list func (b *EventBox) Unwatch(events …EventType) {

b.cond.L.Lock()
for _, event := range events {
        b.ignore[event] = true
}
b.cond.L.Unlock()

}

// WaitFor blocks the execution until the event is received func (b *EventBox) WaitFor(event EventType) {

looping := true
for looping {
        b.Wait(func(events *Events) {
                for evt := range *events {
                        switch evt {
                        case event:
                                looping = false
                                return
                        }
                }
        })
}

}