package syncutils

import "sync"

type RangeFunc[T any] func(index int, e T) bool

type SyncSlice[T any] struct {
	writeLocker sync.Locker
	readLocker  sync.Locker
	s           []T
}

func NewSyncSlice[T any](s []T, isRWMutex bool) *SyncSlice[T] {
	var writeLocker sync.Locker
	var readLocker sync.Locker

	if !isRWMutex {
		mutex := &sync.Mutex{}
		writeLocker = mutex
		readLocker = mutex
	} else {
		mutex := &sync.RWMutex{}
		writeLocker = mutex
		readLocker = mutex.RLocker()
	}

	return &SyncSlice[T]{
		writeLocker: writeLocker,
		readLocker:  readLocker,
		s:           s,
	}
}

func (syncSlice *SyncSlice[T]) Lock() {
	syncSlice.writeLocker.Lock()
}

func (syncSlice *SyncSlice[T]) Unlock() {
	syncSlice.writeLocker.Unlock()
}

func (syncSlice *SyncSlice[T]) RLock() {
	syncSlice.readLocker.Lock()
}

func (syncSlice *SyncSlice[T]) RUnlock() {
	syncSlice.readLocker.Unlock()
}

func (syncSlice *SyncSlice[T]) AppendNoLock(elements ...T) {
	if elements == nil || len(elements) == 0 {
		return
	}

	syncSlice.appendNoLock(elements...)
}

func (syncSlice *SyncSlice[T]) DeleteAtNoLock(index int) T {
	if index < 0 {
		var zero T
		return zero
	}

	return syncSlice.deleteAtNoLock(index)
}

func (syncSlice *SyncSlice[T]) RangeNoLock(rangeFunc RangeFunc[T]) {
	if rangeFunc == nil {
		return
	}

	syncSlice.rangeNoLock(rangeFunc)
}

func (syncSlice *SyncSlice[T]) LenNoLock() int {
	return syncSlice.lenNoLock()
}

func (syncSlice *SyncSlice[T]) CapNoLock() int {
	return syncSlice.capNoLock()
}

func (syncSlice *SyncSlice[T]) Append(elements ...T) {
	if elements == nil || len(elements) == 0 {
		return
	}

	syncSlice.writeLocker.Lock()
	defer syncSlice.writeLocker.Unlock()

	syncSlice.appendNoLock(elements...)
}

func (syncSlice *SyncSlice[T]) DeleteAt(index int) T {
	if index < 0 {
		var zero T
		return zero
	}

	syncSlice.writeLocker.Lock()
	defer syncSlice.writeLocker.Unlock()

	return syncSlice.deleteAtNoLock(index)
}

func (syncSlice *SyncSlice[T]) Range(rangeFunc RangeFunc[T]) {
	if rangeFunc == nil {
		return
	}

	syncSlice.readLocker.Lock()
	defer syncSlice.readLocker.Unlock()

	syncSlice.rangeNoLock(rangeFunc)
}

func (syncSlice *SyncSlice[T]) Len() int {
	syncSlice.readLocker.Lock()
	defer syncSlice.readLocker.Unlock()

	return syncSlice.lenNoLock()
}

func (syncSlice *SyncSlice[T]) Cap() int {
	syncSlice.readLocker.Lock()
	defer syncSlice.readLocker.Unlock()

	return syncSlice.capNoLock()
}

func (syncSlice *SyncSlice[T]) appendNoLock(elements ...T) {
	syncSlice.s = append(syncSlice.s, elements...)
}

func (syncSlice *SyncSlice[T]) deleteAtNoLock(index int) T {
	if len(syncSlice.s)-1 < index {
		var zero T
		return zero
	}

	v := syncSlice.s[index]
	syncSlice.s = append(syncSlice.s[:index], syncSlice.s[index+1:]...)
	return v
}

func (syncSlice *SyncSlice[T]) rangeNoLock(rangeFunc RangeFunc[T]) {
	for i, e := range syncSlice.s {
		stop := rangeFunc(i, e)
		if stop {
			return
		}
	}
}

func (syncSlice *SyncSlice[T]) lenNoLock() int {
	return len(syncSlice.s)
}

func (syncSlice *SyncSlice[T]) capNoLock() int {
	return cap(syncSlice.s)
}