// Package loz contains functionality supplemental to samber/lo.
// Ideally these functions would be merged into that package.
package loz

// All returns a new slice containing elems.
func All[T any](elems ...T) []T {
	a := make([]T, len(elems))
	copy(a, elems)
	return a
}

// Apply returns a new slice whose elements are the result of applying fn to
// each element of collection.
func Apply[T any](collection []T, fn func(item T) T) []T {
	a := make([]T, len(collection))
	for i := range collection {
		a[i] = fn(collection[i])
	}
	return a
}

// ToSliceType returns a new slice of type T, having performed
// type conversion on each element of in.
func ToSliceType[S, T any](in ...S) (out []T, ok bool) {
	out = make([]T, len(in))
	var a any
	for i := range in {
		a = in[i]
		out[i], ok = a.(T)
		if !ok {
			return nil, false
		}
	}

	return out, true
}

// HarmonizeSliceLengths returns slices for a and b such that the
// returned slices have the same lengths and contents as a and b,
// with any additional elements filled with defaultVal. If a and b
// are already the same length, they are returned as-is. At most
// one new slice is allocated.
func HarmonizeSliceLengths[T any](a, b []T, defaultVal T) ([]T, []T) {
	switch {
	case len(a) == len(b):
		return a, b
	case len(a) < len(b):
		a1 := make([]T, len(b))
		for i := range a1 {
			if i < len(a) {
				a1[i] = a[i]
			} else {
				a1[i] = defaultVal
			}
		}
		return a1, b
	default:
		b1 := make([]T, len(a))
		for i := range b1 {
			if i < len(b) {
				b1[i] = b[i]
			} else {
				b1[i] = defaultVal
			}
		}
		return a, b1
	}
}