package fs

import "io"

type GetPathFunc[K comparable] func(key K) ([]string, error)
type MarshalValueFunc[V any] func(value V) (io.Reader, error)
type UnmarshalValueFunc[V any] func(r io.Reader) (V, error)

type Options[K comparable, V any] struct {
	GetPath        GetPathFunc[K]
	MarshalValue   MarshalValueFunc[V]
	UnmarshalValue UnmarshalValueFunc[V]
}

type OptionsFunc[K comparable, V any] func(opts *Options[K, V])

func DefaultOptions[K comparable, V any](funcs ...OptionsFunc[K, V]) *Options[K, V] {
	opts := &Options[K, V]{
		GetPath:        DefaultGetPath[K],
		MarshalValue:   DefaultMarshalValue[V],
		UnmarshalValue: DefaultUnmarshalValue[V],
	}
	for _, fn := range funcs {
		fn(opts)
	}
	return opts
}

func WithGetPath[K comparable, V any](getKeyHash GetPathFunc[K]) OptionsFunc[K, V] {
	return func(opts *Options[K, V]) {
		opts.GetPath = getKeyHash
	}
}

func WithMarshalValue[K comparable, V any](marshalValue MarshalValueFunc[V]) OptionsFunc[K, V] {
	return func(opts *Options[K, V]) {
		opts.MarshalValue = marshalValue
	}
}

func WithUnmarshalValue[K comparable, V any](unmarshalValue UnmarshalValueFunc[V]) OptionsFunc[K, V] {
	return func(opts *Options[K, V]) {
		opts.UnmarshalValue = unmarshalValue
	}
}