package asset

import (
	"errors"
	"io"
	"path/filepath"
)

var (
	ErrCannotResize = errors.New("cannot resize")
)

// LoadOpts are optional parameters to Loader's Load method. Some may only apply
// to specific Loader implementations.
type LoadOpts struct {

	// ImageWidth is used by the ImageLoader to resize images on the fly.
	ImageWidth int
}

// Loader is used to load an asset and write its body into the given io.Writer.
//
// Errors:
//	- ErrNotFound
//	- ErrCannotResize (only if ImageLoader is used)
type Loader interface {
	Load(path string, into io.Writer, opts LoadOpts) error
}

type storeLoader struct {
	store Store
}

// NewStoreLoader returns a Loader which loads assets directly from the given
// Store, with no transformation.
func NewStoreLoader(store Store) Loader {
	return &storeLoader{store}
}

func (l *storeLoader) Load(path string, into io.Writer, opts LoadOpts) error {
	id := filepath.Base(path)
	return l.store.Get(id, into)
}