// Package name implements functionality for parsing package names from OCI
// artifacts and working with them.
package name

import (
	"fmt"

	"github.com/google/go-containerregistry/pkg/name"
	v1 "github.com/google/go-containerregistry/pkg/v1"

	wh "edge-infra.dev/pkg/f8n/warehouse"
	"edge-infra.dev/pkg/f8n/warehouse/lift"
	"edge-infra.dev/pkg/f8n/warehouse/oci"
)

// Type aliases from ggcr
type Reference = name.Reference

// TODO(aw185176): FromIndex, tests

// FromImage reads the Warehouse package name from the input image
func FromImage(img v1.Image) (string, error) {
	return FromArtifact(img)
}

// FromArtifact reads the Warehouse package name from the input Artifact
func FromArtifact(a oci.Artifact) (string, error) {
	annos, err := oci.Annotations(a)
	switch {
	case err != nil:
		return "", err
	case annos[wh.AnnotationName] == "":
		return "", fmt.Errorf("%w", oci.ErrInvalidArtifact)
	default:
		return annos[wh.AnnotationName], nil
	}
}

// Tag creates a tag with weak validation, defaulting to the local
// registry alias for Warehouse packages if not set. Default options can be
// overridden by passing name.Options
func Tag(t string, opts ...name.Option) (name.Tag, error) {
	return name.NewTag(t,
		append([]name.Option{
			name.WeakValidation,
			name.WithDefaultRegistry(lift.LocalRegistryAlias),
			name.WithDefaultTag("latest"),
		}, opts...,
		)...,
	)
}

// Digest creates a digest with weak validation, defaulting to the local
// registry alias for Warehouse packages if not set. Default options can be
// overridden by passing name.Options
func Digest(d string, opts ...name.Option) (name.Digest, error) {
	return name.NewDigest(d,
		append([]name.Option{
			name.WeakValidation,
			name.WithDefaultRegistry(lift.LocalRegistryAlias),
		}, opts...,
		)...,
	)
}

// TruncatedDigest truncates the result of digest.String() to omit "sha256" and
// capture 13 characters of the actual digest value.
func TruncatedDigest(d string) string {
	return d[7:20]
}