package release

import (
	"fmt"

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

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

func ImageIndex(a oci.Artifact) (EdgeRelease, error) {
	idx, isIdx := a.(v1.ImageIndex)
	if !isIdx {
		return EdgeRelease{}, fmt.Errorf("artifact could not be coerced into Image Index")
	}

	idxMan, err := idx.IndexManifest()
	if err != nil {
		return EdgeRelease{}, err
	}

	meta, err := metadataFromAnnotations(idxMan.Annotations)
	if err != nil {
		return EdgeRelease{}, err
	}

	pallets, err := palletsFromManifests(idx, idxMan.Manifests)
	if err != nil {
		return EdgeRelease{}, err
	}
	if len(pallets) == 0 {
		dig, _ := a.Digest()
		return EdgeRelease{}, fmt.Errorf("no pallets found for artifact %s", dig.Hex)
	}
	return New(meta, pallets), nil
}

func palletsFromManifests(idx v1.ImageIndex, descrs []v1.Descriptor) ([]pallet.Pallet, error) {
	pallets := []pallet.Pallet{}

	for _, descr := range descrs {
		switch descr.MediaType {
		case types.OCIImageIndex:
			palletIdx, err := idx.ImageIndex(descr.Digest)
			if err != nil {
				return nil, err
			}

			p, err := pallet.New(palletIdx)
			if err != nil {
				return nil, err
			}

			pallets = append(pallets, p)
		case types.OCIManifestSchema1:
			palletImg, err := idx.Image(descr.Digest)
			if err != nil {
				return nil, err
			}

			p, err := pallet.New(palletImg)
			if err != nil {
				return nil, err
			}

			pallets = append(pallets, p)
		default:
			return nil, fmt.Errorf("unknown MediaType from remote Artifact")
		}
	}
	return pallets, nil
}