package render

import (
	"bytes"
	"context"
	"fmt"
	"io"

	"edge-infra.dev/pkg/f8n/warehouse/cluster"
	"edge-infra.dev/pkg/f8n/warehouse/lift"
	"edge-infra.dev/pkg/f8n/warehouse/lift/cmd/internal"
	"edge-infra.dev/pkg/f8n/warehouse/lift/unpack"
	"edge-infra.dev/pkg/f8n/warehouse/oci/layer"
	"edge-infra.dev/pkg/f8n/warehouse/pallet"
	"edge-infra.dev/pkg/lib/cli/sink"
)

var buffer *bytes.Buffer

func New(cfg lift.Config) *sink.Command {
	var (
		packer   = internal.NewPacker(cfg)
		unpacker = internal.NewUnpacker(cfg.Parameters)
	)
	cmd := &sink.Command{
		Use:        "render [flags] <artifact>",
		Short:      "unpack and render Pallets",
		Commands:   []*sink.Command{newRenderShipmentCmd(cfg)},
		Extensions: []sink.Extension{packer, unpacker},
		Exec: func(_ context.Context, r sink.Run) error {
			switch len(r.Args()) {
			case 0:
				return fmt.Errorf("a pallet is required")
			case 1:
			default:
				return fmt.Errorf("only one pallet can be rendered at a time")
			}

			artifact, err := internal.ResolveArtifact(packer, r.Args()[0])
			if err != nil {
				return err
			}

			unpacker.Info(r)
			err = unpack.Walk(artifact, pkgRender, unpacker.Options()...)
			if err == cluster.ErrNoProviders {
				return fmt.Errorf("%w, pass via --cluster-provider or CLUSTER_PROVIDER environment variable", err)
			}

			if err != nil {
				return err
			}
			fmt.Fprintln(r.Out(), buffer.String())
			return nil
		},
	}
	return cmd
}

// pkgRender is called for each package during unpack.Walk
func pkgRender(_ pallet.Pallet, layers []layer.Layer) error {
	if buffer == nil {
		buffer = bytes.NewBufferString("")
	}
	for _, l := range layers {
		r, err := l.Uncompressed()
		if err != nil {
			return err
		}
		yaml, err := io.ReadAll(r)
		if err != nil {
			return err
		}
		buffer.WriteString(string(yaml))
		buffer.WriteString("---\n")
	}
	return nil
}