/*
   Copyright The containerd Authors.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package image

import (
	"context"
	"errors"
	"fmt"
	"io"
	"net/http"
	"os"
	"path/filepath"

	"github.com/opencontainers/go-digest"
	ocispec "github.com/opencontainers/image-spec/specs-go/v1"

	containerd "github.com/containerd/containerd/v2/client"
	"github.com/containerd/containerd/v2/core/content"
	"github.com/containerd/containerd/v2/core/images"
	"github.com/containerd/containerd/v2/core/images/converter"
	"github.com/containerd/containerd/v2/core/remotes"
	"github.com/containerd/containerd/v2/core/remotes/docker"
	dockerconfig "github.com/containerd/containerd/v2/core/remotes/docker/config"
	"github.com/containerd/containerd/v2/pkg/reference"
	"github.com/containerd/log"
	"github.com/containerd/platforms"
	"github.com/containerd/stargz-snapshotter/estargz"
	"github.com/containerd/stargz-snapshotter/estargz/zstdchunked"
	estargzconvert "github.com/containerd/stargz-snapshotter/nativeconverter/estargz"

	"github.com/containerd/nerdctl/v2/pkg/api/types"
	"github.com/containerd/nerdctl/v2/pkg/containerdutil"
	"github.com/containerd/nerdctl/v2/pkg/errutil"
	"github.com/containerd/nerdctl/v2/pkg/imgutil"
	nerdconverter "github.com/containerd/nerdctl/v2/pkg/imgutil/converter"
	"github.com/containerd/nerdctl/v2/pkg/imgutil/dockerconfigresolver"
	"github.com/containerd/nerdctl/v2/pkg/imgutil/push"
	"github.com/containerd/nerdctl/v2/pkg/internal/filesystem"
	"github.com/containerd/nerdctl/v2/pkg/ipfs"
	"github.com/containerd/nerdctl/v2/pkg/platformutil"
	"github.com/containerd/nerdctl/v2/pkg/referenceutil"
	"github.com/containerd/nerdctl/v2/pkg/signutil"
	"github.com/containerd/nerdctl/v2/pkg/snapshotterutil"
)

// Push pushes an image specified by `rawRef`.
func Push(ctx context.Context, client *containerd.Client, rawRef string, options types.ImagePushOptions) error {
	parsedReference, err := referenceutil.Parse(rawRef)
	if err != nil {
		return err
	}

	if parsedReference.Protocol != "" {
		if parsedReference.Protocol != referenceutil.IPFSProtocol {
			return fmt.Errorf("ipfs scheme is only supported but got %q", parsedReference.Protocol)
		}
		log.G(ctx).Infof("pushing image %q to IPFS", parsedReference)

		// Ensure all the layers are here: https://github.com/containerd/nerdctl/issues/3489
		// XXX what if the image is a CID, or only otherwise available on ipfs?
		platMC, err := platformutil.NewMatchComparer(options.AllPlatforms, options.Platforms)
		if err != nil {
			return err
		}

		err = EnsureAllContent(ctx, client, parsedReference.String(), platMC, options.GOptions)
		if err != nil {
			return err
		}

		var ipfsPath string
		if options.IpfsAddress != "" {
			dir, err := os.MkdirTemp("", "apidirtmp")
			if err != nil {
				return err
			}
			defer os.RemoveAll(dir)
			if err := filesystem.WriteFile(filepath.Join(dir, "api"), []byte(options.IpfsAddress), 0600); err != nil {
				return err
			}
			ipfsPath = dir
		}

		var layerConvert converter.ConvertFunc
		if options.Estargz {
			layerConvert = eStargzConvertFunc()
		}
		c, err := ipfs.Push(ctx, client, parsedReference.String(), layerConvert, options.AllPlatforms, options.Platforms, options.IpfsEnsureImage, ipfsPath)
		if err != nil {
			log.G(ctx).WithError(err).Warnf("ipfs push failed")
			return err
		}
		fmt.Fprintln(options.Stdout, c)
		return nil
	}

	parsedReference, err = referenceutil.Parse(rawRef)
	if err != nil {
		return err
	}
	ref := parsedReference.String()

	platMC, err := platformutil.NewMatchComparer(options.AllPlatforms, options.Platforms)
	if err != nil {
		return err
	}
	pushRef := ref
	if !options.AllPlatforms {
		pushRef = ref + "-tmp-reduced-platform"
		// Push fails with "400 Bad Request" when the manifest is multi-platform but we do not locally have multi-platform blobs.
		// So we create a tmp reduced-platform image to avoid the error.
		// Ensure all the layers are here: https://github.com/containerd/nerdctl/issues/3425
		err = EnsureAllContent(ctx, client, ref, platMC, options.GOptions)
		if err != nil {
			return err
		}
		platImg, err := nerdconverter.Convert(ctx, client, pushRef, ref, converter.WithPlatform(platMC))
		if err != nil {
			if len(options.Platforms) == 0 {
				return fmt.Errorf("failed to create a tmp single-platform image %q: %w", pushRef, err)
			}
			return fmt.Errorf("failed to create a tmp reduced-platform image %q (platform=%v): %w", pushRef, options.Platforms, err)
		}
		defer client.ImageService().Delete(ctx, platImg.Name, images.SynchronousDelete())
		log.G(ctx).Infof("pushing as a reduced-platform image (%s, %s)", platImg.Target.MediaType, platImg.Target.Digest)
	}

	if options.Estargz {
		pushRef = ref + "-tmp-esgz"
		esgzImg, err := nerdconverter.Convert(ctx, client, pushRef, ref, converter.WithPlatform(platMC), converter.WithLayerConvertFunc(eStargzConvertFunc()))
		if err != nil {
			return fmt.Errorf("failed to convert to eStargz: %v", err)
		}
		defer client.ImageService().Delete(ctx, esgzImg.Name, images.SynchronousDelete())
		log.G(ctx).Infof("pushing as an eStargz image (%s, %s)", esgzImg.Target.MediaType, esgzImg.Target.Digest)
	}
	if !options.AllowNondistributableArtifacts {
		if err := pushImageWithLocal(ctx, client, parsedReference, pushRef, ref, options, platMC); err != nil {
			return err
		}
	} else {
		// Transfer service is available in containerd 1.7, but full support is only in 2.0+
		// For containerd 1.7, use the legacy resolver-based push method for better compatibility
		useTransferAPI := containerdutil.SupportsFullTransferService(ctx, client)
		if !useTransferAPI {
			log.G(ctx).Debug("Detected containerd < 2.0, using legacy push method")
		}

		if useTransferAPI {
			if err := imgutil.PushImageWithTransfer(ctx, client, parsedReference, pushRef, ref, options); err != nil {
				return err
			}
		} else {
			if err := pushImageWithLocal(ctx, client, parsedReference, pushRef, ref, options, platMC); err != nil {
				return err
			}
		}
	}

	img, err := client.ImageService().Get(ctx, pushRef)
	if err != nil {
		return err
	}
	refSpec, err := reference.Parse(pushRef)
	if err != nil {
		return err
	}
	signRef := fmt.Sprintf("%s@%s", refSpec.String(), img.Target.Digest.String())
	if err = signutil.Sign(signRef,
		options.GOptions.Experimental,
		options.SignOptions); err != nil {
		return err
	}
	if options.GOptions.Snapshotter == "soci" {
		if err = snapshotterutil.CreateSociIndexV1(ref, options.GOptions, options.AllPlatforms, options.Platforms, options.SociOptions); err != nil {
			return err
		}
		if err = snapshotterutil.PushSoci(ref, options.GOptions, options.AllPlatforms, options.Platforms); err != nil {
			return err
		}
	}
	if options.Quiet {
		fmt.Fprintln(options.Stdout, ref)
	}
	return nil
}

func eStargzConvertFunc() converter.ConvertFunc {
	convertToESGZ := estargzconvert.LayerConvertFunc()
	return func(ctx context.Context, cs content.Store, desc ocispec.Descriptor) (*ocispec.Descriptor, error) {
		if isReusableESGZ(ctx, cs, desc) {
			log.L.Infof("reusing estargz %s without conversion", desc.Digest)
			return nil, nil
		}
		newDesc, err := convertToESGZ(ctx, cs, desc)
		if err != nil {
			return nil, err
		}
		log.L.Infof("converted %q to %s", desc.MediaType, newDesc.Digest)
		return newDesc, err
	}

}

func isReusableESGZ(ctx context.Context, cs content.Store, desc ocispec.Descriptor) bool {
	dgstStr, ok := desc.Annotations[estargz.TOCJSONDigestAnnotation]
	if !ok {
		return false
	}
	tocdgst, err := digest.Parse(dgstStr)
	if err != nil {
		return false
	}
	ra, err := cs.ReaderAt(ctx, desc)
	if err != nil {
		return false
	}
	defer ra.Close()
	r, err := estargz.Open(io.NewSectionReader(ra, 0, desc.Size), estargz.WithDecompressors(new(zstdchunked.Decompressor)))
	if err != nil {
		return false
	}
	if _, err := r.VerifyTOC(tocdgst); err != nil {
		return false
	}
	return true
}

func pushImageWithLocal(ctx context.Context, client *containerd.Client, parsedReference *referenceutil.ImageReference, pushRef, rawRef string, options types.ImagePushOptions, platMC platforms.MatchComparer) error {
	ref := parsedReference.String()
	refDomain := parsedReference.Domain

	// In order to push images where most layers are the same but the
	// repository name is different, it is necessary to refresh the
	// PushTracker. Otherwise, the MANIFEST_BLOB_UNKNOWN error will occur due
	// to the registry not creating the corresponding layer link file,
	// resulting in the failure of the entire image push.
	pushTracker := docker.NewInMemoryTracker()

	pushFunc := func(r remotes.Resolver) error {
		return push.Push(ctx, client, r, pushTracker, options.Stdout, pushRef, ref, platMC, options.AllowNondistributableArtifacts, options.Quiet)
	}

	var dOpts []dockerconfigresolver.Opt
	if options.GOptions.InsecureRegistry {
		log.G(ctx).Warnf("skipping verifying HTTPS certs for %q", refDomain)
		dOpts = append(dOpts, dockerconfigresolver.WithSkipVerifyCerts(true))
	}
	dOpts = append(dOpts, dockerconfigresolver.WithHostsDirs(options.GOptions.HostsDir))

	ho, err := dockerconfigresolver.NewHostOptions(ctx, refDomain, dOpts...)
	if err != nil {
		return err
	}

	resolverOpts := docker.ResolverOptions{
		Tracker: pushTracker,
		Hosts:   dockerconfig.ConfigureHosts(ctx, *ho),
	}

	resolver := docker.NewResolver(resolverOpts)
	if err = pushFunc(resolver); err != nil {
		// In some circumstance (e.g. people just use 80 port to support pure http), the error will contain message like "dial tcp <port>: connection refused"
		if !errors.Is(err, http.ErrSchemeMismatch) && !errutil.IsErrConnectionRefused(err) {
			return err
		}
		if options.GOptions.InsecureRegistry {
			log.G(ctx).WithError(err).Warnf("server %q does not seem to support HTTPS, falling back to plain HTTP", refDomain)
			dOpts = append(dOpts, dockerconfigresolver.WithPlainHTTP(true))
			resolver, err = dockerconfigresolver.New(ctx, refDomain, dOpts...)
			if err != nil {
				return err
			}
			return pushFunc(resolver)
		}
		log.G(ctx).WithError(err).Errorf("server %q does not seem to support HTTPS", refDomain)
		log.G(ctx).Info("Hint: you may want to try --insecure-registry to allow plain HTTP (if you are in a trusted network)")
		return err
	}
	return nil
}