/*
   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 containerd

import (
	"context"

	"github.com/containerd/containerd/containers"
	"github.com/containerd/containerd/defaults"
	"github.com/containerd/containerd/errdefs"
	"github.com/containerd/containerd/namespaces"
	"github.com/containerd/containerd/oci"
	"github.com/containerd/containerd/platforms"
	"github.com/containerd/containerd/snapshots"
	"github.com/containerd/typeurl"
	"github.com/gogo/protobuf/types"
	"github.com/opencontainers/image-spec/identity"
	"github.com/pkg/errors"
)

// DeleteOpts allows the caller to set options for the deletion of a container
type DeleteOpts func(ctx context.Context, client *Client, c containers.Container) error

// NewContainerOpts allows the caller to set additional options when creating a container
type NewContainerOpts func(ctx context.Context, client *Client, c *containers.Container) error

// UpdateContainerOpts allows the caller to set additional options when updating a container
type UpdateContainerOpts func(ctx context.Context, client *Client, c *containers.Container) error

// WithRuntime allows a user to specify the runtime name and additional options that should
// be used to create tasks for the container
func WithRuntime(name string, options interface{}) NewContainerOpts {
	return func(ctx context.Context, client *Client, c *containers.Container) error {
		var (
			any *types.Any
			err error
		)
		if options != nil {
			any, err = typeurl.MarshalAny(options)
			if err != nil {
				return err
			}
		}
		c.Runtime = containers.RuntimeInfo{
			Name:    name,
			Options: any,
		}
		return nil
	}
}

// WithImage sets the provided image as the base for the container
func WithImage(i Image) NewContainerOpts {
	return func(ctx context.Context, client *Client, c *containers.Container) error {
		c.Image = i.Name()
		return nil
	}
}

// WithContainerLabels adds the provided labels to the container
func WithContainerLabels(labels map[string]string) NewContainerOpts {
	return func(_ context.Context, _ *Client, c *containers.Container) error {
		c.Labels = labels
		return nil
	}
}

// WithImageStopSignal sets a well-known containerd label (StopSignalLabel)
// on the container for storing the stop signal specified in the OCI image
// config
func WithImageStopSignal(image Image, defaultSignal string) NewContainerOpts {
	return func(ctx context.Context, _ *Client, c *containers.Container) error {
		if c.Labels == nil {
			c.Labels = make(map[string]string)
		}
		stopSignal, err := GetOCIStopSignal(ctx, image, defaultSignal)
		if err != nil {
			return err
		}
		c.Labels[StopSignalLabel] = stopSignal
		return nil
	}
}

// WithSnapshotter sets the provided snapshotter for use by the container
//
// This option must appear before other snapshotter options to have an effect.
func WithSnapshotter(name string) NewContainerOpts {
	return func(ctx context.Context, client *Client, c *containers.Container) error {
		c.Snapshotter = name
		return nil
	}
}

// WithSnapshot uses an existing root filesystem for the container
func WithSnapshot(id string) NewContainerOpts {
	return func(ctx context.Context, client *Client, c *containers.Container) error {
		setSnapshotterIfEmpty(ctx, client, c)
		// check that the snapshot exists, if not, fail on creation
		if _, err := client.SnapshotService(c.Snapshotter).Mounts(ctx, id); err != nil {
			return err
		}
		c.SnapshotKey = id
		return nil
	}
}

// WithNewSnapshot allocates a new snapshot to be used by the container as the
// root filesystem in read-write mode
func WithNewSnapshot(id string, i Image, opts ...snapshots.Opt) NewContainerOpts {
	return func(ctx context.Context, client *Client, c *containers.Container) error {
		diffIDs, err := i.(*image).i.RootFS(ctx, client.ContentStore(), platforms.Default())
		if err != nil {
			return err
		}
		setSnapshotterIfEmpty(ctx, client, c)
		parent := identity.ChainID(diffIDs).String()
		if _, err := client.SnapshotService(c.Snapshotter).Prepare(ctx, id, parent, opts...); err != nil {
			return err
		}
		c.SnapshotKey = id
		c.Image = i.Name()
		return nil
	}
}

// WithSnapshotCleanup deletes the rootfs snapshot allocated for the container
func WithSnapshotCleanup(ctx context.Context, client *Client, c containers.Container) error {
	if c.SnapshotKey != "" {
		if c.Snapshotter == "" {
			return errors.Wrapf(errdefs.ErrInvalidArgument, "container.Snapshotter must be set to cleanup rootfs snapshot")
		}
		return client.SnapshotService(c.Snapshotter).Remove(ctx, c.SnapshotKey)
	}
	return nil
}

// WithNewSnapshotView allocates a new snapshot to be used by the container as the
// root filesystem in read-only mode
func WithNewSnapshotView(id string, i Image, opts ...snapshots.Opt) NewContainerOpts {
	return func(ctx context.Context, client *Client, c *containers.Container) error {
		diffIDs, err := i.(*image).i.RootFS(ctx, client.ContentStore(), platforms.Default())
		if err != nil {
			return err
		}
		setSnapshotterIfEmpty(ctx, client, c)
		parent := identity.ChainID(diffIDs).String()
		if _, err := client.SnapshotService(c.Snapshotter).View(ctx, id, parent, opts...); err != nil {
			return err
		}
		c.SnapshotKey = id
		c.Image = i.Name()
		return nil
	}
}

func setSnapshotterIfEmpty(ctx context.Context, client *Client, c *containers.Container) {
	if c.Snapshotter == "" {
		defaultSnapshotter := DefaultSnapshotter
		namespaceService := client.NamespaceService()
		if ns, err := namespaces.NamespaceRequired(ctx); err == nil {
			if labels, err := namespaceService.Labels(ctx, ns); err == nil {
				if snapshotLabel, ok := labels[defaults.DefaultSnapshotterNSLabel]; ok {
					defaultSnapshotter = snapshotLabel
				}
			}
		}
		c.Snapshotter = defaultSnapshotter
	}
}

// WithContainerExtension appends extension data to the container object.
// Use this to decorate the container object with additional data for the client
// integration.
//
// Make sure to register the type of `extension` in the typeurl package via
// `typeurl.Register` or container creation may fail.
func WithContainerExtension(name string, extension interface{}) NewContainerOpts {
	return func(ctx context.Context, client *Client, c *containers.Container) error {
		if name == "" {
			return errors.Wrapf(errdefs.ErrInvalidArgument, "extension key must not be zero-length")
		}

		any, err := typeurl.MarshalAny(extension)
		if err != nil {
			if errors.Cause(err) == typeurl.ErrNotFound {
				return errors.Wrapf(err, "extension %q is not registered with the typeurl package, see `typeurl.Register`", name)
			}
			return errors.Wrap(err, "error marshalling extension")
		}

		if c.Extensions == nil {
			c.Extensions = make(map[string]types.Any)
		}
		c.Extensions[name] = *any
		return nil
	}
}

// WithNewSpec generates a new spec for a new container
func WithNewSpec(opts ...oci.SpecOpts) NewContainerOpts {
	return func(ctx context.Context, client *Client, c *containers.Container) error {
		s, err := oci.GenerateSpec(ctx, client, c, opts...)
		if err != nil {
			return err
		}
		c.Spec, err = typeurl.MarshalAny(s)
		return err
	}
}

// WithSpec sets the provided spec on the container
func WithSpec(s *oci.Spec, opts ...oci.SpecOpts) NewContainerOpts {
	return func(ctx context.Context, client *Client, c *containers.Container) error {
		if err := oci.ApplyOpts(ctx, client, c, s, opts...); err != nil {
			return err
		}

		var err error
		c.Spec, err = typeurl.MarshalAny(s)
		return err
	}
}