/*
Copyright IBM Corp. 2016 All Rights Reserved.

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 container

import (
	"bytes"
	"fmt"

	"golang.org/x/net/context"

	"github.com/fsouza/go-dockerclient"
	"github.com/hyperledger/fabric/common/flogging"
	"github.com/hyperledger/fabric/core/chaincode/platforms"
	cutil "github.com/hyperledger/fabric/core/container/util"
	pb "github.com/hyperledger/fabric/protos/peer"
)

// VM implemenation of VM management functionality.
type VM struct {
	Client *docker.Client
}

// NewVM creates a new VM instance.
func NewVM() (*VM, error) {
	client, err := cutil.NewDockerClient()
	if err != nil {
		return nil, err
	}
	VM := &VM{Client: client}
	return VM, nil
}

var vmLogger = flogging.MustGetLogger("container")

// ListImages list the images available
func (vm *VM) ListImages(context context.Context) error {
	imgs, err := vm.Client.ListImages(docker.ListImagesOptions{All: false})
	if err != nil {
		return err
	}
	for _, img := range imgs {
		fmt.Println("ID: ", img.ID)
		fmt.Println("RepoTags: ", img.RepoTags)
		fmt.Println("Created: ", img.Created)
		fmt.Println("Size: ", img.Size)
		fmt.Println("VirtualSize: ", img.VirtualSize)
		fmt.Println("ParentId: ", img.ParentID)
	}

	return nil
}

// BuildChaincodeContainer builds the container for the supplied chaincode specification
func (vm *VM) BuildChaincodeContainer(spec *pb.ChaincodeSpec) error {
	codePackage, err := GetChaincodePackageBytes(spec)
	if err != nil {
		return fmt.Errorf("Error getting chaincode package bytes: %s", err)
	}

	cds := &pb.ChaincodeDeploymentSpec{ChaincodeSpec: spec, CodePackage: codePackage}
	dockerSpec, err := platforms.GenerateDockerBuild(cds)
	if err != nil {
		return fmt.Errorf("Error getting chaincode docker image: %s", err)
	}

	output := bytes.NewBuffer(nil)

	err = vm.Client.BuildImage(docker.BuildImageOptions{
		Name:         spec.ChaincodeId.Name,
		InputStream:  dockerSpec,
		OutputStream: output,
	})
	if err != nil {
		return fmt.Errorf("Error building docker: %s (output = %s)", err, output.String())
	}

	return nil
}

// GetChaincodePackageBytes creates bytes for docker container generation using the supplied chaincode specification
func GetChaincodePackageBytes(spec *pb.ChaincodeSpec) ([]byte, error) {
	if spec == nil || spec.ChaincodeId == nil {
		return nil, fmt.Errorf("invalid chaincode spec")
	}

	return platforms.GetDeploymentPayload(spec)
}