//+build windows

/*
   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 windows

import (
	"context"
	"os"
	"path/filepath"
	"strings"

	"github.com/Microsoft/hcsshim"
	"github.com/containerd/containerd/errdefs"
	specs "github.com/opencontainers/runtime-spec/specs-go"
	"github.com/pkg/errors"
)

// newContainerConfig generates a hcsshim container configuration from the
// provided OCI Spec
func newContainerConfig(ctx context.Context, owner, id string, spec *specs.Spec) (*hcsshim.ContainerConfig, error) {
	var (
		conf = &hcsshim.ContainerConfig{
			SystemType: "Container",
			Name:       id,
			Owner:      owner,
			HostName:   spec.Hostname,
		}
	)

	if spec.Windows.Network != nil {
		conf.AllowUnqualifiedDNSQuery = spec.Windows.Network.AllowUnqualifiedDNSQuery
		conf.EndpointList = spec.Windows.Network.EndpointList
		conf.NetworkSharedContainerName = spec.Windows.Network.NetworkSharedContainerName
		if spec.Windows.Network.DNSSearchList != nil {
			conf.DNSSearchList = strings.Join(spec.Windows.Network.DNSSearchList, ",")
		}
	}

	return conf, nil
}

// newWindowsContainerConfig generates a hcsshim Windows container
// configuration from the provided OCI Spec
func newWindowsContainerConfig(ctx context.Context, owner, id string, spec *specs.Spec) (*hcsshim.ContainerConfig, error) {
	conf, err := newContainerConfig(ctx, owner, id, spec)
	if err != nil {
		return nil, err
	}
	conf.IgnoreFlushesDuringBoot = spec.Windows.IgnoreFlushesDuringBoot

	if len(spec.Windows.LayerFolders) < 2 {
		return nil, errors.Wrap(errdefs.ErrInvalidArgument,
			"spec.Windows.LayerFolders must have at least 2 layers")
	}
	var (
		layerFolderPath = spec.Windows.LayerFolders[0]
		layerFolders    = spec.Windows.LayerFolders[1:]
		layerID         = filepath.Base(layerFolderPath)
	)

	// TODO: use the create request Mount for those
	for _, layerPath := range layerFolders {
		_, filename := filepath.Split(layerPath)
		guid, err := hcsshim.NameToGuid(filename)
		if err != nil {
			return nil, errors.Wrapf(err, "unable to get GUID for %s", filename)
		}
		conf.Layers = append(conf.Layers, hcsshim.Layer{
			ID:   guid.ToString(),
			Path: layerPath,
		})
	}
	conf.LayerFolderPath = layerFolderPath

	var di = hcsshim.DriverInfo{
		HomeDir: filepath.Dir(layerFolderPath),
	}
	conf.VolumePath, err = hcsshim.GetLayerMountPath(di, layerID)
	if err != nil {
		return nil, errors.Wrapf(err, "failed to getmount path for layer %s: driverInfo: %#v", id, di)
	}

	if spec.Windows.HyperV != nil {
		conf.HvPartition = true
		for _, layerPath := range layerFolders {
			utilityVMPath := spec.Windows.HyperV.UtilityVMPath
			_, err := os.Stat(utilityVMPath)
			if err == nil {
				conf.HvRuntime = &hcsshim.HvRuntime{ImagePath: utilityVMPath}
				break
			} else if !os.IsNotExist(err) {
				return nil, errors.Wrapf(err, "failed to access layer %s", layerPath)
			}
		}
	}

	if spec.Windows.CredentialSpec != nil {
		conf.Credentials = spec.Windows.CredentialSpec.(string)
	}

	if len(spec.Mounts) > 0 {
		mds := make([]hcsshim.MappedDir, len(spec.Mounts))
		for i, mount := range spec.Mounts {
			mds[i] = hcsshim.MappedDir{
				HostPath:      mount.Source,
				ContainerPath: mount.Destination,
				ReadOnly:      false,
			}
			for _, o := range mount.Options {
				if strings.ToLower(o) == "ro" {
					mds[i].ReadOnly = true
				}
			}
		}
		conf.MappedDirectories = mds
	}

	return conf, nil
}

func newProcessConfig(processSpec *specs.Process, pset *pipeSet) *hcsshim.ProcessConfig {
	conf := &hcsshim.ProcessConfig{
		EmulateConsole:   pset.src.Terminal,
		CreateStdInPipe:  pset.stdin != nil,
		CreateStdOutPipe: pset.stdout != nil,
		CreateStdErrPipe: pset.stderr != nil,
		User:             processSpec.User.Username,
		Environment:      make(map[string]string),
		WorkingDirectory: processSpec.Cwd,
	}

	if processSpec.ConsoleSize != nil {
		conf.ConsoleSize = [2]uint{processSpec.ConsoleSize.Height, processSpec.ConsoleSize.Width}
	}

	// Convert OCI Env format to HCS's
	for _, s := range processSpec.Env {
		arr := strings.SplitN(s, "=", 2)
		if len(arr) == 2 {
			conf.Environment[arr[0]] = arr[1]
		}
	}

	return conf
}

func newWindowsProcessConfig(processSpec *specs.Process, pset *pipeSet) *hcsshim.ProcessConfig {
	conf := newProcessConfig(processSpec, pset)
	conf.CommandLine = strings.Join(processSpec.Args, " ")
	return conf
}