package system

import (
	"fmt"
	"io"
	"os"
	"strings"
	"text/tabwriter"
	"time"

	"github.com/containers/buildah/pkg/formats"
	"github.com/containers/libpod/cmd/podman/registry"
	"github.com/containers/libpod/libpod/define"
	"github.com/containers/libpod/pkg/domain/entities"
	"github.com/pkg/errors"
	"github.com/spf13/cobra"
)

var (
	versionCommand = &cobra.Command{
		Use:   "version",
		Args:  cobra.NoArgs,
		Short: "Display the Podman Version Information",
		RunE:  version,
		Annotations: map[string]string{
			registry.ParentNSRequired: "",
		},
	}
	versionFormat string
)

type versionStruct struct {
	Client define.Version
	Server define.Version
}

func init() {
	registry.Commands = append(registry.Commands, registry.CliCommand{
		Mode:    []entities.EngineMode{entities.ABIMode, entities.TunnelMode},
		Command: versionCommand,
	})
	flags := versionCommand.Flags()
	flags.StringVarP(&versionFormat, "format", "f", "", "Change the output format to JSON or a Go template")
}

func version(cmd *cobra.Command, args []string) error {
	var (
		v   versionStruct
		err error
	)
	v.Client, err = define.GetVersion()
	if err != nil {
		return errors.Wrapf(err, "unable to determine version")
	}
	// TODO we need to discuss how to implement
	// this more. current endpoints dont have a
	// version endpoint.  maybe we use info?
	//if remote {
	//	v.Server, err = getRemoteVersion(c)
	//	if err != nil {
	//		return err
	//	}
	//} else {
	v.Server = v.Client
	//}

	versionOutputFormat := versionFormat
	if versionOutputFormat != "" {
		if strings.Join(strings.Fields(versionOutputFormat), "") == "{{json.}}" {
			versionOutputFormat = formats.JSONString
		}
		var out formats.Writer
		switch versionOutputFormat {
		case formats.JSONString:
			out = formats.JSONStruct{Output: v}
			return out.Out()
		default:
			out = formats.StdoutTemplate{Output: v, Template: versionOutputFormat}
			err := out.Out()
			if err != nil {
				// On Failure, assume user is using older version of podman version --format and check client
				out = formats.StdoutTemplate{Output: v.Client, Template: versionOutputFormat}
				if err1 := out.Out(); err1 != nil {
					return err
				}
			}
		}
		return nil
	}
	w := tabwriter.NewWriter(os.Stdout, 0, 0, 2, ' ', 0)
	defer w.Flush()

	if registry.IsRemote() {
		if _, err := fmt.Fprintf(w, "Client:\n"); err != nil {
			return err
		}
		formatVersion(w, v.Client)
		if _, err := fmt.Fprintf(w, "\nServer:\n"); err != nil {
			return err
		}
		formatVersion(w, v.Server)
	} else {
		formatVersion(w, v.Client)
	}
	return nil
}

func formatVersion(writer io.Writer, version define.Version) {
	fmt.Fprintf(writer, "Version:\t%s\n", version.Version)
	fmt.Fprintf(writer, "RemoteAPI Version:\t%d\n", version.RemoteAPIVersion)
	fmt.Fprintf(writer, "Go Version:\t%s\n", version.GoVersion)
	if version.GitCommit != "" {
		fmt.Fprintf(writer, "Git Commit:\t%s\n", version.GitCommit)
	}
	// Prints out the build time in readable format
	if version.Built != 0 {
		fmt.Fprintf(writer, "Built:\t%s\n", time.Unix(version.Built, 0).Format(time.ANSIC))
	}

	fmt.Fprintf(writer, "OS/Arch:\t%s\n", version.OsArch)
}