package client

import (
	"encoding/json"
	"runtime"
	"text/template"

	"github.com/docker/docker/api"
	"github.com/docker/docker/api/types"
	"github.com/docker/docker/autogen/dockerversion"
	flag "github.com/docker/docker/pkg/mflag"
	"github.com/docker/docker/utils"
)

var VersionTemplate = `Client:
 Version:      {{.Client.Version}}
 API version:  {{.Client.ApiVersion}}
 Go version:   {{.Client.GoVersion}}
 Git commit:   {{.Client.GitCommit}}
 Built:        {{.Client.BuildTime}}
 OS/Arch:      {{.Client.Os}}/{{.Client.Arch}}{{if .Client.Experimental}}
 Experimental: {{.Client.Experimental}}{{end}}{{if .ServerOK}}

Server:
 Version:      {{.Server.Version}}
 API version:  {{.Server.ApiVersion}}
 Go version:   {{.Server.GoVersion}}
 Git commit:   {{.Server.GitCommit}}
 Built:        {{.Server.BuildTime}}
 OS/Arch:      {{.Server.Os}}/{{.Server.Arch}}{{if .Server.Experimental}}
 Experimental: {{.Server.Experimental}}{{end}}{{end}}`

type VersionData struct {
	Client   types.Version
	ServerOK bool
	Server   types.Version
}

// CmdVersion shows Docker version information.
//
// Available version information is shown for: client Docker version, client API version, client Go version, client Git commit, client OS/Arch, server Docker version, server API version, server Go version, server Git commit, and server OS/Arch.
//
// Usage: docker version
func (cli *DockerCli) CmdVersion(args ...string) (err error) {
	cmd := cli.Subcmd("version", nil, "Show the Docker version information.", true)
	tmplStr := cmd.String([]string{"f", "#format", "-format"}, "", "Format the output using the given go template")
	cmd.Require(flag.Exact, 0)

	cmd.ParseFlags(args, true)
	if *tmplStr == "" {
		*tmplStr = VersionTemplate
	}

	var tmpl *template.Template
	if tmpl, err = template.New("").Funcs(funcMap).Parse(*tmplStr); err != nil {
		return StatusError{StatusCode: 64,
			Status: "Template parsing error: " + err.Error()}
	}

	vd := VersionData{
		Client: types.Version{
			Version:      dockerversion.VERSION,
			ApiVersion:   api.Version,
			GoVersion:    runtime.Version(),
			GitCommit:    dockerversion.GITCOMMIT,
			BuildTime:    dockerversion.BUILDTIME,
			Os:           runtime.GOOS,
			Arch:         runtime.GOARCH,
			Experimental: utils.ExperimentalBuild(),
		},
	}

	defer func() {
		if err2 := tmpl.Execute(cli.out, vd); err2 != nil && err == nil {
			err = err2
		}
		cli.out.Write([]byte{'\n'})
	}()

	serverResp, err := cli.call("GET", "/version", nil, nil)
	if err != nil {
		return err
	}

	defer serverResp.body.Close()

	if err = json.NewDecoder(serverResp.body).Decode(&vd.Server); err != nil {
		return StatusError{StatusCode: 1,
			Status: "Error reading remote version: " + err.Error()}
	}

	vd.ServerOK = true

	return
}