Refactor almost complete

1 files changed, 99 insertions, 22 deletions

diff --git a/cmd/version.go b/cmd/version.go
index 99097b5..219684d 100644
--- a/cmd/version.go
+++ b/cmd/version.go
@@ -21,33 +21,89 @@ package cmd
 
 import (
 	"fmt"
+	"time"
 
 	"github.com/blang/semver"
+	"github.com/pkg/errors"
 )
 
-// Templates for use with the version command, which both parse the Info var.
-var (
-	VersionTemplate     = "{{.FullName}} {{.Info.Version}}\n"
-	VersionLongTemplate = `{{if .Info.BuildTime}}
-Compiled:
-	{{.Info.BuildTime}}
-{{end}}
+// Info contains global information about the program.
+var Info = &InfoData{}
 
-{{with $length := len .Info.Authors}}
-{{if $length}}
-Author{{if ne 1 $length}}s{{end}}:
-{{range .Info.Authors}}
-	{{.Name}}{{if .Email}} <{{.Email}}>{{end}}
-{{end}}
-{{end}}
-{{end}}
+// InfoData describes the structure of our global program information
+type InfoData struct {
+	// Version (if set) will be displayed in both the short and long version
+	// output. This can be set directly or using VersionTag at link time.
+	Version semver.Version
+	// BuildTime (if set) will be displayed in the long version output. This
+	// can be set directory or by setting cmd.BuildTimeTag in a linking
+	// flag. s
+	//
+	BuildTime time.Time
+	// Authors (if non-empty) are displayed in the long version output.
+	Authors []Author
+	// Copyright (if set) is displayed in the long version output.
+	Copyright string
+}
 
-{{if .Info.Copyright}}
-Copyright:
-{{.Info.Copyright}}
-{{end}}`
+// Author contains the contact information for a contributor.
+type Author struct {
+	Name  string
+	Email string
+}
+
+// We have to use separate Tag variables, because build tags of the form:
+//	"-X cmd.Info.Version=foo"
+// are invalid.
+var (
+	// VersionTag can be set via the linker, and its value will be used to
+	// set Info.Version. Format this tag using Semver (http://semver.org/).
+	// Example:
+	//	"-X cmd.VersionTag=1.2.3-beta"
+	VersionTag string
+	// BuildTimeTag can be set via the linker, and its value will be used to
+	// set Info.BuildTime. Format this tag like the output of UNIX's `date`.
+	// Example:
+	//	"-X cmd.BuildTimeTag=Thu Oct 12 21:32:02 PDT 2017"
+	BuildTimeTag string
 )
 
+func init() {
+	var err error
+	// parse the tag variables
+	if VersionTag != "" {
+		Info.Version, err = semver.ParseTolerant(VersionTag)
+		if err != nil {
+			panic(errors.Wrapf(err, "semver: parsing %q", VersionTag))
+		}
+	}
+	if BuildTimeTag != "" {
+		Info.BuildTime, err = time.Parse(time.UnixDate, BuildTimeTag)
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	// fscrypt specific initialization
+	Info.Authors = []Author{{
+		Name:  "Joe Richey",
+		Email: "joerichey@google.com",
+	}}
+	Info.Copyright = `Copyright 2017 Google, Inc.
+
+	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.`
+}
+
 // VersionCommand is a command which will display either the VersionTag (by
 // default) or the full version information: version, copyright, authors, etc...
 var VersionCommand = &Command{
@@ -67,13 +123,34 @@ var longFlag = &BoolFlag{
 	Usage: "Print the detailed version, build, and copyright information.",
 }
 
+// TemplateVersionShort describes the format of the one line version command.
+var TemplateVersionShort = "{{.FullName}} {{.Info.Version}}\n"
+
+// TemplateVersionLong describes the format of the additional version data.
+var TemplateVersionLong = `{{if not .Info.BuildTime.IsZero}}
+Compiled:
+	{{.Info.BuildTime}}
+{{end -}}
+
+{{with $length := len .Info.Authors}}
+Author{{if ne 1 $length}}s{{end}}:
+{{- range $.Info.Authors}}
+	{{.Name}}{{if .Email}} <{{.Email}}>{{end -}}
+{{end}}
+{{end -}}
+
+{{if .Info.Copyright}}
+Copyright:
+	{{.Info.Copyright}}
+{{end}}`
+
 func versionAction(ctx *Context) error {
-	if ctx.Info.Version.Equals(semver.Version{}) {
+	if Info.Version.Equals(semver.Version{}) {
 		return ErrUnknownVersion
 	}
-	ctx.executeTemplate(Output, VersionTemplate)
+	ExecuteTemplate(Output, TemplateVersionShort, ctx)
 	if longFlag.Value {
-		ctx.executeTemplate(Output, VersionLongTemplate)
+		ExecuteTemplate(Output, TemplateVersionLong, ctx)
 	}
 	return nil
 }