Implement update command

notifier.go

@@ -0,0 +1,86 @@
+/*
+ * Minio Cloud Storage, (C) 2015 Minio, 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.
+ */
+
+package main
+
+import (
+	"fmt"
+	"math"
+	"runtime"
+	"strings"
+
+	"github.com/fatih/color"
+	"github.com/minio/minio-xl/pkg/probe"
+	"github.com/olekukonko/ts"
+)
+
+// colorizeUpdateMessage - inspired from Yeoman project npm package https://github.com/yeoman/update-notifier
+func colorizeUpdateMessage(updateString string) (string, *probe.Error) {
+	// initialize coloring
+	cyan := color.New(color.FgCyan, color.Bold).SprintFunc()
+	yellow := color.New(color.FgYellow, color.Bold).SprintfFunc()
+
+	// calculate length without color coding, due to ANSI color characters padded to actual
+	// string the final length is wrong than the original string length
+	line1Str := fmt.Sprintf("  Update available: ")
+	line2Str := fmt.Sprintf("  Run \"%s\" to update. ", updateString)
+	line1Length := len(line1Str)
+	line2Length := len(line2Str)
+
+	// populate lines with color coding
+	line1InColor := line1Str
+	line2InColor := fmt.Sprintf("  Run \"%s\" to update. ", cyan(updateString))
+
+	// calculate the rectangular box size
+	maxContentWidth := int(math.Max(float64(line1Length), float64(line2Length)))
+	line1Rest := maxContentWidth - line1Length
+	line2Rest := maxContentWidth - line2Length
+
+	terminal, err := ts.GetSize()
+	if err != nil {
+		return "", probe.NewError(err)
+	}
+
+	var message string
+	switch {
+	case len(line2Str) > terminal.Col():
+		message = "\n" + line1InColor + "\n" + line2InColor + "\n"
+	default:
+		// on windows terminal turn off unicode characters
+		var top, bottom, sideBar string
+		if runtime.GOOS == "windows" {
+			top = yellow("*" + strings.Repeat("*", maxContentWidth) + "*")
+			bottom = yellow("*" + strings.Repeat("*", maxContentWidth) + "*")
+			sideBar = yellow("|")
+		} else {
+			// color the rectangular box, use unicode characters here
+			top = yellow("┏" + strings.Repeat("━", maxContentWidth) + "┓")
+			bottom = yellow("┗" + strings.Repeat("━", maxContentWidth) + "┛")
+			sideBar = yellow("┃")
+		}
+		// fill spaces to the rest of the area
+		spacePaddingLine1 := strings.Repeat(" ", line1Rest)
+		spacePaddingLine2 := strings.Repeat(" ", line2Rest)
+
+		// construct the final message
+		message = "\n" + top + "\n" +
+			sideBar + line1InColor + spacePaddingLine1 + sideBar + "\n" +
+			sideBar + line2InColor + spacePaddingLine2 + sideBar + "\n" +
+			bottom + "\n"
+	}
+	// finally print the message
+	return message, nil
+}