MM-10495 Updated user agent detection to match output of previous library (#8748)

* MM-10495 Updated user agent detection to match output of previous library

* Fixed missing license header

app/user_agent.go

@@ -0,0 +1,132 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package app
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/avct/uasurfer"
+)
+
+var platformNames = map[uasurfer.Platform]string{
+	uasurfer.PlatformUnknown:      "Windows",
+	uasurfer.PlatformWindows:      "Windows",
+	uasurfer.PlatformMac:          "Macintosh",
+	uasurfer.PlatformLinux:        "Linux",
+	uasurfer.PlatformiPad:         "iPad",
+	uasurfer.PlatformiPhone:       "iPhone",
+	uasurfer.PlatformiPod:         "iPod",
+	uasurfer.PlatformBlackberry:   "BlackBerry",
+	uasurfer.PlatformWindowsPhone: "Windows Phone",
+}
+
+func getPlatformName(ua *uasurfer.UserAgent) string {
+	platform := ua.OS.Platform
+
+	if name, ok := platformNames[platform]; !ok {
+		return platformNames[uasurfer.PlatformUnknown]
+	} else {
+		return name
+	}
+}
+
+var osNames = map[uasurfer.OSName]string{
+	uasurfer.OSUnknown:      "",
+	uasurfer.OSWindowsPhone: "Windows Phone",
+	uasurfer.OSWindows:      "Windows",
+	uasurfer.OSMacOSX:       "Mac OS",
+	uasurfer.OSiOS:          "iOS",
+	uasurfer.OSAndroid:      "Android",
+	uasurfer.OSBlackberry:   "BlackBerry",
+	uasurfer.OSChromeOS:     "Chrome OS",
+	uasurfer.OSKindle:       "Kindle",
+	uasurfer.OSWebOS:        "webOS",
+	uasurfer.OSLinux:        "Linux",
+}
+
+func getOSName(ua *uasurfer.UserAgent) string {
+	os := ua.OS
+
+	if os.Name == uasurfer.OSWindows {
+		major := os.Version.Major
+		minor := os.Version.Minor
+
+		name := "Windows"
+
+		// Adapted from https://github.com/mssola/user_agent/blob/master/operating_systems.go#L26
+		if major == 5 {
+			if minor == 0 {
+				name = "Windows 2000"
+			} else if minor == 1 {
+				name = "Windows XP"
+			} else if minor == 2 {
+				name = "Windows XP x64 Edition"
+			}
+		} else if major == 6 {
+			if minor == 0 {
+				name = "Windows Vista"
+			} else if minor == 1 {
+				name = "Windows 7"
+			} else if minor == 2 {
+				name = "Windows 8"
+			} else if minor == 3 {
+				name = "Windows 8.1"
+			}
+		} else if major == 10 {
+			name = "Windows 10"
+		}
+
+		return name
+	} else if name, ok := osNames[os.Name]; ok {
+		return name
+	} else {
+		return osNames[uasurfer.OSUnknown]
+	}
+}
+
+func getBrowserVersion(ua *uasurfer.UserAgent, userAgentString string) string {
+	if index := strings.Index(userAgentString, "Mattermost/"); index != -1 {
+		afterVersion := userAgentString[index+len("Mattermost/"):]
+		return strings.Fields(afterVersion)[0]
+	} else if index := strings.Index(userAgentString, "Franz/"); index != -1 {
+		afterVersion := userAgentString[index+len("Franz/"):]
+		return strings.Fields(afterVersion)[0]
+	} else {
+		return getUAVersion(ua.Browser.Version)
+	}
+}
+
+func getUAVersion(version uasurfer.Version) string {
+	if version.Patch == 0 {
+		return fmt.Sprintf("%v.%v", version.Major, version.Minor)
+	} else {
+		return fmt.Sprintf("%v.%v.%v", version.Major, version.Minor, version.Patch)
+	}
+}
+
+var browserNames = map[uasurfer.BrowserName]string{
+	uasurfer.BrowserUnknown:    "Unknown",
+	uasurfer.BrowserChrome:     "Chrome",
+	uasurfer.BrowserIE:         "Internet Explorer",
+	uasurfer.BrowserSafari:     "Safari",
+	uasurfer.BrowserFirefox:    "Firefox",
+	uasurfer.BrowserAndroid:    "Android",
+	uasurfer.BrowserOpera:      "Opera",
+	uasurfer.BrowserBlackberry: "BlackBerry",
+}
+
+func getBrowserName(ua *uasurfer.UserAgent, userAgentString string) string {
+	browser := ua.Browser.Name
+
+	if strings.Contains(userAgentString, "Mattermost") {
+		return "Desktop App"
+	} else if browser == uasurfer.BrowserIE && ua.Browser.Version.Major > 11 {
+		return "Edge"
+	} else if name, ok := browserNames[browser]; ok {
+		return name
+	} else {
+		return browserNames[uasurfer.BrowserUnknown]
+	}
+}