From 0cd84ada1e66b6d917ea47c0c88693707f92f405 Mon Sep 17 00:00:00 2001
From: Martin Polden <martin.polden@gmail.com>
Date: Sat, 27 May 2017 15:31:50 +0200
Subject: [PATCH] Extract useragent package

Fixes #30
---
 api/api.go                  | 13 +++++++------
 api/api_test.go             |  1 +
 useragent/useragent.go      | 38 +++++++++++++++++++++++++++++++++++++
 useragent/useragent_test.go | 36 +++++++++++++++++++++++++++++++++++
 4 files changed, 82 insertions(+), 6 deletions(-)
 create mode 100644 useragent/useragent.go
 create mode 100644 useragent/useragent_test.go

diff --git a/api/api.go b/api/api.go
index 74f7932..aa7ba35 100644
--- a/api/api.go
+++ b/api/api.go
@@ -6,13 +6,13 @@ import (
 	"html/template"
 	"io"
 
+	"github.com/mpolden/ipd/useragent"
 	"github.com/sirupsen/logrus"
 
 	"math/big"
 	"net"
 	"net/http"
 	"path/filepath"
-	"regexp"
 	"strconv"
 	"strings"
 
@@ -24,10 +24,6 @@ const (
 	textMediaType = "text/plain"
 )
 
-var userAgentPattern = regexp.MustCompile(
-	`^(?:curl|Wget|fetch\slibfetch|ddclient|Go-http-client|HTTPie)\/.*|Go\s1\.1\spackage\shttp$`,
-)
-
 type API struct {
 	Template string
 	IPHeader string
@@ -210,7 +206,12 @@ func (a *API) NotFoundHandler(w http.ResponseWriter, r *http.Request) *appError
 }
 
 func cliMatcher(r *http.Request, rm *mux.RouteMatch) bool {
-	return userAgentPattern.MatchString(r.UserAgent())
+	ua := useragent.Parse(r.UserAgent())
+	switch ua.Product {
+	case "curl", "HTTPie", "Wget", "fetch libfetch", "Go", "Go-http-client", "ddclient":
+		return true
+	}
+	return false
 }
 
 type appHandler func(http.ResponseWriter, *http.Request) *appError
diff --git a/api/api_test.go b/api/api_test.go
index bb92ea5..fec6236 100644
--- a/api/api_test.go
+++ b/api/api_test.go
@@ -150,6 +150,7 @@ func TestCLIMatcher(t *testing.T) {
 	}{
 		{"curl/7.26.0", true},
 		{"Wget/1.13.4 (linux-gnu)", true},
+		{"Wget", true},
 		{"fetch libfetch/2.0", true},
 		{"HTTPie/0.9.3", true},
 		{"Go 1.1 package http", true},
diff --git a/useragent/useragent.go b/useragent/useragent.go
new file mode 100644
index 0000000..e533662
--- /dev/null
+++ b/useragent/useragent.go
@@ -0,0 +1,38 @@
+package useragent
+
+import (
+	"strings"
+)
+
+type UserAgent struct {
+	Product string
+	Version string
+	Comment string
+}
+
+func Parse(s string) UserAgent {
+	parts := strings.SplitN(s, "/", 2)
+	var version, comment string
+	if len(parts) > 1 {
+		// If first character is a number, treat it as version
+		if parts[1][0] >= 48 && parts[1][0] <= 57 {
+			rest := strings.SplitN(parts[1], " ", 2)
+			version = rest[0]
+			if len(rest) > 1 {
+				comment = rest[1]
+			}
+		} else {
+			comment = parts[1]
+		}
+	} else {
+		parts = strings.SplitN(s, " ", 2)
+		if len(parts) > 1 {
+			comment = parts[1]
+		}
+	}
+	return UserAgent{
+		Product: parts[0],
+		Version: version,
+		Comment: comment,
+	}
+}
diff --git a/useragent/useragent_test.go b/useragent/useragent_test.go
new file mode 100644
index 0000000..14ff09a
--- /dev/null
+++ b/useragent/useragent_test.go
@@ -0,0 +1,36 @@
+package useragent
+
+import (
+	"testing"
+)
+
+func TestParse(t *testing.T) {
+	var tests = []struct {
+		in  string
+		out UserAgent
+	}{
+		{"", UserAgent{}},
+		{"curl/7.26.0", UserAgent{Product: "curl", Version: "7.26.0"}},
+		{"Wget/1.13.4 (linux-gnu)", UserAgent{Product: "Wget", Version: "1.13.4", Comment: "(linux-gnu)"}},
+		{"Wget", UserAgent{Product: "Wget"}},
+		{"fetch libfetch/2.0", UserAgent{Product: "fetch libfetch", Version: "2.0"}},
+		{"Go 1.1 package http", UserAgent{Product: "Go", Comment: "1.1 package http"}},
+		{"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_4) " +
+			"AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.28 " +
+			"Safari/537.36", UserAgent{Product: "Mozilla", Version: "5.0", Comment: "(Macintosh; Intel Mac OS X 10_8_4) " +
+			"AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.28 " +
+			"Safari/537.36"}},
+	}
+	for _, tt := range tests {
+		ua := Parse(tt.in)
+		if got := ua.Product; got != tt.out.Product {
+			t.Errorf("got Product=%q for %q, want %q", got, tt.in, tt.out.Product)
+		}
+		if got := ua.Version; got != tt.out.Version {
+			t.Errorf("got Version=%q for %q, want %q", got, tt.in, tt.out.Version)
+		}
+		if got := ua.Comment; got != tt.out.Comment {
+			t.Errorf("got Comment=%q for %q, want %q", got, tt.in, tt.out.Comment)
+		}
+	}
+}