From 8f1fd2fcd9983a5ecc79e6a1ed0e8b89737a903b Mon Sep 17 00:00:00 2001
From: Henry <cryptix@riseup.net>
Date: Mon, 20 Oct 2014 17:10:12 +0200
Subject: [PATCH] ShouldAutoUpdate function

---
 config/version.go       |  1 +
 updates/updates.go      | 49 ++++++++++++++++++++++++++++++++++++++++
 updates/updates_test.go | 50 ++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 99 insertions(+), 1 deletion(-)

diff --git a/config/version.go b/config/version.go
index 417be5bd8..1bd641ad4 100644
--- a/config/version.go
+++ b/config/version.go
@@ -44,6 +44,7 @@ const (
 )
 
 // supported Version.AutoUpdate values
+// BUG(cryptix): make this a custom type that implements json.Unmarshaller() to verify values
 const (
 	UpdateNever = "never"
 	UpdatePatch = "patch"
diff --git a/updates/updates.go b/updates/updates.go
index 754f559ab..c6cf45783 100644
--- a/updates/updates.go
+++ b/updates/updates.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 
+	"github.com/jbenet/go-ipfs/config"
 	u "github.com/jbenet/go-ipfs/util"
 
 	"github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/coreos/go-semver/semver"
@@ -60,3 +61,51 @@ func CheckForUpdate() (*check.Result, error) {
 func AbleToApply() error {
 	return update.New().CanUpdate()
 }
+
+// ShouldAutoUpdate decides wether a new version should be applied
+// checks against config setting and new version string. returns false in case of error
+func ShouldAutoUpdate(setting, newVer string) bool {
+	if setting == config.UpdateNever {
+		return false
+	}
+
+	nv, err := semver.NewVersion(newVer)
+	if err != nil {
+		log.Error("could not parse version string: %s", err)
+		return false
+	}
+
+	n := nv.Slice()
+	c := currentVersion.Slice()
+
+	switch setting {
+
+	case config.UpdatePatch:
+		if n[0] < c[0] {
+			return false
+		}
+
+		if n[1] < c[1] {
+			return false
+		}
+
+		return n[2] > c[2]
+
+	case config.UpdateMinor:
+		if n[0] != c[0] {
+			return false
+		}
+
+		return n[1] > c[1] || (n[1] == c[1] && n[2] > c[2])
+
+	case config.UpdateMajor:
+		for i := 0; i < 3; i++ {
+			if n[i] < c[i] {
+				return false
+			}
+		}
+		return true
+	}
+
+	return false
+}
diff --git a/updates/updates_test.go b/updates/updates_test.go
index 4b258fe5d..02d7b9e9a 100644
--- a/updates/updates_test.go
+++ b/updates/updates_test.go
@@ -1,6 +1,11 @@
 package updates
 
-import "testing"
+import (
+	"testing"
+
+	"github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/coreos/go-semver/semver"
+	"github.com/jbenet/go-ipfs/config"
+)
 
 // TestParseVersion just makes sure that we dont commit a bad version number
 func TestParseVersion(t *testing.T) {
@@ -9,3 +14,46 @@ func TestParseVersion(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestShouldAutoUpdate(t *testing.T) {
+	tests := []struct {
+		setting, currV, newV string
+		should               bool
+	}{
+		{config.UpdateNever, "0.0.1", "1.0.0", false},
+		{config.UpdateNever, "0.0.1", "0.1.0", false},
+		{config.UpdateNever, "0.0.1", "0.0.1", false},
+		{config.UpdateNever, "0.0.1", "0.0.2", false},
+
+		{config.UpdatePatch, "0.0.1", "1.0.0", false},
+		{config.UpdatePatch, "0.0.1", "0.1.0", false},
+		{config.UpdatePatch, "0.0.1", "0.0.1", false},
+		{config.UpdatePatch, "0.0.2", "0.0.1", false},
+		{config.UpdatePatch, "0.0.1", "0.0.2", true},
+
+		{config.UpdateMinor, "0.1.1", "1.0.0", false},
+		{config.UpdateMinor, "0.1.1", "0.2.0", true},
+		{config.UpdateMinor, "0.1.1", "0.1.2", true},
+		{config.UpdateMinor, "0.2.1", "0.1.9", false},
+		{config.UpdateMinor, "0.1.2", "0.1.1", false},
+
+		{config.UpdateMajor, "1.0.0", "2.0.0", true},
+		{config.UpdateMajor, "1.0.0", "1.1.0", true},
+		{config.UpdateMajor, "1.0.0", "1.0.1", true},
+		{config.UpdateMajor, "2.0.0", "1.0.0", false}, // don't downgrade
+		{config.UpdateMajor, "2.5.0", "2.4.0", false},
+		{config.UpdateMajor, "2.0.2", "2.0.1", false},
+	}
+
+	for i, tc := range tests {
+		var err error
+		currentVersion, err = semver.NewVersion(tc.currV)
+		if err != nil {
+			t.Fatalf("Could not parse test version: %v", err)
+		}
+
+		if tc.should != ShouldAutoUpdate(tc.setting, tc.newV) {
+			t.Fatalf("#%d failed for %+v", i, tc)
+		}
+	}
+}