From f70de0bdff7c9ddf2126fc1f37e4c9adfdca1631 Mon Sep 17 00:00:00 2001
From: Jinzhu <wosmvp@gmail.com>
Date: Sun, 10 Jan 2016 22:56:22 +0800
Subject: [PATCH] Generate more friendly names for table and columns

---
 utils.go      | 42 +++++++++++++++++++++++++++++++++++-------
 utils_test.go | 28 ++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+), 7 deletions(-)
 create mode 100644 utils_test.go

diff --git a/utils.go b/utils.go
index b457f321..158d8a3b 100644
--- a/utils.go
+++ b/utils.go
@@ -41,21 +41,49 @@ func newSafeMap() *safeMap {
 
 var smap = newSafeMap()
 
+type Case bool
+
+const (
+	lower Case = false
+	upper Case = true
+)
+
 func ToDBName(name string) string {
 	if v := smap.Get(name); v != "" {
 		return v
 	}
 
-	value := commonInitialismsReplacer.Replace(name)
-	buf := bytes.NewBufferString("")
-	for i, v := range value {
-		if i > 0 && v >= 'A' && v <= 'Z' {
-			buf.WriteRune('_')
+	var (
+		value                        = commonInitialismsReplacer.Replace(name)
+		buf                          = bytes.NewBufferString("")
+		lastCase, currCase, nextCase Case
+	)
+
+	for i, v := range value[:len(value)-1] {
+		nextCase = value[i+1] >= 'A' && value[i+1] <= 'Z'
+		if i > 0 {
+			if currCase == upper {
+				if lastCase == upper && nextCase == upper {
+					buf.WriteRune(v)
+				} else {
+					buf.WriteRune('_')
+					buf.WriteRune(v)
+				}
+			} else {
+				buf.WriteRune(v)
+			}
+		} else {
+			currCase = upper
+			buf.WriteRune(v)
 		}
-		buf.WriteRune(v)
+		lastCase = currCase
+		currCase = nextCase
 	}
 
-	s := strings.ToLower(buf.String())
+	buf.WriteByte(value[len(value)-1])
+
+	s := strings.Replace(strings.ToLower(buf.String()), "__", "_", -1)
+
 	smap.Set(name, s)
 	return s
 }
diff --git a/utils_test.go b/utils_test.go
new file mode 100644
index 00000000..81b8ce9d
--- /dev/null
+++ b/utils_test.go
@@ -0,0 +1,28 @@
+package gorm_test
+
+import (
+	"testing"
+
+	"github.com/jinzhu/gorm"
+)
+
+func TestToDBNameGenerateFriendlyName(t *testing.T) {
+	var maps = map[string]string{
+		"ThisIsATest":               "this_is_a_test",
+		"PFAndESI":                  "pf_and_esi",
+		"AbcAndJkl":                 "abc_and_jkl",
+		"EmployeeID":                "employee_id",
+		"HTTPAndSMTP":               "http_and_smtp",
+		"HTTPServerHandlerForURLID": "http_server_handler_for_url_id",
+		"UUID":     "uuid",
+		"HTTPURL":  "http_url",
+		"HTTP_URL": "http_url",
+		"ThisIsActuallyATestSoWeMayBeAbleToUseThisCodeInGormPackageAlsoIdCanBeUsedAtTheEndAsID": "this_is_actually_a_test_so_we_may_be_able_to_use_this_code_in_gorm_package_also_id_can_be_used_at_the_end_as_id",
+	}
+
+	for key, value := range maps {
+		if gorm.ToDBName(key) != value {
+			t.Errorf("%v ToDBName should equal %v, but got %v", key, value, gorm.ToDBName(key))
+		}
+	}
+}