From ce920decde15f810581a141dc6b0266718c0f8f3 Mon Sep 17 00:00:00 2001
From: alexissavin <alexis.savin@gmail.com>
Date: Thu, 17 Jun 2021 14:31:34 +0200
Subject: [PATCH] Workaround regarding issue
 https://github.com/hashicorp/terraform-plugin-sdk/issues/477 For handling
 Application GSLB members

---
 solidserver/resource_application.go | 43 ++++-------------------------
 solidserver/solidserver-helper.go   | 40 +++++++++++++++++++++++++++
 2 files changed, 45 insertions(+), 38 deletions(-)

diff --git a/solidserver/resource_application.go b/solidserver/resource_application.go
index 175337b..95d800d 100644
--- a/solidserver/resource_application.go
+++ b/solidserver/resource_application.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"github.com/hashicorp/terraform/helper/schema"
 	"log"
-	"sort"
 	"net/url"
 	"strings"
 )
@@ -286,47 +285,15 @@ func resourceapplicationRead(d *schema.ResourceData, meta interface{}) error {
 			d.Set("class", buf[0]["appapplication_class_name"].(string))
 
 			// Updating gslb_members information
-			// Suspended because of issue https://github.com/hashicorp/terraform-plugin-sdk/issues/477
+			// Removed because of issue https://github.com/hashicorp/terraform-plugin-sdk/issues/477
 			// Doesn't make sense to read this information until this issue is fixed
 			//if buf[0]["appapplication_gslbserver_list"].(string) != "" {
 			//	d.Set("gslb_members", toStringArrayInterface(strings.Split(strings.TrimSuffix(buf[0]["appapplication_gslbserver_list"].(string), ","), ",")))
 			//}
-
-			if buf[0]["appapplication_gslbserver_list"].(string) != "" {
-				// Retrieve the list of the remotely configured members
-				remote_members := toStringArrayInterface(strings.Split(strings.TrimSuffix(buf[0]["appapplication_gslbserver_list"].(string), ","), ","))
-
-				// Build local list of member indexed by their offset
-				local_members := toStringArray(d.Get("gslb_members").([]interface{}))
-				local_members_offsets := make(map[int]string, len(local_members))
-				diff := make([]string, 0, len(remote_members))
-				res := make([]interface{}, 0, len(remote_members))
-
-				for _, remote_member := range remote_members {
-					offset := stringOffsetInSlice(remote_member.(string), local_members)
-
-					if offset != -1 {
-						local_members_offsets[offset] = remote_member.(string)
-					} else {
-						diff = append(diff, remote_member.(string))
-					}
-				}
-
-				// Concat sorted members from by their offset and the diff into d.Set("gslb_members")
-				keys := make([]int, 0, len(local_members))
-				for k := range local_members_offsets {
-					keys = append(keys, k)
-				}
-				sort.Ints(keys)
-				for _, k := range keys {
-					res = append(res, local_members_offsets[k])
-				}
-				for _, v := range diff {
-					res = append(res, v)
-				}
-
-				d.Set("gslb_members", res)
-			}
+			// Workaround
+			remote_members := strings.Split(strings.TrimSuffix(buf[0]["appapplication_gslbserver_list"].(string), ","), ",")
+			local_members := toStringArray(d.Get("gslb_members").([]interface{}))
+			d.Set("gslb_members", typeListConsistentMerge(local_members, remote_members))
 
 			// Updating local class_parameters
 			currentClassParameters := d.Get("class_parameters").(map[string]interface{})
diff --git a/solidserver/solidserver-helper.go b/solidserver/solidserver-helper.go
index c8caf53..bb52efe 100644
--- a/solidserver/solidserver-helper.go
+++ b/solidserver/solidserver-helper.go
@@ -7,6 +7,7 @@ import (
 	"log"
 	"math/big"
 	"net/url"
+	"sort"
 	"strconv"
 	"strings"
 )
@@ -56,6 +57,45 @@ func toStringArrayInterface(in []string) []interface{} {
 	return out
 }
 
+// Consistent merge of TypeList elements, maintaining entries position within the list
+// Workaround to TF Plugin SDK issue https://github.com/hashicorp/terraform-plugin-sdk/issues/477
+func typeListConsistentMerge(old []string, new []string) []interface{} {
+	// Step 1 Build local list of member indexed by their offset
+	old_offsets := make(map[int]string, len(old))
+	diff := make([]string, 0, len(new))
+	res := make([]interface{}, 0, len(new))
+
+	for _, n := range new {
+		if n != "" {
+			offset := stringOffsetInSlice(n, old)
+
+			if offset != -1 {
+				old_offsets[offset] = n
+			} else {
+				diff = append(diff, n)
+			}
+		}
+	}
+
+	// Merge sorted entries ordered by their offset with the diff array that contain the new ones
+	// Step 2 Sort the index
+	keys := make([]int, 0, len(old))
+	for k := range old_offsets {
+		keys = append(keys, k)
+	}
+	sort.Ints(keys)
+
+	// Step 3 build the result
+	for _, k := range keys {
+		res = append(res, old_offsets[k])
+	}
+	for _, v := range diff {
+		res = append(res, v)
+	}
+
+	return res
+}
+
 // BigIntToHexStr convert a Big Integer into an Hexa String
 func BigIntToHexStr(bigInt *big.Int) string {
 	return fmt.Sprintf("%x", bigInt)