tgc-revival: Set the fields to state and then read state to hcl data during cai2hcl (#15975)

Author: zli82016

mmv1/products/compute/BackendService.yaml

@@ -55,7 +55,6 @@ custom_code:
   decoder: 'templates/terraform/decoders/backend_service.go.tmpl'
   post_create: 'templates/terraform/post_create/compute_backend_service_security_policy.go.tmpl'
   post_update: 'templates/terraform/post_create/compute_backend_service_security_policy.go.tmpl'
-  tgc_decoder: 'templates/tgc_next/decoders/compute_backend_service.go.tmpl'
 schema_version: 1
 examples:
   - name: 'backend_service_basic'

mmv1/templates/tgc_next/cai2hcl/resource_converter.go.tmpl

@@ -143,9 +143,6 @@ func (c *{{ $.ResourceName -}}Cai2hclConverter) convertResourceData(asset caiass
 	}
 {{ end}}
 
-{{/* Attempt to parse all self-link parameters from asset name. */}}
-	outputFields := {{ $.OutputFieldSetStr }}
-	utils.ParseUrlParamValuesFromAssetName(asset.Name, "{{ $.Cai2hclAssetNameTemplate }}", outputFields, hclData)
 {{ range $prop := $.ReadPropertiesForTgc }}
 	{{ if $prop.FlattenObject -}}
 	if flattenedProp := flatten{{ if $.NestedQuery -}}Nested{{end}}{{ $.ResourceName -}}{{ camelize $prop.Name "upper"  -}}(res["{{ $prop.ApiName -}}"], d, config); flattenedProp != nil {
@@ -154,10 +151,22 @@ func (c *{{ $.ResourceName -}}Cai2hclConverter) convertResourceData(asset caiass
 		}
 	}
 	{{- else -}}
-	hclData["{{ underscore $prop.Name -}}"] = flatten{{ if $.NestedQuery -}}Nested{{end}}{{ $.ResourceName -}}{{ camelize $prop.Name "upper" -}}(res["{{ $prop.ApiName -}}"], d, config)
+    if err := d.Set("{{ underscore $prop.Name -}}", flatten{{ if $.NestedQuery -}}Nested{{end}}{{ $.ResourceName -}}{{ camelize $prop.Name "upper" -}}(res["{{ $prop.ApiName -}}"], d, config)); err != nil {
+        return nil, fmt.Errorf("Error reading {{ $.Name -}}: %s", err)
+    }
 	{{- end}}
 {{- end}}
 
+	for key, sch := range c.schema {
+		if val, ok := d.GetOk(key); ok || sch.Required {
+			hclData[key] = val
+		}
+	}
+
+{{/* Attempt to parse all self-link parameters from asset name. */}}
+	outputFields := {{ $.OutputFieldSetStr }}
+	utils.ParseUrlParamValuesFromAssetName(asset.Name, "{{ $.Cai2hclAssetNameTemplate }}", outputFields, hclData)
+
 	ctyVal, err := utils.MapToCtyValWithSchema(hclData, c.schema)
 	if err != nil {
 		return nil, err

mmv1/templates/tgc_next/decoders/cloud_asset_feed.go.tmpl

@@ -1,4 +1,4 @@
 // billing_project is the required url_param_only property, but is not in CAI asset name or data
 // TODO: handle it in a generic way
-hclData["billing_project"] = "null"
+d.Set("billing_project", "null")
 return res, hclData, nil

mmv1/templates/tgc_next/decoders/compute_backend_service.go.tmpl

@@ -1,12 +1,3 @@
-if v, ok := res["nextHopInstance"]; ok {
-		val, err := tpgresource.ParseZonalFieldValue("instances", v.(string), "project", "next_hop_instance_zone", d, meta.(*transport_tpg.Config), true)
-		if err != nil {
-				return nil, nil, err
-		}
-		hclData["next_hop_instance_zone"] = val.Zone
-		res["nextHopInstance"] = val.RelativeLink()
-}
-
 // next_hop_ip is Computed + Optional and conflict with next_hop_ilb
 if _, ok := res["nextHopIp"]; ok {
 	if _, ok := res["nextHopIlb"]; ok {