Support ReadMany operations with slices in SetResourceIdentifiers (#170)

Fixes aws-controllers-k8s/community#874

Description of changes:
Automatically detects pluralised fields from the operation shape and sets the corresponding CR field. Refactor `SetResourceIdentifiers` to re-use common logic from `CheckRequiredFieldsMissingFromShape`. Now supports `primary_identifier_field_names` that reference `[]string` types.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Author: RedbackThomson

pkg/generate/code/check.go

@@ -18,7 +18,6 @@ import (
 	"strings"
 
 	awssdkmodel "github.com/aws/aws-sdk-go/private/model/api"
-	"github.com/gertd/go-pluralize"
 
 	ackgenconfig "github.com/aws-controllers-k8s/code-generator/pkg/generate/config"
 	"github.com/aws-controllers-k8s/code-generator/pkg/model"
@@ -184,37 +183,7 @@ func checkRequiredFieldsMissingFromShapeReadMany(
 	indent := strings.Repeat("\t", indentLevel)
 	result := fmt.Sprintf("%sreturn false", indent)
 
-	shapeIdentifiers := FindIdentifiersInShape(r, shape)
-	crIdentifiers := FindIdentifiersInCRD(r)
-	if len(shapeIdentifiers) == 0 || len(crIdentifiers) == 0 {
-		return result
-	}
-
-	pluralize := pluralize.NewClient()
-	reqIdentifier := ""
-	for _, si := range shapeIdentifiers {
-		for _, ci := range crIdentifiers {
-			if strings.EqualFold(pluralize.Singular(si),
-				pluralize.Singular(ci)) {
-				// The CRD identifiers being used for comparison reflect the
-				// *original* field names in the API model shape.
-				// Field renames are handled below in the call to
-				// getSanitizedMemberPath.
-				if reqIdentifier == "" {
-					reqIdentifier = ci
-				} else {
-					// If there are multiple identifiers, then prioritize the
-					// 'Id' identifier. Checking 'Id' to determine resource
-					// creation should be safe as the field is usually
-					// present in CR.Status.
-					if !strings.HasSuffix(reqIdentifier, "Id") ||
-						!strings.HasSuffix(reqIdentifier, "Ids") {
-						reqIdentifier = ci
-					}
-				}
-			}
-		}
-	}
+	reqIdentifier, _ := FindPluralizedIdentifiersInShape(r, shape)
 
 	resVarPath, err := getSanitizedMemberPath(reqIdentifier, r, op, koVarName)
 	if err != nil {

pkg/generate/code/common.go

@@ -14,12 +14,20 @@
 package code
 
 import (
+	"strings"
+
 	awssdkmodel "github.com/aws/aws-sdk-go/private/model/api"
+	"github.com/gertd/go-pluralize"
 
+	ackgenconfig "github.com/aws-controllers-k8s/code-generator/pkg/generate/config"
 	"github.com/aws-controllers-k8s/code-generator/pkg/model"
 	"github.com/aws-controllers-k8s/code-generator/pkg/util"
 )
 
+var (
+	PrimaryIdentifierARNOverride = "ARN"
+)
+
 // FindIdentifiersInShape returns the identifier fields of a given shape which
 // can be singular or plural.
 func FindIdentifiersInShape(
@@ -49,6 +57,26 @@ func FindIdentifiersInShape(
 	return identifiers
 }
 
+// FindIdentifiersInShape returns the identifier fields of a given shape which
+// fit expect an ARN.
+func FindARNIdentifiersInShape(
+	r *model.CRD,
+	shape *awssdkmodel.Shape,
+) []string {
+	var identifiers []string
+	if r == nil || shape == nil {
+		return identifiers
+	}
+
+	for _, memberName := range shape.MemberNames() {
+		if r.IsPrimaryARNField(memberName) {
+			identifiers = append(identifiers, memberName)
+		}
+	}
+
+	return identifiers
+}
+
 // FindIdentifiersInCRD returns the identifier fields of a given CRD which
 // can be singular or plural. Note, these fields will be the *original* field
 // names from the API model shape, not renamed field names.
@@ -81,3 +109,114 @@ func FindIdentifiersInCRD(
 
 	return identifiers
 }
+
+// FindPluralizedIdentifiersInShape returns the name of a Spec OR Status field
+// that has a matching pluralized field in the given shape and the name of
+// the corresponding shape field name. This method will returns the original
+// field name - renames will need to be handled separately.
+// For example, DescribeVpcsInput has a `VpcIds` field which would be matched
+// to the `Status.VPCID` CRD field - the return value would be
+// "VPCID", "VpcIds".
+func FindPluralizedIdentifiersInShape(
+	r *model.CRD,
+	shape *awssdkmodel.Shape,
+) (crField string, shapeField string) {
+	shapeIdentifiers := FindIdentifiersInShape(r, shape)
+	crIdentifiers := FindIdentifiersInCRD(r)
+	if len(shapeIdentifiers) == 0 || len(crIdentifiers) == 0 {
+		return "", ""
+	}
+
+	pluralize := pluralize.NewClient()
+	for _, si := range shapeIdentifiers {
+		for _, ci := range crIdentifiers {
+			if strings.EqualFold(pluralize.Singular(si),
+				pluralize.Singular(ci)) {
+				// The CRD identifiers being used for comparison reflect the
+				// *original* field names in the API model shape.
+				if crField == "" {
+					crField = ci
+					shapeField = si
+				} else {
+					// If there are multiple identifiers, then prioritize the
+					// 'Id' identifier. Checking 'Id' to determine resource
+					// creation should be safe as the field is usually
+					// present in CR.Status.
+					if !strings.HasSuffix(crField, "Id") ||
+						!strings.HasSuffix(crField, "Ids") {
+						crField = ci
+						shapeField = si
+					}
+				}
+			}
+		}
+	}
+	return crField, shapeField
+}
+
+// FindPrimaryIdentifierFieldNames returns the resource identifier field name
+// for the primary identifier used in a given operation and its corresponding
+// shape field name.
+func FindPrimaryIdentifierFieldNames(
+	cfg *ackgenconfig.Config,
+	r *model.CRD,
+	op *awssdkmodel.Operation,
+) (crField string, shapeField string) {
+	shape := op.InputRef.Shape
+
+	// Attempt to fetch the primary identifier override from the configuration
+	opConfig, ok := cfg.Operations[op.Name]
+	if ok {
+		shapeField = opConfig.PrimaryIdentifierFieldName
+	}
+
+	if shapeField == "" {
+		// For ReadOne, search for a direct identifier
+		if op == r.Ops.ReadOne {
+			identifiers := FindIdentifiersInShape(r, shape)
+			identifiers = append(identifiers, FindARNIdentifiersInShape(r, shape)...)
+
+			switch len(identifiers) {
+			case 0:
+				break
+			case 1:
+				shapeField = identifiers[0]
+			default:
+				panic("Found multiple possible primary identifiers for " +
+					r.Names.Original + ". Set " +
+					"`primary_identifier_field_name` for the " + op.Name +
+					" operation in the generator config.")
+			}
+		} else {
+			// For ReadMany, search for pluralized identifiers
+			crField, shapeField = FindPluralizedIdentifiersInShape(r, shape)
+		}
+
+		// Require override if still can't find any identifiers
+		if shapeField == "" {
+			panic("Could not find primary identifier for " + r.Names.Original +
+				". Set `primary_identifier_field_name` for the " + op.Name +
+				" operation in the generator config.")
+		}
+	}
+
+	if r.IsPrimaryARNField(shapeField) || shapeField == PrimaryIdentifierARNOverride {
+		return "", PrimaryIdentifierARNOverride
+	}
+
+	if crField == "" {
+		renamedName, _ := r.InputFieldRename(
+			op.Name, shapeField,
+		)
+
+		_, inSpec := r.SpecFields[renamedName]
+		_, inStatus := r.StatusFields[renamedName]
+		if inSpec || inStatus {
+			crField = renamedName
+		} else {
+			panic("Could not find corresponding spec or status field for primary identifier " + shapeField)
+		}
+	}
+
+	return crField, shapeField
+}