From 19afe30fd2687bbd70c82f52b42c5748eca266b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?M=C3=A1ximo=20Cuadros?= <mcuadros@gmail.com>
Date: Thu, 21 May 2020 18:46:49 +0200
Subject: [PATCH] starlark/types: Provider, set_prefix

---
 starlark/types/provider.go       | 35 ++++++++++++++++++++++++++++++++
 starlark/types/resource.go       |  6 +++++-
 starlark/types/testdata/hcl.star | 17 ++++++++++++++++
 3 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/starlark/types/provider.go b/starlark/types/provider.go
index c64f78d..e629322 100644
--- a/starlark/types/provider.go
+++ b/starlark/types/provider.go
@@ -97,9 +97,20 @@ func MakeProvider(
 //             Blocks defined by the provider schema, thus are nested resources,
 //             containing other arguments and/or blocks.
 //
+//         methods:
+//           set_prefix(enable, prefix="")
+//             If enabled, all the resource names belonging to this provider
+//             are prefixed, with the given prefix or by default the alias name.
+//             params:
+//               enable bool
+//                 if True enables the the prefix of resources.
+//               prefix string
+//                 string to be used as prefix of the resources, if None, the
+//                 provider name it's used as prefix.
 type Provider struct {
 	provider *plugin.GRPCProvider
 	meta     discovery.PluginMeta
+	prefix   string
 
 	dataSources *ResourceCollectionGroup
 	resources   *ResourceCollectionGroup
@@ -190,6 +201,8 @@ func (p *Provider) Type() string {
 // Attr honors the starlark.Attr interface.
 func (p *Provider) Attr(name string) (starlark.Value, error) {
 	switch name {
+	case "set_prefix":
+		return starlark.NewBuiltin("set_prefix", p.setPrefix), nil
 	case "__version__":
 		return starlark.String(p.meta.Version), nil
 	case "data":
@@ -201,6 +214,28 @@ func (p *Provider) Attr(name string) (starlark.Value, error) {
 	return p.Resource.Attr(name)
 }
 
+func (p *Provider) setPrefix(_ *starlark.Thread, _ *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
+
+	var enable bool
+	var prefix string
+	err := starlark.UnpackArgs("set_prefix", args, kwargs, "enable", &enable, "prefix?", &prefix)
+	if err != nil {
+		return nil, err
+	}
+
+	if enable == false {
+		p.prefix = ""
+		return starlark.Bool(enable), nil
+	}
+
+	p.prefix = p.name
+	if prefix != "" {
+		p.prefix = prefix
+	}
+
+	return starlark.Bool(enable), nil
+}
+
 // AttrNames honors the starlark.HasAttrs interface.
 func (p *Provider) AttrNames() []string {
 	return append(p.Resource.AttrNames(), "data", "resource", "__version__")
diff --git a/starlark/types/resource.go b/starlark/types/resource.go
index eb97830..56a70e3 100644
--- a/starlark/types/resource.go
+++ b/starlark/types/resource.go
@@ -286,8 +286,12 @@ func (r *Resource) Truth() starlark.Bool {
 // Freeze honors the starlark.Value interface.
 func (r *Resource) Freeze() {}
 
-// Name returns the resource name based on the hash.
+// Name returns the resource name based.
 func (r *Resource) Name() string {
+	if r.kind == ResourceKind && r.provider.prefix != "" {
+		return fmt.Sprintf("%s-%s", r.provider.prefix, r.name)
+	}
+
 	return r.name
 }
 
diff --git a/starlark/types/testdata/hcl.star b/starlark/types/testdata/hcl.star
index e502dfd..d735dfd 100644
--- a/starlark/types/testdata/hcl.star
+++ b/starlark/types/testdata/hcl.star
@@ -51,4 +51,21 @@ assert.eq(hcl(google), "" +
 '  bucket   = "main-storage"\n' + \
 '  member   = "serviceAccount:${google_service_account.sa.email}"\n' + \
 '  role     = "roles/storage.objectAdmin"\n' + \
+'}\n\n')
+
+# hcl with prefixed provider
+google = tf.provider("google", "3.16.0", "alias")
+google.set_prefix(True)
+
+sa = google.resource.service_account("sa")
+sa.account_id = "service-account"
+assert.eq(hcl(google), "" +
+'provider "google" {\n' + \
+'  alias   = "alias"\n' + \
+'  version = "3.16.0"\n' + \
+'}\n' + \
+'\n' + \
+'resource "google_service_account" "alias-sa" {\n' + \
+'  provider   = google.alias\n' + \
+'  account_id = "service-account"\n' + \
 '}\n\n')
\ No newline at end of file