From 5feba7e3a9a16893177bae9041d7a4b6ff904e42 Mon Sep 17 00:00:00 2001
From: Adam Chalmers <achalmers@cloudflare.com>
Date: Mon, 5 Aug 2019 17:40:22 -0500
Subject: [PATCH] TUN-2147: Implemented ScopeUnmarshaler

---
 tunnelrpc/pogs/unmarshal.go      | 41 ++++++++++++++++++++++
 tunnelrpc/pogs/unmarshal_test.go | 60 ++++++++++++++++++++++++++++++++
 2 files changed, 101 insertions(+)
 create mode 100644 tunnelrpc/pogs/unmarshal.go
 create mode 100644 tunnelrpc/pogs/unmarshal_test.go

diff --git a/tunnelrpc/pogs/unmarshal.go b/tunnelrpc/pogs/unmarshal.go
new file mode 100644
index 00000000..ef40ff0a
--- /dev/null
+++ b/tunnelrpc/pogs/unmarshal.go
@@ -0,0 +1,41 @@
+package pogs
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/pkg/errors"
+)
+
+// ScopeUnmarshaler can marshal a Scope pog from JSON.
+type ScopeUnmarshaler struct {
+	Scope Scope
+}
+
+// UnmarshalJSON takes in a JSON string, and attempts to marshal it into a Scope.
+// If successful, the Scope member of this ScopeUnmarshaler is set and nil is returned.
+// If unsuccessful, returns an error.
+func (su *ScopeUnmarshaler) UnmarshalJSON(b []byte) error {
+	var scopeJSON map[string]interface{}
+	if err := json.Unmarshal(b, &scopeJSON); err != nil {
+		return errors.Wrapf(err, "cannot unmarshal %s into scopeJSON", string(b))
+	}
+
+	if group, ok := scopeJSON["group"]; ok {
+		if val, ok := group.(string); ok {
+			su.Scope = NewGroup(val)
+			return nil
+		}
+		return fmt.Errorf("JSON should have been a Scope, but the 'group' key contained %v", group)
+	}
+
+	if systemName, ok := scopeJSON["system_name"]; ok {
+		if val, ok := systemName.(string); ok {
+			su.Scope = NewSystemName(val)
+			return nil
+		}
+		return fmt.Errorf("JSON should have been a Scope, but the 'system_name' key contained %v", systemName)
+	}
+
+	return fmt.Errorf("JSON should have been an object with one root key, either 'system_name' or 'group'")
+}
diff --git a/tunnelrpc/pogs/unmarshal_test.go b/tunnelrpc/pogs/unmarshal_test.go
new file mode 100644
index 00000000..16f83eac
--- /dev/null
+++ b/tunnelrpc/pogs/unmarshal_test.go
@@ -0,0 +1,60 @@
+package pogs
+
+import "testing"
+
+func TestScopeUnmarshaler_UnmarshalJSON(t *testing.T) {
+	type fields struct {
+		Scope Scope
+	}
+	type args struct {
+		b []byte
+	}
+	tests := []struct {
+		name      string
+		fields    fields
+		args      args
+		wantErr   bool
+		wantScope Scope
+	}{
+		{
+			name:      "group_successful",
+			args:      args{b: []byte(`{"group": "my-group"}`)},
+			wantScope: NewGroup("my-group"),
+		},
+		{
+			name:      "system_name_successful",
+			args:      args{b: []byte(`{"system_name": "my-computer"}`)},
+			wantScope: NewSystemName("my-computer"),
+		},
+		{
+			name:    "not_a_scope",
+			args:    args{b: []byte(`{"x": "y"}`)},
+			wantErr: true,
+		},
+		{
+			name:    "malformed_group",
+			args:    args{b: []byte(`{"group": ["a", "b"]}`)},
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			su := &ScopeUnmarshaler{
+				Scope: tt.fields.Scope,
+			}
+			err := su.UnmarshalJSON(tt.args.b)
+			if !tt.wantErr {
+				if err != nil {
+					t.Errorf("ScopeUnmarshaler.UnmarshalJSON() error = %v, wantErr %v", err, tt.wantErr)
+				}
+				if !eqScope(tt.wantScope, su.Scope) {
+					t.Errorf("Wanted scope %v but got scope %v", tt.wantScope, su.Scope)
+				}
+			}
+		})
+	}
+}
+
+func eqScope(s1, s2 Scope) bool {
+	return s1.Value() == s2.Value() && s1.PostgresType() == s2.PostgresType()
+}