Request cpython if there is a node-gyp dependency

constants.go

@@ -4,6 +4,7 @@ const (
 	NodeModules = "node_modules"
 	Node        = "node"
 	Npm         = "npm"
+	Cpython     = "cpython"
 
 	LayerNameNodeModules = "modules"
 	LayerNameCache       = "npm-cache"

detect.go

@@ -38,6 +38,8 @@ func Detect() packit.DetectFunc {
 			return packit.DetectResult{}, err
 		}
 		version := pkg.GetVersion()
+		pythonNeeded := false
+		// TODO: check if a dependency to node-gyp is present
 
 		nodeDependency := packit.BuildPlanRequirement{
 			Name: Node,
@@ -54,21 +56,36 @@ func Detect() packit.DetectFunc {
 			}
 		}
 
-		return packit.DetectResult{
+		npmDependency := packit.BuildPlanRequirement{
+			Name: Npm,
+			Metadata: BuildPlanMetadata{
+				Build: true,
+			},
+		}
+
+		cPythonDependency := packit.BuildPlanRequirement{
+			Name: Cpython,
+			Metadata: BuildPlanMetadata{
+				Build: true,
+			},
+		}
+
+		result := packit.DetectResult{
 			Plan: packit.BuildPlan{
 				Provides: []packit.BuildPlanProvision{
 					{Name: NodeModules},
 				},
 				Requires: []packit.BuildPlanRequirement{
 					nodeDependency,
-					{
-						Name: Npm,
-						Metadata: BuildPlanMetadata{
-							Build: true,
-						},
-					},
+					npmDependency,
 				},
 			},
-		}, nil
+		}
+
+		if pythonNeeded {
+			result.Plan.Requires = append(result.Plan.Requires, cPythonDependency)
+		}
+
+		return result, nil
 	}
 }