Initial work on workflows

1 files changed, 101 insertions, 0 deletions

diff --git a/core/src/Model/Workflow.hpp b/core/src/Model/Workflow.hpp
new file mode 100644
index 0000000..a90ef21
--- /dev/null
+++ b/core/src/Model/Workflow.hpp
@@ -0,0 +1,101 @@
+#pragma once
+
+#include "EvaluatedValue.hpp"
+
+#include <cstddef>
+#include <cstdint>
+#include <limits>
+#include <memory>
+#include <vector>
+
+class WorkflowConnection {
+public:
+	size_t Source;
+	size_t Destination;
+};
+
+class WorkflowStep {
+public:
+	static constexpr auto kInvalidId = std::numeric_limits<size_t>::max();
+
+	// TODO do we even need this?
+	//	enum Type {
+	//		NumericAdditionType,
+	//		NumericSubtractionType,
+	//		NumericMultiplicationType,
+	//		NumericDivisionType,
+	//		NumericExpressionType,
+	//		TextFormattingType,
+	//		FormInputType,
+	//		DatabaseRowsInputType,
+	//		DocumentTemplateExpansionType,
+	//
+	//		InvalidType,
+	//		TypeCount = InvalidType,
+	//	};
+
+protected:
+	struct InputNode {
+		size_t ConnectedStep = kInvalidId;
+		int ConnectedNodeIndex = -1;
+		BaseValue::Type MatchingType = BaseValue::InvalidType;
+
+		bool IsConnected() const;
+	};
+
+	struct OutputNode {
+		size_t ConnectedStep = kInvalidId;
+		int ConnectedNodeIndex = -1;
+		BaseValue::Type MatchingType = BaseValue::InvalidType;
+
+		bool IsConnected() const;
+	};
+
+	friend class Workflow;
+	Workflow* mWorkflow;
+	size_t mId;
+	std::vector<InputNode> mInputs;
+	std::vector<OutputNode> mOutputs;
+
+public:
+	virtual ~WorkflowStep() = default;
+
+	WorkflowStep(const WorkflowStep&) = delete;
+	WorkflowStep& operator=(const WorkflowStep&) = delete;
+	WorkflowStep(WorkflowStep&&) = default;
+	WorkflowStep& operator=(WorkflowStep&&) = default;
+
+	size_t GetId() const;
+
+	void ConnectInput(int nodeId, size_t outputId, int outputNodeId);
+	void DisconnectInput(int nodeId);
+	bool IsInputConnected(int nodeId) const;
+
+	void ConnectOutput(int nodeId, size_t inputId, int inputNodeId);
+	void DisconnectOutput(int nodeId);
+	bool IsOutputConnected(int nodeId) const;
+
+protected:
+	/// Child classes should call this whenever \c mInputs and \c mOutputs are about to be modified (append or remove)
+	/// after invocation of the constructor.
+	void OnIOAboutToChange();
+	void OnIOChanged();
+};
+
+class Workflow {
+private:
+	std::vector<WorkflowConnection> mConnections;
+	std::vector<std::unique_ptr<WorkflowStep>> mSteps;
+
+public:
+	WorkflowConnection* GetConnectionById(size_t id);
+	WorkflowStep* GetStepById(size_t id);
+
+	void Connect(size_t source, int sourceNode, size_t destination, int destinationNode);
+	void DisconnectBySource(size_t source, int sourceNode);
+	void DisconnectByDestination(size_t destination, int destinationNode);
+};
+
+class WorkflowEvaluationContext {
+
+};