#include "WorkflowNodes.hpp"

#include "Utils/Macros.hpp"
#include "Utils/RTTI.hpp"
#include "Utils/Variant.hpp"

#include <cassert>
#include <utility>
#include <variant>

WorkflowNode::Kind NumericOperationNode::OperationTypeToNodeKind(OperationType type) {
	switch (type) {
		case Addition: return KD_NumericAddition;
		case Subtraction: return KD_NumericSubtraction;
		case Multiplication: return KD_NumericMultiplication;
		case Division: return KD_NumericDivision;
		default: UNREACHABLE;
	}
}

NumericOperationNode::OperationType NumericOperationNode::NodeKindToOperationType(Kind kind) {
	switch (kind) {
		case KD_NumericAddition: return Addition;
		case KD_NumericSubtraction: return Subtraction;
		case KD_NumericMultiplication: return Multiplication;
		case KD_NumericDivision: return Division;
		default: UNREACHABLE;
	}
}

bool NumericOperationNode::IsInstance(const WorkflowNode* node) {
	return node->GetKind() >= KD_NumericAddition && node->GetKind() <= KD_NumericDivision;
}

NumericOperationNode::NumericOperationNode(OperationType type)
	: WorkflowNode(TransformType, OperationTypeToNodeKind(type))
	, mType{ type } {
	mInputs.resize(2);
	mInputs[0].MatchingType = BaseValue::KD_Numeric;
	mInputs[1].MatchingType = BaseValue::KD_Numeric;

	mOutputs.resize(1);
	mOutputs[0].MatchingType = BaseValue::KD_Numeric;
}

void NumericOperationNode::Evaluate(WorkflowEvaluationContext& ctx) {
	auto lhsVal = dyn_cast<NumericValue>(ctx.GetConnectionValue(mInputs[0]));
	if (!lhsVal) return;
	double lhs = lhsVal->GetValue();

	auto rhsVal = dyn_cast<NumericValue>(ctx.GetConnectionValue(mInputs[1]));
	if (!rhsVal) return;
	double rhs = rhsVal->GetValue();

	double res;
	switch (mType) {
		case Addition: res = lhs + rhs; break;
		case Subtraction: res = lhs - rhs; break;
		case Multiplication: res = lhs * rhs; break;
		case Division: {
			if (rhs == 0.0) {
				// TODO localize
				ctx.ReportError("Error: division by 0", *this);
				return;
			}
			res = lhs / rhs;
		} break;

		default: return;
	}

	auto value = std::make_unique<NumericValue>();
	value->SetValue(res);
	ctx.SetConnectionValue(mOutputs[0], std::move(value));
}

bool NumericExpressionNode::IsInstance(const WorkflowNode* node) {
	return node->GetKind() == KD_NumericExpression;
}

NumericExpressionNode::NumericExpressionNode()
	: WorkflowNode(TransformType, KD_NumericExpression) {
}

struct FormatTextNode::Argument {
	ArgumentType ArgumentType;
	int PinIdx;

	template <class TFunction>
	static void ForArguments(std::vector<Element>::iterator begin, std::vector<Element>::iterator end, const TFunction& func) {
		for (auto it = begin; it != end; ++it) {
			auto& elm = *it;
			if (auto arg = std::get_if<Argument>(&elm)) {
				func(*arg);
			}
		}
	}

	/// Find the pin index that the \c elmIdx -th element should have, based on the elements coming before it.
	static int FindPinForElement(const std::vector<Element>& vec, int elmIdx) {
		for (int i = elmIdx; i >= 0; --i) {
			auto& elm = vec[i];
			if (auto arg = std::get_if<Argument>(&elm)) {
				return arg->PinIdx + 1;
			}
		}
		return 0;
	}
};

BaseValue::Kind FormatTextNode::ArgumentTypeToValueKind(FormatTextNode::ArgumentType arg) {
	switch (arg) {
		case NumericArgument: return BaseValue::KD_Numeric;
		case TextArgument: return BaseValue::KD_Text;
		case DateTimeArgument: return BaseValue::KD_DateTime;
		default: UNREACHABLE;
	}
}

bool FormatTextNode::IsInstance(const WorkflowNode* node) {
	return node->GetKind() == KD_TextFormatting;
}

FormatTextNode::FormatTextNode()
	: WorkflowNode(TransformType, KD_TextFormatting) {
}

int FormatTextNode::GetElementCount() const {
	return mElements.size();
}

const FormatTextNode::Element& FormatTextNode::GetElement(int idx) const {
	return mElements[idx];
}

void FormatTextNode::SetElement(int idx, std::string text) {
	assert(idx >= 0 && idx < mElements.size());

	std::visit(
		Overloaded{
			[&](const std::string& original) { mMinOutputChars -= original.size(); },
			[&](const Argument& original) { PreRemoveElement(idx); },
		},
		mElements[idx]);

	mMinOutputChars += text.size();
	mElements[idx] = std::move(text);
}

void FormatTextNode::SetElement(int idx, ArgumentType argument) {
	assert(idx >= 0 && idx < mElements.size());

	std::visit(
		Overloaded{
			[&](const std::string& original) {
				mMinOutputChars -= original.size();

				mElements[idx] = Argument{
					.ArgumentType = argument,
					.PinIdx = Argument::FindPinForElement(mElements, idx),
				};
				/* `original` is invalid from this point */
			},
			[&](const Argument& original) {
				int pinIdx = original.PinIdx;

				// Create pin
				auto& pin = mInputs[pinIdx];
				pin.MatchingType = ArgumentTypeToValueKind(argument);

				// Create element
				mElements[idx] = Argument{
					.ArgumentType = argument,
					.PinIdx = pinIdx,
				};
				/* `original` is invalid from this point */
			},
		},
		mElements[idx]);
}

void FormatTextNode::InsertElement(int idx, std::string text) {
	assert(idx >= 0);
	if (idx >= mElements.size()) AppendElement(std::move(text));

	mMinOutputChars += text.size();
	mElements.insert(mElements.begin() + idx, std::move(text));
}

void FormatTextNode::InsertElement(int idx, ArgumentType argument) {
	assert(idx >= 0);
	if (idx >= mElements.size()) AppendElement(argument);

	int pinIdx = Argument::FindPinForElement(mElements, idx);

	// Create pin
	auto& pin = InsertInputPin(pinIdx);
	pin.MatchingType = ArgumentTypeToValueKind(argument);

	// Create element
	mElements.insert(
		mElements.begin() + idx,
		Argument{
			.ArgumentType = argument,
			.PinIdx = pinIdx,
		});
}

void FormatTextNode::AppendElement(std::string text) {
	mMinOutputChars += text.size();
	mElements.push_back(std::move(text));
}

void FormatTextNode::AppendElement(ArgumentType argument) {
	int pinIdx = mInputs.size();
	// Create pin
	mInputs.push_back(InputPin{});
	mInputs.back().MatchingType = ArgumentTypeToValueKind(argument);
	// Creat eelement
	mElements.push_back(Argument{
		.ArgumentType = argument,
		.PinIdx = pinIdx,
	});
}

void FormatTextNode::RemoveElement(int idx) {
	assert(idx >= 0 && idx < mElements.size());

	PreRemoveElement(idx);
	if (auto arg = std::get_if<Argument>(&mElements[idx])) {
		RemoveInputPin(arg->PinIdx);
	}
	mElements.erase(mElements.begin() + idx);
}

void FormatTextNode::Evaluate(WorkflowEvaluationContext& ctx) {
	std::string result;
	result.reserve((size_t)(mMinOutputChars * 1.5f));

	auto HandleText = [&](const std::string& str) {
		result += str;
	};
	auto HandleArgument = [&](const Argument& arg) {
		switch (arg.ArgumentType) {
			case NumericArgument: {
				if (auto val = dyn_cast<NumericValue>(ctx.GetConnectionValue(mInputs[arg.PinIdx]))) {
					result += val->GetString();
				} else {
					// TODO localize
					ctx.ReportError("Non-numeric value connected to a numeric text format parameter.", *this);
				}
			} break;
			case TextArgument: {
				if (auto val = dyn_cast<TextValue>(ctx.GetConnectionValue(mInputs[arg.PinIdx]))) {
					result += val->GetValue();
				} else {
					// TODO localize
					ctx.ReportError("Non-text value connected to a textual text format parameter.", *this);
				}
			} break;
			case DateTimeArgument: {
				if (auto val = dyn_cast<DateTimeValue>(ctx.GetConnectionValue(mInputs[arg.PinIdx]))) {
					result += val->GetString();
				} else {
					// TODO localize
					ctx.ReportError("Non-date/time value connected to a date/time text format parameter.", *this);
				}
			} break;
		}
	};

	for (auto& elm : mElements) {
		std::visit(Overloaded{ HandleText, HandleArgument }, elm);
	}
}

void FormatTextNode::PreRemoveElement(int idx) {
	auto& elm = mElements[idx];
	if (auto arg = std::get_if<Argument>(&elm)) {
		RemoveInputPin(arg->PinIdx);
		Argument::ForArguments(
			mElements.begin() + idx + 1,
			mElements.end(),
			[&](Argument& arg) {
				arg.PinIdx--;
			});
	}
}

bool DocumentTemplateExpansionNode::IsInstance(const WorkflowNode* node) {
	return node->GetKind() == KD_DocumentTemplateExpansion;
}

DocumentTemplateExpansionNode::DocumentTemplateExpansionNode()
	: WorkflowNode(TransformType, KD_DocumentTemplateExpansion) {
}

bool FormInputNode::IsInstance(const WorkflowNode* node) {
	return node->GetKind() == KD_FormInput;
}

FormInputNode::FormInputNode()
	: WorkflowNode(InputType, KD_FormInput) {
}

bool DatabaseRowsInputNode::IsInstance(const WorkflowNode* node) {
	return node->GetKind() == KD_DatabaseRowsInput;
}

DatabaseRowsInputNode::DatabaseRowsInputNode()
	: WorkflowNode(InputType, KD_DatabaseRowsInput) {
}