// Copyright Epic Games, Inc. All Rights Reserved.

#pragma once

#include "CoreMinimal.h"

////////////////////////////////////////////////////////////////////////////////////////////////////

enum class ETableCellDataType : uint32
{
    Unknown,

    // Basic types.
    Bool,
    // Int32,
    Int64,
    Float,
    Double,
    CString,

    // Custom types.
    Custom,
    Custom_Text,  // FTextCustomTableCellValue
    Text = Custom_Text,

    /** Invalid enum type, may be used as a number of enumerations. */
    InvalidOrMax,
};

////////////////////////////////////////////////////////////////////////////////////////////////////

class ICustomTableCellValue
{
public:
    virtual bool AsBool() const     = 0;
    virtual int64 AsInt64() const   = 0;
    virtual double AsDouble() const = 0;
    virtual FText AsText() const    = 0;
};

////////////////////////////////////////////////////////////////////////////////////////////////////

class FTextCustomTableCellValue: public ICustomTableCellValue
{
public:
    FTextCustomTableCellValue(const FText& InText): Text(InText) {}
    virtual ~FTextCustomTableCellValue() {}

    virtual bool AsBool() const override { return false; }
    virtual int64 AsInt64() const override { return 0; }
    virtual double AsDouble() const override { return 0.0; }
    virtual FText AsText() const override { return Text; }

    const FText& GetText() const { return Text; }

private:
    const FText Text;
};

////////////////////////////////////////////////////////////////////////////////////////////////////

struct FTableCellValue
{
public:
    FTableCellValue(): DataType(ETableCellDataType::Unknown) {}

    FTableCellValue(bool Value): DataType(ETableCellDataType::Bool), Bool(Value) {}
    FTableCellValue(int64 Value): DataType(ETableCellDataType::Int64), Int64(Value) {}
    FTableCellValue(float Value): DataType(ETableCellDataType::Float), Float(Value) {}
    FTableCellValue(double Value): DataType(ETableCellDataType::Double), Double(Value) {}
    FTableCellValue(const TCHAR* Value): DataType(ETableCellDataType::CString), CString(Value) {}
    FTableCellValue(TSharedPtr<ICustomTableCellValue> Value): DataType(ETableCellDataType::Custom), Custom(Value) {}
    FTableCellValue(const FText& Value): DataType(ETableCellDataType::Custom_Text), Custom(MakeShared<FTextCustomTableCellValue>(Value)) {}

    bool AsBool() const
    {
        switch (DataType)
        {
            case ETableCellDataType::Unknown: return false;
            case ETableCellDataType::Bool:    return Bool;
            case ETableCellDataType::Int64:   return Int64 != 0;
            case ETableCellDataType::Float:   return Float != 0.0f;
            case ETableCellDataType::Double:  return Double != 0.0;
            case ETableCellDataType::CString: return CString != nullptr;
            default:                          return Custom.IsValid() ? Custom->AsBool() : false;
        }
    }

    int64 AsInt64() const
    {
        switch (DataType)
        {
            case ETableCellDataType::Unknown: return 0;
            case ETableCellDataType::Bool:    return Bool ? 1 : 0;
            case ETableCellDataType::Int64:   return Int64;
            case ETableCellDataType::Float:   return static_cast<int64>(Float);
            case ETableCellDataType::Double:  return static_cast<int64>(Double);
            case ETableCellDataType::CString: return FCString::Atoi64(CString);
            default:                          return Custom.IsValid() ? Custom->AsInt64() : 0;
        }
    }

    float AsFloat() const
    {
        switch (DataType)
        {
            case ETableCellDataType::Unknown: return 0.0f;
            case ETableCellDataType::Bool:    return Bool ? 1.0f : 0.0f;
            case ETableCellDataType::Int64:   return static_cast<float>(Int64);
            case ETableCellDataType::Float:   return Float;
            case ETableCellDataType::Double:  return static_cast<float>(Double);
            case ETableCellDataType::CString: return FCString::Atof(CString);
            default:                          return Custom.IsValid() ? static_cast<float>(Custom->AsDouble()) : 0.0f;
        }
    }

    float AsDouble() const
    {
        switch (DataType)
        {
            case ETableCellDataType::Unknown: return 0.0;
            case ETableCellDataType::Bool:    return Bool ? 1.0 : 0.0;
            case ETableCellDataType::Int64:   return static_cast<double>(Int64);
            case ETableCellDataType::Float:   return static_cast<double>(Float);
            case ETableCellDataType::Double:  return Double;
            case ETableCellDataType::CString: return FCString::Atod(CString);
            default:                          return Custom.IsValid() ? Custom->AsDouble() : 0.0;
        }
    }

    FString AsString() const
    {
        switch (DataType)
        {
            case ETableCellDataType::Unknown: return FString();
            case ETableCellDataType::Bool:    return Bool ? FString(TEXT("True")) : FString(TEXT("False"));
            case ETableCellDataType::Int64:   return FString::Printf(TEXT("%lld"), Int64);
            case ETableCellDataType::Float:   return FString::Printf(TEXT("%f"), Float);
            case ETableCellDataType::Double:  return FString::Printf(TEXT("%f"), Double);
            case ETableCellDataType::CString: return FString(CString);
            default:                          return Custom.IsValid() ? Custom->AsText().ToString() : FString();
        }
        return FString();
    }

    FText AsText() const
    {
        switch (DataType)
        {
            case ETableCellDataType::Unknown: return FText::GetEmpty();
            case ETableCellDataType::Bool:    return Bool ? NSLOCTEXT("Table", "Bool_True", "True") : NSLOCTEXT("Table", "Bool_False", "False");
            case ETableCellDataType::Int64:   return FText::AsNumber(Int64);
            case ETableCellDataType::Float:   return FText::AsNumber(Float);
            case ETableCellDataType::Double:  return FText::AsNumber(Double);
            case ETableCellDataType::CString: return FText::FromString(FString(CString));
            default:                          return Custom.IsValid() ? Custom->AsText() : FText::GetEmpty();
        }
    }

    const FText& GetText() const
    {
        if (DataType == ETableCellDataType::Custom_Text && Custom.IsValid())
        {
            return StaticCastSharedPtr<FTextCustomTableCellValue>(Custom)->GetText();
        }
        return FText::GetEmpty();
    }

public:
    ETableCellDataType DataType;

    union
    {
        bool Bool;
        int64 Int64;
        float Float;
        double Double;
        const TCHAR* CString;  // should be valid for the lieftime of the owner table
    };

    TSharedPtr<ICustomTableCellValue> Custom;
};

////////////////////////////////////////////////////////////////////////////////////////////////////