using System;
using System.Runtime.InteropServices;
using Unity.Collections.LowLevel.Unsafe;

public struct OfflineButtons : IEquatable<OfflineButtons>
{
    // [FieldOffset(0)]
    private int _bits;

    //
    // Summary:
    //     Gets the bits representing the state of the buttons.
    public int Bits => _bits;

    //
    // Summary:
    //     Initializes a new instance of the NetworkButtons struct with the specified buttons
    //     state.
    //
    // Parameters:
    //   buttons:
    //     The integer representing the state of the buttons.
    public OfflineButtons(int buttons)
    {
        _bits = buttons;
    }

    //
    // Summary:
    //     Checks if the button at the specified index is set.
    //
    // Parameters:
    //   button:
    //     The index of the button to check.
    //
    // Returns:
    //     true if the button is set; otherwise, false.
    public bool IsSet(int button)
    {
        return (_bits & (1 << button)) != 0;
    }

    //
    // Summary:
    //     Sets the button at the specified index to down.
    //
    // Parameters:
    //   button:
    //     The index of the button to set to down.
    public void SetDown(int button)
    {
        _bits |= 1 << button;
    }

    //
    // Summary:
    //     Sets the button at the specified index to up.
    //
    // Parameters:
    //   button:
    //     The index of the button to set to up.
    public void SetUp(int button)
    {
        _bits &= ~(1 << button);
    }

    //
    // Summary:
    //     Sets the button at the specified index to the specified state.
    //
    // Parameters:
    //   button:
    //     The index of the button to set.
    //
    //   state:
    //     The state to set the button to.
    public void Set(int button, bool state)
    {
        if (state)
        {
            SetDown(button);
        }
        else
        {
            SetUp(button);
        }
    }

    //
    // Summary:
    //     Sets all buttons to up.
    public void SetAllUp()
    {
        _bits = 0;
    }

    //
    // Summary:
    //     Sets all buttons to down.
    public void SetAllDown()
    {
        _bits = -1;
    }

    //
    // Summary:
    //     Checks if the button of the specified enum type is set.
    //
    // Parameters:
    //   button:
    //     The button of type T to check.
    //
    // Type parameters:
    //   T:
    //     The enum type of the button.
    //
    // Returns:
    //     true if the button is set; otherwise, false.
    public bool IsSet<T>(T button) where T : unmanaged, Enum
    {
        return IsSet(UnsafeUtility.EnumToInt(button));
    }

    //
    // Summary:
    //     Sets the button of the specified enum type to down.
    //
    // Parameters:
    //   button:
    //     The button of type T to set to down.
    //
    // Type parameters:
    //   T:
    //     The enum type of the button.
    public void SetDown<T>(T button) where T : unmanaged, Enum
    {
        SetDown(UnsafeUtility.EnumToInt(button));
    }

    //
    // Summary:
    //     Sets the button of the specified enum type to up.
    //
    // Parameters:
    //   button:
    //     The button of type T to set to up.
    //
    // Type parameters:
    //   T:
    //     The enum type of the button.
    public void SetUp<T>(T button) where T : unmanaged, Enum
    {
        SetDown(UnsafeUtility.EnumToInt(button));
    }

    //
    // Summary:
    //     Sets the button of the specified enum type to the specified state.
    //
    // Parameters:
    //   button:
    //     The button of type T to set.
    //
    //   state:
    //     The state to set the button to.
    //
    // Type parameters:
    //   T:
    //     The enum type of the button.
    public void Set<T>(T button, bool state) where T : unmanaged, Enum
    {
        Set(UnsafeUtility.EnumToInt(button), state);
    }

    //
    // Summary:
    //     Gets the buttons that were pressed or released since the previous state.
    //
    // Parameters:
    //   previous:
    //     The previous state of the buttons.
    //
    // Returns:
    //     A tuple containing the buttons that were pressed and the buttons that were released.
    public (OfflineButtons, OfflineButtons) GetPressedOrReleased(OfflineButtons previous)
    {
        return (GetPressed(previous), GetReleased(previous));
    }

    //
    // Summary:
    //     Gets the buttons that were pressed since the previous state.
    //
    // Parameters:
    //   previous:
    //     The previous state of the buttons.
    //
    // Returns:
    //     The buttons that were pressed.
    public OfflineButtons GetPressed(OfflineButtons previous)
    {
        previous._bits = (previous._bits ^ _bits) & _bits;
        return previous;
    }

    //
    // Summary:
    //     Gets the buttons that were released since the previous state.
    //
    // Parameters:
    //   previous:
    //     The previous state of the buttons.
    //
    // Returns:
    //     The buttons that were released.
    public OfflineButtons GetReleased(OfflineButtons previous)
    {
        previous._bits = (previous._bits ^ _bits) & previous._bits;
        return previous;
    }

    //
    // Summary:
    //     Checks if the button at the specified index was pressed since the previous state.
    //
    //
    // Parameters:
    //   previous:
    //     The previous state of the buttons.
    //
    //   button:
    //     The index of the button to check.
    //
    // Returns:
    //     true if the button was pressed; otherwise, false.
    public bool WasPressed(OfflineButtons previous, int button)
    {
        return GetPressed(previous).IsSet(button);
    }

    //
    // Summary:
    //     Checks if the button at the specified index was released since the previous state.
    //
    //
    // Parameters:
    //   previous:
    //     The previous state of the buttons.
    //
    //   button:
    //     The index of the button to check.
    //
    // Returns:
    //     true if the button was released; otherwise, false.
    public bool WasReleased(OfflineButtons previous, int button)
    {
        return GetReleased(previous).IsSet(button);
    }

    //
    // Summary:
    //     Checks if the button of the specified enum type was pressed since the previous
    //     state.
    //
    // Parameters:
    //   previous:
    //     The previous state of the buttons.
    //
    //   button:
    //     The button of type T to check.
    //
    // Type parameters:
    //   T:
    //     The enum type of the button.
    //
    // Returns:
    //     true if the button was pressed; otherwise, false.
    public bool WasPressed<T>(OfflineButtons previous, T button) where T : unmanaged, Enum
    {
        return GetPressed(previous).IsSet(button);
    }

    //
    // Summary:
    //     Checks if the button of the specified enum type was released since the previous
    //     state.
    //
    // Parameters:
    //   previous:
    //     The previous state of the buttons.
    //
    //   button:
    //     The button of type T to check.
    //
    // Type parameters:
    //   T:
    //     The enum type of the button.
    //
    // Returns:
    //     true if the button was released; otherwise, false.
    public bool WasReleased<T>(OfflineButtons previous, T button) where T : unmanaged, Enum
    {
        return GetReleased(previous).IsSet(button);
    }

    //
    // Summary:
    //     Determines whether the specified NetworkButtons is equal to the current NetworkButtons.
    //
    //
    // Parameters:
    //   other:
    //     The NetworkButtons to compare with the current NetworkButtons.
    //
    // Returns:
    //     true if the specified NetworkButtons is equal to the current NetworkButtons;
    //     otherwise, false.
    public bool Equals(OfflineButtons other)
    {
        return _bits == other._bits;
    }

    //
    // Summary:
    //     Determines whether the specified object is equal to the current NetworkButtons.
    //
    //
    // Parameters:
    //   obj:
    //     The object to compare with the current NetworkButtons.
    //
    // Returns:
    //     true if the specified object is equal to the current NetworkButtons; otherwise,
    //     false.
    public override bool Equals(object obj)
    {
        if (obj is OfflineButtons other)
        {
            return Equals(other);
        }

        return false;
    }

    //
    // Summary:
    //     Serves as the default hash function.
    //
    // Returns:
    //     A hash code for the current NetworkButtons.
    public override int GetHashCode()
    {
        return _bits;
    }
}