gb-emu/lib/src/processor/memory/addresses.rs

use std::ops::{Add, Sub};

pub(crate) use self::types::*;

mod types;

pub(crate) type VramAddress = BoundedAddress<0x8000, 0xA000>;
pub(crate) type CartRamAddress = BoundedAddress<0xA000, 0xC000>;
pub(crate) type WorkRamAddress = BoundedAddress<0xC000, 0xD000>;
pub(crate) type BankedWorkRamAddress = BoundedAddress<0xD000, 0xE000>;
pub(crate) type MirroredRamAddress = BoundedAddress<0xE000, 0xFE00>;
pub(crate) type OamAddress = BoundedAddress<0xFE00, 0xFEA0>;
pub(crate) type ProhibitedAddress = BoundedAddress<0xFEA0, 0xFF00>;
pub(crate) type HramAddress = BoundedAddress<0xFF80, 0xFFFF>;
pub(crate) type InterruptEnable = ();

pub(crate) type Bank0Address = BoundedAddress<0x0, 0x4000>;
pub(crate) type MappedBankAddress = BoundedAddress<0x4000, 0x8000>;

pub(crate) type SerialAddress = BoundedAddress<0xFF01, 0xFF03>;
pub(crate) type TimerAddress = BoundedAddress<0xFF04, 0xFF08>;
pub(crate) type AudioAddress = BoundedAddress<0xFF10, 0xFF27>;
pub(crate) type WaveRamAddress = BoundedAddress<0xFF30, 0xFF40>;
pub(crate) type VideoAddress = BoundedAddress<0xFF40, 0xFF4C>;

pub(crate) enum RomAddress {
    Bank0(Bank0Address),
    MappedBank(MappedBankAddress),
}

pub(crate) enum IoAddress {
    Joypad,
    Serial(SerialAddress),
    Timer(TimerAddress),
    InterruptFlag,
    Audio(AudioAddress),
    WaveRam(WaveRamAddress),
    Video(VideoAddress),
    Unused(u16),
}

pub(crate) enum Address {
    Rom(RomAddress),
    Vram(VramAddress),
    CartRam(CartRamAddress),
    WorkRam(WorkRamAddress),
    BankedWorkRam(BankedWorkRamAddress),
    MirroredRam(MirroredRamAddress),
    Oam(OamAddress),
    Prohibited(ProhibitedAddress),
    Io(IoAddress),
    Hram(HramAddress),
    InterruptEnable(InterruptEnable),
}

impl TryInto<RomAddress> for u16 {
    type Error = AddressError;

    fn try_into(self) -> Result<RomAddress, Self::Error> {
        match self {
            0x0..0x4000 => Ok(RomAddress::Bank0(self.try_into().unwrap())),
            0x4000..0x8000 => Ok(RomAddress::MappedBank(self.try_into().unwrap())),
            _ => Err(AddressError::OutOfBounds),
        }
    }
}

impl AddressMarker for RomAddress {
    fn inner(&self) -> u16 {
        match self {
            RomAddress::Bank0(v) => v.inner(),
            RomAddress::MappedBank(v) => v.inner(),
        }
    }
}

impl From<u16> for Address {
    fn from(value: u16) -> Self {
        match value {
            0x0..0x8000 => Address::Rom(value.try_into().unwrap()),
            0x8000..0xA000 => Address::Vram(value.try_into().unwrap()),
            0xA000..0xC000 => Address::CartRam(value.try_into().unwrap()),
            0xC000..0xD000 => Address::WorkRam(value.try_into().unwrap()),
            0xD000..0xE000 => Address::BankedWorkRam(value.try_into().unwrap()),
            0xE000..0xFE00 => Address::MirroredRam(value.try_into().unwrap()),
            0xFE00..0xFEA0 => Address::Oam(value.try_into().unwrap()),
            0xFEA0..0xFF00 => Address::Prohibited(value.try_into().unwrap()),
            0xFF00..0xFF80 => Address::Io(value.try_into().unwrap()),
            0xFF80..0xFFFF => Address::Hram(value.try_into().unwrap()),
            0xFFFF => Address::InterruptEnable(()),
        }
    }
}

impl TryInto<IoAddress> for u16 {
    type Error = AddressError;

    fn try_into(self) -> Result<IoAddress, Self::Error> {
        match self {
            0xFF00 => Ok(IoAddress::Joypad),
            0xFF01..0xFF03 => Ok(IoAddress::Serial(self.try_into().unwrap())),
            0xFF04..0xFF08 => Ok(IoAddress::Timer(self.try_into().unwrap())),
            0xFF0F => Ok(IoAddress::InterruptFlag),
            0xFF10..0xFF27 => Ok(IoAddress::Audio(self.try_into().unwrap())),
            0xFF30..0xFF40 => Ok(IoAddress::WaveRam(self.try_into().unwrap())),
            0xFF40..0xFF4C => Ok(IoAddress::Video(self.try_into().unwrap())),
            0x0..0xFF00 => Err(AddressError::OutOfBounds),
            0xFFFF => Err(AddressError::OutOfBounds),
            _ => Ok(IoAddress::Unused(self)),
        }
    }
}

impl AddressMarker for IoAddress {
    fn inner(&self) -> u16 {
        match self {
            IoAddress::Joypad => 0xFF00,
            IoAddress::Serial(v) => v.inner(),
            IoAddress::Timer(v) => v.inner(),
            IoAddress::InterruptFlag => 0xFF0F,
            IoAddress::Audio(v) => v.inner(),
            IoAddress::WaveRam(v) => v.inner(),
            IoAddress::Video(v) => v.inner(),
            IoAddress::Unused(v) => *v,
        }
    }
}

impl AddressMarker for Address {
    fn inner(&self) -> u16 {
        match self {
            Address::Rom(v) => v.inner(),
            Address::Vram(v) => v.inner(),
            Address::CartRam(v) => v.inner(),
            Address::WorkRam(v) => v.inner(),
            Address::BankedWorkRam(v) => v.inner(),
            Address::MirroredRam(v) => v.inner(),
            Address::Oam(v) => v.inner(),
            Address::Prohibited(v) => v.inner(),
            Address::Io(v) => v.inner(),
            Address::Hram(v) => v.inner(),
            Address::InterruptEnable(_) => 0xFFFF,
        }
    }
}

impl From<Address> for u16 {
    fn from(value: Address) -> Self {
        value.inner()
    }
}

impl Add for Address {
    type Output = Address;

    fn add(self, rhs: Self) -> Self::Output {
        self.inner().wrapping_add(rhs.inner()).into()
    }
}

impl Sub for Address {
    type Output = Address;

    fn sub(self, rhs: Self) -> Self::Output {
        self.inner().wrapping_sub(rhs.inner()).into()
    }
}