gb.rs

use crate::{
    apu::Apu,
    cpu::Cpu,
    data::{BootRom, CGB_BOOT, DMG_BOOT, DMG_BOOTIX, MGB_BOOTIX, SGB_BOOT},
    devices::{printer::PrinterDevice, stdout::StdoutDevice},
    gen::{COMPILATION_DATE, COMPILATION_TIME, COMPILER, COMPILER_VERSION, VERSION},
    mmu::Mmu,
    pad::{Pad, PadKey},
    ppu::{Ppu, PpuMode, Tile, FRAME_BUFFER_SIZE},
    rom::{Cartridge, RamSize},
    serial::{NullDevice, Serial, SerialDevice},
    timer::Timer,
    util::read_file,
};

use std::{
    cell::RefCell,
    collections::VecDeque,
    fmt::{self, Display, Formatter},
    rc::Rc,
};

#[cfg(feature = "wasm")]
use wasm_bindgen::prelude::*;

#[cfg(feature = "wasm")]
use crate::{
    gen::dependencies_map,
    ppu::{Palette, Pixel},
};

#[cfg(feature = "wasm")]
use std::{
    convert::TryInto,
    panic::{set_hook, take_hook, PanicInfo},
};

/// Enumeration that describes the multiple running
// modes of the Game Boy emulator.
// DMG = Original Game Boy
// CGB = Game Boy Color
// SGB = Super Game Boy
#[cfg_attr(feature = "wasm", wasm_bindgen)]
#[derive(Clone, Copy, PartialEq, Eq)]
pub enum GameBoyMode {
    Dmg = 1,
    Cgb = 2,
    Sgb = 3,
}

impl GameBoyMode {
    pub fn description(&self) -> &'static str {
        match self {
            GameBoyMode::Dmg => "Game Boy (DMG)",
            GameBoyMode::Cgb => "Game Boy Color (CGB)",
            GameBoyMode::Sgb => "Super Game Boy (SGB)",
        }
    }

    pub fn from_u8(value: u8) -> GameBoyMode {
        match value {
            1 => GameBoyMode::Dmg,
            2 => GameBoyMode::Cgb,
            3 => GameBoyMode::Sgb,
            _ => panic!("Invalid mode value: {}", value),
        }
    }

    pub fn from_str(value: &str) -> GameBoyMode {
        match value {
            "dmg" => GameBoyMode::Dmg,
            "cgb" => GameBoyMode::Cgb,
            "sgb" => GameBoyMode::Sgb,
            _ => panic!("Invalid mode value: {}", value),
        }
    }
}

impl Display for GameBoyMode {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        write!(f, "{}", self.description())
    }
}

#[cfg_attr(feature = "wasm", wasm_bindgen)]
#[derive(Clone, Copy, PartialEq, Eq)]
pub struct GameBoyConfig {
    /// The current running mode of the emulator, this
    /// may affect many aspects of the emulation, like
    /// CPU frequency, PPU frequency, Boot rome size, etc.
    mode: GameBoyMode,

    /// If the PPU is enabled, it will be clocked.
    ppu_enabled: bool,

    /// If the APU is enabled, it will be clocked.
    apu_enabled: bool,

    /// If the timer is enabled, it will be clocked.
    timer_enabled: bool,

    /// If the serial is enabled, it will be clocked.
    serial_enabled: bool,

    /// The current frequency at which the Game Boy
    /// emulator is being handled. This is a "hint" that
    /// may help components to adjust their internal
    /// logic to match the current frequency. For example
    /// the APU will adjust its internal clock to match
    /// this hint.
    clock_freq: u32,
}

#[cfg_attr(feature = "wasm", wasm_bindgen)]
impl GameBoyConfig {
    pub fn is_dmg(&self) -> bool {
        self.mode == GameBoyMode::Dmg
    }

    pub fn is_cgb(&self) -> bool {
        self.mode == GameBoyMode::Cgb
    }

    pub fn is_sgb(&self) -> bool {
        self.mode == GameBoyMode::Sgb
    }

    pub fn mode(&self) -> GameBoyMode {
        self.mode
    }

    pub fn set_mode(&mut self, value: GameBoyMode) {
        self.mode = value;
    }

    pub fn ppu_enabled(&self) -> bool {
        self.ppu_enabled
    }

    pub fn set_ppu_enabled(&mut self, value: bool) {
        self.ppu_enabled = value;
    }

    pub fn apu_enabled(&self) -> bool {
        self.apu_enabled
    }

    pub fn set_apu_enabled(&mut self, value: bool) {
        self.apu_enabled = value;
    }

    pub fn timer_enabled(&self) -> bool {
        self.timer_enabled
    }

    pub fn set_timer_enabled(&mut self, value: bool) {
        self.timer_enabled = value;
    }

    pub fn serial_enabled(&self) -> bool {
        self.serial_enabled
    }

    pub fn set_serial_enabled(&mut self, value: bool) {
        self.serial_enabled = value;
    }

    pub fn clock_freq(&self) -> u32 {
        self.clock_freq
    }

    pub fn set_clock_freq(&mut self, value: u32) {
        self.clock_freq = value;
    }
}

/// Top level structure that abstracts the usage of the
/// Game Boy system under the Boytacean emulator.
/// Should serve as the main entry-point API.
#[cfg_attr(feature = "wasm", wasm_bindgen)]
pub struct GameBoy {
    /// The current running mode of the emulator, this
    /// may affect many aspects of the emulation, like
    /// CPU frequency, PPU frequency, Boot rome size, etc.
    /// This is a clone of the configuration value
    /// kept for performance reasons.
    mode: GameBoyMode,

    /// If the PPU is enabled, it will be clocked.
    /// This is a clone of the configuration value
    /// kept for performance reasons.
    ppu_enabled: bool,

    /// If the APU is enabled, it will be clocked.
    /// This is a clone of the configuration value
    /// kept for performance reasons.
    apu_enabled: bool,

    /// If the timer is enabled, it will be clocked.
    /// This is a clone of the configuration value
    /// kept for performance reasons.
    timer_enabled: bool,

    /// If the serial is enabled, it will be clocked.
    /// This is a clone of the configuration value
    /// kept for performance reasons.
    serial_enabled: bool,

    /// The current frequency at which the Game Boy
    /// emulator is being handled. This is a "hint" that
    /// may help components to adjust their internal
    /// logic to match the current frequency. For example
    /// the APU will adjust its internal clock to match
    /// this hint.
    /// This is a clone of the configuration value
    /// kept for performance reasons.
    clock_freq: u32,

    /// Reference to the Game Boy CPU component to be
    /// used as the main element of the system, when
    /// clocked, the amount of ticks from it will be
    /// used as reference or the rest of the components.
    cpu: Cpu,

    /// Rhe reference counted and mutable reference to
    /// Game Boy configuration structure that can be
    /// used by the GB components to access global
    /// configuration values on the current emulator.
    /// If performance is required (may value access)
    /// the values should be cloned and stored locally.
    gbc: Rc<RefCell<GameBoyConfig>>,
}

#[cfg_attr(feature = "wasm", wasm_bindgen)]
pub struct Registers {
    pub pc: u16,
    pub sp: u16,
    pub a: u8,
    pub b: u8,
    pub c: u8,
    pub d: u8,
    pub e: u8,
    pub h: u8,
    pub l: u8,
    pub scy: u8,
    pub scx: u8,
    pub wy: u8,
    pub wx: u8,
    pub ly: u8,
    pub lyc: u8,
}

pub trait AudioProvider {
    fn audio_output(&self) -> u8;
    fn audio_buffer(&self) -> &VecDeque<u8>;
    fn clear_audio_buffer(&mut self);
}

#[cfg_attr(feature = "wasm", wasm_bindgen)]
impl GameBoy {
    #[cfg_attr(feature = "wasm", wasm_bindgen(constructor))]
    pub fn new(mode: GameBoyMode) -> Self {
        let gbc = Rc::new(RefCell::new(GameBoyConfig {
            mode,
            ppu_enabled: true,
            apu_enabled: true,
            timer_enabled: true,
            serial_enabled: true,
            clock_freq: GameBoy::CPU_FREQ,
        }));

        let ppu = Ppu::default();
        let apu = Apu::default();
        let pad = Pad::default();
        let timer = Timer::default();
        let serial = Serial::default();
        let mmu = Mmu::new(ppu, apu, pad, timer, serial, mode, gbc.clone());
        let cpu = Cpu::new(mmu, gbc.clone());

        Self {
            mode,
            ppu_enabled: true,
            apu_enabled: true,
            timer_enabled: true,
            serial_enabled: true,
            clock_freq: GameBoy::CPU_FREQ,
            cpu,
            gbc,
        }
    }

    pub fn reset(&mut self) {
        self.ppu().reset();
        self.apu().reset();
        self.timer().reset();
        self.serial().reset();
        self.mmu().reset();
        self.cpu.reset();
    }

    pub fn clock(&mut self) -> u8 {
        let cycles = self.cpu_clock();
        if self.ppu_enabled {
            self.ppu_clock(cycles);
        }
        if self.apu_enabled {
            self.apu_clock(cycles);
        }
        if self.timer_enabled {
            self.timer_clock(cycles);
        }
        if self.serial_enabled {
            self.serial_clock(cycles);
        }
        cycles
    }

    pub fn key_press(&mut self, key: PadKey) {
        self.pad().key_press(key);
    }

    pub fn key_lift(&mut self, key: PadKey) {
        self.pad().key_lift(key);
    }

    pub fn cpu_clock(&mut self) -> u8 {
        self.cpu.clock()
    }

    pub fn ppu_clock(&mut self, cycles: u8) {
        self.ppu().clock(cycles)
    }

    pub fn apu_clock(&mut self, cycles: u8) {
        self.apu().clock(cycles)
    }

    pub fn timer_clock(&mut self, cycles: u8) {
        self.timer().clock(cycles)
    }

    pub fn serial_clock(&mut self, cycles: u8) {
        self.serial().clock(cycles)
    }

    pub fn ppu_ly(&mut self) -> u8 {
        self.ppu().ly()
    }

    pub fn ppu_mode(&mut self) -> PpuMode {
        self.ppu().mode()
    }

    pub fn ppu_frame(&mut self) -> u16 {
        self.ppu().frame_index()
    }

    pub fn boot(&mut self) {
        self.cpu.boot();
    }

    pub fn load(&mut self, boot: bool) {
        match self.mode() {
            GameBoyMode::Dmg => self.load_dmg(boot),
            GameBoyMode::Cgb => self.load_cgb(boot),
            GameBoyMode::Sgb => todo!(),
        }
    }

    pub fn load_dmg(&mut self, boot: bool) {
        self.mmu().allocate_dmg();
        if boot {
            self.load_boot_dmg();
        }
    }

    pub fn load_cgb(&mut self, boot: bool) {
        self.mmu().allocate_cgb();
        if boot {
            self.load_boot_cgb();
        }
    }

    pub fn load_boot(&mut self, data: &[u8]) {
        self.cpu.mmu().write_boot(0x0000, data);
    }

    pub fn load_boot_static(&mut self, boot_rom: BootRom) {
        match boot_rom {
            BootRom::Dmg => self.load_boot(&DMG_BOOT),
            BootRom::Sgb => self.load_boot(&SGB_BOOT),
            BootRom::DmgBootix => self.load_boot(&DMG_BOOTIX),
            BootRom::MgbBootix => self.load_boot(&MGB_BOOTIX),
            BootRom::Cgb => self.load_boot(&CGB_BOOT),
        }
    }

    pub fn load_boot_default(&mut self) {
        self.load_boot_dmg();
    }

    pub fn load_boot_dmg(&mut self) {
        self.load_boot_static(BootRom::DmgBootix);
    }

    pub fn load_boot_cgb(&mut self) {
        self.load_boot_static(BootRom::Cgb);
    }

    pub fn vram_eager(&mut self) -> Vec<u8> {
        self.ppu().vram().to_vec()
    }

    pub fn hram_eager(&mut self) -> Vec<u8> {
        self.ppu().vram().to_vec()
    }

    pub fn frame_buffer_eager(&mut self) -> Vec<u8> {
        self.frame_buffer().to_vec()
    }

    pub fn audio_buffer_eager(&mut self, clear: bool) -> Vec<u8> {
        let buffer = Vec::from(self.audio_buffer().clone());
        if clear {
            self.clear_audio_buffer();
        }
        buffer
    }

    pub fn audio_output(&self) -> u8 {
        self.apu_i().output()
    }

    pub fn audio_all_output(&self) -> Vec<u8> {
        vec![
            self.audio_output(),
            self.audio_ch1_output(),
            self.audio_ch2_output(),
            self.audio_ch3_output(),
            self.audio_ch4_output(),
        ]
    }

    pub fn audio_ch1_output(&self) -> u8 {
        self.apu_i().ch1_output()
    }

    pub fn audio_ch2_output(&self) -> u8 {
        self.apu_i().ch2_output()
    }

    pub fn audio_ch3_output(&self) -> u8 {
        self.apu_i().ch3_output()
    }

    pub fn audio_ch4_output(&self) -> u8 {
        self.apu_i().ch4_output()
    }

    pub fn cartridge_eager(&mut self) -> Cartridge {
        self.mmu().rom().clone()
    }

    pub fn ram_data_eager(&mut self) -> Vec<u8> {
        self.mmu().rom().ram_data_eager()
    }

    pub fn set_ram_data(&mut self, ram_data: Vec<u8>) {
        self.mmu().rom().set_ram_data(ram_data)
    }

    pub fn registers(&mut self) -> Registers {
        let ppu_registers = self.ppu().registers();
        Registers {
            pc: self.cpu.pc,
            sp: self.cpu.sp,
            a: self.cpu.a,
            b: self.cpu.b,
            c: self.cpu.c,
            d: self.cpu.d,
            e: self.cpu.e,
            h: self.cpu.h,
            l: self.cpu.l,
            scy: ppu_registers.scy,
            scx: ppu_registers.scx,
            wy: ppu_registers.wy,
            wx: ppu_registers.wx,
            ly: ppu_registers.ly,
            lyc: ppu_registers.lyc,
        }
    }

    /// Obtains the tile structure for the tile at the
    /// given index, no conversion in the pixel buffer
    /// is done so that the color reference is the GB one.
    pub fn get_tile(&mut self, index: usize) -> Tile {
        self.ppu().tiles()[index]
    }

    /// Obtains the pixel buffer for the tile at the
    /// provided index, converting the color buffer
    /// using the currently loaded palette.
    pub fn get_tile_buffer(&mut self, index: usize) -> Vec<u8> {
        let tile = self.get_tile(index);
        tile.palette_buffer(self.ppu().palette())
    }

    /// Obtains the name of the compiler that has been
    /// used in the compilation of the base Boytacean
    /// library. Can be used for diagnostics.
    pub fn compiler(&self) -> String {
        String::from(COMPILER)
    }

    pub fn compiler_version(&self) -> String {
        String::from(COMPILER_VERSION)
    }

    pub fn compilation_date(&self) -> String {
        String::from(COMPILATION_DATE)
    }

    pub fn compilation_time(&self) -> String {
        String::from(COMPILATION_TIME)
    }

    pub fn mode(&self) -> GameBoyMode {
        self.mode
    }

    pub fn set_mode(&mut self, value: GameBoyMode) {
        self.mode = value;
        (*self.gbc).borrow_mut().set_mode(value);
        self.mmu().set_mode(value);
    }

    pub fn ppu_enabled(&self) -> bool {
        self.ppu_enabled
    }

    pub fn set_ppu_enabled(&mut self, value: bool) {
        self.ppu_enabled = value;
        (*self.gbc).borrow_mut().set_ppu_enabled(value);
    }

    pub fn apu_enabled(&self) -> bool {
        self.apu_enabled
    }

    pub fn set_apu_enabled(&mut self, value: bool) {
        self.apu_enabled = value;
        (*self.gbc).borrow_mut().set_apu_enabled(value);
    }

    pub fn timer_enabled(&self) -> bool {
        self.timer_enabled
    }

    pub fn set_timer_enabled(&mut self, value: bool) {
        self.timer_enabled = value;
        (*self.gbc).borrow_mut().set_timer_enabled(value);
    }

    pub fn serial_enabled(&self) -> bool {
        self.serial_enabled
    }

    pub fn set_serial_enabled(&mut self, value: bool) {
        self.serial_enabled = value;
        (*self.gbc).borrow_mut().set_serial_enabled(value);
    }

    pub fn clock_freq(&self) -> u32 {
        self.clock_freq
    }

    pub fn set_clock_freq(&mut self, value: u32) {
        self.clock_freq = value;
        (*self.gbc).borrow_mut().set_clock_freq(value);
        self.apu().set_clock_freq(value);
    }

    pub fn attach_null_serial(&mut self) {
        self.attach_serial(Box::<NullDevice>::default());
    }

    pub fn attach_stdout_serial(&mut self) {
        self.attach_serial(Box::<StdoutDevice>::default());
    }

    pub fn attach_printer_serial(&mut self) {
        self.attach_serial(Box::<PrinterDevice>::default());
    }

    pub fn ram_size(&self) -> RamSize {
        match self.mode {
            GameBoyMode::Dmg => RamSize::Size8K,
            GameBoyMode::Cgb => RamSize::Size32K,
            GameBoyMode::Sgb => RamSize::Size8K,
        }
    }

    pub fn vram_size(&self) -> RamSize {
        match self.mode {
            GameBoyMode::Dmg => RamSize::Size8K,
            GameBoyMode::Cgb => RamSize::Size16K,
            GameBoyMode::Sgb => RamSize::Size8K,
        }
    }

    pub fn description(&self, column_length: usize) -> String {
        format!(
            "{}  {}\n{}  {}\n{}  {}\n{}  {}",
            format!("{:width$}", "Version", width = column_length),
            VERSION,
            format!("{:width$}", "Mode", width = column_length),
            self.mode(),
            format!("{:width$}", "RAM Size", width = column_length),
            self.ram_size(),
            format!("{:width$}", "VRAM Size", width = column_length),
            self.vram_size(),
        )
    }
}

/// Gameboy implementations that are meant with performance
/// in mind and that do not support WASM interface of copy.
impl GameBoy {
    /// The logic frequency of the Game Boy
    /// CPU in hz.
    pub const CPU_FREQ: u32 = 4194304;

    /// The visual frequency (refresh rate)
    /// of the Game Boy, close to 60 hz.
    pub const VISUAL_FREQ: f32 = 59.7275;

    /// The cycles taken to run a complete frame
    /// loop in the Game Boy's PPU (in CPU cycles).
    pub const LCD_CYCLES: u32 = 70224;

    pub fn cpu(&mut self) -> &mut Cpu {
        &mut self.cpu
    }

    pub fn mmu(&mut self) -> &mut Mmu {
        self.cpu.mmu()
    }

    pub fn ppu(&mut self) -> &mut Ppu {
        self.cpu.ppu()
    }

    pub fn apu(&mut self) -> &mut Apu {
        self.cpu.apu()
    }

    pub fn apu_i(&self) -> &Apu {
        self.cpu.apu_i()
    }

    pub fn pad(&mut self) -> &mut Pad {
        self.cpu.pad()
    }

    pub fn timer(&mut self) -> &mut Timer {
        self.cpu.timer()
    }

    pub fn serial(&mut self) -> &mut Serial {
        self.cpu.serial()
    }

    pub fn frame_buffer(&mut self) -> &[u8; FRAME_BUFFER_SIZE] {
        &(self.ppu().frame_buffer)
    }

    pub fn audio_buffer(&mut self) -> &VecDeque<u8> {
        self.apu().audio_buffer()
    }

    pub fn load_boot_path(&mut self, path: &str) {
        let data = read_file(path);
        self.load_boot(&data);
    }

    pub fn load_boot_file(&mut self, boot_rom: BootRom) {
        match boot_rom {
            BootRom::Dmg => self.load_boot_path("./res/boot/dmg_boot.bin"),
            BootRom::Sgb => self.load_boot_path("./res/boot/sgb_boot.bin"),
            BootRom::DmgBootix => self.load_boot_path("./res/boot/dmg_bootix.bin"),
            BootRom::MgbBootix => self.load_boot_path("./res/boot/mgb_bootix.bin"),
            BootRom::Cgb => self.load_boot_path("./res/boot/cgb_boot.bin"),
        }
    }

    pub fn load_boot_default_f(&mut self) {
        self.load_boot_dmg_f();
    }

    pub fn load_boot_dmg_f(&mut self) {
        self.load_boot_file(BootRom::DmgBootix);
    }

    pub fn load_boot_cgb_f(&mut self) {
        self.load_boot_file(BootRom::Cgb);
    }

    pub fn load_rom(&mut self, data: &[u8]) -> &Cartridge {
        let rom = Cartridge::from_data(data);
        self.mmu().set_rom(rom);
        self.mmu().rom()
    }

    pub fn load_rom_file(&mut self, path: &str) -> &Cartridge {
        let data = read_file(path);
        self.load_rom(&data)
    }

    pub fn attach_serial(&mut self, device: Box<dyn SerialDevice>) {
        self.serial().set_device(device);
    }
}

#[cfg(feature = "wasm")]
#[cfg_attr(feature = "wasm", wasm_bindgen)]
impl GameBoy {
    pub fn set_panic_hook_ws() {
        let prev = take_hook();
        set_hook(Box::new(move |info| {
            hook_impl(info);
            prev(info);
        }));
    }

    pub fn load_rom_ws(&mut self, data: &[u8]) -> Cartridge {
        self.load_rom(data).clone()
    }

    pub fn load_null_ws(&mut self) {
        let null = Box::<NullDevice>::default();
        self.attach_serial(null);
    }

    pub fn load_logger_ws(&mut self) {
        let mut logger = Box::<StdoutDevice>::default();
        logger.set_callback(|data| {
            logger_callback(data.to_vec());
        });
        self.attach_serial(logger);
    }

    pub fn load_printer_ws(&mut self) {
        let mut printer = Box::<PrinterDevice>::default();
        printer.set_callback(|image_buffer| {
            printer_callback(image_buffer.to_vec());
        });
        self.attach_serial(printer);
    }

    pub fn set_palette_colors_ws(&mut self, value: Vec<JsValue>) {
        let palette: Palette = value
            .into_iter()
            .map(|v| Self::js_to_pixel(&v))
            .collect::<Vec<Pixel>>()
            .try_into()
            .unwrap();
        self.ppu().set_palette_colors(&palette);
    }

    pub fn wasm_engine_ws(&self) -> Option<String> {
        let dependencies = dependencies_map();
        if !dependencies.contains_key("wasm-bindgen") {
            return None;
        }
        Some(String::from(format!(
            "wasm-bindgen/{}",
            *dependencies.get("wasm-bindgen").unwrap()
        )))
    }

    fn js_to_pixel(value: &JsValue) -> Pixel {
        value
            .as_string()
            .unwrap()
            .chars()
            .collect::<Vec<char>>()
            .chunks(2)
            .map(|s| s.iter().collect::<String>())
            .map(|s| u8::from_str_radix(&s, 16).unwrap())
            .collect::<Vec<u8>>()
            .try_into()
            .unwrap()
    }
}

#[cfg(feature = "wasm")]
#[wasm_bindgen]
extern "C" {
    #[wasm_bindgen(js_namespace = window)]
    fn panic(message: &str);

    #[wasm_bindgen(js_namespace = window, js_name = loggerCallback)]
    fn logger_callback(data: Vec<u8>);

    #[wasm_bindgen(js_namespace = window, js_name = printerCallback)]
    fn printer_callback(image_buffer: Vec<u8>);
}

#[cfg(feature = "wasm")]
pub fn hook_impl(info: &PanicInfo) {
    let message = info.to_string();
    panic(message.as_str());
}

impl AudioProvider for GameBoy {
    fn audio_output(&self) -> u8 {
        self.apu_i().output()
    }

    fn audio_buffer(&self) -> &VecDeque<u8> {
        self.apu_i().audio_buffer()
    }

    fn clear_audio_buffer(&mut self) {
        self.apu().clear_audio_buffer()
    }
}

impl Default for GameBoy {
    fn default() -> Self {
        Self::new(GameBoyMode::Dmg)
    }
}

impl Display for GameBoy {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        write!(f, "{}", self.description(9))
    }
}