use crate::*;
use bedrock_core::*;


pub struct HeadlessDeviceBus {
    pub sys: SystemDevice,
    pub mem: MemoryDevice,
    pub mat: MathDevice,
    pub clk: ClockDevice,
    pub loc: LocalDevice,
    pub rem: RemoteDevice,
    pub fs1: FileDevice,
    pub fs2: FileDevice,
}

impl HeadlessDeviceBus {
    pub fn new(config: &EmulatorConfig) -> Self {
        Self {
            sys: SystemDevice::new(),
            mem: MemoryDevice::new(),
            mat: MathDevice::new(),
            clk: ClockDevice::new(),
            loc: LocalDevice::new(config),
            rem: RemoteDevice::new(),
            fs1: FileDevice::new(),
            fs2: FileDevice::new(),
        }
    }
}

impl DeviceBus for HeadlessDeviceBus {
    fn read(&mut self, port: u8) -> u8 {
        match port & 0xf0 {
            0x00 => self.sys.read(port & 0x0f),
            0x10 => self.mem.read(port & 0x0f),
            0x20 => self.mat.read(port & 0x0f),
            0x30 => self.clk.read(port & 0x0f),
            0x80 => self.loc.read(port & 0x0f),
            0x90 => self.rem.read(port & 0x0f),
            0xa0 => self.fs1.read(port & 0x0f),
            0xb0 => self.fs2.read(port & 0x0f),
            _ => 0
        }
    }

    fn write(&mut self, port: u8, value: u8) -> Option<Signal> {
        match port & 0xf0 {
            0x00 => self.sys.write(port & 0x0f, value),
            0x10 => self.mem.write(port & 0x0f, value),
            0x20 => self.mat.write(port & 0x0f, value),
            0x30 => self.clk.write(port & 0x0f, value),
            0x80 => self.loc.write(port & 0x0f, value),
            0x90 => self.rem.write(port & 0x0f, value),
            0xa0 => self.fs1.write(port & 0x0f, value),
            0xb0 => self.fs2.write(port & 0x0f, value),
            _ => None
        }
    }

    fn wake(&mut self) -> bool {
        macro_rules! rouse {
            ($id:expr, $dev:ident) => {
                if self.sys.can_wake($id) && self.$dev.wake() {
                    self.sys.wake_id = $id;
                    self.sys.asleep = false;
                    return true;
                }
            };
        }
        rouse!(0xb, fs2);
        rouse!(0xa, fs1);
        rouse!(0x9, rem);
        rouse!(0x8, loc);
        rouse!(0x3, clk);
        rouse!(0x2, mat);
        rouse!(0x1, mem);
        rouse!(0x0, sys);
        return false;
    }
}


pub struct HeadlessEmulator {
    pub br: BedrockEmulator<HeadlessDeviceBus>,
    pub debug: DebugState,
}

impl HeadlessEmulator {
    pub fn new(config: &EmulatorConfig, debug: bool, verbose: bool) -> Self {
        Self {
            br: BedrockEmulator::new(HeadlessDeviceBus::new(config)),
            debug: DebugState::new(debug, verbose, config.symbols_path.as_ref()),
        }
    }

    pub fn load_program(&mut self, bytecode: &[u8]) {
        self.br.core.mem.load_program(bytecode);
    }

    pub fn run(&mut self, debug: bool) -> EmulatorSignal {
        loop {
            match self.br.evaluate(BATCH_SIZE, self.debug.enabled) {
                Some(Signal::Fork) => {
                    self.br.core.mem.pc = 0;
                    self.br.core.wst.sp = 0;
                    self.br.core.rst.sp = 0;
                }
                Some(Signal::Sleep) => loop {
                    if self.br.dev.wake() { break; }
                    std::thread::sleep(MIN_TICK_DURATION);
                }
                Some(Signal::Halt) => {
                    self.br.dev.loc.flush();
                    self.debug.info("Program halted, exiting.");
                    self.debug.debug_summary(&self.br.core);
                    return EmulatorSignal::Halt;
                }
                Some(Signal::Debug1) => if debug {
                    self.debug.debug_summary(&self.br.core);
                }
                _ => (),
            }
        }
    }
}