#![cfg_attr(not(test), no_std)]
#![cfg_attr(not(test), no_main)]
#![feature(maybe_uninit_extra, maybe_uninit_ref)]
#![cfg_attr(test, allow(unused))]
// TODO: #![deny(warnings, unused)]

#[cfg(not(any(feature = "semihosting", test)))]
use panic_abort as _;
#[cfg(all(feature = "semihosting", not(test)))]
use panic_semihosting as _;

use log::{error, info, warn};

use core::fmt::Write;
use cortex_m::asm::wfi;
use cortex_m_rt::entry;
use stm32f4xx_hal::{
    hal::watchdog::{WatchdogEnable, Watchdog},
    rcc::RccExt,
    watchdog::IndependentWatchdog,
    time::{U32Ext, MegaHertz},
    stm32::{CorePeripherals, Peripherals, SCB},
};
use smoltcp::{
    time::Instant,
    socket::TcpSocket,
    wire::EthernetAddress,
};
use uom::{
    fmt::DisplayStyle::Abbreviation,
    si::{
        f64::{
            ElectricCurrent,
            ElectricPotential,
            ElectricalResistance,
            ThermodynamicTemperature,
        },
        electric_current::ampere,
        electric_potential::volt,
        electrical_resistance::ohm,
        thermodynamic_temperature::degree_celsius,
    },
};

mod init_log;
use init_log::init_log;
mod usb;
mod leds;
mod pins;
use pins::Pins;
mod ad7172;
mod ad5680;
mod net;
mod server;
use server::Server;
mod session;
use session::{Session, SessionOutput};
mod command_parser;
use command_parser::{CenterPoint, Command, ShowCommand, PwmPin};
mod timer;
mod pid;
mod steinhart_hart;
mod channels;
use channels::{CHANNELS, Channels};
mod channel;
mod channel_state;
mod config;
use config::Config;


const HSE: MegaHertz = MegaHertz(8);
#[cfg(not(feature = "semihosting"))]
const WATCHDOG_INTERVAL: u32 = 1_000;
#[cfg(feature = "semihosting")]
const WATCHDOG_INTERVAL: u32 = 30_000;

pub const EEPROM_PAGE_SIZE: usize = 8;
pub const EEPROM_SIZE: usize = 128;

const TCP_PORT: u16 = 23;


fn report_to(channel: usize, channels: &mut Channels, socket: &mut TcpSocket) -> bool {
    let send_free = socket.send_capacity() - socket.send_queue();
    match channels.report(channel).to_json() {
        Ok(buf) if buf.len() > send_free + 1 => {
            // Not enough buffer space, skip report for now
            warn!(
                "TCP socket has only {}/{} needed {}",
                send_free + 1, socket.send_capacity(), buf.len(),
            );
        }
        Ok(buf) => {
            match socket.send_slice(&buf) {
                Ok(sent) if sent == buf.len() => {
                    let _ = socket.send_slice(b"\n");
                    // success
                    return true
                }
                Ok(sent) =>
                    warn!("sent only {}/{} bytes of report", sent, buf.len()),
                Err(e) =>
                    error!("error sending report: {:?}", e),
            }
        }
        Err(e) =>
            error!("unable to serialize report: {:?}", e),
    }
    // not success
    false
}

/// Initialization and main loop
#[cfg(not(test))]
#[entry]
fn main() -> ! {
    init_log();
    info!("tecpak");

    let mut cp = CorePeripherals::take().unwrap();
    cp.SCB.enable_icache();
    cp.SCB.enable_dcache(&mut cp.CPUID);

    let dp = Peripherals::take().unwrap();
    let clocks = dp.RCC.constrain()
        .cfgr
        .use_hse(HSE)
        .sysclk(168.mhz())
        .hclk(168.mhz())
        .pclk1(32.mhz())
        .pclk2(64.mhz())
        .freeze();

    let mut wd = IndependentWatchdog::new(dp.IWDG);
    wd.start(WATCHDOG_INTERVAL.ms());
    wd.feed();

    timer::setup(cp.SYST, clocks);

    let (pins, mut leds, mut eeprom, eth_pins, usb) = Pins::setup(
        clocks, dp.TIM1, dp.TIM3,
        dp.GPIOA, dp.GPIOB, dp.GPIOC, dp.GPIOD, dp.GPIOE, dp.GPIOF, dp.GPIOG,
        dp.I2C1,
        dp.SPI2, dp.SPI4, dp.SPI5,
        dp.ADC1,
        dp.OTG_FS_GLOBAL,
        dp.OTG_FS_DEVICE,
        dp.OTG_FS_PWRCLK,
    );

    leds.r1.on();
    leds.g3.off();
    leds.g4.off();

    usb::State::setup(usb);

    let mut channels = Channels::new(pins);
    let _ = Config::load(&mut eeprom)
        .map(|config| config.apply(&mut channels))
        .map_err(|e| warn!("error loading config: {:?}", e));

    // EEPROM ships with a read-only EUI-48 identifier
    let mut eui48 = [0; 6];
    eeprom.read_data(0xFA, &mut eui48).unwrap();
    let hwaddr = EthernetAddress(eui48);
    info!("EEPROM MAC address: {}", hwaddr);

    net::run(clocks, dp.ETHERNET_MAC, dp.ETHERNET_DMA, eth_pins, hwaddr, |iface| {
        Server::<Session>::run(iface, |server| {
            leds.r1.off();

            loop {
                let instant = Instant::from_millis(i64::from(timer::now()));
                let updated_channel = channels.poll_adc(instant);
                if let Some(channel) = updated_channel {
                    server.for_each(|_, session| session.set_report_pending(channel.into()));
                }

                let instant = Instant::from_millis(i64::from(timer::now()));
                cortex_m::interrupt::free(net::clear_pending);
                server.poll(instant)
                    .unwrap_or_else(|e| {
                        warn!("poll: {:?}", e);
                    });

                // TCP protocol handling
                server.for_each(|mut socket, session| {
                    if ! socket.is_active() {
                        let _ = socket.listen(TCP_PORT);
                        session.reset();
                    } else if socket.can_send() && socket.can_recv() && socket.send_capacity() - socket.send_queue() > 1024 {
                        match socket.recv(|buf| session.feed(buf)) {
                            Ok(SessionOutput::Nothing) => {}
                            Ok(SessionOutput::Command(command)) => match command {
                                Command::Quit =>
                                    socket.close(),
                                Command::Reporting(reporting) => {
                                    let _ = writeln!(socket, "report={}", if reporting { "on" } else { "off" });
                                }
                                Command::Show(ShowCommand::Reporting) => {
                                    let _ = writeln!(socket, "report={}", if session.reporting() { "on" } else { "off" });
                                }
                                Command::Show(ShowCommand::Input) => {
                                    for channel in 0..CHANNELS {
                                        report_to(channel, &mut channels, &mut socket);
                                    }
                                }
                                Command::Show(ShowCommand::Pid) => {
                                    for channel in 0..CHANNELS {
                                        let send_free = socket.send_capacity() - socket.send_queue();
                                        match channels.channel_state(channel).pid.summary(channel).to_json() {
                                            Ok(buf) if buf.len() > send_free + 1 => {
                                                // Not enough buffer space, skip report for now
                                                warn!(
                                                    "TCP socket has only {}/{} needed {}",
                                                    send_free + 1, socket.send_capacity(), buf.len(),
                                                );
                                            }
                                            Ok(buf) => {
                                                match socket.send_slice(&buf) {
                                                    Ok(sent) if sent == buf.len() => {
                                                        let _ = socket.send_slice(b"\n");
                                                        // success
                                                    }
                                                    Ok(sent) =>
                                                        warn!("sent only {}/{} bytes of summary", sent, buf.len()),
                                                    Err(e) =>
                                                        error!("error sending summary: {:?}", e),
                                                }
                                            }
                                            Err(e) =>
                                                error!("unable to serialize pid summary: {:?}", e),
                                        }
                                    }
                                }
                                Command::Show(ShowCommand::Pwm) => {
                                    for channel in 0..CHANNELS {
                                        let i_set = channels.get_i(channel);
                                        let state = channels.channel_state(channel);
                                        let _ = writeln!(
                                            socket, "channel {}: PID={}",
                                            channel,
                                            if state.pid_engaged { "engaged" } else { "disengaged" }
                                        );
                                        let _ = write!(
                                            socket, "- i_set={:.3} / {:.3} ",
                                            i_set.0.into_format_args(ampere, Abbreviation),
                                            i_set.1.into_format_args(ampere, Abbreviation),
                                        );
                                        match state.center {
                                            CenterPoint::Vref => {
                                                let _ = writeln!(
                                                    socket, "center=vref vref={:.3}",
                                                    state.vref.into_format_args(volt, Abbreviation),
                                                );
                                            }
                                            CenterPoint::Override(volts) => {
                                                let _ = writeln!(
                                                    socket, "center={:.3} V",
                                                    volts,
                                                );
                                            }
                                        }
                                        let max_v = channels.get_max_v(channel);
                                        let _ = writeln!(
                                            socket, "- max_v={:.3} / {:.3}",
                                            max_v.0.into_format_args(volt, Abbreviation),
                                            max_v.1.into_format_args(volt, Abbreviation),
                                        );
                                        let max_i_pos = channels.get_max_i_pos(channel);
                                        let _ = writeln!(
                                            socket, "- max_i_pos={:.3} / {:.3}",
                                            max_i_pos.0.into_format_args(ampere, Abbreviation),
                                            max_i_pos.1.into_format_args(ampere, Abbreviation),
                                        );
                                        let max_i_neg = channels.get_max_i_neg(channel);
                                        let _ = writeln!(
                                            socket, "- max_i_neg={:.3} / {:.3}",
                                            max_i_neg.0.into_format_args(ampere, Abbreviation),
                                            max_i_neg.1.into_format_args(ampere, Abbreviation),
                                        );
                                    }
                                    let _ = writeln!(socket, "");
                                }
                                Command::Show(ShowCommand::SteinhartHart) => {
                                    for channel in 0..CHANNELS {
                                        let state = channels.channel_state(channel);
                                        let _ = writeln!(
                                            socket, "channel {}: Steinhart-Hart equation parameters",
                                            channel,
                                        );
                                        let _ = writeln!(socket, "- t0={}", state.sh.t0.into_format_args(degree_celsius, Abbreviation));
                                        let _ = writeln!(socket, "- b={}", state.sh.b);
                                        let _ = writeln!(socket, "- r0={}", state.sh.r0.into_format_args(ohm, Abbreviation));
                                        match (state.get_adc(), state.get_sens(), state.get_temperature()) {
                                            (Some(adc), Some(sens), Some(temp)) => {
                                                let _ = writeln!(
                                                    socket, "- adc={:.6} r={:.0} temp{}={:.3}",
                                                    adc.into_format_args(volt, Abbreviation),
                                                    sens.into_format_args(ohm, Abbreviation),
                                                    channel,
                                                    temp.into_format_args(degree_celsius, Abbreviation),
                                                );
                                            }
                                            _ => {}
                                        }
                                        let _ = writeln!(socket, "");
                                    }
                                }
                                Command::Show(ShowCommand::PostFilter) => {
                                    for channel in 0..CHANNELS {
                                        match channels.adc.get_postfilter(channel as u8).unwrap() {
                                            Some(filter) => {
                                                let _ = writeln!(
                                                    socket, "channel {}: postfilter={:.2} SPS",
                                                    channel, filter.output_rate().unwrap()
                                                );
                                            }
                                            None => {
                                                let _ = writeln!(
                                                    socket, "channel {}: postfilter disabled",
                                                    channel
                                                );
                                            }
                                        }
                                    }
                                }
                                Command::PwmPid { channel } => {
                                    channels.channel_state(channel).pid_engaged = true;
                                    leds.g3.on();
                                    let _ = writeln!(socket, "channel {}: PID enabled to control PWM", channel
                                    );
                                }
                                Command::Pwm { channel, pin, value } => {
                                    match pin {
                                        PwmPin::ISet => {
                                            channels.channel_state(channel).pid_engaged = false;
                                            leds.g3.off();
                                            let current = ElectricCurrent::new::<ampere>(value);
                                            let (current, max) = channels.set_i(channel, current);
                                            channels.power_up(channel);
                                            let _ = writeln!(
                                                socket, "channel {}: i_set DAC output set to {:.3} / {:.3}",
                                                channel,
                                                current.into_format_args(ampere, Abbreviation),
                                                max.into_format_args(ampere, Abbreviation),
                                            );
                                        }
                                        PwmPin::MaxV => {
                                            let voltage = ElectricPotential::new::<volt>(value);
                                            let (voltage, max) = channels.set_max_v(channel, voltage);
                                            let _ = writeln!(
                                                socket, "channel {}: max_v set to {:.3} / {:.3}",
                                                channel,
                                                voltage.into_format_args(volt, Abbreviation),
                                                max.into_format_args(volt, Abbreviation),
                                            );
                                        }
                                        PwmPin::MaxIPos => {
                                            let current = ElectricCurrent::new::<ampere>(value);
                                            let (current, max) = channels.set_max_i_pos(channel, current);
                                            let _ = writeln!(
                                                socket, "channel {}: max_i_pos set to {:.3} / {:.3}",
                                                channel,
                                                current.into_format_args(ampere, Abbreviation),
                                                max.into_format_args(ampere, Abbreviation),
                                            );
                                        }
                                        PwmPin::MaxINeg => {
                                            let current = ElectricCurrent::new::<ampere>(value);
                                            let (current, max) = channels.set_max_i_neg(channel, current);
                                            let _ = writeln!(
                                                socket, "channel {}: max_i_neg set to {:.3} / {:.3}",
                                                channel,
                                                current.into_format_args(ampere, Abbreviation),
                                                max.into_format_args(ampere, Abbreviation),
                                            );
                                        }
                                    }
                                }
                                Command::CenterPoint { channel, center } => {
                                    let (i_tec, _) = channels.get_i(channel);
                                    let state = channels.channel_state(channel);
                                    state.center = center;
                                    if !state.pid_engaged {
                                        channels.set_i(channel, i_tec);
                                        let _ = writeln!(
                                            socket, "channel {}: center point updated, output readjusted for {:.3}",
                                            channel, i_tec.into_format_args(ampere, Abbreviation),
                                        );
                                    } else {
                                        let _ = writeln!(
                                            socket, "channel {}: center point updated",
                                            channel,
                                        );
                                    }
                                }
                                Command::Pid { channel, parameter, value } => {
                                    let pid = &mut channels.channel_state(channel).pid;
                                    use command_parser::PidParameter::*;
                                    match parameter {
                                        Target => {
                                            pid.target = value;
                                            // reset pid.integral
                                            pid.reset();
                                        }
                                        KP =>
                                            pid.parameters.kp = value as f32,
                                        KI =>
                                            pid.parameters.ki = value as f32,
                                        KD =>
                                            pid.parameters.kd = value as f32,
                                        OutputMin =>
                                            pid.parameters.output_min = value as f32,
                                        OutputMax =>
                                            pid.parameters.output_max = value as f32,
                                        IntegralMin =>
                                            pid.parameters.integral_min = value as f32,
                                        IntegralMax =>
                                            pid.parameters.integral_max = value as f32,
                                    }
                                    let _ = writeln!(socket, "PID parameter updated");
                                }
                                Command::SteinhartHart { channel, parameter, value } => {
                                    let sh = &mut channels.channel_state(channel).sh;
                                    use command_parser::ShParameter::*;
                                    match parameter {
                                        T0 => sh.t0 = ThermodynamicTemperature::new::<degree_celsius>(value),
                                        B => sh.b = value,
                                        R0 => sh.r0 = ElectricalResistance::new::<ohm>(value),
                                    }
                                    let _ = writeln!(socket, "Steinhart-Hart equation parameter updated");
                                }
                                Command::PostFilter { channel, rate: None } => {
                                    channels.adc.set_postfilter(channel as u8, None).unwrap();
                                    let _ = writeln!(
                                        socket, "channel {}: postfilter disabled",
                                        channel
                                    );
                                }
                                Command::PostFilter { channel, rate: Some(rate) } => {
                                    let filter = ad7172::PostFilter::closest(rate);
                                    match filter {
                                        Some(filter) => {
                                            channels.adc.set_postfilter(channel as u8, Some(filter)).unwrap();
                                            let _ = writeln!(
                                                socket, "channel {}: postfilter set to {:.2} SPS",
                                                channel, filter.output_rate().unwrap()
                                            );
                                        }
                                        None => {
                                            let _ = writeln!(socket, "Unable to choose postfilter");
                                        }
                                    }
                                }
                                Command::Load => {
                                    match Config::load(&mut eeprom) {
                                        Ok(config) => {
                                            config.apply(&mut channels);
                                            let _ = writeln!(socket, "Config loaded from EEPROM.");
                                        }
                                        Err(e) => {
                                            let _ = writeln!(socket, "Error: {:?}", e);
                                        }
                                    }
                                }
                                Command::Save => {
                                    let config = Config::new(&mut channels);
                                    match config.save(&mut eeprom) {
                                        Ok(()) => {
                                            let _ = writeln!(socket, "Config saved to EEPROM.");
                                        }
                                        Err(e) => {
                                            let _ = writeln!(socket, "Error saving config: {:?}", e);
                                        }
                                    }
                                }
                                Command::Reset => {
                                    for i in 0..CHANNELS {
                                        channels.power_down(i);
                                    }

                                    SCB::sys_reset();
                                }
                            }
                            Ok(SessionOutput::Error(e)) => {
                                let _ = writeln!(socket, "Command error: {:?}", e);
                            }
                            Err(_) =>
                                socket.close(),
                        }
                    } else if socket.can_send() {
                        if let Some(channel) = session.is_report_pending() {
                            if report_to(channel, &mut channels, &mut socket) {
                                session.mark_report_sent(channel);
                            }
                        }
                    }
                });

                // Update watchdog
                wd.feed();

                leds.g4.off();
                cortex_m::interrupt::free(|cs| {
                    if !net::is_pending(cs) {
                        // Wait for interrupts
                        // (Ethernet, SysTick, or USB)
                        wfi();
                    }
                });
                leds.g4.on();
            }
        });
    });

    unreachable!()
}