#![no_std]
#![no_main]
#![deny(
    clippy::mem_forget,
    reason = "mem::forget is generally not safe to do with esp_hal types, especially those \
    holding buffers for the duration of a data transfer."
)]
#![deny(clippy::large_stack_frames)]

use embassy_executor::Spawner;
use embassy_time::{Duration, Timer};
use esp_backtrace as _;
use esp_hal::clock::CpuClock;
use esp_hal::timer::timg::TimerGroup;
use log::{debug, error, info, warn};

extern crate alloc;

const WIFI_CHANNEL: core::ffi::c_int = 180;

unsafe extern "C" {
    /// Changes the 802.11 PHY channel
    ///
    /// C function signature: `void phy_change_channel(int,int,int,int)`
    ///
    /// Options:
    /// - `primary`: Channel frequency in MHz
    /// - `ignored1`: Ignored (set to 1)
    /// - `ignored2`: Ignored (set to 0)
    /// - `ht_mode`: Probably HT mode
    pub unsafe fn phy_change_channel(
        primary: core::ffi::c_int,
        ignored1: core::ffi::c_int,
        ignored2: core::ffi::c_int,
        ht_mode: core::ffi::c_int,
    ) -> core::ffi::c_int;

    /// Enables 802.11p mode on the ESP32-C5
    ///
    /// C function signature: `void phy_11p_set(int,int)`
    ///
    /// Options:
    /// - `enable`: Boolean option to enable 802.11p mode
    /// - `zero`: Unknown, but need to be zero
    pub unsafe fn phy_11p_set(enable: u8, zero: u8);
}

#[repr(u8)]
#[derive(Debug)]
#[allow(dead_code)]
enum EspWifiPromiscuousPktType {
    /// Management frame, indicates 'buf' argument is wifi_promiscuous_pkt_t
    MGMT = 0,
    /// Control frame, indicates 'buf' argument is wifi_promiscuous_pkt_t
    CTRL = 1,
    /// Data frame, indicates 'buf' argument is wifi_promiscuous_pkt_t
    DATA = 2,
    /// Other type, such as MIMO etc. 'buf' argument is wifi_promiscuous_pkt_t but the payload is zero length.
    MISC = 3,
}

impl EspWifiPromiscuousPktType {
    #[allow(dead_code)]
    pub fn as_repr(self) -> u8 {
        self as u8
    }

    /// Converts to underlying type of `wifi_promiscuous_pkt_type_t` (used by `esp_radio::wifi::sniffer::PromiscuousPkt::frame_type`)
    pub fn as_frame_type(self) -> core::ffi::c_uint {
        (self as u8) as core::ffi::c_uint
    }
}

// This creates a default app-descriptor required by the esp-idf bootloader.
// For more information see: <https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/system/app_image_format.html#application-description>
esp_bootloader_esp_idf::esp_app_desc!();

#[allow(
    clippy::large_stack_frames,
    reason = "it's not unusual to allocate larger buffers etc. in main"
)]
#[esp_rtos::main]
async fn main(spawner: Spawner) -> ! {
    // generator version: 1.3.0
    // generator parameters: --chip esp32c5 -o esp32c5-wroom-1-psram -o alloc -o log -o unstable-hal -o wifi -o esp-backtrace -o embassy

    esp_println::logger::init_logger_from_env();

    let config = esp_hal::Config::default().with_cpu_clock(CpuClock::max());
    let peripherals = esp_hal::init(config);

    // The following pins are used to bootstrap the chip. They are available
    // for use, but check the datasheet of the module for more information on them.
    // - GPIO2
    // - GPIO3
    // - GPIO7
    // - GPIO25
    // - GPIO26
    // - GPIO27
    // - GPIO28

    esp_alloc::heap_allocator!(#[esp_hal::ram(reclaimed)] size: 65536);

    let timg0 = TimerGroup::new(peripherals.TIMG0);
    let sw_interrupt =
        esp_hal::interrupt::software::SoftwareInterruptControl::new(peripherals.SW_INTERRUPT);
    esp_rtos::start(timg0.timer0, sw_interrupt.software_interrupt0);

    info!("Embassy initialized!");

    let (_wifi_controller, interfaces) = esp_radio::wifi::new(
        peripherals.WIFI,
        esp_radio::wifi::ControllerConfig::default(),
    )
    .expect("Failed to initialize Wi-Fi controller");

    let mut sniffer = interfaces.sniffer;
    sniffer
        .set_promiscuous_mode(true)
        .expect("Failed to enable promiscuous mode");

    sniffer.set_receive_cb(|packet| {
        // Ignore frames with errors and non-data frames
        if packet.rx_cntl.rx_state != 0 {
            warn!("Received frame has RX error: {}", packet.rx_cntl.rx_state);
            return;
        }
        if packet.frame_type != EspWifiPromiscuousPktType::DATA.as_frame_type() {
            debug!("Received frame is not a DATA frame: {}", packet.frame_type);
            return;
        }

        // TODO: handle 802.11 frame
        info!("Received frame with {} bytes", packet.len);
    });

    unsafe {
        phy_11p_set(1, 0);
        match phy_change_channel(5000 + (WIFI_CHANNEL * 5), 1, 0, 0) {
            0 => {}
            ret => {
                error!("ERROR: Failed to change channel: {ret}");
            }
        }
    }
    info!("WiFi promiscuous mode on channel {WIFI_CHANNEL} running");

    // TODO: Spawn some tasks
    let _ = spawner;

    loop {
        // nothing to do here, all data is handled in RX callback for now
        // but use a timer so that this is yields to other tasks
        Timer::after(Duration::from_secs(1)).await;
    }
}