//! Access point
//!
//! Creates an open access-point with SSID `esp-radio`.
//! You can connect to it using a static IP in range 192.168.2.2 ..
//! 192.168.2.255, gateway 192.168.2.1
//!
//! Open http://192.168.2.1:8080/ in your browser
//!
//! On Android you might need to choose _Keep Accesspoint_ when it tells you the
//! WiFi has no internet connection, Chrome might not want to load the URL - you
//! can use a shell and try `curl` and `ping`

#![no_std]
#![no_main]

use blocking_network_stack::Stack;
use embedded_io::*;
use esp_alloc as _;
use esp_backtrace as _;
use esp_hal::{
    clock::CpuClock,
    main,
    rng::Rng,
    time::{self, Duration},
    timer::timg::TimerGroup,
};
use esp_println::{print, println};
use esp_radio::wifi::{
    AccessPointConfig,
    Config,
    event::{self, EventExt},
};
use smoltcp::iface::{SocketSet, SocketStorage};

esp_bootloader_esp_idf::esp_app_desc!();

#[main]
fn main() -> ! {
    esp_println::logger::init_logger_from_env();
    let config = esp_hal::Config::default().with_cpu_clock(CpuClock::max());
    let peripherals = esp_hal::init(config);

    esp_alloc::heap_allocator!(size: 72 * 1024);

    let timg0 = TimerGroup::new(peripherals.TIMG0);
    esp_preempt::start(timg0.timer0);

    // Set event handlers for wifi before init to avoid missing any.
    let mut connections = 0u32;
    _ = event::ApStart::replace_handler(|_| println!("ap start event"));
    event::ApStaConnected::update_handler(move |event| {
        connections += 1;
        esp_println::println!("connected {}, mac: {:?}", connections, event.mac());
    });
    event::ApStaConnected::update_handler(|event| {
        esp_println::println!("connected aid: {}", event.aid());
    });
    event::ApStaDisconnected::update_handler(|event| {
        println!(
            "disconnected mac: {:?}, reason: {:?}",
            event.mac(),
            event.reason()
        );
    });

    let esp_radio_ctrl = esp_radio::init().unwrap();

    let (mut controller, interfaces) =
        esp_radio::wifi::new(&esp_radio_ctrl, peripherals.WIFI).unwrap();

    let mut device = interfaces.ap;
    let iface = create_interface(&mut device);

    let now = || time::Instant::now().duration_since_epoch().as_millis();

    let rng = Rng::new();
    let mut socket_set_entries: [SocketStorage; 3] = Default::default();
    let socket_set = SocketSet::new(&mut socket_set_entries[..]);
    let mut stack = Stack::new(iface, device, socket_set, now, rng.random());

    let ap_config = Config::AccessPoint(AccessPointConfig::default().with_ssid("esp-radio".into()));
    let res = controller.set_config(&ap_config);
    println!("wifi_set_configuration returned {:?}", res);

    controller.start().unwrap();
    println!("is wifi started: {:?}", controller.is_started());

    println!("{:?}", controller.capabilities());

    stack
        .set_iface_configuration(&blocking_network_stack::ipv4::Configuration::Client(
            blocking_network_stack::ipv4::ClientConfiguration::Fixed(
                blocking_network_stack::ipv4::ClientSettings {
                    ip: blocking_network_stack::ipv4::Ipv4Addr::from(parse_ip("192.168.2.1")),
                    subnet: blocking_network_stack::ipv4::Subnet {
                        gateway: blocking_network_stack::ipv4::Ipv4Addr::from(parse_ip(
                            "192.168.2.1",
                        )),
                        mask: blocking_network_stack::ipv4::Mask(24),
                    },
                    dns: None,
                    secondary_dns: None,
                },
            ),
        ))
        .unwrap();

    println!(
        "Start busy loop on main. Connect to the AP `esp-radio` and point your browser to http://192.168.2.1:8080/"
    );
    println!("Use a static IP in the range 192.168.2.2 .. 192.168.2.255, use gateway 192.168.2.1");

    let mut rx_buffer = [0u8; 1536];
    let mut tx_buffer = [0u8; 1536];
    let mut socket = stack.get_socket(&mut rx_buffer, &mut tx_buffer);

    socket.listen(8080).unwrap();

    loop {
        socket.work();

        if !socket.is_open() {
            socket.listen(8080).unwrap();
        }

        if socket.is_connected() {
            println!("Connected");

            let mut time_out = false;
            let deadline = time::Instant::now() + Duration::from_secs(20);
            let mut buffer = [0u8; 1024];
            let mut pos = 0;
            while let Ok(len) = socket.read(&mut buffer[pos..]) {
                let to_print = unsafe { core::str::from_utf8_unchecked(&buffer[..(pos + len)]) };

                if to_print.contains("\r\n\r\n") {
                    print!("{}", to_print);
                    println!();
                    break;
                }

                pos += len;

                if time::Instant::now() > deadline {
                    println!("Timeout");
                    time_out = true;
                    break;
                }
            }

            if !time_out {
                socket
                    .write_all(
                        b"HTTP/1.0 200 OK\r\n\r\n\
                    <html>\
                        <body>\
                            <h1>Hello Rust! Hello esp-radio!</h1>\
                        </body>\
                    </html>\r\n\
                    ",
                    )
                    .unwrap();

                socket.flush().unwrap();
            }

            socket.close();

            println!("Done\n");
            println!();
        }

        let start = time::Instant::now();
        while start.elapsed() < Duration::from_secs(5) {
            socket.work();
        }
    }
}

fn parse_ip(ip: &str) -> [u8; 4] {
    let mut result = [0u8; 4];
    for (idx, octet) in ip.split(".").into_iter().enumerate() {
        result[idx] = u8::from_str_radix(octet, 10).unwrap();
    }
    result
}

// some smoltcp boilerplate
fn timestamp() -> smoltcp::time::Instant {
    smoltcp::time::Instant::from_micros(
        esp_hal::time::Instant::now()
            .duration_since_epoch()
            .as_micros() as i64,
    )
}

pub fn create_interface(device: &mut esp_radio::wifi::WifiDevice) -> smoltcp::iface::Interface {
    // users could create multiple instances but since they only have one WifiDevice
    // they probably can't do anything bad with that
    smoltcp::iface::Interface::new(
        smoltcp::iface::Config::new(smoltcp::wire::HardwareAddress::Ethernet(
            smoltcp::wire::EthernetAddress::from_bytes(&device.mac_address()),
        )),
        device,
        timestamp(),
    )
}