//! K422: read six real virtio-net config bytes after DeviceID/feature gates.
//! Legacy v1 config is read twice for stability; no queue is initialized.
use super::*;
use turkos_kernel::{net_mac, virtio_mmio};

fn read_mac(base: u64) -> [u8; 6] {
    let mut mac = [0u8; 6];
    for (index, byte) in mac.iter_mut().enumerate() {
        // SAFETY: K322 mapped the validated 0x200-byte MMIO slot as Device;
        // config offsets 0x100..0x105 are within that slot and byte aligned.
        *byte = unsafe { read_volatile((base + 0x100 + index as u64) as *const u8) };
    }
    mac
}

pub fn smoke_test(boot: &BootData) -> ! {
    let mut net_base = None;
    for node in boot.virtio_mmio.as_slice() {
        let magic = unsafe { read_volatile(node.base as *const u32) };
        let version = unsafe { read_volatile((node.base + 4) as *const u32) };
        let id = unsafe { read_volatile((node.base + 8) as *const u32) };
        let vendor = unsafe { read_volatile((node.base + 12) as *const u32) };
        if virtio_mmio::validate_magic(magic).is_err()
            || virtio_mmio::validate_version(version).is_err()
            || virtio_mmio::validate_fixture_vendor(vendor).is_err()
        {
            write_line("TURKOS/NET-MAC-ERROR: transport identity");
            park();
        }
        if virtio_mmio::require_net_device(id).is_ok() {
            if net_base.replace(node.base).is_some() {
                write_line("TURKOS/NET-MAC-ERROR: ambiguous net");
                park();
            }
        }
    }
    let Some(base) = net_base else {
        write_line("TURKOS/NET-MAC-ERROR: missing net");
        park();
    };
    // SAFETY: HostFeaturesSel/HostFeatures are aligned within the selected
    // K322 Device-mapped network bridge. Reading does not negotiate a driver.
    let offered = unsafe {
        write_volatile((base + 0x14) as *mut u32, 0);
        read_volatile((base + 0x10) as *const u32)
    };
    if offered & net_mac::VIRTIO_NET_F_MAC == 0 {
        write_line("TURKOS/NET-MAC-ERROR: missing feature");
        park();
    }
    let first = read_mac(base);
    let second = read_mac(base);
    if first != second {
        write_line("TURKOS/NET-MAC-ERROR: unstable config");
        park();
    }
    let packed = first
        .iter()
        .fold(0usize, |value, byte| (value << 8) | *byte as usize);
    write_str("TURKOS/NET-MAC: BASE=0x");
    write_hex(base as usize);
    write_str(" OFFERED=0x");
    write_hex(offered as usize);
    write_str(" VALUE=0x");
    write_hex(packed);
    write_str(" STABLE=0x");
    write_hex(1);
    write_str("\r\n");
    match net_mac::validate(offered, first) {
        Ok(_) => write_line("TURKOS/NET-MAC: PASS UNICAST=1"),
        Err(net_mac::Error::ZeroAddress) => write_line("TURKOS/NET-MAC-ERROR: zero address"),
        Err(net_mac::Error::Multicast) => write_line("TURKOS/NET-MAC-ERROR: multicast address"),
        Err(net_mac::Error::MissingFeature) => write_line("TURKOS/NET-MAC-ERROR: missing feature"),
    }
    park()
}