use {
    crate::{alloc::string::ToString, device_tree::DeviceTree, kmain::DEVICE_TREE},
    alloc::string::String,
    core::arch::asm,
    xml::XMLElement,
};

pub fn collect_device_info() {
    log::trace!("Collecting devices on aarch64");
    // Lock device tree
    unsafe {
        DEVICE_TREE.force_unlock();
    }
    let device_tree = &mut DEVICE_TREE.lock();
    collect_cpu_info(device_tree);
    // let dt = DEVICE_TREE.lock();
}

fn collect_cpu_info(device_tree: &mut DeviceTree) {
    let mut cpu = XMLElement::new("cpu");

    let cpu_id = cpu_id();

    cpu.set_attribute("CPU Name", cpu_id.0);
    cpu.set_attribute("CPU Id", cpu_id.1);

    let cpus = device_tree.devices.get_mut("CPUs").unwrap();
    cpus.push(cpu);
}

fn cpu_id() -> (String, u64) {
    let mut cpu_id: u64 = 0;
    unsafe {
        asm!("mrs {cpu_id}, MIDR_EL1",
                cpu_id = out(reg) cpu_id,
        )
    }

    let cpu_name = match cpu_id {
        // the source of these two was a stackoverflow question
        // https://raspberrypi.stackexchange.com/questions/117175/how-do-i-read-the-cpuid-in-aarch64-asm
        0x410FD034 => "Cortex-A53".to_string(),
        0x410FD083 => "Cortex-A72".to_string(),
        _ => "Unknown".to_string(),
    };
    log::trace!("CPU Name: {cpu_name} - CPU ID: 0x{:X}", cpu_id);

    (cpu_name, cpu_id)
}