//! AbleOS Kernel Entrypoint

use {
    crate::{
        arch::hardware_random_u64,
        bootmodules::BootModules,
        //bootmodules::build_cmd,
        device_tree::DeviceTree,
        holeybytes::ExecThread,
        ipc::buffer::IpcBuffer,
        task::Executor,
    },
    alloc::boxed::Box,
    core::cell::LazyCell,
    hashbrown::HashMap,
    hbvm::mem::Address,
    limine::{Framebuffer, FramebufferRequest, NonNullPtr},
    log::{debug, error, trace},
    spin::{Lazy, Mutex},
};

pub fn kmain(_cmdline: &str, boot_modules: BootModules) -> ! {
    debug!("Entered kmain");

    // let kcmd = build_cmd("Kernel Command Line", cmdline);
    // trace!("Cmdline: {kcmd:?}");

    // for (i, bm) in boot_modules.iter().enumerate() {
    //     let name = format!("module-{}", i);
    //     let _bmcmd: XMLElement;
    //     if bm.cmd.len() >= 2 {
    //         // TODO: pass into the program
    //         // Pass CMDLine into an IPCBuffer and put the ptr to the IPCBuffer in r200
    //         _bmcmd = build_cmd(name, bm.cmd.clone());
    //         log::info!("{:?}", _bmcmd);
    //     }
    // }

    let dt = DEVICE_TREE.lock();

    // TODO(Able): This line causes a deadlock
    debug!("Device Tree: {}", dt);

    trace!("Boot complete. Moving to init_system");

    // TODO: schedule the disk driver from the initramfs
    // TODO: schedule the filesystem driver from the initramfs
    // TODO: Schedule the VFS from initramfs
    // TODO: schedule the init system from the initramfs

    drop(dt);

    let fb1: &NonNullPtr<Framebuffer> = &FB_REQ.get_response().get().unwrap().framebuffers()[0];

    {
        let mut dt = DEVICE_TREE.lock();
        let mut disp = xml::XMLElement::new("display_0");

        disp.set_attribute("width", fb1.width);
        disp.set_attribute("height", fb1.height);
        disp.set_attribute("bpp", fb1.bpp);
        disp.set_attribute("pitch", fb1.pitch);
        dt.devices.insert("Displays", alloc::vec![disp]);
    }
    debug!("Graphics initialised");
    debug!(
        "Graphics front ptr {:?}",
        fb1.address.as_ptr().unwrap() as *const u8
    );

    unsafe {
        let executor = LazyCell::<Executor>::force_mut(&mut EXECUTOR);
        for module in boot_modules.iter() {
            let cmd = module.cmd.trim_matches('"');
            let cmd_len = cmd.len() as u64;

            log::info!(
                "Starting {}",
                module
                    .path
                    .split('/')
                    .last()
                    .unwrap()
                    .split('.')
                    .next()
                    .unwrap()
            );
            log::debug!("Spawning {} with arguments \"{}\"", module.path, cmd);

            // decode AbleOS Executable format
            let header = &module.bytes[0..46];
            let magic_slice = &header[0..3];
            if magic_slice != [0x15, 0x91, 0xD2] {
                log::error!("Invalid magic number at the start of executable.");
                continue;
            }

            let executable_format_version = u32::from_le_bytes(header[3..7].try_into().unwrap());
            let offset = if executable_format_version == 0 {
                47
            } else {
                error!("Invalid executable format.");
                continue;
            };

            let code_length = u64::from_le_bytes(header[7..15].try_into().unwrap());
            let data_length = u64::from_le_bytes(header[15..23].try_into().unwrap());
            let end = (code_length + data_length) as usize;
            log::debug!("{code_length} + {data_length} = {end}");

            let mut thr = ExecThread::new(&module.bytes[offset..end], Address::new(0));
            if cmd_len > 0 {
                thr.set_arguments(cmd.as_ptr() as u64, cmd_len);
            }
            executor.spawn(Box::pin(async move {
                if let Err(e) = thr.await {
                    log::error!("{e:?}");
                }
            }));
        }

        debug!("Random number: {}", hardware_random_u64());

        executor.run();
    };

    crate::arch::spin_loop()
}

// ! SAFETY: this is not threadsafe at all, like even a little bit.
// ! SERIOUSLY
pub static mut EXECUTOR: LazyCell<Executor> = LazyCell::new(|| Executor::new());

pub static DEVICE_TREE: Lazy<Mutex<DeviceTree>> = Lazy::new(|| {
    let dt = DeviceTree::new();
    Mutex::new(dt)
});
pub static FB_REQ: FramebufferRequest = FramebufferRequest::new(0);

pub type IpcBuffers<'a> = HashMap<u64, IpcBuffer<'a>>;
pub static IPC_BUFFERS: Lazy<Mutex<IpcBuffers>> = Lazy::new(|| {
    let mut bufs = HashMap::new();
    let log_buffer = IpcBuffer::new(false, 0);
    let file_buffer = IpcBuffer::new(false, 0);

    bufs.insert(1, log_buffer);
    bufs.insert(2, file_buffer);

    Mutex::new(bufs)
});

#[test_case]
fn trivial_assertion() {
    trace!("trivial assertion... ");
    assert_eq!(1, 1);
    info!("[ok]");
}