#include <zinnia/spin.h>
#include <zinnia/syscall.h>
#include <zinnia/usercopy.h>
#include <config.h>
#include <string.h>
#include <uapi/utsname.h>

static struct spinlock uname_lock = {};

static struct __utsname uname_buf = {
    .sysname = "Zinnia",
    .release = ZINNIA_VERSION,
    .version = CONFIG_KERNEL_FLAVOR,
    .nodename = "localhost",
    .machine = ZINNIA_ARCH,
    .domainname = "(none)",
};

struct syscall_ret sys_setuname(const __user struct __utsname* ptr) {
    struct syscall_ret ret = {};

    if (!ptr) {
        ret.error = EINVAL;
        return ret;
    }

    // TODO: User has to be root to do this.

    struct __utsname read_buf;
    if (!usercopy_read(&read_buf, ptr, sizeof(read_buf))) {
        ret.error = EFAULT;
        return ret;
    }

    spin_lock(&uname_lock);

    strncpy(uname_buf.sysname, read_buf.sysname, sizeof(uname_buf.sysname) - 1);
    strncpy(uname_buf.release, read_buf.release, sizeof(uname_buf.release) - 1);
    strncpy(uname_buf.version, read_buf.version, sizeof(uname_buf.version) - 1);
    strncpy(uname_buf.nodename, read_buf.nodename, sizeof(uname_buf.nodename) - 1);
    strncpy(uname_buf.machine, read_buf.machine, sizeof(uname_buf.machine) - 1);
    strncpy(uname_buf.domainname, read_buf.domainname, sizeof(uname_buf.domainname) - 1);

    spin_unlock(&uname_lock);

    return ret;
}

struct syscall_ret sys_getuname(__user struct __utsname* ptr) {
    struct syscall_ret ret = {};

    if (!ptr) {
        ret.error = EINVAL;
        return ret;
    }

    spin_lock(&uname_lock);
    struct __utsname write_buf = uname_buf;
    spin_unlock(&uname_lock);

    if (!usercopy_write(ptr, &write_buf, sizeof(write_buf)))
        ret.error = EFAULT;

    return ret;
}