use crate::error::KernelError;
use crate::proc::context::CpuContext;
use crate::syscall::{SyscallResult, copy_from_user};

pub fn sys_debug_print(ctx: &mut CpuContext) {
    let ptr = ctx.rdi;
    let len = ctx.rsi;

    let irq = match crate::sync::InterruptsDisabledToken::new_checked() {
        Some(tok) => tok,
        None => {
            x86_64::instructions::interrupts::disable();
            match crate::sync::InterruptsDisabledToken::new_checked() {
                Some(tok) => tok,
                None => {
                    ctx.rax = SyscallResult::error(KernelError::BadState).raw();
                    return;
                }
            }
        }
    };
    if len > 256 {
        ctx.rax = SyscallResult::error(KernelError::InvalidAddress).raw();
        return;
    }

    let mut buf = [0u8; 256];
    match copy_from_user(ptr, &mut buf, len as usize, &irq) {
        Err(e) => ctx.rax = SyscallResult::error(e).raw(),
        Ok(()) => match core::str::from_utf8(&buf[..len as usize]) {
            Ok(s) => {
                crate::kprint!("{}", s);
                ctx.rax = SyscallResult::ok().raw();
            }
            Err(_) => ctx.rax = SyscallResult::error(KernelError::InvalidParameter).raw(),
        },
    }
}