#![no_main]
#![feature(compiler_builtins_lib)]
#![feature(custom_test_frameworks)]
#![feature(abi_x86_interrupt)]
#![feature(panic_info_message)]
#![test_runner(crate::testing::serial_test_runner)]
#![reexport_test_harness_main = "test_main"]
#![no_std]

pub mod interrupts;
pub mod io;
pub mod testing;

use core::fmt::Write;
pub use io::qemu::{exit_qemu, QemuExitCode};
pub use io::vga_text::OStream;
pub use io::{qemu, serial, vga_text};

#[no_mangle]
pub extern "C" fn _start() -> ! {
    interrupts::gdt::init();
    interrupts::table::init();
    if cfg!(test) {
        #[cfg(test)]
        test_main();
        qemu::exit_qemu(qemu::QemuExitCode::Success);
    }
    x86_64::instructions::interrupts::int3();

    let stdout = OStream::new();
    stdout.clear();
    panic!("panic! at the disco");

    /// TODO: write test
    ///fn _loop(i: u64) -> u64 {
    ///    if i > 0b1010101001101101 {
    ///         return i;
    ///    }
    ///    let n = i;
    ///    let mut stdout = OStream::new();
    ///    write!(&mut stdout, "{:x}", &n as *const u64 as u64).unwrap();
    ///    _loop(i + 1)
    ///}
    ///_loop(0);
    /// TODO: write test
    ///x86_64::instructions::interrupts::int3();
    loop {}
}

#[panic_handler]
#[no_mangle]
pub extern "C" fn panic_handler(info: &core::panic::PanicInfo) -> ! {
    let mut stderr = OStream::new();
    stderr.set_state(vga_text::CharState::from_colors(
        vga_text::Color::LightRed,
        vga_text::Color::Red,
    ));
    stderr.clear();
    stderr.print(b"uff-os");
    stderr.set_row(10);
    stderr.set_state(vga_text::CharState::from_colors(
        vga_text::Color::White,
        vga_text::Color::Red,
    ));
    stderr.print_centered(b"<kernel panic>");
    stderr.set_row(14);
    stderr.set_state(vga_text::CharState::from_colors(
        vga_text::Color::Cyan,
        vga_text::Color::Red,
    ));
    stderr.set_centered(true);
    write!(
        &mut stderr,
        "{:?}",
        info.message()
            .unwrap_or(&format_args!("no panic information obtainable"))
    );
    stderr.set_centered(false);
    if cfg!(test) {
        write!(serial::SerialStream::new(), "Testing failed\n").unwrap();
        qemu::exit_qemu(qemu::QemuExitCode::Failed);
    }
    loop {}
}