use core::sync::atomic::AtomicI32;

use alloc::sync::{Arc, Weak};

use crate::{
    driver::tty::tty_device::TTY_DEVICES,
    filesystem::{
        devfs::{devfs_register, DevFS, DeviceINode},
        vfs::{core::generate_inode_id, file::FileMode, FileType, IndexNode, Metadata, PollStatus},
    },
    include::bindings::bindings::{vfs_file_operations_t, vfs_file_t, vfs_index_node_t},
    libs::{keyboard_parser::TypeOneFSM, rwlock::RwLock, spinlock::SpinLock},
    syscall::SystemError,
    time::TimeSpec,
};

#[derive(Debug)]
pub struct LockedPS2KeyBoardInode(RwLock<PS2KeyBoardInode>, AtomicI32); // self.1 用来记录有多少个文件打开了这个inode

lazy_static! {
    static ref PS2_KEYBOARD_FSM: SpinLock<TypeOneFSM> = {
        let tty0 = TTY_DEVICES
            .read()
            .get("tty0")
            .expect("Initializing PS2_KEYBOARD_FSM: Cannot found TTY0!")
            .clone();
        SpinLock::new(TypeOneFSM::new(tty0))
    };
}

#[derive(Debug)]
pub struct PS2KeyBoardInode {
    /// uuid 暂时不知道有什么用（x
    // uuid: Uuid,
    /// 指向自身的弱引用
    self_ref: Weak<LockedPS2KeyBoardInode>,
    /// 指向inode所在的文件系统对象的指针
    fs: Weak<DevFS>,
    /// INode 元数据
    metadata: Metadata,
    /// 键盘操作函数
    f_ops: vfs_file_operations_t,
}

impl LockedPS2KeyBoardInode {
    pub fn new(f_ops: &vfs_file_operations_t) -> Arc<Self> {
        let inode = PS2KeyBoardInode {
            // uuid: Uuid::new_v5(),
            self_ref: Weak::default(),
            fs: Weak::default(),
            f_ops: f_ops.clone(), // 从引用复制一遍获取所有权
            metadata: Metadata {
                dev_id: 1,
                inode_id: generate_inode_id(),
                size: 0,
                blk_size: 0,
                blocks: 0,
                atime: TimeSpec::default(),
                mtime: TimeSpec::default(),
                ctime: TimeSpec::default(),
                file_type: FileType::CharDevice, // 文件夹，block设备，char设备
                mode: 0o666,
                nlinks: 1,
                uid: 0,
                gid: 0,
                raw_dev: 0, // 这里用来作为device number
            },
        };

        let result = Arc::new(LockedPS2KeyBoardInode(
            RwLock::new(inode),
            AtomicI32::new(0),
        ));
        result.0.write().self_ref = Arc::downgrade(&result);

        return result;
    }
}

impl DeviceINode for LockedPS2KeyBoardInode {
    fn set_fs(&self, fs: Weak<DevFS>) {
        self.0.write().fs = fs;
    }
}

#[no_mangle] // 不重命名
pub extern "C" fn ps2_keyboard_register(f_ops: &vfs_file_operations_t) {
    devfs_register("ps2_keyboard", LockedPS2KeyBoardInode::new(f_ops))
        .expect("Failed to register ps/2 keyboard");
}

impl IndexNode for LockedPS2KeyBoardInode {
    fn read_at(
        &self,
        _offset: usize,
        len: usize,
        buf: &mut [u8],
        _data: &mut crate::filesystem::vfs::FilePrivateData,
    ) -> Result<usize, SystemError> {
        let guard = self.0.read();
        let func = guard.f_ops.read.unwrap();
        let r = unsafe {
            func(
                0 as *mut vfs_file_t,
                &mut buf[0..len] as *mut [u8] as *mut i8,
                len as i64,
                0 as *mut i64,
            )
        };
        return Ok(r as usize);
    }

    fn write_at(
        &self,
        _offset: usize,
        _len: usize,
        _buf: &[u8],
        _data: &mut crate::filesystem::vfs::FilePrivateData,
    ) -> Result<usize, SystemError> {
        return Err(SystemError::ENOTSUP);
    }

    fn open(
        &self,
        _data: &mut crate::filesystem::vfs::FilePrivateData,
        _mode: &FileMode,
    ) -> Result<(), SystemError> {
        let prev_ref_count = self.1.fetch_add(1, core::sync::atomic::Ordering::SeqCst);
        if prev_ref_count == 0 {
            // 第一次打开，需要初始化
            let guard = self.0.write();
            let func = guard.f_ops.open.unwrap();
            let _ = unsafe { func(0 as *mut vfs_index_node_t, 0 as *mut vfs_file_t) };
        }
        return Ok(());
    }

    fn close(
        &self,
        _data: &mut crate::filesystem::vfs::FilePrivateData,
    ) -> Result<(), SystemError> {
        let prev_ref_count = self.1.fetch_sub(1, core::sync::atomic::Ordering::SeqCst);
        if prev_ref_count == 1 {
            // 最后一次关闭，需要释放
            let guard = self.0.write();
            let func = guard.f_ops.close.unwrap();
            let _ = unsafe { func(0 as *mut vfs_index_node_t, 0 as *mut vfs_file_t) };
        }
        return Ok(());
    }

    fn poll(&self) -> Result<PollStatus, SystemError> {
        return Ok(PollStatus {
            flags: PollStatus::READ_MASK,
        });
    }

    fn metadata(&self) -> Result<Metadata, SystemError> {
        return Ok(self.0.read().metadata.clone());
    }

    fn set_metadata(&self, metadata: &Metadata) -> Result<(), SystemError> {
        let mut inode = self.0.write();
        inode.metadata.atime = metadata.atime;
        inode.metadata.mtime = metadata.mtime;
        inode.metadata.ctime = metadata.ctime;
        inode.metadata.mode = metadata.mode;
        inode.metadata.uid = metadata.uid;
        inode.metadata.gid = metadata.gid;

        return Ok(());
    }

    fn fs(&self) -> alloc::sync::Arc<dyn crate::filesystem::vfs::FileSystem> {
        return self.0.read().fs.upgrade().unwrap();
    }

    fn as_any_ref(&self) -> &dyn core::any::Any {
        self
    }

    fn list(&self) -> Result<alloc::vec::Vec<alloc::string::String>, SystemError> {
        return Err(SystemError::ENOTSUP);
    }
}

#[allow(dead_code)]
#[no_mangle]
/// for test
pub extern "C" fn ps2_keyboard_parse_keycode(input: u8) {
    PS2_KEYBOARD_FSM.lock().parse(input);
}