use crate::quartz;
use std::marker::PhantomData;
use std::sync::{Arc, Mutex, TryLockError};
use std::{io, mem, ops};

pub struct Capturer {
    inner: quartz::Capturer,
    frame: Arc<Mutex<Option<quartz::Frame>>>,
    use_yuv: bool,
    i420: Vec<u8>,
    saved_raw_data: Vec<u128>, // for faster compare and copy
}

impl Capturer {
    pub fn new(display: Display, use_yuv: bool) -> io::Result<Capturer> {
        let frame = Arc::new(Mutex::new(None));

        let f = frame.clone();
        let inner = quartz::Capturer::new(
            display.0,
            display.width(),
            display.height(),
            if use_yuv {
                quartz::PixelFormat::YCbCr420Video
            } else {
                quartz::PixelFormat::Argb8888
            },
            Default::default(),
            move |inner| {
                if let Ok(mut f) = f.lock() {
                    *f = Some(inner);
                }
            },
        )
        .map_err(|_| io::Error::from(io::ErrorKind::Other))?;

        Ok(Capturer {
            inner,
            frame,
            use_yuv,
            i420: Vec::new(),
            saved_raw_data: Vec::new(),
        })
    }

    pub fn width(&self) -> usize {
        self.inner.width()
    }

    pub fn height(&self) -> usize {
        self.inner.height()
    }

    pub fn frame<'a>(&'a mut self, _timeout_ms: u32) -> io::Result<Frame<'a>> {
        match self.frame.try_lock() {
            Ok(mut handle) => {
                let mut frame = None;
                mem::swap(&mut frame, &mut handle);

                match frame {
                    Some(mut frame) => {
                        crate::would_block_if_equal(&mut self.saved_raw_data, frame.inner())?;
                        if self.use_yuv {
                            frame.nv12_to_i420(self.width(), self.height(), &mut self.i420);
                        }
                        Ok(Frame(frame, PhantomData))
                    }

                    None => Err(io::ErrorKind::WouldBlock.into()),
                }
            }

            Err(TryLockError::WouldBlock) => Err(io::ErrorKind::WouldBlock.into()),

            Err(TryLockError::Poisoned(..)) => Err(io::ErrorKind::Other.into()),
        }
    }
}

pub struct Frame<'a>(quartz::Frame, PhantomData<&'a [u8]>);

impl<'a> ops::Deref for Frame<'a> {
    type Target = [u8];
    fn deref(&self) -> &[u8] {
        &*self.0
    }
}

pub struct Display(quartz::Display);

impl Display {
    pub fn primary() -> io::Result<Display> {
        Ok(Display(quartz::Display::primary()))
    }

    pub fn all() -> io::Result<Vec<Display>> {
        Ok(quartz::Display::online()
            .map_err(|_| io::Error::from(io::ErrorKind::Other))?
            .into_iter()
            .map(Display)
            .collect())
    }

    pub fn width(&self) -> usize {
        self.0.width()
    }

    pub fn height(&self) -> usize {
        self.0.height()
    }

    pub fn name(&self) -> String {
        self.0.id().to_string()
    }

    pub fn is_online(&self) -> bool {
        self.0.is_online()
    }

    pub fn origin(&self) -> (i32, i32) {
        let o = self.0.bounds().origin;
        (o.x as _, o.y as _)
    }

    pub fn is_primary(&self) -> bool {
        self.0.is_primary()
    }
}
