mod ffi;

#[link(name = "mpv")]
extern "C" {}

pub struct Error(std::ffi::c_int);

impl Error {
    fn from_return_code(rc: std::ffi::c_int) -> Result<(), Self> {
        if rc == 0 {
            Ok(())
        } else {
            Err(Self(rc))
        }
    }
}

impl std::fmt::Debug for Error {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
        f.debug_tuple("Error")
            .field(unsafe {
                &std::ffi::CStr::from_ptr(ffi::mpv_error_string(self.0 as std::ffi::c_int))
            })
            .finish()
    }
}

use std::borrow::Cow;
use std::ptr::NonNull;

pub struct Handle(NonNull<ffi::mpv_handle>);

impl Handle {
    pub fn create() -> Self {
        Self(NonNull::new(unsafe { ffi::mpv_create() }).expect("could not create mpv handle"))
    }

    pub fn initialize(&self) -> Result<(), Error> {
        Error::from_return_code(unsafe { ffi::mpv_initialize(self.0.as_ptr()) })
    }

    pub fn wait_event(&mut self, timeout: f64) -> Option<Event<'_>> {
        let event = unsafe { &*ffi::mpv_wait_event(self.0.as_ptr(), timeout) };
        match event.event_id {
            0 => None,
            1 => Some(Event::Shutdown),
            2 => todo!("Event::LogMessage"),
            3 => Some(Event::GetPropertyReply(
                event.reply_userdata,
                Error::from_return_code(event.error).map(|()| {
                    let data = unsafe { &*(event.data as *mut ffi::mpv_event_property) };
                    EventProperty {
                        name: unsafe { std::ffi::CStr::from_ptr(data.name) }
                            .to_str()
                            .unwrap(),
                        value: unsafe { FormatData::new(data.format, data.data) },
                    }
                }),
            )),
            4 => todo!("Event::SetPropertyReply"),
            5 => todo!("Event::CommandReply"),
            6 => todo!("Event::StartFile"),
            7 => todo!("Event::EndFile"),
            8 => todo!("Event::FileLoaded"),
            16 => todo!("Event::ClientMessage"),
            17 => todo!("Event::VideoReconfig"),
            18 => todo!("Event::AudioReconfig"),
            20 => todo!("Event::Seek"),
            21 => todo!("Event::PlaybackRestart"),
            22 => todo!("Event::PropertyChange"),
            24 => todo!("Event::QueueOverflow"),
            25 => todo!("Event::Hook"),
            _ => Some(Event::Ignore(event.event_id)),
        }
    }
}

pub enum FormatData<'a> {
    None,
    String(Cow<'a, str>),
    OsdString(&'a str),
    Flag(bool),
    Int64(i64),
    Double(f64),
    //Node(Node<'a>),
}

impl<'a> FormatData<'a> {
    unsafe fn new(format: ffi::mpv_format, data: *mut std::ffi::c_void) -> Self {
        match format {
            0 => Self::None,
            1 => {
                let data = data as *mut *mut std::ffi::c_char;
                Self::String(String::from_utf8_lossy(
                    std::ffi::CStr::from_ptr(*data).to_bytes(),
                ))
            }
            2 => {
                let data = data as *mut *mut std::ffi::c_char;
                Self::OsdString(
                    std::ffi::CStr::from_ptr(*data)
                        .to_str()
                        .expect("OSD string wasn't UTF-8"),
                )
            }
            3 => {
                let data = data as *mut std::ffi::c_int;
                Self::Flag(match *data {
                    0 => false,
                    1 => true,
                    _ => panic!("invalid mpv flag value"),
                })
            }
            4 => {
                let data = data as *mut i64;
                Self::Int64(*data)
            }
            5 => {
                let data = data as *mut f64;
                Self::Double(*data)
            }
            6 => todo!(),
            7 => todo!(),
            8 => todo!(),
            9 => todo!(),
            _ => panic!("invalid mpv format"),
        }
    }
}

pub struct EventProperty<'a> {
    pub name: &'a str,
    pub value: FormatData<'a>,
}

pub struct EventLogMessage<'a> {
    pub prefix: &'a str,
    pub level: &'a str,
    pub text: &'a str,
    pub log_level: i32,
}

pub enum EndFileReason {
    Eof,
    Stop,
    Quit,
    Error(Error),
    Redirect,
}

pub struct EventStartFile {
    pub playlist_entry_id: i64,
}

pub struct EventEndFile {
    pub reason: EndFileReason,
    pub playlist_entry_id: i64,
    pub playlist_insert_id: i64,
    pub playlist_insert_num_entries: i32,
}

pub struct EventClientMessage<'a> {
    pub num_args: i32,
    pub args: &'a [&'a str],
}

pub struct EventHook<'a> {
    pub name: &'a str,
    pub id: u64,
}

pub enum Event<'a> {
    Shutdown,
    LogMessage(EventLogMessage<'a>),
    GetPropertyReply(u64, Result<EventProperty<'a>, Error>),
    SetPropertyReply(u64, Result<(), Error>),
    //CommandReply(u64, Result<Node<'a>, Error>),
    StartFile(EventStartFile),
    EndFile(EventEndFile),
    FileLoaded,
    ClientMessage(EventClientMessage<'a>),
    VideoReconfig,
    AudioReconfig,
    Seek,
    PlaybackRestart,
    PropertyChange(u64, EventProperty<'a>),
    QueueOverflow,
    Hook(u64, EventHook<'a>),
    // "Keep in mind that later ABI compatible releases might add new event
    // types. These should be ignored by the API user."
    Ignore(u32),
}

impl Drop for Handle {
    fn drop(&mut self) {
        // destroy? terminate_destroy??
        todo!()
    }
}