gstreamer-rs/gstreamer-sdp/src/sdp_message.rs

// Copyright (C) 2018 Sebastian Dröge <sebastian@centricular.com>
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use std::ffi::CStr;
use std::fmt;
use std::mem;
use std::ops;
#[cfg(any(feature = "v1_8_1", feature = "dox"))]
use std::ptr;

use ffi;
use glib::translate::*;
use glib_ffi;
use gobject_ffi;
use gst;
use gst::MiniObject;

use sdp_attribute::SDPAttribute;
use sdp_bandwidth::SDPBandwidth;
use sdp_connection::SDPConnection;
use sdp_key::SDPKey;
use sdp_media::SDPMedia;
use sdp_media::SDPMediaRef;
use sdp_origin::SDPOrigin;
use sdp_time::SDPTime;
use sdp_zone::SDPZone;

#[cfg(any(feature = "v1_8_1", feature = "dox"))]
use MIKEYMessage;

glib_wrapper! {
    #[derive(PartialEq, Eq, PartialOrd, Ord, Hash)]
    pub struct SDPMessage(Boxed<ffi::GstSDPMessage>);

    match fn {
        copy => |ptr| gobject_ffi::g_boxed_copy(ffi::gst_sdp_message_get_type(), ptr as *mut _) as *mut ffi::GstSDPMessage,
        free => |ptr| gobject_ffi::g_boxed_free(ffi::gst_sdp_message_get_type(), ptr as *mut _),
        get_type => || ffi::gst_sdp_message_get_type(),
    }
}

unsafe impl Send for SDPMessage {}
unsafe impl Sync for SDPMessage {}

impl Default for SDPMessage {
    fn default() -> Self {
        Self::new()
    }
}

impl ops::Deref for SDPMessage {
    type Target = SDPMessageRef;

    fn deref(&self) -> &SDPMessageRef {
        unsafe { &*(self.to_glib_none().0 as *const SDPMessageRef) }
    }
}

impl ops::DerefMut for SDPMessage {
    fn deref_mut(&mut self) -> &mut SDPMessageRef {
        unsafe { &mut *(self.to_glib_none_mut().0 as *mut SDPMessageRef) }
    }
}

impl fmt::Debug for SDPMessage {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        <SDPMessageRef as fmt::Debug>::fmt(&*self, f)
    }
}

impl fmt::Display for SDPMessage {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        <SDPMessageRef as fmt::Display>::fmt(&*self, f)
    }
}

impl SDPMessage {
    pub fn new() -> SDPMessage {
        assert_initialized_main_thread!();
        unsafe {
            let mut msg = mem::zeroed();
            ffi::gst_sdp_message_new(&mut msg);
            from_glib_full(msg)
        }
    }

    pub fn parse_buffer(data: &[u8]) -> Result<Self, ()> {
        assert_initialized_main_thread!();
        unsafe {
            let size = data.len() as u32;
            let mut msg = mem::zeroed();
            ffi::gst_sdp_message_new(&mut msg);
            let result = ffi::gst_sdp_message_parse_buffer(data.to_glib_none().0, size, msg);
            match result {
                ffi::GST_SDP_OK => Ok(from_glib_full(msg)),
                _ => {
                    glib_ffi::g_free(msg as *mut _);
                    Err(())
                }
            }
        }
    }

    pub fn parse_uri(uri: &str) -> Result<Self, ()> {
        assert_initialized_main_thread!();
        unsafe {
            let mut msg = mem::zeroed();
            ffi::gst_sdp_message_new(&mut msg);
            let result = ffi::gst_sdp_message_parse_uri(uri.to_glib_none().0, msg);
            match result {
                ffi::GST_SDP_OK => Ok(from_glib_full(msg)),
                _ => {
                    glib_ffi::g_free(msg as *mut _);
                    Err(())
                }
            }
        }
    }
}

#[repr(C)]
pub struct SDPMessageRef(ffi::GstSDPMessage);

impl fmt::Debug for SDPMessageRef {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        use std::cell::RefCell;

        struct DebugIter<I>(RefCell<I>);
        impl<I: Iterator> fmt::Debug for DebugIter<I>
        where
            I::Item: fmt::Debug,
        {
            fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
                f.debug_list().entries(&mut *self.0.borrow_mut()).finish()
            }
        }

        f.debug_struct("SDPMessage").finish()
    }
}

impl fmt::Display for SDPMessageRef {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self.as_text() {
            Some(text) => f.write_str(text.as_str()),
            None => Err(fmt::Error),
        }
    }
}

unsafe impl Send for SDPMessageRef {}
unsafe impl Sync for SDPMessageRef {}

impl SDPMessageRef {
    pub fn add_attribute<'a, P: Into<Option<&'a str>>>(
        &mut self,
        key: &str,
        value: P,
    ) -> Result<(), ()> {
        let result = unsafe {
            ffi::gst_sdp_message_add_attribute(
                &mut self.0,
                key.to_glib_none().0,
                value.into().to_glib_none().0,
            )
        };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn add_email(&mut self, email: &str) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_add_email(&mut self.0, email.to_glib_none().0) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn add_media(&mut self, media: SDPMedia) -> Result<(), ()> {
        let result = unsafe {
            ffi::gst_sdp_message_add_media(
                &mut self.0,
                media.to_glib_full() as *mut ffi::GstSDPMedia,
            )
        };
        mem::forget(media);
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn add_phone(&mut self, phone: &str) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_add_phone(&mut self.0, phone.to_glib_none().0) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn add_time(&mut self, start: &str, stop: &str, repeat: &[&str]) -> Result<(), ()> {
        let result = unsafe {
            ffi::gst_sdp_message_add_time(
                &mut self.0,
                start.to_glib_none().0,
                stop.to_glib_none().0,
                repeat.to_glib_none().0,
            )
        };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn add_zone(&mut self, adj_time: &str, typed_time: &str) -> Result<(), ()> {
        let result = unsafe {
            ffi::gst_sdp_message_add_zone(
                &mut self.0,
                adj_time.to_glib_none().0,
                typed_time.to_glib_none().0,
            )
        };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn as_text(&self) -> Option<String> {
        unsafe { from_glib_full(ffi::gst_sdp_message_as_text(&self.0)) }
    }

    pub fn attributes_len(&self) -> u32 {
        unsafe { ffi::gst_sdp_message_attributes_len(&self.0) }
    }

    pub fn attributes_to_caps(&self, caps: &mut gst::CapsRef) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_attributes_to_caps(&self.0, caps.as_mut_ptr()) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn bandwidths_len(&self) -> u32 {
        unsafe { ffi::gst_sdp_message_bandwidths_len(&self.0) }
    }

    pub fn dump(&self) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_dump(&self.0) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn emails_len(&self) -> u32 {
        unsafe { ffi::gst_sdp_message_emails_len(&self.0) }
    }

    pub fn get_attribute(&self, idx: u32) -> Option<&SDPAttribute> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_attribute(&self.0, idx);
            if ptr.is_null() {
                None
            } else {
                Some(&*(ptr as *mut SDPAttribute))
            }
        }
    }

    pub fn get_attribute_val(&self, key: &str) -> Option<&str> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_attribute_val(&self.0, key.to_glib_none().0);
            if ptr.is_null() {
                None
            } else {
                let result = CStr::from_ptr(ptr).to_str();
                match result {
                    Ok(attr) => Some(attr),
                    Err(_) => None,
                }
            }
        }
    }

    pub fn get_attribute_val_n(&self, key: &str, nth: u32) -> Option<&str> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_attribute_val_n(&self.0, key.to_glib_none().0, nth);
            if ptr.is_null() {
                None
            } else {
                let result = CStr::from_ptr(ptr).to_str();
                match result {
                    Ok(attr) => Some(attr),
                    Err(_) => None,
                }
            }
        }
    }

    pub fn get_bandwidth(&self, idx: u32) -> Option<&SDPBandwidth> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_bandwidth(&self.0, idx);
            if ptr.is_null() {
                None
            } else {
                Some(&*(ptr as *mut SDPBandwidth))
            }
        }
    }

    pub fn get_connection(&self) -> Option<&SDPConnection> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_connection(&self.0);
            if ptr.is_null() {
                None
            } else {
                Some(&*(ptr as *mut SDPConnection))
            }
        }
    }

    pub fn get_email(&self, idx: u32) -> Option<&str> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_email(&self.0, idx);
            if ptr.is_null() {
                None
            } else {
                let result = CStr::from_ptr(ptr).to_str();
                match result {
                    Ok(attr) => Some(attr),
                    Err(_) => None,
                }
            }
        }
    }

    pub fn get_information(&self) -> Option<&str> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_information(&self.0);
            if ptr.is_null() {
                None
            } else {
                let result = CStr::from_ptr(ptr).to_str();
                match result {
                    Ok(attr) => Some(attr),
                    Err(_) => None,
                }
            }
        }
    }

    pub fn get_key(&self) -> Option<&SDPKey> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_key(&self.0);
            if ptr.is_null() {
                None
            } else {
                Some(&*(ptr as *mut SDPKey))
            }
        }
    }

    pub fn get_media(&self, idx: u32) -> Option<&SDPMediaRef> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_media(&self.0, idx);
            if ptr.is_null() {
                None
            } else {
                Some(&*(ptr as *const SDPMediaRef))
            }
        }
    }

    pub fn get_origin(&self) -> Option<&SDPOrigin> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_origin(&self.0);
            if ptr.is_null() {
                None
            } else {
                Some(&*(ptr as *mut SDPOrigin))
            }
        }
    }

    pub fn get_phone(&self, idx: u32) -> Option<&str> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_phone(&self.0, idx);
            if ptr.is_null() {
                None
            } else {
                let result = CStr::from_ptr(ptr).to_str();
                match result {
                    Ok(attr) => Some(attr),
                    Err(_) => None,
                }
            }
        }
    }

    pub fn get_session_name(&self) -> Option<&str> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_session_name(&self.0);
            if ptr.is_null() {
                None
            } else {
                let result = CStr::from_ptr(ptr).to_str();
                match result {
                    Ok(attr) => Some(attr),
                    Err(_) => None,
                }
            }
        }
    }

    pub fn get_time(&self, idx: u32) -> Option<&SDPTime> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_time(&self.0, idx);
            if ptr.is_null() {
                None
            } else {
                Some(&*(ptr as *mut SDPTime))
            }
        }
    }

    pub fn get_uri(&self) -> Option<&str> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_uri(&self.0);
            if ptr.is_null() {
                None
            } else {
                let result = CStr::from_ptr(ptr).to_str();
                match result {
                    Ok(attr) => Some(attr),
                    Err(_) => None,
                }
            }
        }
    }

    pub fn get_version(&self) -> Option<&str> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_version(&self.0);
            if ptr.is_null() {
                None
            } else {
                let result = CStr::from_ptr(ptr).to_str();
                match result {
                    Ok(attr) => Some(attr),
                    Err(_) => None,
                }
            }
        }
    }

    pub fn get_zone(&self, idx: u32) -> Option<&SDPZone> {
        unsafe {
            let ptr = ffi::gst_sdp_message_get_zone(&self.0, idx);
            if ptr.is_null() {
                None
            } else {
                Some(&*(ptr as *mut SDPZone))
            }
        }
    }

    pub fn insert_attribute(&mut self, idx: i32, mut attr: SDPAttribute) -> Result<(), ()> {
        let result =
            unsafe { ffi::gst_sdp_message_insert_attribute(&mut self.0, idx, &mut attr.0) };
        mem::forget(attr);
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn insert_bandwidth(&mut self, idx: i32, mut bw: SDPBandwidth) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_insert_bandwidth(&mut self.0, idx, &mut bw.0) };
        mem::forget(bw);
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn insert_email(&mut self, idx: i32, email: &str) -> Result<(), ()> {
        let result =
            unsafe { ffi::gst_sdp_message_insert_email(&mut self.0, idx, email.to_glib_none().0) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn insert_phone(&mut self, idx: i32, phone: &str) -> Result<(), ()> {
        let result =
            unsafe { ffi::gst_sdp_message_insert_phone(&mut self.0, idx, phone.to_glib_none().0) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn insert_time(&mut self, idx: i32, mut time: SDPTime) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_insert_time(&mut self.0, idx, &mut time.0) };
        mem::forget(time);
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn insert_zone(&mut self, idx: i32, mut zone: SDPZone) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_insert_zone(&mut self.0, idx, &mut zone.0) };
        mem::forget(zone);
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn medias_len(&self) -> u32 {
        unsafe { ffi::gst_sdp_message_medias_len(&self.0) }
    }

    #[cfg(any(feature = "v1_8_1", feature = "dox"))]
    pub fn parse_keymgmt(&self) -> Result<MIKEYMessage, ()> {
        unsafe {
            let mut mikey = ptr::null_mut();
            let result = ffi::gst_sdp_message_parse_keymgmt(&self.0, &mut mikey);
            match result {
                ffi::GST_SDP_OK => Ok(from_glib_full(mikey)),
                _ => Err(()),
            }
        }
    }

    pub fn phones_len(&self) -> u32 {
        unsafe { ffi::gst_sdp_message_phones_len(&self.0) }
    }

    pub fn remove_attribute(&mut self, idx: u32) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_remove_attribute(&mut self.0, idx) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn remove_bandwidth(&mut self, idx: u32) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_remove_bandwidth(&mut self.0, idx) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn remove_email(&mut self, idx: u32) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_remove_email(&mut self.0, idx) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn remove_phone(&mut self, idx: u32) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_remove_phone(&mut self.0, idx) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn remove_time(&mut self, idx: u32) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_remove_time(&mut self.0, idx) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn remove_zone(&mut self, idx: u32) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_remove_zone(&mut self.0, idx) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn replace_attribute(&mut self, idx: u32, mut attr: SDPAttribute) -> Result<(), ()> {
        let result =
            unsafe { ffi::gst_sdp_message_replace_attribute(&mut self.0, idx, &mut attr.0) };
        mem::forget(attr);
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn replace_bandwidth(&mut self, idx: u32, mut bw: SDPBandwidth) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_replace_bandwidth(&mut self.0, idx, &mut bw.0) };
        mem::forget(bw);
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn replace_email(&mut self, idx: u32, email: &str) -> Result<(), ()> {
        let result =
            unsafe { ffi::gst_sdp_message_replace_email(&mut self.0, idx, email.to_glib_none().0) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn replace_phone(&mut self, idx: u32, phone: &str) -> Result<(), ()> {
        let result =
            unsafe { ffi::gst_sdp_message_replace_phone(&mut self.0, idx, phone.to_glib_none().0) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn replace_time(&mut self, idx: u32, mut time: SDPTime) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_replace_time(&mut self.0, idx, &mut time.0) };
        mem::forget(time);
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn replace_zone(&mut self, idx: u32, mut zone: SDPZone) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_replace_zone(&mut self.0, idx, &mut zone.0) };
        mem::forget(zone);
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn set_connection(
        &mut self,
        nettype: &str,
        addrtype: &str,
        address: &str,
        ttl: u32,
        addr_number: u32,
    ) -> Result<(), ()> {
        let result = unsafe {
            ffi::gst_sdp_message_set_connection(
                &mut self.0,
                nettype.to_glib_none().0,
                addrtype.to_glib_none().0,
                address.to_glib_none().0,
                ttl,
                addr_number,
            )
        };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn set_information(&mut self, information: &str) -> Result<(), ()> {
        let result = unsafe {
            ffi::gst_sdp_message_set_information(&mut self.0, information.to_glib_none().0)
        };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn set_key(&mut self, type_: &str, data: &str) -> Result<(), ()> {
        let result = unsafe {
            ffi::gst_sdp_message_set_key(&mut self.0, type_.to_glib_none().0, data.to_glib_none().0)
        };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn set_origin(
        &mut self,
        username: &str,
        sess_id: &str,
        sess_version: &str,
        nettype: &str,
        addrtype: &str,
        addr: &str,
    ) -> Result<(), ()> {
        let result = unsafe {
            ffi::gst_sdp_message_set_origin(
                &mut self.0,
                username.to_glib_none().0,
                sess_id.to_glib_none().0,
                sess_version.to_glib_none().0,
                nettype.to_glib_none().0,
                addrtype.to_glib_none().0,
                addr.to_glib_none().0,
            )
        };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn set_session_name(&mut self, session_name: &str) -> Result<(), ()> {
        let result = unsafe {
            ffi::gst_sdp_message_set_session_name(&mut self.0, session_name.to_glib_none().0)
        };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn set_uri(&mut self, uri: &str) -> Result<(), ()> {
        let result = unsafe { ffi::gst_sdp_message_set_uri(&mut self.0, uri.to_glib_none().0) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn set_version(&mut self, version: &str) -> Result<(), ()> {
        let result =
            unsafe { ffi::gst_sdp_message_set_version(&mut self.0, version.to_glib_none().0) };
        match result {
            ffi::GST_SDP_OK => Ok(()),
            _ => Err(()),
        }
    }

    pub fn times_len(&self) -> u32 {
        unsafe { ffi::gst_sdp_message_times_len(&self.0) }
    }

    pub fn zones_len(&self) -> u32 {
        unsafe { ffi::gst_sdp_message_zones_len(&self.0) }
    }

    pub fn as_uri(&self, scheme: &str) -> Option<String> {
        assert_initialized_main_thread!();
        unsafe {
            from_glib_full(ffi::gst_sdp_message_as_uri(
                scheme.to_glib_none().0,
                &self.0,
            ))
        }
    }

    pub fn attributes(&self) -> AttributesIter {
        AttributesIter::new(self)
    }

    pub fn bandwidths(&self) -> BandwidthsIter {
        BandwidthsIter::new(self)
    }

    pub fn emails(&self) -> EmailsIter {
        EmailsIter::new(self)
    }

    pub fn medias(&self) -> MediasIter {
        MediasIter::new(self)
    }

    pub fn phones(&self) -> PhonesIter {
        PhonesIter::new(self)
    }

    pub fn times(&self) -> TimesIter {
        TimesIter::new(self)
    }

    pub fn zones(&self) -> ZonesIter {
        ZonesIter::new(self)
    }
}

macro_rules! define_iter(
    ($name:ident, $typ:ty, $get_item:expr, $get_len:expr) => {
    #[derive(Debug)]
    pub struct $name<'a> {
        message: &'a SDPMessageRef,
        idx: u32,
        len: u32,
    }

    impl<'a> $name<'a> {
        fn new(message: &'a SDPMessageRef) -> $name<'a> {
            skip_assert_initialized!();
            let len = $get_len(message);

            $name {
                message,
                idx: 0,
                len,
            }
        }
    }

    impl<'a> Iterator for $name<'a> {
        type Item = $typ;

        fn next(&mut self) -> Option<Self::Item> {
            if self.idx >= self.len {
                return None;
            }

            let item = $get_item(self.message, self.idx)?;
            self.idx += 1;
            Some(item)
        }

        fn size_hint(&self) -> (usize, Option<usize>) {
            if self.idx == self.len {
                return (0, Some(0))
            }

            let remaining = (self.len - self.idx) as usize;

            (remaining, Some(remaining))
        }
    }

    impl<'a> DoubleEndedIterator for $name<'a> {
        fn next_back(&mut self) -> Option<Self::Item> {
            if self.idx == self.len {
                return None;
            }

            self.len -= 1;

            $get_item(self.message, self.len)
        }
    }

    impl<'a> ExactSizeIterator for $name<'a> {}
    }
);

define_iter!(
    AttributesIter,
    &'a SDPAttribute,
    |message: &'a SDPMessageRef, idx| message.get_attribute(idx),
    |message: &SDPMessageRef| message.attributes_len()
);
define_iter!(
    BandwidthsIter,
    &'a SDPBandwidth,
    |message: &'a SDPMessageRef, idx| message.get_bandwidth(idx),
    |message: &SDPMessageRef| message.bandwidths_len()
);
define_iter!(
    EmailsIter,
    &'a str,
    |message: &'a SDPMessageRef, idx| message.get_email(idx),
    |message: &SDPMessageRef| message.emails_len()
);
define_iter!(
    MediasIter,
    &'a SDPMediaRef,
    |message: &'a SDPMessageRef, idx| message.get_media(idx),
    |message: &SDPMessageRef| message.medias_len()
);
define_iter!(
    PhonesIter,
    &'a str,
    |message: &'a SDPMessageRef, idx| message.get_phone(idx),
    |message: &SDPMessageRef| message.phones_len()
);
define_iter!(
    TimesIter,
    &'a SDPTime,
    |message: &'a SDPMessageRef, idx| message.get_time(idx),
    |message: &SDPMessageRef| message.times_len()
);
define_iter!(
    ZonesIter,
    &'a SDPZone,
    |message: &'a SDPMessageRef, idx| message.get_zone(idx),
    |message: &SDPMessageRef| message.zones_len()
);

#[cfg(test)]
mod tests {
    use super::*;
    use SDPMessage;

    fn init() {
        gst::init().unwrap();
    }

    #[test]
    fn media_from_message() {
        init();

        let sdp = "v=0\r\no=- 1938737043334325940 0 IN IP4 0.0.0.0\r\ns=-\r\nt=0 0\r\na=ice-options:trickle\r\nm=video 9 UDP/TLS/RTP/SAVPF 96\r\nc=IN IP4 0.0.0.0\r\na=setup:actpass\r\na=ice-ufrag:YZxU9JlWHzHcF6O2U09/q3PvBhbTPdZW\r\na=ice-pwd:fyrt730GWo5mFGc9m2z/vbUu3z1lewla\r\na=sendrecv\r\na=rtcp-mux\r\na=rtcp-rsize\r\na=rtpmap:96 VP8/90000\r\na=rtcp-fb:96 nack\r\na=rtcp-fb:96 nack pli\r\na=framerate:30\r\na=mid:video0\r\na=fingerprint:sha-256 DB:48:8F:18:13:F3:AA:13:31:B3:75:3D:1A:D3:BA:88:4A:ED:1B:56:14:C3:09:CD:BC:4D:18:42:B9:6A:5F:98\r\nm=audio 9 UDP/TLS/RTP/SAVPF 97\r\nc=IN IP4 0.0.0.0\r\na=setup:actpass\r\na=ice-ufrag:04KZM9qE2S4r06AN6A9CeXOM6mzO0LZY\r\na=ice-pwd:cJTSfHF6hHDAcsTJXZVJeuYCC6rKqBvW\r\na=sendrecv\r\na=rtcp-mux\r\na=rtcp-rsize\r\na=rtpmap:97 OPUS/48000/2\r\na=rtcp-fb:97 nack\r\na=rtcp-fb:97 nack pli\r\na=mid:audio1\r\na=fingerprint:sha-256 DB:48:8F:18:13:F3:AA:13:31:B3:75:3D:1A:D3:BA:88:4A:ED:1B:56:14:C3:09:CD:BC:4D:18:42:B9:6A:5F:98\r\n";
        let sdp = SDPMessage::parse_buffer(sdp.as_bytes()).unwrap();
        let media = sdp.get_media(0).unwrap();
        assert_eq!(media.formats_len(), 1);
    }
}