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use {List, Tweet, User};
use serde::de::{Deserialize, Deserializer, Error, IgnoredAny, MapAccess, Visitor};
use std::fmt;
use types::{DateTime, JsonValue};
use util;
/// Represents notifications about non-Tweet events are also sent over a stream.
///
/// # Reference
///
/// 1. [Streaming message types — Twitter Developers]
/// (https://dev.twitter.com/streaming/overview/messages-types#Events_event)
#[derive(Clone, Debug, PartialEq)]
pub struct Event {
pub created_at: DateTime,
/// An object which indicates the name of the event and contains an optional object which
/// represents the target of the event.
pub event: EventKind,
pub target: User,
pub source: User,
}
macro_rules! impl_event {
(
$(#[$attr:meta])*
pub enum $T:ident {
$(
$(#[$c_attr:meta])*
:$Container:ident($c_tag:expr, $Content:ty)
),*;
$(
$(#[$l_attr:meta])*
:$Label:ident($l_tag:expr)
),*;
$(#[$cu_attr:meta])*
:$Custom:ident(_, _),
}
) => {
$(#[$attr])*
pub enum $T {
$(
$(#[$c_attr])*
$Container($Content),
)*
$(
$(#[$l_attr])*
$Label,
)*
$(#[$cu_attr])*
$Custom(String, Option<JsonValue>),
}
impl<'x> Deserialize<'x> for Event {
fn deserialize<D: Deserializer<'x>>(d: D) -> Result<Self, D::Error> {
struct EventVisitor;
impl<'x> Visitor<'x> for EventVisitor {
type Value = Event;
fn visit_map<V: MapAccess<'x>>(self, mut v: V) -> Result<Event, V::Error> {
#[derive(Default)]
struct EventBuffer {
created_at: Option<DateTime>,
event: Option<EventKind>,
target: Option<User>,
source: Option<User>,
}
let mut event = EventBuffer::default();
let mut event_kind: Option<String> = None;
let mut target_obj: Option<JsonValue> = None;
macro_rules! err_map {
() => (|e| V::Error::custom(e.to_string()));
}
while let Some(k) = v.next_key::<String>()? {
match k.as_str() {
"created_at" => {
let val = v.next_value::<String>()?;
event.created_at = Some(util::parse_datetime(&val).map_err(err_map!())?);
},
"event" => {
let e = v.next_value::<String>()?;
event.event = if let Some(t) = target_obj.take() {
match e.as_str() {
$($c_tag => {
$T::$Container(<$Content>::deserialize(t).map_err(err_map!())?)
},)*
$($l_tag => $T::$Label,)*
_ => $T::$Custom(e, Some(t)),
}.into()
} else {
match e.as_str() {
$($l_tag => Some($T::$Label),)*
$($c_tag)|* => { event_kind = Some(e); None },
_ => Some($T::Custom(e, None)),
}
};
},
"target" => event.target = Some(v.next_value()?),
"source" => event.source = Some(v.next_value()?),
"target_object" => if let Some(e) = event_kind.take() {
event.event = match e.as_str() {
$($c_tag => $T::$Container(v.next_value()?),)*
$($l_tag => { v.next_value::<IgnoredAny>()?; $T::$Label },)*
_ => $T::$Custom(e, v.next_value()?),
}.into();
} else if event.event.is_none() {
target_obj = Some(v.next_value()?);
} else {
v.next_value::<IgnoredAny>()?;
},
_ => { v.next_value::<IgnoredAny>()?; },
}
if let EventBuffer {
created_at: Some(ca), event: Some(e), target: Some(t), source: Some(s),
} = event
{
while v.next_entry::<IgnoredAny, IgnoredAny>()?.is_some() {}
return Ok(Event { created_at: ca, event: e, target: t, source: s });
}
}
Err(V::Error::missing_field(if event.created_at.is_none() {
"created_at"
} else if event.target.is_none() {
"target"
} else if event.source.is_none() {
"source"
} else if event.event.is_none() {
if target_obj.is_some() {
"event"
} else {
"target_object"
}
} else {
unreachable!();
}))
}
fn expecting(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "a map")
}
}
d.deserialize_map(EventVisitor)
}
}
};
}
impl_event! {
/// An object which indicates the name of an event.
/// It may contain an object called "target object" which represents the target of the event.
///
/// The meaning of `target` and `source` field of an `Event` will be different based on the name of the event,
/// as described below.
///
/// | Description | Event Name | `source` | `target` |
/// | ----------------------------------- | ---------------------- | ------------------ | -------------- |
/// | User deauthorizes stream | `AccessRevoked` | Deauthorizing user | App owner |
/// | User blocks someone | `Block` | Current user | Blocked user |
/// | User removes a block | `Unblock` | Current user | Unblocked user |
/// | User favorites a Tweet | `Favorite` | Current user | Tweet author |
/// | User's Tweet is favorited | `Favorite` | Favoriting user | Current user |
/// | User unfavorites a Tweet | `Unfavorite` | Current user | Tweet author |
/// | User's Tweet is unfavorited | `Unfavorite` | Unfavoriting user | Current user |
/// | User follows someone | `Follow` | Current user | Followed user |
/// | User is followed | `Follow` | Following user | Current user |
/// | User unfollows someone | `Unfollow` | Current user | Followed user |
/// | User creates a list | `ListCreated` | Current user | Current user |
/// | User deletes a list | `ListDestroyed` | Current user | Current user |
/// | User edits a list | `ListUpdated` | Current user | Current user |
/// | User adds someone to a list | `ListMemberAdded` | Current user | Added user |
/// | User is added to a list | `ListMemberAdded` | Adding user | Current user |
/// | User removes someone from a list | `ListMemberRemoved` | Current user | Removed user |
/// | User is removed from a list | `ListMemberRemoved` | Removing user | Current user |
/// | User subscribes to a list | `ListUserSubscribed` | Current user | List owner |
/// | User's list is subscribed to | `ListUserSubscribed` | Subscribing user | Current user |
/// | User unsubscribes from a list | `ListUserUnsubscribed` | Current user | List owner |
/// | User's list is unsubscribed from | `ListUserUnsubscribed` | Unsubscribing user | Current user |
/// | User's Tweet is quoted | `QuotedTweet` | quoting User | Current User |
/// | User updates their profile | `UserUpdate` | Current user | Current user |
/// | User updates their protected status | `UserUpdate` | Current user | Current user |
#[derive(Clone, Debug, PartialEq)]
pub enum EventKind {
:Favorite("favorite", Box<Tweet>),
:Unfavorite("unfavorite", Box<Tweet>),
:ListCreated("list_created", Box<List>),
:ListDestroyed("list_destroyed", Box<List>),
:ListUpdated("list_updated", Box<List>),
:ListMemberAdded("list_member_added", Box<List>),
:ListMemberRemoved("list_member_removed", Box<List>),
:ListUserSubscribed("list_user_subscribed", Box<List>),
:ListUserUnsubscribed("list_user_unsubscribed", Box<List>),
:QuotedTweet("quoted_tweet", Box<Tweet>);
:AccessRevoked("access_revoked"),
:Block("block"),
:Unblock("unblock"),
:Follow("follow"),
:Unfollow("unfollow"),
:UserUpdate("user_update");
/// An event this library does not know. The first value is raw event name
/// and the second is the target object.
:Custom(_, _),
}
}