1016 lines
34 KiB
Rust

//! Implementation of event enum and event content enum macros.
use proc_macro2::{Span, TokenStream};
use quote::{format_ident, quote, ToTokens};
use syn::{Attribute, Ident, LitStr};
use crate::event_parse::{EventEnumDecl, EventEnumEntry, EventKind, EventKindVariation};
fn is_non_stripped_room_event(kind: &EventKind, var: &EventKindVariation) -> bool {
matches!(kind, EventKind::Message | EventKind::State)
&& matches!(
var,
EventKindVariation::Full
| EventKindVariation::Sync
| EventKindVariation::Redacted
| EventKindVariation::RedactedSync
)
}
fn has_prev_content_field(kind: &EventKind, var: &EventKindVariation) -> bool {
matches!(kind, EventKind::State)
&& matches!(var, EventKindVariation::Full | EventKindVariation::Sync)
}
type EventKindFn = fn(&EventKind, &EventKindVariation) -> bool;
/// This const is used to generate the accessor methods for the `Any*Event` enums.
///
/// DO NOT alter the field names unless the structs in `ruma_events::event_kinds` have changed.
const EVENT_FIELDS: &[(&str, EventKindFn)] = &[
("origin_server_ts", is_non_stripped_room_event),
("room_id", |kind, var| {
matches!(kind, EventKind::Message | EventKind::State | EventKind::Ephemeral)
&& matches!(var, EventKindVariation::Full | EventKindVariation::Redacted)
}),
("event_id", is_non_stripped_room_event),
("sender", |kind, &var| {
matches!(kind, EventKind::Message | EventKind::State | EventKind::ToDevice)
&& var != EventKindVariation::Initial
}),
("state_key", |kind, _| matches!(kind, EventKind::State)),
("unsigned", is_non_stripped_room_event),
];
/// Create a content enum from `EventEnumInput`.
pub fn expand_event_enum(input: &EventEnumDecl) -> syn::Result<TokenStream> {
let ruma_events = crate::import_ruma_events();
let name = &input.name;
let attrs = &input.attrs;
let events: Vec<_> = input.events.iter().map(|entry| entry.ev_type.clone()).collect();
let variants: Vec<_> =
input.events.iter().map(EventEnumEntry::to_variant).collect::<syn::Result<_>>()?;
let event_enum = expand_any_with_deser(
name,
&events,
attrs,
&variants,
&EventKindVariation::Full,
&ruma_events,
);
let sync_event_enum = expand_any_with_deser(
name,
&events,
attrs,
&variants,
&EventKindVariation::Sync,
&ruma_events,
);
let stripped_event_enum = expand_any_with_deser(
name,
&events,
attrs,
&variants,
&EventKindVariation::Stripped,
&ruma_events,
);
let initial_event_enum = expand_any_with_deser(
name,
&events,
attrs,
&variants,
&EventKindVariation::Initial,
&ruma_events,
);
let redacted_event_enums = expand_any_redacted(name, &events, attrs, &variants, &ruma_events);
let event_content_enum = expand_content_enum(name, &events, attrs, &variants, &ruma_events);
Ok(quote! {
#event_enum
#sync_event_enum
#stripped_event_enum
#initial_event_enum
#redacted_event_enums
#event_content_enum
})
}
fn expand_any_with_deser(
kind: &EventKind,
events: &[LitStr],
attrs: &[Attribute],
variants: &[EventEnumVariant],
var: &EventKindVariation,
ruma_events: &TokenStream,
) -> Option<TokenStream> {
let serde = quote! { #ruma_events::exports::serde };
let serde_json = quote! { #ruma_events::exports::serde_json };
// If the event cannot be generated this bails out returning None which is rendered the same
// as an empty `TokenStream`. This is effectively the check if the given input generates
// a valid event enum.
let (event_struct, ident) = generate_event_idents(kind, var)?;
let content: Vec<_> =
events.iter().map(|event| to_event_path(event, &event_struct, ruma_events)).collect();
let variant_decls = variants.iter().map(|v| v.decl());
let self_variants = variants.iter().map(|v| v.ctor(quote!(Self)));
let (custom_variant, custom_deserialize) =
generate_custom_variant(&event_struct, var, ruma_events);
let any_enum = quote! {
#( #attrs )*
#[derive(Clone, Debug, #serde::Serialize)]
#[serde(untagged)]
#[allow(clippy::large_enum_variant)]
pub enum #ident {
#(
#[doc = #events]
#variant_decls(#content),
)*
#custom_variant
}
};
let variant_attrs = variants.iter().map(|v| {
let attrs = &v.attrs;
quote! { #(#attrs)* }
});
let event_deserialize_impl = quote! {
impl<'de> #serde::de::Deserialize<'de> for #ident {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: #serde::de::Deserializer<'de>,
{
use #serde::de::Error as _;
let json = Box::<#serde_json::value::RawValue>::deserialize(deserializer)?;
let #ruma_events::EventDeHelper { ev_type, .. } =
#ruma_events::from_raw_json_value(&json)?;
match ev_type.as_str() {
#(
#variant_attrs #events => {
let event = #serde_json::from_str::<#content>(json.get())
.map_err(D::Error::custom)?;
Ok(#self_variants(event))
},
)*
#custom_deserialize
}
}
}
};
let event_enum_to_from_sync = expand_conversion_impl(kind, var, variants, ruma_events);
let redacted_enum = expand_redacted_enum(kind, var, ruma_events);
let field_accessor_impl = accessor_methods(kind, var, variants, ruma_events);
let redact_impl = expand_redact(&ident, kind, var, variants, ruma_events);
Some(quote! {
#any_enum
#event_enum_to_from_sync
#field_accessor_impl
#redact_impl
#event_deserialize_impl
#redacted_enum
})
}
fn expand_conversion_impl(
kind: &EventKind,
var: &EventKindVariation,
variants: &[EventEnumVariant],
ruma_events: &TokenStream,
) -> Option<TokenStream> {
let ruma_identifiers = quote! { #ruma_events::exports::ruma_identifiers };
let ident = kind.to_event_enum_ident(var)?;
let variants: Vec<_> = variants
.iter()
.filter(|v| {
// We filter this variant out only for non redacted events.
// The type of the struct held in the enum variant is different in this case
// so we construct the variant manually.
!(v.ident == "RoomRedaction"
&& matches!(var, EventKindVariation::Full | EventKindVariation::Sync))
})
.collect();
match var {
EventKindVariation::Full | EventKindVariation::Redacted => {
// the opposite event variation full -> sync, redacted -> redacted sync
let variation = if var == &EventKindVariation::Full {
EventKindVariation::Sync
} else {
EventKindVariation::RedactedSync
};
let sync = kind.to_event_enum_ident(&variation)?;
let sync_struct = kind.to_event_ident(&variation)?;
let ident_variants = variants.iter().map(|v| v.match_arm(&ident));
let self_variants = variants.iter().map(|v| v.ctor(quote!(Self)));
let redaction = if let (EventKind::Message, EventKindVariation::Full) = (kind, var) {
quote! {
#ident::RoomRedaction(event) => Self::RoomRedaction(
#ruma_events::room::redaction::SyncRedactionEvent::from(event),
),
}
} else {
TokenStream::new()
};
Some(quote! {
impl From<#ident> for #sync {
fn from(event: #ident) -> Self {
match event {
#(
#ident_variants(event) => {
#self_variants(#ruma_events::#sync_struct::from(event))
},
)*
#redaction
#ident::Custom(event) => {
Self::Custom(#ruma_events::#sync_struct::from(event))
},
}
}
}
})
}
EventKindVariation::Sync | EventKindVariation::RedactedSync => {
let variation = if var == &EventKindVariation::Sync {
EventKindVariation::Full
} else {
EventKindVariation::Redacted
};
let full = kind.to_event_enum_ident(&variation)?;
let self_variants = variants.iter().map(|v| v.match_arm(quote!(Self)));
let full_variants = variants.iter().map(|v| v.ctor(&full));
let redaction = if let (EventKind::Message, EventKindVariation::Sync) = (kind, var) {
quote! {
Self::RoomRedaction(event) => {
#full::RoomRedaction(event.into_full_event(room_id))
},
}
} else {
TokenStream::new()
};
Some(quote! {
#[automatically_derived]
impl #ident {
/// Convert this sync event into a full event, one with a room_id field.
pub fn into_full_event(
self,
room_id: #ruma_identifiers::RoomId
) -> #full {
match self {
#(
#self_variants(event) => {
#full_variants(event.into_full_event(room_id))
},
)*
#redaction
Self::Custom(event) => {
#full::Custom(event.into_full_event(room_id))
},
}
}
}
})
}
_ => None,
}
}
/// Generates the 3 redacted state enums, 2 redacted message enums,
/// and `Deserialize` implementations.
///
/// No content enums are generated since no part of the API deals with
/// redacted event's content. There are only five state variants that contain content.
fn expand_any_redacted(
kind: &EventKind,
events: &[LitStr],
attrs: &[Attribute],
variants: &[EventEnumVariant],
ruma_events: &TokenStream,
) -> TokenStream {
use EventKindVariation as V;
if kind.is_state() {
let full_state =
expand_any_with_deser(kind, events, attrs, variants, &V::Redacted, ruma_events);
let sync_state =
expand_any_with_deser(kind, events, attrs, variants, &V::RedactedSync, ruma_events);
let stripped_state =
expand_any_with_deser(kind, events, attrs, variants, &V::RedactedStripped, ruma_events);
quote! {
#full_state
#sync_state
#stripped_state
}
} else if kind.is_message() {
let full_message =
expand_any_with_deser(kind, events, attrs, variants, &V::Redacted, ruma_events);
let sync_message =
expand_any_with_deser(kind, events, attrs, variants, &V::RedactedSync, ruma_events);
quote! {
#full_message
#sync_message
}
} else {
TokenStream::new()
}
}
/// Create a content enum from `EventEnumInput`.
fn expand_content_enum(
kind: &EventKind,
events: &[LitStr],
attrs: &[Attribute],
variants: &[EventEnumVariant],
ruma_events: &TokenStream,
) -> TokenStream {
let serde = quote! { #ruma_events::exports::serde };
let serde_json = quote! { #ruma_events::exports::serde_json };
let ident = kind.to_content_enum();
let event_type_str = events;
let content: Vec<_> =
events.iter().map(|ev| to_event_content_path(kind, ev, ruma_events)).collect();
let variant_decls = variants.iter().map(|v| v.decl());
let content_enum = quote! {
#( #attrs )*
#[derive(Clone, Debug, #serde::Serialize)]
#[serde(untagged)]
#[allow(clippy::large_enum_variant)]
pub enum #ident {
#(
#[doc = #event_type_str]
#variant_decls(#content),
)*
/// Content of an event not defined by the Matrix specification.
Custom(#ruma_events::custom::CustomEventContent),
}
};
let variant_attrs = variants.iter().map(|v| {
let attrs = &v.attrs;
quote! { #(#attrs)* }
});
let variant_arms = variants.iter().map(|v| v.match_arm(quote!(Self)));
let variant_ctors = variants.iter().map(|v| v.ctor(quote!(Self)));
let event_content_impl = quote! {
#[automatically_derived]
impl #ruma_events::EventContent for #ident {
fn event_type(&self) -> &::std::primitive::str {
match self {
#( #variant_arms(content) => content.event_type(), )*
Self::Custom(content) => content.event_type(),
}
}
fn from_parts(
event_type: &::std::primitive::str,
input: ::std::boxed::Box<#serde_json::value::RawValue>,
) -> ::std::result::Result<Self, #serde_json::Error> {
match event_type {
#(
#variant_attrs #event_type_str => {
let content = #content::from_parts(event_type, input)?;
::std::result::Result::Ok(#variant_ctors(content))
},
)*
ev_type => {
let content =
#ruma_events::custom::CustomEventContent::from_parts(ev_type, input)?;
::std::result::Result::Ok(Self::Custom(content))
},
}
}
}
};
let marker_trait_impls = marker_traits(kind, ruma_events);
quote! {
#content_enum
#event_content_impl
#marker_trait_impls
}
}
fn expand_redact(
ident: &Ident,
kind: &EventKind,
var: &EventKindVariation,
variants: &[EventEnumVariant],
ruma_events: &TokenStream,
) -> Option<TokenStream> {
let ruma_identifiers = quote! { #ruma_events::exports::ruma_identifiers };
if let EventKindVariation::Full | EventKindVariation::Sync | EventKindVariation::Stripped = var
{
let (redaction_type, redacted_type, redacted_enum) = match var {
EventKindVariation::Full => {
let struct_id = kind.to_event_ident(&EventKindVariation::Redacted)?;
(
quote! { #ruma_events::room::redaction::RedactionEvent },
quote! { #ruma_events::#struct_id },
kind.to_event_enum_ident(&EventKindVariation::Redacted)?,
)
}
EventKindVariation::Sync => {
let struct_id = kind.to_event_ident(&EventKindVariation::RedactedSync)?;
(
quote! { #ruma_events::room::redaction::SyncRedactionEvent },
quote! { #ruma_events::#struct_id },
kind.to_event_enum_ident(&EventKindVariation::RedactedSync)?,
)
}
EventKindVariation::Stripped => {
let struct_id = kind.to_event_ident(&EventKindVariation::RedactedStripped)?;
(
quote! { #ruma_events::room::redaction::SyncRedactionEvent },
quote! { #ruma_events::#struct_id },
kind.to_event_enum_ident(&EventKindVariation::RedactedStripped)?,
)
}
_ => return None,
};
let self_variants = variants.iter().map(|v| v.match_arm(quote!(Self)));
let redaction_variants = variants.iter().map(|v| v.ctor(&redacted_enum));
let fields = EVENT_FIELDS.iter().map(|(name, has_field)| {
generate_redacted_fields(name, kind, var, *has_field, ruma_events)
});
let fields = quote! { #( #fields )* };
Some(quote! {
#[automatically_derived]
impl #ident {
/// Redacts `Self` given a valid `Redaction[Sync]Event`.
pub fn redact(
self,
redaction: #redaction_type,
version: &#ruma_identifiers::RoomVersionId,
) -> #redacted_enum {
match self {
#(
#self_variants(event) => {
let content = event.content.redact(version);
#redaction_variants(#redacted_type {
content,
#fields
})
}
)*
Self::Custom(event) => {
let content = event.content.redact(version);
#redacted_enum::Custom(#redacted_type {
content,
#fields
})
}
}
}
}
})
} else {
None
}
}
fn expand_redacted_enum(
kind: &EventKind,
var: &EventKindVariation,
ruma_events: &TokenStream,
) -> Option<TokenStream> {
let serde = quote! { #ruma_events::exports::serde };
let serde_json = quote! { #ruma_events::exports::serde_json };
if let EventKind::State | EventKind::Message = kind {
let ident = format_ident!("AnyPossiblyRedacted{}", kind.to_event_ident(var)?);
// FIXME: Use Option::zip once MSRV >= 1.46
let (regular_enum_ident, redacted_enum_ident) = match inner_enum_idents(kind, var) {
(Some(regular_enum_ident), Some(redacted_enum_ident)) => {
(regular_enum_ident, redacted_enum_ident)
}
_ => return None,
};
Some(quote! {
/// An enum that holds either regular un-redacted events or redacted events.
#[derive(Clone, Debug, #serde::Serialize)]
#[serde(untagged)]
pub enum #ident {
/// An un-redacted event.
Regular(#regular_enum_ident),
/// A redacted event.
Redacted(#redacted_enum_ident),
}
impl<'de> #serde::de::Deserialize<'de> for #ident {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: #serde::de::Deserializer<'de>,
{
let json = Box::<#serde_json::value::RawValue>::deserialize(deserializer)?;
let #ruma_events::EventDeHelper { unsigned, .. } =
#ruma_events::from_raw_json_value(&json)?;
Ok(match unsigned {
Some(unsigned) if unsigned.redacted_because.is_some() => {
Self::Redacted(#ruma_events::from_raw_json_value(&json)?)
}
_ => Self::Regular(#ruma_events::from_raw_json_value(&json)?),
})
}
}
})
} else {
None
}
}
fn generate_event_idents(kind: &EventKind, var: &EventKindVariation) -> Option<(Ident, Ident)> {
Some((kind.to_event_ident(var)?, kind.to_event_enum_ident(var)?))
}
fn generate_redacted_fields(
name: &str,
kind: &EventKind,
var: &EventKindVariation,
is_event_kind: EventKindFn,
ruma_events: &TokenStream,
) -> TokenStream {
if is_event_kind(kind, var) {
let name = Ident::new(name, Span::call_site());
if name == "unsigned" {
let redacted_type = if let EventKindVariation::Sync = var {
quote! { RedactedSyncUnsigned }
} else {
quote! { RedactedUnsigned }
};
quote! {
unsigned: #ruma_events::#redacted_type {
redacted_because: Some(::std::boxed::Box::new(redaction)),
},
}
} else {
quote! {
#name: event.#name,
}
}
} else {
TokenStream::new()
}
}
fn generate_custom_variant(
event_struct: &Ident,
var: &EventKindVariation,
ruma_events: &TokenStream,
) -> (TokenStream, TokenStream) {
use EventKindVariation as V;
let serde_json = quote! { #ruma_events::exports::serde_json };
if matches!(var, V::Redacted | V::RedactedSync | V::RedactedStripped) {
(
quote! {
/// A redacted event not defined by the Matrix specification
Custom(
#ruma_events::#event_struct<#ruma_events::custom::RedactedCustomEventContent>,
),
},
quote! {
event => {
let event = #serde_json::from_str::<#ruma_events::#event_struct<
#ruma_events::custom::RedactedCustomEventContent,
>>(json.get())
.map_err(D::Error::custom)?;
Ok(Self::Custom(event))
},
},
)
} else {
(
quote! {
/// An event not defined by the Matrix specification
Custom(#ruma_events::#event_struct<#ruma_events::custom::CustomEventContent>),
},
quote! {
event => {
let event =
#serde_json::from_str::<
#ruma_events::#event_struct<#ruma_events::custom::CustomEventContent>
>(json.get())
.map_err(D::Error::custom)?;
Ok(Self::Custom(event))
},
},
)
}
}
fn marker_traits(kind: &EventKind, ruma_events: &TokenStream) -> TokenStream {
let ident = kind.to_content_enum();
match kind {
EventKind::State => quote! {
#[automatically_derived]
impl #ruma_events::RoomEventContent for #ident {}
#[automatically_derived]
impl #ruma_events::StateEventContent for #ident {}
},
EventKind::Message => quote! {
#[automatically_derived]
impl #ruma_events::RoomEventContent for #ident {}
#[automatically_derived]
impl #ruma_events::MessageEventContent for #ident {}
},
EventKind::Ephemeral => quote! {
#[automatically_derived]
impl #ruma_events::EphemeralRoomEventContent for #ident {}
},
EventKind::GlobalAccountData => quote! {
#[automatically_derived]
impl #ruma_events::GlobalAccountDataEventContent for #ident {}
},
EventKind::RoomAccountData => quote! {
#[automatically_derived]
impl #ruma_events::RoomAccountDataEventContent for #ident {}
},
EventKind::ToDevice => quote! {
#[automatically_derived]
impl #ruma_events::ToDeviceEventContent for #ident {}
},
_ => TokenStream::new(),
}
}
fn accessor_methods(
kind: &EventKind,
var: &EventKindVariation,
variants: &[EventEnumVariant],
ruma_events: &TokenStream,
) -> Option<TokenStream> {
use EventKindVariation as V;
let ident = kind.to_event_enum_ident(var)?;
// matching `EventKindVariation`s
if let V::Redacted | V::RedactedSync | V::RedactedStripped = var {
return redacted_accessor_methods(kind, var, variants, ruma_events);
}
let methods = EVENT_FIELDS.iter().map(|(name, has_field)| {
generate_accessor(name, kind, var, *has_field, variants, ruma_events)
});
let content_enum = kind.to_content_enum();
let self_variants: Vec<_> = variants.iter().map(|v| v.match_arm(quote!(Self))).collect();
let content_variants: Vec<_> = variants.iter().map(|v| v.ctor(&content_enum)).collect();
let event_type = quote! {
/// Returns the `type` of this event.
pub fn event_type(&self) -> &::std::primitive::str {
match self {
#( #self_variants(event) =>
#ruma_events::EventContent::event_type(&event.content), )*
Self::Custom(event) =>
#ruma_events::EventContent::event_type(&event.content),
}
}
};
let content = quote! {
/// Returns the any content enum for this event.
pub fn content(&self) -> #content_enum {
match self {
#( #self_variants(event) => #content_variants(event.content.clone()), )*
Self::Custom(event) => #content_enum::Custom(event.content.clone()),
}
}
};
let prev_content = if has_prev_content_field(kind, var) {
quote! {
/// Returns the any content enum for this events prev_content.
pub fn prev_content(&self) -> Option<#content_enum> {
match self {
#(
#self_variants(event) => {
event.prev_content.as_ref().map(|c| #content_variants(c.clone()))
},
)*
Self::Custom(event) => {
event.prev_content.as_ref().map(|c| #content_enum::Custom(c.clone()))
},
}
}
}
} else {
TokenStream::new()
};
Some(quote! {
#[automatically_derived]
impl #ident {
#content
#event_type
#prev_content
#( #methods )*
}
})
}
fn inner_enum_idents(kind: &EventKind, var: &EventKindVariation) -> (Option<Ident>, Option<Ident>) {
match var {
EventKindVariation::Full => {
(kind.to_event_enum_ident(var), kind.to_event_enum_ident(&EventKindVariation::Redacted))
}
EventKindVariation::Sync => (
kind.to_event_enum_ident(var),
kind.to_event_enum_ident(&EventKindVariation::RedactedSync),
),
EventKindVariation::Stripped => (
kind.to_event_enum_ident(var),
kind.to_event_enum_ident(&EventKindVariation::RedactedStripped),
),
EventKindVariation::Initial => (kind.to_event_enum_ident(var), None),
_ => (None, None),
}
}
/// Redacted events do NOT generate `content` or `prev_content` methods like
/// un-redacted events; otherwise, they are the same.
fn redacted_accessor_methods(
kind: &EventKind,
var: &EventKindVariation,
variants: &[EventEnumVariant],
ruma_events: &TokenStream,
) -> Option<TokenStream> {
let ident = kind.to_event_enum_ident(var)?;
let methods = EVENT_FIELDS.iter().map(|(name, has_field)| {
generate_accessor(name, kind, var, *has_field, variants, ruma_events)
});
Some(quote! {
#[automatically_derived]
impl #ident {
#( #methods )*
}
})
}
fn to_event_path(name: &LitStr, struct_name: &Ident, ruma_events: &TokenStream) -> TokenStream {
let span = name.span();
let name = name.value();
// There is no need to give a good compiler error as `to_camel_case` is called first.
assert_eq!(&name[..2], "m.");
let path: Vec<_> = name[2..].split('.').collect();
let event_str = path.last().unwrap();
let event: String = event_str
.split('_')
.map(|s| s.chars().next().unwrap().to_uppercase().to_string() + &s[1..])
.collect();
let path = path.iter().map(|s| Ident::new(s, span));
match struct_name.to_string().as_str() {
"MessageEvent" | "SyncMessageEvent" if name == "m.room.redaction" => {
let redaction = if struct_name == "MessageEvent" {
quote! { RedactionEvent }
} else {
quote! { SyncRedactionEvent }
};
quote! { #ruma_events::room::redaction::#redaction }
}
"SyncStateEvent"
| "StrippedStateEvent"
| "InitialStateEvent"
| "SyncMessageEvent"
| "SyncEphemeralRoomEvent" => {
let content = format_ident!("{}EventContent", event);
quote! { #ruma_events::#struct_name<#ruma_events::#( #path )::*::#content> }
}
"ToDeviceEvent" => {
let content = format_ident!("{}ToDeviceEventContent", event);
quote! { #ruma_events::#struct_name<#ruma_events::#( #path )::*::#content> }
}
struct_str if struct_str.contains("Redacted") => {
let content = format_ident!("Redacted{}EventContent", event);
quote! { #ruma_events::#struct_name<#ruma_events::#( #path )::*::#content> }
}
_ => {
let event_name = format_ident!("{}Event", event);
quote! { #ruma_events::#( #path )::*::#event_name }
}
}
}
fn to_event_content_path(
kind: &EventKind,
name: &LitStr,
ruma_events: &TokenStream,
) -> TokenStream {
let span = name.span();
let name = name.value();
// There is no need to give a good compiler error as `to_camel_case` is called first.
assert_eq!(&name[..2], "m.");
let path: Vec<_> = name[2..].split('.').collect();
let event_str = path.last().unwrap();
let event: String = event_str
.split('_')
.map(|s| s.chars().next().unwrap().to_uppercase().to_string() + &s[1..])
.collect();
let content_str = match kind {
EventKind::ToDevice => format_ident!("{}ToDeviceEventContent", event),
_ => format_ident!("{}EventContent", event),
};
let path = path.iter().map(|s| Ident::new(s, span));
quote! {
#ruma_events::#( #path )::*::#content_str
}
}
/// Splits the given `event_type` string on `.` and `_` removing the `m.room.` then
/// camel casing to give the `Event` struct name.
fn to_camel_case(name: &LitStr) -> syn::Result<Ident> {
let span = name.span();
let name = name.value();
if &name[..2] != "m." {
return Err(syn::Error::new(
span,
format!("well-known matrix events have to start with `m.` found `{}`", name),
));
}
let s: String = name[2..]
.split(&['.', '_'] as &[char])
.map(|s| s.chars().next().unwrap().to_uppercase().to_string() + &s[1..])
.collect();
Ok(Ident::new(&s, span))
}
fn generate_accessor(
name: &str,
kind: &EventKind,
var: &EventKindVariation,
is_event_kind: EventKindFn,
variants: &[EventEnumVariant],
ruma_events: &TokenStream,
) -> TokenStream {
if is_event_kind(kind, var) {
let docs = format!("Returns this event's {} field.", name);
let ident = Ident::new(name, Span::call_site());
let field_type = field_return_type(name, var, ruma_events);
let variants = variants.iter().map(|v| v.match_arm(quote!(Self)));
quote! {
#[doc = #docs]
pub fn #ident(&self) -> &#field_type {
match self {
#( #variants(event) => &event.#ident, )*
Self::Custom(event) => &event.#ident,
}
}
}
} else {
TokenStream::new()
}
}
fn field_return_type(
name: &str,
var: &EventKindVariation,
ruma_events: &TokenStream,
) -> TokenStream {
let ruma_common = quote! { #ruma_events::exports::ruma_common };
let ruma_identifiers = quote! { #ruma_events::exports::ruma_identifiers };
match name {
"origin_server_ts" => quote! { #ruma_common::MilliSecondsSinceUnixEpoch },
"room_id" => quote! { #ruma_identifiers::RoomId },
"event_id" => quote! { #ruma_identifiers::EventId },
"sender" => quote! { #ruma_identifiers::UserId },
"state_key" => quote! { str },
"unsigned" if &EventKindVariation::RedactedSync == var => {
quote! { #ruma_events::RedactedSyncUnsigned }
}
"unsigned" if &EventKindVariation::Redacted == var => {
quote! { #ruma_events::RedactedUnsigned }
}
"unsigned" => quote! { #ruma_events::Unsigned },
_ => panic!("the `ruma_events_macros::event_enum::EVENT_FIELD` const was changed"),
}
}
pub(crate) struct EventEnumVariant {
pub attrs: Vec<Attribute>,
pub ident: Ident,
}
impl EventEnumVariant {
pub(crate) fn to_tokens<T>(&self, prefix: Option<T>, with_attrs: bool) -> TokenStream
where
T: ToTokens,
{
let mut tokens = TokenStream::new();
if with_attrs {
for attr in &self.attrs {
attr.to_tokens(&mut tokens);
}
}
if let Some(p) = prefix {
tokens.extend(quote! { #p :: })
}
self.ident.to_tokens(&mut tokens);
tokens
}
pub(crate) fn decl(&self) -> TokenStream {
self.to_tokens::<TokenStream>(None, true)
}
pub(crate) fn match_arm(&self, prefix: impl ToTokens) -> TokenStream {
self.to_tokens(Some(prefix), true)
}
pub(crate) fn ctor(&self, prefix: impl ToTokens) -> TokenStream {
self.to_tokens(Some(prefix), false)
}
}
impl EventEnumEntry {
pub(crate) fn to_variant(&self) -> syn::Result<EventEnumVariant> {
let attrs = self.attrs.clone();
let ident = to_camel_case(&self.ev_type)?;
Ok(EventEnumVariant { attrs, ident })
}
}