bevy/crates/bevy_property/src/dynamic_properties.rs

use crate::{
    Properties, Property, PropertyIter, PropertyTypeRegistration,
    PropertyTypeRegistry, PropertyVal,
};
use serde::{
    de::{self, DeserializeSeed, MapAccess, Visitor},
    ser::SerializeMap,
    Serialize,
};
use std::{any::Any, borrow::Cow, cell::RefCell, collections::HashMap, rc::Rc};

#[derive(Default)]
pub struct DynamicProperties {
    pub type_name: String,
    pub props: Vec<(Cow<'static, str>, Box<dyn Property>)>,
    pub prop_indices: HashMap<Cow<'static, str>, usize>,
}

impl DynamicProperties {
    fn push(&mut self, name: &str, prop: Box<dyn Property>) {
        let name: Cow<'static, str> = Cow::Owned(name.to_string());
        self.props.push((name.clone(), prop));
        self.prop_indices.insert(name, self.props.len());
    }
    pub fn set<T: Property>(&mut self, name: &str, prop: T) {
        if let Some(index) = self.prop_indices.get(name) {
            self.props[*index].1 = Box::new(prop);
        } else {
            self.push(name, Box::new(prop));
        }
    }
    pub fn set_box(&mut self, name: &str, prop: Box<dyn Property>) {
        if let Some(index) = self.prop_indices.get(name) {
            self.props[*index].1 = prop;
        } else {
            self.push(name, prop);
        }
    }
}

impl Properties for DynamicProperties {
    #[inline]
    fn type_name(&self) -> &str {
        &self.type_name
    }
    #[inline]
    fn prop(&self, name: &str) -> Option<&dyn Property> {
        if let Some(index) = self.prop_indices.get(name) {
            Some(&*self.props[*index].1)
        } else {
            None
        }
    }

    #[inline]
    fn prop_mut(&mut self, name: &str) -> Option<&mut dyn Property> {
        if let Some(index) = self.prop_indices.get(name) {
            Some(&mut *self.props[*index].1)
        } else {
            None
        }
    }

    #[inline]
    fn prop_with_index(&self, index: usize) -> Option<&dyn Property> {
        self.props.get(index).map(|(_i, prop)| &**prop)
    }

    #[inline]
    fn prop_with_index_mut(&mut self, index: usize) -> Option<&mut dyn Property> {
        self.props.get_mut(index).map(|(_i, prop)| &mut **prop)
    }

    #[inline]
    fn prop_name(&self, index: usize) -> Option<&str> {
        self.props.get(index).map(|(name, _)| name.as_ref())
    }

    #[inline]
    fn prop_len(&self) -> usize {
        self.props.len()
    }

    fn iter_props(&self) -> PropertyIter {
        PropertyIter {
            props: self,
            index: 0,
        }
    }
}

impl Serialize for DynamicProperties {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: serde::Serializer,
    {
        let mut state = serializer.serialize_map(Some(self.props.len()))?;
        state.serialize_entry("type", self.type_name())?;
        for (name, prop) in self.iter_props() {
            state.serialize_entry(name, prop)?;
        }
        state.end()
    }
}

pub struct DynamicPropertiesDeserializer<'a> {
    pub property_type_registry: &'a PropertyTypeRegistry,
    pub current_type_name: Rc<RefCell<Option<String>>>,
}

impl<'a, 'de> DeserializeSeed<'de> for DynamicPropertiesDeserializer<'a> {
    type Value = DynamicProperties;
    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
    where
        D: serde::Deserializer<'de>,
    {
        let mut dynamic_properties = DynamicProperties::default();
        deserializer.deserialize_map(PropMapVisiter {
            dynamic_properties: &mut dynamic_properties,
            property_type_registry: self.property_type_registry,
            current_type_name: self.current_type_name,
        })?;

        Ok(dynamic_properties)
    }
}

struct PropMapVisiter<'a> {
    dynamic_properties: &'a mut DynamicProperties,
    property_type_registry: &'a PropertyTypeRegistry,
    current_type_name: Rc<RefCell<Option<String>>>,
}

impl<'a, 'de> Visitor<'de> for PropMapVisiter<'a> {
    type Value = ();
    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
        formatter.write_str("map of properties")
    }

    fn visit_map<V>(self, mut map: V) -> Result<(), V::Error>
    where
        V: MapAccess<'de>,
    {
        let mut type_name: Option<String> = None;
        while let Some(key) = map.next_key::<String>()? {
            if &key == "type" {
                type_name = Some(map.next_value()?);
            } else {
                let prop = map.next_value_seed(MapValueDeserializer {
                    property_type_registry: self.property_type_registry,
                    current_type_name: self.current_type_name.clone(),
                })?;
                self.dynamic_properties.set_box(&key, prop);
            }
        }

        let type_name = type_name.ok_or_else(|| de::Error::missing_field("type"))?;
        self.dynamic_properties.type_name = type_name.to_string();
        Ok(())
    }
}

pub struct MapValueDeserializer<'a> {
    property_type_registry: &'a PropertyTypeRegistry,
    current_type_name: Rc<RefCell<Option<String>>>,
}

impl<'a, 'de> DeserializeSeed<'de> for MapValueDeserializer<'a> {
    type Value = Box<dyn Property>;
    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
    where
        D: serde::Deserializer<'de>,
    {
        if self.current_type_name.borrow().is_some() {
            let registration = {
                let current_type_name= self.current_type_name.borrow();
                let type_name = current_type_name.as_ref().unwrap();
                self
                    .property_type_registry
                    .get(type_name)
                    .ok_or_else(|| {
                        de::Error::custom(format!(
                            "TypeRegistration is missing for {}",
                            type_name
                        ))
                    })?
            };
            let mut erased = erased_serde::Deserializer::erase(deserializer);
            let res = (registration.deserialize)(&mut erased)
                .map_err(<<D as serde::Deserializer<'de>>::Error as serde::de::Error>::custom);
            res
        }  else {
            deserializer.deserialize_any(AnyPropVisiter {
                property_type_registry: self.property_type_registry,
                current_type_name: self.current_type_name,
            })
        }
    }
}

struct AnyPropVisiter<'a> {
    property_type_registry: &'a PropertyTypeRegistry,
    current_type_name: Rc<RefCell<Option<String>>>,
}

impl<'a, 'de> Visitor<'de> for AnyPropVisiter<'a> {
    type Value = Box<dyn Property>;
    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
        formatter.write_str("property value")
    }

    fn visit_u8<E>(self, v: u8) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Box::new(v))
    }

    fn visit_u16<E>(self, v: u16) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Box::new(v))
    }

    fn visit_u32<E>(self, v: u32) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Box::new(v))
    }

    fn visit_u64<E>(self, v: u64) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Box::new(v))
    }

    fn visit_i8<E>(self, v: i8) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Box::new(v))
    }

    fn visit_i16<E>(self, v: i16) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Box::new(v))
    }

    fn visit_i32<E>(self, v: i32) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Box::new(v))
    }

    fn visit_i64<E>(self, v: i64) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Box::new(v))
    }

    fn visit_f32<E>(self, v: f32) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Box::new(v))
    }

    fn visit_f64<E>(self, v: f64) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Box::new(v))
    }

    fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Box::new(v))
    }

    fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Box::new(v.to_string()))
    }

    fn visit_map<V>(self, mut map: V) -> Result<Self::Value, V::Error>
    where
        V: MapAccess<'de>,
    {
        let mut dynamic_properties = DynamicProperties::default();
        while let Some(key) = map.next_key()? {
            let prop = map.next_value_seed(MapValueDeserializer {
                property_type_registry: self.property_type_registry,
                current_type_name: self.current_type_name.clone(),
            })?;
            if key == "type" {
                dynamic_properties.type_name = prop
                    .val::<String>()
                    .map(|s| s.clone())
                    .ok_or_else(|| de::Error::custom("type must be a string"))?;
            } else {
                dynamic_properties.set_box(key, prop);
            }
        }

        Ok(Box::new(dynamic_properties))
    }
}

struct PropertyTypeDeserializer<'a> {
    registration: &'a PropertyTypeRegistration,
}

impl<'a, 'de> DeserializeSeed<'de> for PropertyTypeDeserializer<'a> {
    type Value = Box<dyn Property>;
    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
    where
        D: serde::Deserializer<'de>,
    {
        let mut erased = erased_serde::Deserializer::erase(deserializer);
        (self.registration.deserialize)(&mut erased)
            .map_err(<<D as serde::Deserializer<'de>>::Error as serde::de::Error>::custom)
    }
}

impl Property for DynamicProperties {
    #[inline]
    fn any(&self) -> &dyn Any {
        self
    }
    #[inline]
    fn any_mut(&mut self) -> &mut dyn Any {
        self
    }
    #[inline]
    fn clone_prop(&self) -> Box<dyn Property> {
        Box::new(self.to_dynamic())
    }
    #[inline]
    fn set(&mut self, value: &dyn Property) {
        if let Some(properties) = value.as_properties() {
            *self = properties.to_dynamic();
        } else {
            panic!("attempted to apply non-Properties type to Properties type");
        }
    }

    #[inline]
    fn apply(&mut self, value: &dyn Property) {
        if let Some(properties) = value.as_properties() {
            for (name, prop) in properties.iter_props() {
                self.prop_mut(name).map(|p| p.apply(prop));
            }
        } else {
            panic!("attempted to apply non-Properties type to Properties type");
        }
    }

    fn as_properties(&self) -> Option<&dyn Properties> {
        Some(self)
    }
}