From 079588d5dad43c20073483565e0cde8a512bdb07 Mon Sep 17 00:00:00 2001
From: Jonah Seguin <me@jonahseguin.com>
Date: Sat, 21 Jan 2023 19:36:34 -0700
Subject: [PATCH] initial Ref<M> impl (#10)

---
 musty-proc-macro/src/model/meta_model.rs |  2 +-
 musty/examples/filter.rs                 |  2 +-
 musty/src/filter/value.rs                | 20 +++++-
 musty/src/lib.rs                         |  1 +
 musty/src/model.rs                       |  2 +-
 musty/src/reference.rs                   | 91 ++++++++++++++++++++++++
 6 files changed, 114 insertions(+), 4 deletions(-)
 create mode 100644 musty/src/reference.rs

diff --git a/musty-proc-macro/src/model/meta_model.rs b/musty-proc-macro/src/model/meta_model.rs
index 6517880..5d9bc5a 100644
--- a/musty-proc-macro/src/model/meta_model.rs
+++ b/musty-proc-macro/src/model/meta_model.rs
@@ -135,7 +135,7 @@ impl MetaModelDerive {
             #(
                 #attrs
             )*
-            #[derive(Debug, serde::Serialize, serde::Deserialize)]
+            #[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
             #vis struct #ident {
                 #id_attr
                 #id_vis id: musty::prelude::Id<#ident, #id_type>,
diff --git a/musty/examples/filter.rs b/musty/examples/filter.rs
index fccf882..2a1b895 100644
--- a/musty/examples/filter.rs
+++ b/musty/examples/filter.rs
@@ -11,7 +11,7 @@ struct User {
     address: Address,
 }
 
-#[derive(Debug, Filter, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize, Filter)]
 struct Address {
     country: String,
     labels: Vec<String>,
diff --git a/musty/src/filter/value.rs b/musty/src/filter/value.rs
index 13f78a3..990c4a6 100644
--- a/musty/src/filter/value.rs
+++ b/musty/src/filter/value.rs
@@ -1,4 +1,4 @@
-use crate::{prelude::{Filter, ModelFilter, IdGuard, Id}, Model};
+use crate::{prelude::{Filter, ModelFilter, IdGuard, Id}, Model, reference::Ref};
 
 #[derive(Debug, Clone)]
 pub enum FilterValue {
@@ -77,4 +77,22 @@ impl<M: Model, I: IdGuard> From<Id<M, I>> for FilterValue {
     fn from(id: Id<M, I>) -> Self {
         Self::Id(id.inner.map(|i| i.to_string()))
     }
+}
+
+impl<M: Model, I: IdGuard> From<&Id<M, I>> for FilterValue {
+    fn from(id: &Id<M, I>) -> Self {
+        Self::Id(id.inner.as_ref().map(|i| i.to_string()))
+    }
+}
+
+impl<M: Model> From<Ref<M>> for FilterValue {
+    fn from(r: Ref<M>) -> Self {
+        r.take_id().into()
+    }
+}
+
+impl<M: Model> From<&Ref<M>> for FilterValue {
+    fn from(r: &Ref<M>) -> Self {
+        r.id().into()
+    }
 }
\ No newline at end of file
diff --git a/musty/src/lib.rs b/musty/src/lib.rs
index 13c5922..df32f7c 100644
--- a/musty/src/lib.rs
+++ b/musty/src/lib.rs
@@ -9,6 +9,7 @@ mod error;
 mod id;
 mod model;
 pub mod filter;
+mod reference;
 
 #[cfg(feature = "bson")]
 pub use bson;
diff --git a/musty/src/model.rs b/musty/src/model.rs
index 1c8de93..72da3aa 100644
--- a/musty/src/model.rs
+++ b/musty/src/model.rs
@@ -18,7 +18,7 @@ use async_trait::async_trait;
 #[async_trait]
 pub trait Model
 where
-    Self: Sized + Send + Sync + Serialize + DeserializeOwned + Unpin,
+    Self: Sized + Send + Sync + Serialize + DeserializeOwned + Unpin + Clone,
 {
     type Id: IdGuard;
 
diff --git a/musty/src/reference.rs b/musty/src/reference.rs
new file mode 100644
index 0000000..8b30969
--- /dev/null
+++ b/musty/src/reference.rs
@@ -0,0 +1,91 @@
+use serde::{Serialize, Deserialize};
+
+use crate::{Model, id::Id, prelude::Backend, Result, context::Context};
+
+#[derive(Clone)]
+pub enum Ref<M: Model> {
+    Id(Id<M, <M as Model>::Id>),
+    Model(M),
+}
+
+impl<M: Model> Ref<M> {
+    pub async fn get<B, I>(&self, db: &crate::Musty<B>) -> Result<Option<M>>
+    where 
+        M: Context<<M as Model>::Id, B> + 'static,
+        I: Into<Id<M, <M as Model>::Id>> + Send + Sync,
+        B: Backend,
+    {
+        match self {
+            Self::Id(id) => Ok(db.inner.get_model_by_id(id.into()).await?),
+            Self::Model(model) => Ok(Some(model.clone())),
+        }
+    }
+
+    pub async fn take<B, I>(self, db: &crate::Musty<B>) -> Result<Option<M>>
+    where 
+        M: Context<<M as Model>::Id, B> + 'static,
+        I: Into<Id<M, <M as Model>::Id>> + Send + Sync,
+        B: Backend,
+    {
+        match self {
+            Self::Id(id) => Ok(db.inner.get_model_by_id(&id.into()).await?),
+            Self::Model(model) => Ok(Some(model)),
+        }
+    }
+
+    pub fn id(&self) -> &Id<M, <M as Model>::Id> {
+        match self {
+            Self::Id(id) => id,
+            Self::Model(model) => model.id(),
+        }
+    }
+
+    pub fn take_id(self) -> Id<M, <M as Model>::Id> {
+        match self {
+            Self::Id(id) => id,
+            Self::Model(model) => model.id().clone(),
+        }
+    }
+}
+
+impl<M: Model> From<Id<M, <M as Model>::Id>> for Ref<M> {
+    fn from(id: Id<M, <M as Model>::Id>) -> Self {
+        Ref::Id(id)
+    }
+}
+
+impl<M: Model> From<Ref<M>> for Id<M, <M as Model>::Id> {
+    fn from(id: Ref<M>) -> Self {
+        match id {
+            Ref::Id(id) => id,
+            Ref::Model(model) => model.id().clone(),
+        }
+    }
+}
+
+impl<'a, M: Model> From<&'a Ref<M>> for &'a Id<M, <M as Model>::Id> {
+    fn from(id: &'a Ref<M>) -> Self {
+        match id {
+            Ref::Id(id) => id,
+            Ref::Model(model) => model.id(),
+        }
+    }
+}
+
+impl<M: Model> Serialize for Ref<M> {
+    fn serialize<S>(&self, serializer: S) -> core::result::Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        self.id().serialize(serializer)
+    }
+}
+
+impl<'de, M: Model> Deserialize<'de> for Ref<M> {
+    fn deserialize<D>(deserializer: D) -> core::result::Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        Ok(Ref::Id(Id::deserialize(deserializer)?))
+    }
+}
\ No newline at end of file