From 28564b11bde31a7ba3b0468bfb0ecf813fb44ae5 Mon Sep 17 00:00:00 2001
From: brnrs <brnrs@brnrs.pl>
Date: Fri, 17 Apr 2020 15:30:38 +0200
Subject: [PATCH] WIP: contexts

---
 src/contexts/component.rs     |  38 ++++++++++++
 src/contexts/component_map.rs |  28 +++++++++
 src/contexts/mod.rs           |   3 +
 src/contexts/model_i.rs       | 111 ++++++++++++++++++++++++++++++++++
 src/main.rs                   |   2 +
 5 files changed, 182 insertions(+)
 create mode 100644 src/contexts/component.rs
 create mode 100644 src/contexts/component_map.rs
 create mode 100644 src/contexts/mod.rs
 create mode 100644 src/contexts/model_i.rs

diff --git a/src/contexts/component.rs b/src/contexts/component.rs
new file mode 100644
index 0000000..0b90dc6
--- /dev/null
+++ b/src/contexts/component.rs
@@ -0,0 +1,38 @@
+use std::any::{Any, TypeId, type_name};
+use std::convert::TryFrom;
+use std::cell::RefCell;
+use std::ops::Deref;
+use std::rc::Rc;
+
+#[derive(Clone)]
+pub struct Component<T: Any + ?Sized + 'static>(Rc<RefCell<T>>);
+
+impl <T> Deref for Component<T> {
+    type Target = RefCell<T>;
+
+    fn deref(&self) -> &Self::Target {
+        self.0.deref()
+    }
+}
+
+#[allow(dead_code)]
+impl <T: Any + Sized + 'static> Component<T> {
+    pub fn from(t: T) -> Component<T> {
+        Component(Rc::new(RefCell::new(t)))
+    }
+
+    pub fn type_id() -> TypeId {
+        TypeId::of::<T>()
+    }
+
+    pub fn type_name() -> &'static str {
+        type_name::<T>()
+    }
+}
+
+impl <T: Any + Sized + 'static> TryFrom<Rc<dyn Any + 'static>> for Component<T> {
+    type Error = Rc<dyn Any + 'static>;
+    fn try_from(rc: Rc<dyn Any + 'static>) -> Result<Component<T>, Self::Error> {
+        Ok(Component(rc.downcast::<RefCell<T>>()?))
+    }
+}
\ No newline at end of file
diff --git a/src/contexts/component_map.rs b/src/contexts/component_map.rs
new file mode 100644
index 0000000..a935d63
--- /dev/null
+++ b/src/contexts/component_map.rs
@@ -0,0 +1,28 @@
+use std::any::{Any, TypeId};
+use std::cell::RefCell;
+use std::collections::HashMap;
+use std::convert::TryInto;
+use std::rc::Rc;
+
+use super::component::Component;
+
+pub struct ComponentMap(HashMap<TypeId, Rc<dyn Any + 'static>>);
+
+#[allow(dead_code)]
+impl ComponentMap {
+    pub fn new() -> ComponentMap {
+        ComponentMap(HashMap::new())
+    }
+
+    pub fn contains<T: Any + Sized + 'static>(&self) -> bool {
+        self.0.contains_key(&TypeId::of::<T>())
+    }
+
+    pub fn get<T: Any + Sized + 'static>(&self) -> Option<Component<T>> {
+        self.0.get(&TypeId::of::<T>()).cloned().map(|c| c.try_into().unwrap())
+    }
+
+    pub fn set<T: Any + Sized + 'static>(&mut self, component: T) {
+        self.0.insert(TypeId::of::<T>(), Rc::new(RefCell::new(component)));
+    }
+}
diff --git a/src/contexts/mod.rs b/src/contexts/mod.rs
new file mode 100644
index 0000000..b6acac3
--- /dev/null
+++ b/src/contexts/mod.rs
@@ -0,0 +1,3 @@
+mod model_i;
+mod component;
+mod component_map;
diff --git a/src/contexts/model_i.rs b/src/contexts/model_i.rs
new file mode 100644
index 0000000..7788a97
--- /dev/null
+++ b/src/contexts/model_i.rs
@@ -0,0 +1,111 @@
+use std::any::Any;
+
+use super::component::*;
+use super::component_map::*;
+
+#[allow(dead_code)]
+struct Context<'t> {
+    map: ComponentMap,
+    base_context: Option<&'t Context<'t>>,
+}
+
+#[allow(dead_code)]
+impl<'t> Context<'t> {
+    fn new() -> Context<'t> {
+        Context {
+            map: ComponentMap::new(),
+            base_context: None,
+        }
+    }
+
+    fn get<T: Any + Sized + 'static>(&self) -> Option<Component<T>> {
+        match self.map.get() {
+            component @ Some(_) => component,
+            _ => match self.base_context {
+                Some(context) => context.get(),
+                None => None,
+            },
+        }
+    }
+
+    fn set<T: Any + Sized + 'static>(&mut self, component: T) {
+        self.map.set(component)
+    }
+
+    fn subcontext(&self) -> Context {
+        let mut context = Context::new();
+        context.base_context = Some(self);
+        context
+    }
+}
+
+trait FromContext: Sized {
+    fn from(context: &Context) -> Option<Self>;
+}
+
+impl <T> FromContext for Component<T> {
+    fn from(context: &Context) -> Option<Self> {
+        context.get()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn get_from_context() {
+        // Given
+        #[derive(Debug, Eq, PartialEq)]
+        struct TestStruct(&'static str);
+        let context = {
+            let mut tmp = Context::new();
+            tmp.set(TestStruct("hello"));
+            tmp
+        };
+
+        // When
+        let test_struct = context.get::<TestStruct>().unwrap();
+
+        // Then
+        assert_eq!(*test_struct.borrow(), TestStruct("hello"));
+    }
+
+    #[test]
+    fn get_from_base_context() {
+        // Given
+        #[derive(Debug, Eq, PartialEq)]
+        struct TestStruct(&'static str);
+        let context = {
+            let mut tmp = Context::new();
+            tmp.set(TestStruct("hello"));
+            tmp
+        };
+        let subcontext = context.subcontext();
+
+        // When
+        let test_struct = subcontext.get::<TestStruct>().unwrap();
+
+        // Then
+        assert_eq!(*test_struct.borrow(), TestStruct("hello"));
+    }
+
+    #[test]
+    fn get_from_subcontext() {
+        // Given
+        #[derive(Debug, Eq, PartialEq)]
+        struct TestStruct(&'static str);
+        let context = Context::new();
+        let subcontext =  {
+            let mut tmp = context.subcontext(); 
+            tmp.set(TestStruct("hello"));
+            tmp
+        };
+
+        // When
+        let test_struct = subcontext.get::<TestStruct>().unwrap();
+
+        // Then
+        assert_eq!(*test_struct.borrow(), TestStruct("hello"));
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index e29f1ce..e708f17 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,6 +1,7 @@
 #![feature(trait_alias, option_unwrap_none)]
 mod battle;
 mod context;
+mod contexts;
 
 use battle::actor::*;
 use battle::base::*;
@@ -8,6 +9,7 @@ use battle::skill::*;
 use battle::uic::Uic;
 use context::Context;
 
+
 fn main() {
     println!("Hello, world!");