From 34170ed0f930d0047076e405d611d21485faad5d Mon Sep 17 00:00:00 2001
From: cha0s <git@cha0s.io>
Date: Fri, 26 Mar 2021 10:51:24 -0500
Subject: [PATCH] feat: gathered HMR!!

---
 packages/core/src/gather.js | 87 +++++++++++++++++++++++++++----------
 packages/core/src/index.js  |  4 ++
 2 files changed, 67 insertions(+), 24 deletions(-)

diff --git a/packages/core/src/gather.js b/packages/core/src/gather.js
index c4550fa..98ec3b6 100644
--- a/packages/core/src/gather.js
+++ b/packages/core/src/gather.js
@@ -6,6 +6,8 @@ import {camelCase} from './string';
 
 const debug = D('@latus/core/gather');
 
+export const hotGathered = new Map();
+
 export const decorateWithLatus = (
   context,
   {
@@ -47,51 +49,88 @@ export const gatherWithLatus = (
   }))
 );
 
+const wrapperClass = (Class, id, idAttribute, type, typeAttribute) => {
+  class Subclass extends Class {
+
+    static get [idAttribute]() {
+      return id;
+    }
+
+    static get [typeAttribute]() {
+      return type;
+    }
+
+  }
+  return Subclass;
+};
+
 export default (
   latus,
   {
-    type,
+    type: hook,
     idAttribute = 'id',
     typeAttribute = 'type',
     check = () => {},
   },
 ) => {
-  const gathered = latus.invokeReduce(type);
-  check(gathered, type);
-  const composed = latus.invokeComposed(`${type}.decorate`, gathered);
-  check(composed, `${type}.decorate`);
+  const raw = latus.invokeReduce(hook);
+  check(raw, hook);
+  const composed = latus.invokeComposed(`${hook}.decorate`, raw);
+  check(composed, `${hook}.decorate`);
   let uid = 1;
   const fromId = {};
   const fromType = Object.fromEntries(
     Object.entries(composed)
       .sort(([lname], [rname]) => (lname < rname ? -1 : 1))
       .map(([type, Class]) => {
-        const thisUid = uid++;
-        class Subclass extends Class {
-
-          static get [idAttribute]() {
-            return thisUid;
-          }
-
-          static get [typeAttribute]() {
-            return type;
-          }
-
-        }
-        if (!Subclass.name) {
-          Subclass.name = type;
-        }
-        fromId[thisUid] = Subclass;
+        const id = uid++;
+        const Subclass = wrapperClass(Class, id, idAttribute, type, typeAttribute);
+        fromId[id] = Subclass;
         return [
           type,
           Subclass,
         ];
       }),
   );
-  const result = {
+  const gathered = {
     ...fromId,
     ...fromType,
   };
-  debug("gathered '%s': %O", type, result);
-  return result;
+  hotGathered.set(hook, {
+    idAttribute,
+    gathered,
+    typeAttribute,
+  });
+  debug("gathered '%s': %O", hook, gathered);
+  return gathered;
+};
+
+export const refresh = (path, latus) => {
+  const it = hotGathered.entries();
+  for (let current = it.next(); current.done !== true; current = it.next()) {
+    const {
+      value: [
+        hook,
+        {
+          idAttribute,
+          gathered,
+          typeAttribute,
+        },
+      ],
+    } = current;
+    const updates = latus.invokePlugin(hook, path);
+    if (!updates) {
+      // eslint-disable-next-line no-continue
+      continue;
+    }
+    const entries = Object.entries(updates);
+    for (let i = 0; i < entries.length; ++i) {
+      const [type, Class] = entries[i];
+      const {[type]: {[idAttribute]: id}} = gathered;
+      const Subclass = wrapperClass(Class, id, idAttribute, type, typeAttribute);
+      gathered[type] = Subclass;
+      gathered[id] = Subclass;
+      latus.invoke('@latus/core/gathered/hmr', Subclass, hook);
+    }
+  }
 };
diff --git a/packages/core/src/index.js b/packages/core/src/index.js
index 46cf688..3992065 100644
--- a/packages/core/src/index.js
+++ b/packages/core/src/index.js
@@ -1,3 +1,6 @@
+// eslint-disable-next-line max-classes-per-file
+import {refresh} from './gather';
+
 export {
   unique as arrayUnique,
   flatten as arrayFlatten,
@@ -22,5 +25,6 @@ export default {
     '@latus/core/config': () => ({
       id: 'latus',
     }),
+    '@latus/core/hmr': refresh,
   },
 };