From 2b7a679156cf6d9b33691f7e313b483ccec64c46 Mon Sep 17 00:00:00 2001
From: jshrt <ouaghad.hamza@gmail.com>
Date: Thu, 25 Jul 2019 16:04:17 +0200
Subject: [PATCH] feat(wip): local state

---
 examples/todo/components/Form.jsx     |  56 ++++++++
 examples/todo/components/TodoList.jsx |   8 ++
 src/index.js                          |   7 +-
 src/local-state.js                    | 195 ++++++++++++++++++++++++++
 4 files changed, 261 insertions(+), 5 deletions(-)
 create mode 100644 examples/todo/components/Form.jsx
 create mode 100644 src/local-state.js

diff --git a/examples/todo/components/Form.jsx b/examples/todo/components/Form.jsx
new file mode 100644
index 0000000..f72740b
--- /dev/null
+++ b/examples/todo/components/Form.jsx
@@ -0,0 +1,56 @@
+import * as React from 'react'
+import { View, LocalState } from '../../../src'
+
+const {
+  state,
+  setState
+} = LocalState({
+  schema: {
+    name: "",
+    age: 0,
+  },
+
+  setter: (mutation) => {
+    return {
+      name: mutation.name ? mutation.name.toLowerCase() : "",
+      age: mutation.age
+        ? mutation.age > 0
+          ? mutation.age * 2
+          : mutation.age * 10
+        : mutation.age + 1,
+    }
+  },
+
+  getter: (state) => {
+    const [
+      firstName, lastName
+    ] = state.name.split(" ")
+
+    return {
+      firstName,
+      lastName,
+    }
+  }
+})
+
+export default View(
+  () =>
+  <div>
+    <pre>
+      {
+        <p>
+          name: { state.name }
+          age: { state.age }
+        </p>
+      }
+    </pre>
+    <li>
+      <label htmlFor="name">Name</label>
+      <input type="text" name="name" value={state.name} onChange={({ target: { value } }) => setState("name")(value)}/>
+    </li>
+    <li>
+      <label htmlFor="name">Age</label>
+      <input type="text" name="name" value={state.age} onChange={({ target: { value }}) => setState("age")(value)}/>
+    </li>
+  </div>
+)
diff --git a/examples/todo/components/TodoList.jsx b/examples/todo/components/TodoList.jsx
index 7d8aad4..f818e45 100644
--- a/examples/todo/components/TodoList.jsx
+++ b/examples/todo/components/TodoList.jsx
@@ -4,10 +4,18 @@ import { createTodo, login, logout } from '../actions.jsx'
 import { userState, todoState } from '../state.jsx'
 
 import ListItem from './ListItem.jsx'
+import Form from "./Form"
+
+console.log({
+  todoState, userState
+})
 
 export default View(() => {
   return (
     <div>
+        <Form />
+        <br/>
+        <hr/>
         Hi, we have {todoState.size} total todos.
         Pending:
       <ul>
diff --git a/src/index.js b/src/index.js
index 25b9cef..9b1005d 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,9 +1,6 @@
-import { configure } from 'mobx'
-
-configure({ enforceActions: 'strict', isolatedGlobalState: true })
-
 export * from 'mobx'
 
 export { Model, Propose } from './model'
 export { State } from './state'
-export { observer as View } from 'mobx-react'
\ No newline at end of file
+export { observer as View } from 'mobx-react'
+export { LocalState } from "./local-state"
diff --git a/src/local-state.js b/src/local-state.js
new file mode 100644
index 0000000..569165b
--- /dev/null
+++ b/src/local-state.js
@@ -0,0 +1,195 @@
+/**
+ *
+ * @example:
+ *  import { LocalState } from "samx"
+ *
+ *  const { state, setState } = LocalState({
+ *    schema: {
+ *    },
+ *    setter: (mutation) => {
+ *      return mutation
+ *    },
+ *    getter: (state) => {
+ *      return state
+ *    },
+ *  })
+ * */
+
+import { observable, set } from "mobx"
+
+const LocalStateError = (msg) => new Error(msg)
+
+const Errors = {
+  setter: {
+    InvalidMutation: LocalStateError("Invalid Mutation"),
+    notAllowed: LocalStateError("Operation not allowed"),
+  },
+  setState: {
+    args: {
+      one: LocalStateError("Invalid arguments. First argument should be either a string prop name or a mutation object"),
+      two: LocalStateError("Invalid arguments. First argument must be a string, second must be an object/number/string"),
+      invalid: LocalStateError("Invalid argument list.")
+    }
+  },
+  Constructor: {
+    InvalidArgs: {
+      first: {
+        schema: LocalStateError("Schema must be an object"),
+      }
+    }
+  },
+  getter: {
+    prop: {
+      invalid: LocalStateError("Invalid property access. No such property is defined in the getter."),
+    }
+  },
+}
+
+/**
+ * Encapsulated Mobx.set for validation and interfacing purposes
+ * 
+ * @param {Mobx.observable} observable 
+ * @param {Object} mutation 
+ */
+const Setter = (interceptor) =>  (observableState, mutation) => {
+  console.log(observableState, mutation)
+  Object.keys(mutation).forEach(
+    (key) => {
+      if (typeof mutation[key] === "function") {
+        throw Errors.setter.InvalidMutation
+      }
+    }
+  )
+
+  if (typeof interceptor === "function") {
+    const newMutation = interceptor(toJS(observableState), mutation)
+    set(observableState, newMutation)
+  } else {
+    set(observableState, mutation)
+  }
+  
+  return true
+}
+
+/**
+ * 
+ * @example:
+ *  first:
+ *    setState({ property: value })
+ * 
+ *  second:
+ *    setState("property")(value)
+ * 
+ *  third:
+ *    setState("property", value)
+ */
+const SetState = (observableState, interceptor) => (...args) => {
+  const interceptedSetter = Setter(interceptor)
+  const argsLength = args.length
+
+  switch (argsLength) {
+    case 1:
+      const arg = args[0]
+      if (typeof arg === "object") {
+        return interceptedSetter(observableState, arg)
+      } else if (typeof arg === "string") {
+        return (mutation) => interceptedSetter(observableState, mutation)
+      } else throw Errors.setState.args.one
+
+    case 2 || argsLength > 2:
+      const [ first, second ] = args
+
+      if (
+        typeof first === "string"
+        && (
+          typeof second === "object"
+          || typeof second === "string"
+          || typeof second === "number"
+        )
+      ) {
+        return interceptedSetter(observableState, {
+          [first]: second,
+        })
+      } else throw Errors.setState.args.two
+    
+    default:
+      throw Errors.setState.args.invalid
+  }
+}
+
+/**
+ * 
+ * @param {Object} opts
+ * @param {Object} opts.schema
+ * @optional {Function} opts.setter
+ * @optional {Function} opts.getter
+ *
+ */
+const LocalState = (opts) => {
+  const options = {}
+
+  if (typeof opts.schema !== "object") {
+    throw Errors.Constructor.InvalidArgs.first.schema
+  }
+
+  options.schema = opts.schema
+
+  if (opts.setter && typeof opts.setter === "Function") {
+    options.setter = opts.setter
+  }
+
+  if (opts.getter && typeof opts.getter === "Function") {
+    options.getter = opts.getter
+  }
+
+  const observableState = observable(options.schema)
+
+  const state = new Proxy({
+    __data: observableState,
+
+    getCurrentState() {
+      return toJS(observableState)
+    },
+
+    __getObservable() {
+      return observableState
+    },
+
+  }, {
+    get(target, prop) {
+      console.log({ target, prop })
+      if (typeof target[prop] === "function") {
+        const r = Reflect.get(...arguments)
+        console.log({ target, prop, value: target[prop], r })
+        return r
+      }
+
+      if (options.getter) {
+        const currentValue = options.getter(target.__data)
+
+        if (prop in Object.keys(currentValue)) {
+          return currentValue[prop]
+        } else {
+          throw Errors.getter.prop.invalid
+        }
+      } else {
+        return target.__data[prop]
+      }
+    },
+
+    set() {
+      throw Errors.setter.notAllowed
+    }
+  })
+
+  const setState = SetState(state.__getObservable(), options.setter || undefined)
+
+  return {
+    state,
+    setState,
+  }
+}
+
+export {
+  LocalState,
+}