login/logout

1 files changed, 71 insertions, 0 deletions

diff --git a/client/src/user.js b/client/src/user.js
new file mode 100644
index 0000000..dfa6384
--- /dev/null
+++ b/client/src/user.js
@@ -0,0 +1,71 @@
+import { h, createContext } from 'preact';
+import { useRef, useState, useCallback, useEffect, useContext } from 'preact/hooks';
+import { API_PREFIX } from './config';
+
+const fetchJSON = async (url, method='GET', data=undefined) => {
+  const res = await fetch(API_PREFIX + url, {
+    method,
+    credentials: 'include',
+    headers: { 'content-type': data && 'application/json' },
+    body: data && JSON.stringify(data),
+  });
+
+  if (res.status !== 200)
+    throw new Error("wrong status");
+
+  return res.json();
+};
+
+const initialState = { user: null, discussions: [] };
+const reducer = async (action, ref) => {
+  switch (action.type) {
+    case 'login': {
+      const { username, password } = action;
+      await fetchJSON('/discdag/login', 'POST', { username, password });
+      return await reducer({ type: 'refresh' }, ref);
+    }
+
+    case 'logout': {
+      await fetchJSON('/discdag/logout', 'POST');
+      return await reducer({ type: 'refresh' }, ref);
+    }
+
+    case 'refresh': {
+      const { user, discussions } = await fetchJSON('/discdag/list');
+      return { ...ref.current, user, discussions };
+    }
+
+    default:
+      throw new Error('Unexpected action');
+  }
+};
+
+const UserContext = createContext({
+  state: initialState,
+  dispatch: () => {
+    throw new Error("no UserContext Provider!");
+  },
+});
+
+export const UserContainer = ({ children }) => {
+  const ref = useRef();
+  const [state, setState] = useState(initialState);
+  ref.current = state;
+
+  const dispatch = useCallback(async (action) => {
+    const nextState = await reducer(action, ref);
+    setState(nextState);
+  }, [ref]);
+
+  useEffect(() => dispatch({ type: 'refresh' }), []);
+
+  return (
+    <UserContext.Provider value={{ state, dispatch }}>
+      {children}
+    </UserContext.Provider>
+  );
+};
+
+export const useUser = () => useContext(UserContext).state;
+export const useDispatch = () => useContext(UserContext).dispatch;
+export const useUserCtx = () => useContext(UserContext);