add task solution

src/App.tsx

@@ -1,156 +1,18 @@
 /* eslint-disable jsx-a11y/control-has-associated-label */
 import React from 'react';
+import { Header } from './components/Header';
+import { TodoList } from './components/TodoList';
+import { Footer } from './components/Footer';
 
 export const App: React.FC = () => {
   return (
     <div className="todoapp">
       <h1 className="todoapp__title">todos</h1>
 
       <div className="todoapp__content">
-        <header className="todoapp__header">
-          {/* this button should have `active` class only if all todos are completed */}
-          <button
-            type="button"
-            className="todoapp__toggle-all active"
-            data-cy="ToggleAllButton"
-          />
-
-          {/* Add a todo on form submit */}
-          <form>
-            <input
-              data-cy="NewTodoField"
-              type="text"
-              className="todoapp__new-todo"
-              placeholder="What needs to be done?"
-            />
-          </form>
-        </header>
-
-        <section className="todoapp__main" data-cy="TodoList">
-          {/* This is a completed todo */}
-          <div data-cy="Todo" className="todo completed">
-            <label className="todo__status-label">
-              <input
-                data-cy="TodoStatus"
-                type="checkbox"
-                className="todo__status"
-                checked
-              />
-            </label>
-
-            <span data-cy="TodoTitle" className="todo__title">
-              Completed Todo
-            </span>
-
-            {/* Remove button appears only on hover */}
-            <button type="button" className="todo__remove" data-cy="TodoDelete">
-              ×
-            </button>
-          </div>
-
-          {/* This todo is an active todo */}
-          <div data-cy="Todo" className="todo">
-            <label className="todo__status-label">
-              <input
-                data-cy="TodoStatus"
-                type="checkbox"
-                className="todo__status"
-              />
-            </label>
-
-            <span data-cy="TodoTitle" className="todo__title">
-              Not Completed Todo
-            </span>
-
-            <button type="button" className="todo__remove" data-cy="TodoDelete">
-              ×
-            </button>
-          </div>
-
-          {/* This todo is being edited */}
-          <div data-cy="Todo" className="todo">
-            <label className="todo__status-label">
-              <input
-                data-cy="TodoStatus"
-                type="checkbox"
-                className="todo__status"
-              />
-            </label>
-
-            {/* This form is shown instead of the title and remove button */}
-            <form>
-              <input
-                data-cy="TodoTitleField"
-                type="text"
-                className="todo__title-field"
-                placeholder="Empty todo will be deleted"
-                value="Todo is being edited now"
-              />
-            </form>
-          </div>
-
-          {/* This todo is in loadind state */}
-          <div data-cy="Todo" className="todo">
-            <label className="todo__status-label">
-              <input
-                data-cy="TodoStatus"
-                type="checkbox"
-                className="todo__status"
-              />
-            </label>
-
-            <span data-cy="TodoTitle" className="todo__title">
-              Todo is being saved now
-            </span>
-
-            <button type="button" className="todo__remove" data-cy="TodoDelete">
-              ×
-            </button>
-          </div>
-        </section>
-
-        {/* Hide the footer if there are no todos */}
-        <footer className="todoapp__footer" data-cy="Footer">
-          <span className="todo-count" data-cy="TodosCounter">
-            3 items left
-          </span>
-
-          {/* Active link should have the 'selected' class */}
-          <nav className="filter" data-cy="Filter">
-            <a
-              href="#/"
-              className="filter__link selected"
-              data-cy="FilterLinkAll"
-            >
-              All
-            </a>
-
-            <a
-              href="#/active"
-              className="filter__link"
-              data-cy="FilterLinkActive"
-            >
-              Active
-            </a>
-
-            <a
-              href="#/completed"
-              className="filter__link"
-              data-cy="FilterLinkCompleted"
-            >
-              Completed
-            </a>
-          </nav>
-
-          {/* this button should be disabled if there are no completed todos */}
-          <button
-            type="button"
-            className="todoapp__clear-completed"
-            data-cy="ClearCompletedButton"
-          >
-            Clear completed
-          </button>
-        </footer>
+        <Header />
+        <TodoList />
+        <Footer />
       </div>
     </div>
   );

src/GlobalProvider.tsx

@@ -0,0 +1,67 @@
+import { Action } from './types/Action';
+import { Filter } from './types/Filter';
+import { State } from './types/State';
+import { useEffect, useReducer } from 'react';
+import React from 'react';
+
+const reducer = (state: State, action: Action): State => {
+  switch (action.type) {
+    case 'addTodo':
+      return {
+        ...state,
+        todos: [...state.todos, action.payload],
+      };
+
+    case 'deleteTodo':
+      return {
+        ...state,
+        todos: state.todos.filter(todo => todo.id !== action.payload),
+      };
+
+    case 'updateTodo':
+      return {
+        ...state,
+        todos: state.todos.map(todo =>
+          todo.id === action.payload.id ? action.payload : todo,
+        ),
+      };
+
+    case 'setFilter':
+      return {
+        ...state,
+        filter: action.payload,
+      };
+
+    default:
+      return state;
+  }
+};
+
+const loadedTodos = localStorage.getItem('todos');
+const initialState: State = {
+  todos: loadedTodos ? JSON.parse(loadedTodos) : [],
+  filter: Filter.All,
+};
+
+export const StateContext = React.createContext<State>(initialState);
+export const DispatchContext = React.createContext<React.Dispatch<Action>>(
+  () => {},
+);
+
+type Props = {
+  children: React.ReactNode;
+};
+
+export const GlobalProvider: React.FC<Props> = ({ children }) => {
+  const [state, dispatch] = useReducer(reducer, initialState);
+
+  useEffect(() => {
+    localStorage.setItem('todos', JSON.stringify(state.todos));
+  }, [state.todos]);
+
+  return (
+    <DispatchContext.Provider value={dispatch}>
+      <StateContext.Provider value={state}>{children}</StateContext.Provider>
+    </DispatchContext.Provider>
+  );
+};

src/components/Footer.tsx

@@ -0,0 +1,64 @@
+import { useContext, useMemo } from 'react';
+import { DispatchContext, StateContext } from '../GlobalProvider';
+import { Filter } from '../types/Filter';
+import classNames from 'classnames';
+
+export const Footer = () => {
+  const { todos, filter } = useContext(StateContext);
+  const dispatch = useContext(DispatchContext);
+
+  const activeTodosCount = useMemo(
+    () => todos.filter(todo => !todo.completed).length,
+    [todos],
+  );
+
+  const deleteCompleted = () => {
+    todos.forEach(todo => {
+      if (todo.completed) {
+        dispatch({ type: 'deleteTodo', payload: todo.id });
+      }
+    });
+  };
+
+  if (!todos.length) {
+    return;
+  }
+
+  return (
+    <>
+      <footer className="todoapp__footer" data-cy="Footer">
+        <span className="todo-count" data-cy="TodosCounter">
+          {`${activeTodosCount} items left`}
+        </span>
+
+        <nav className="filter" data-cy="Filter">
+          {Object.values(Filter).map(currFilter => (
+            <a
+              href={`#/${currFilter === Filter.All ? '' : currFilter.toLowerCase()}`}
+              className={classNames('filter__link', {
+                selected: currFilter === filter,
+              })}
+              data-cy={`FilterLink${currFilter}`}
+              key={currFilter}
+              onClick={() => {
+                dispatch({ type: 'setFilter', payload: currFilter });
+              }}
+            >
+              {currFilter}
+            </a>
+          ))}
+        </nav>
+
+        <button
+          type="button"
+          className="todoapp__clear-completed"
+          data-cy="ClearCompletedButton"
+          disabled={activeTodosCount === todos.length}
+          onClick={deleteCompleted}
+        >
+          Clear completed
+        </button>
+      </footer>
+    </>
+  );
+};

src/components/Header.tsx

@@ -0,0 +1,92 @@
+import { useContext, useEffect, useMemo, useRef, useState } from 'react';
+import { Todo } from '../types/Todo';
+import classNames from 'classnames';
+import { DispatchContext, StateContext } from '../GlobalProvider';
+
+
+export const Header = () => {
+  const [title, setTitle] = useState('');
+
+  const titleField = useRef<HTMLInputElement>(null);
+
+  const { todos } = useContext(StateContext);
+  const dispatch = useContext(DispatchContext);
+
+  useEffect(() => {
+    if (titleField.current) {
+      titleField.current.focus();
+    }
+  }, [todos.length]);
+
+  const handleSubmit = (e: React.FormEvent) => {
+    e.preventDefault();
+
+    if (!title.trim()) {
+      return;
+    }
+
+    const newTodo: Todo = {
+      id: +Date.now(),
+      title: title.trim(),
+      completed: false,
+    };
+
+    dispatch({ type: 'addTodo', payload: newTodo });
+    setTitle('');
+  };
+
+  const handleTitleChange = (e: React.ChangeEvent<HTMLInputElement>) => {
+    setTitle(e.target.value);
+  };
+
+  const allTodosCompleted = useMemo(() => {
+    return todos.filter(todo => todo.completed).length === todos.length;
+  }, [todos]);
+
+  const handleToggleAllButtonClick = () => {
+    let todosToChange = [];
+
+    if (allTodosCompleted) {
+      todosToChange = [...todos];
+    } else {
+      todosToChange = todos.filter(todo => !todo.completed);
+    }
+
+    todosToChange.forEach(todo => {
+      const { id, title: todoTitle, completed } = todo;
+
+      dispatch({
+        type: 'updateTodo',
+        payload: { id, title: todoTitle, completed: !completed },
+      });
+    });
+  };
+
+  return (
+    <header className="todoapp__header">
+      {!!todos.length && (
+        <button
+          type="button"
+          className={classNames('todoapp__toggle-all', {
+            active: allTodosCompleted,
+          })}
+          data-cy="ToggleAllButton"
+          onClick={handleToggleAllButtonClick}
+        />
+      )}
+
+      <form onSubmit={handleSubmit}>
+        <input
+          ref={titleField}
+          data-cy="NewTodoField"
+          type="text"
+          className="todoapp__new-todo"
+          placeholder="What needs to be done?"
+          value={title}
+          onChange={handleTitleChange}
+          autoFocus
+        />
+      </form>
+    </header>
+  );
+};