Solution

src/App.tsx

@@ -1,26 +1,252 @@
-/* eslint-disable max-len */
 /* eslint-disable jsx-a11y/control-has-associated-label */
-import React from 'react';
+import React, { useState, useEffect, useRef } from 'react';
 import { UserWarning } from './UserWarning';
-
-const USER_ID = 0;
+import {
+  USER_ID,
+  getTodos,
+  addTodo,
+  deleteTodo,
+  updateTodo,
+} from './api/todos';
+import { Todo } from './types/Todo';
+import { Status } from './types/Status';
+import { ErrorMessage } from './types/ErrorMessage';
+import { TodoList } from './components/TodoList';
+import { Header } from './components/Header';
+import { Footer } from './components/Footer';
+import { ErrorNotification } from './components/ErrorNotification';
 
 export const App: React.FC = () => {
+  const [todos, setTodos] = useState<Todo[]>([]);
+  const [filter, setFilter] = useState<Status>(Status.All);
+  const [errorMessage, setErrorMessage] = useState('');
+
+  const [title, setTitle] = useState('');
+  const [tempTodo, setTempTodo] = useState<Todo | null>(null);
+  const [processingIds, setProcessingIds] = useState<number[]>([]);
+
+  const titleField = useRef<HTMLInputElement>(null);
+
+  const showError = (message: string) => {
+    setErrorMessage(message);
+    setTimeout(() => {
+      setErrorMessage('');
+    }, 3000);
+  };
+
+  useEffect(() => {
+    if (!USER_ID) {
+      return;
+    }
+
+    getTodos()
+      .then(setTodos)
+      .catch(() => showError(ErrorMessage.Load));
+  }, []);
+
+  useEffect(() => {
+    if (titleField.current) {
+      titleField.current.focus();
+    }
+  }, [todos.length]);
+
+  const handleAddTodo = (e: React.FormEvent) => {
+    e.preventDefault();
+    const normalizedTitle = title.trim();
+
+    if (!normalizedTitle) {
+      showError(ErrorMessage.EmptyTitle);
+
+      return;
+    }
+
+    setTempTodo({
+      id: 0,
+      title: normalizedTitle,
+      completed: false,
+      userId: USER_ID,
+    });
+
+    addTodo(normalizedTitle)
+      .then(newTodo => {
+        setTodos(currentTodos => [...currentTodos, newTodo]);
+        setTitle('');
+      })
+      .catch(() => {
+        showError(ErrorMessage.Add);
+      })
+      .finally(() => {
+        setTempTodo(null);
+        setTimeout(() => {
+          titleField.current?.focus();
+        }, 0);
+      });
+  };
+
+  const handleUpdateTodo = (todoId: number, data: Partial<Todo>) => {
+    setProcessingIds(current => [...current, todoId]);
+
+    return updateTodo(todoId, data)
+      .then(updatedTodo => {
+        setTodos(current =>
+          current.map(todo => (todo.id === todoId ? updatedTodo : todo)),
+        );
+      })
+      .catch(() => {
+        showError(ErrorMessage.Update);
+        throw new Error('Update failed');
+      })
+      .finally(() => {
+        setProcessingIds(current => current.filter(id => id !== todoId));
+      });
+  };
+
+  const handleToggleAll = () => {
+    const activeTodosCount = todos.filter(todo => !todo.completed).length;
+    const shouldComplete = activeTodosCount > 0;
+
+    const todosToUpdate = todos.filter(
+      todo => todo.completed !== shouldComplete,
+    );
+    const idsToUpdate = todosToUpdate.map(todo => todo.id);
+
+    setProcessingIds(current => [...current, ...idsToUpdate]);
+
+    Promise.all(
+      todosToUpdate.map(todo =>
+        updateTodo(todo.id, { completed: shouldComplete })
+          .then(updatedTodo => updatedTodo)
+          .catch(() => {
+            showError(ErrorMessage.Update);
+
+            return null;
+          }),
+      ),
+    )
+      .then(results => {
+        const successfulUpdates = results.filter((r): r is Todo => r !== null);
+
+        setTodos(current =>
+          current.map(todo => {
+            const updated = successfulUpdates.find(u => u.id === todo.id);
+
+            return updated || todo;
+          }),
+        );
+      })
+      .finally(() => {
+        setProcessingIds(current =>
+          current.filter(id => !idsToUpdate.includes(id)),
+        );
+      });
+  };
+
+  const handleDeleteTodo = (todoId: number) => {
+    setProcessingIds(current => [...current, todoId]);
+
+    deleteTodo(todoId)
+      .then(() => {
+        setTodos(current => current.filter(todo => todo.id !== todoId));
+      })
+      .catch(() => {
+        showError(ErrorMessage.Delete);
+      })
+      .finally(() => {
+        setProcessingIds(current => current.filter(id => id !== todoId));
+      });
+  };
+
+  const handleClearCompleted = () => {
+    const completedTodos = todos.filter(todo => todo.completed);
+    const idsToDelete = completedTodos.map(todo => todo.id);
+
+    setProcessingIds(current => [...current, ...idsToDelete]);
+
+    Promise.all(
+      completedTodos.map(todo =>
+        deleteTodo(todo.id)
+          .then(() => todo.id)
+          .catch(() => {
+            showError(ErrorMessage.Delete);
+
+            return null;
+          }),
+      ),
+    )
+      .then(results => {
+        const successfulIds = results.filter(id => id !== null);
+
+        setTodos(current =>
+          current.filter(todo => !successfulIds.includes(todo.id)),
+        );
+      })
+      .finally(() => {
+        setProcessingIds(current =>
+          current.filter(id => !idsToDelete.includes(id)),
+        );
+      });
+  };
+
+  const visibleTodos = todos.filter(todo => {
+    switch (filter) {
+      case Status.Active:
+        return !todo.completed;
+      case Status.Completed:
+        return todo.completed;
+      case Status.All:
+      default:
+        return true;
+    }
+  });
+
+  const activeTodosCount = todos.filter(todo => !todo.completed).length;
+  const hasCompletedTodos = todos.some(todo => todo.completed);
+
   if (!USER_ID) {
     return <UserWarning />;
   }
 
   return (
-    <section className="section container">
-      <p className="title is-4">
-        Copy all you need from the prev task:
-        <br />
-        <a href="https://github.com/mate-academy/react_todo-app-add-and-delete#react-todo-app-add-and-delete">
-          React Todo App - Add and Delete
-        </a>
-      </p>
-
-      <p className="subtitle">Styles are already copied</p>
-    </section>
+    <div className="todoapp">
+      <h1 className="todoapp__title">todos</h1>
+
+      <div className="todoapp__content">
+        <Header
+          title={title}
+          setTitle={setTitle}
+          onAddTodo={handleAddTodo}
+          activeTodosCount={activeTodosCount}
+          todosLength={todos.length}
+          tempTodo={tempTodo}
+          titleField={titleField}
+          onToggleAll={handleToggleAll}
+        />
+
+        {(todos.length > 0 || tempTodo !== null) && (
+          <TodoList
+            todos={visibleTodos}
+            tempTodo={tempTodo}
+            processingIds={processingIds}
+            onDelete={handleDeleteTodo}
+            onUpdate={handleUpdateTodo}
+          />
+        )}
+
+        {todos.length > 0 && (
+          <Footer
+            activeTodosCount={activeTodosCount}
+            filter={filter}
+            onFilterChange={setFilter}
+            hasCompletedTodos={hasCompletedTodos}
+            onClearCompleted={handleClearCompleted}
+          />
+        )}
+      </div>
+
+      <ErrorNotification
+        errorMessage={errorMessage}
+        onClose={() => setErrorMessage('')}
+      />
+    </div>
   );
 };

src/api/todos.ts

@@ -0,0 +1,24 @@
+import { Todo } from '../types/Todo';
+import { client } from '../utils/fetchClient';
+
+export const USER_ID = 4213;
+
+export const getTodos = () => {
+  return client.get<Todo[]>(`/todos?userId=${USER_ID}`);
+};
+
+export const addTodo = (title: string) => {
+  return client.post<Todo>('/todos', {
+    title,
+    completed: false,
+    userId: USER_ID,
+  });
+};
+
+export const deleteTodo = (todoId: number) => {
+  return client.delete(`/todos/${todoId}`);
+};
+
+export const updateTodo = (todoId: number, data: Partial<Todo>) => {
+  return client.patch<Todo>(`/todos/${todoId}`, data);
+};

src/components/ErrorNotification.tsx

@@ -0,0 +1,32 @@
+import React from 'react';
+import classNames from 'classnames';
+
+type Props = {
+  errorMessage: string;
+  onClose: () => void;
+};
+
+export const ErrorNotification: React.FC<Props> = ({
+  errorMessage,
+  onClose,
+}) => {
+  return (
+    <div
+      data-cy="ErrorNotification"
+      className={classNames(
+        'notification is-danger is-light has-text-weight-normal',
+        {
+          hidden: !errorMessage,
+        },
+      )}
+    >
+      <button
+        data-cy="HideErrorButton"
+        type="button"
+        className="delete"
+        onClick={onClose}
+      />
+      {errorMessage}
+    </div>
+  );
+};

src/components/Filter.tsx

@@ -0,0 +1,28 @@
+import React from 'react';
+import classNames from 'classnames';
+import { Status } from '../types/Status';
+
+type Props = {
+  filter: Status;
+  onFilterChange: (status: Status) => void;
+};
+
+export const Filter: React.FC<Props> = ({ filter, onFilterChange }) => {
+  return (
+    <nav className="filter" data-cy="Filter">
+      {Object.values(Status).map(statusValue => (
+        <a
+          key={statusValue}
+          href={`#/${statusValue === Status.All ? '' : statusValue}`}
+          className={classNames('filter__link', {
+            selected: filter === statusValue,
+          })}
+          data-cy={`FilterLink${statusValue.charAt(0).toUpperCase() + statusValue.slice(1)}`}
+          onClick={() => onFilterChange(statusValue)}
+        >
+          {statusValue.charAt(0).toUpperCase() + statusValue.slice(1)}
+        </a>
+      ))}
+    </nav>
+  );
+};

src/components/Footer.tsx

@@ -0,0 +1,39 @@
+import React from 'react';
+import { Filter } from './Filter';
+import { Status } from '../types/Status';
+
+type Props = {
+  activeTodosCount: number;
+  filter: Status;
+  onFilterChange: (status: Status) => void;
+  hasCompletedTodos: boolean;
+  onClearCompleted: () => void;
+};
+
+export const Footer: React.FC<Props> = ({
+  activeTodosCount,
+  filter,
+  onFilterChange,
+  hasCompletedTodos,
+  onClearCompleted,
+}) => {
+  return (
+    <footer className="todoapp__footer" data-cy="Footer">
+      <span className="todo-count" data-cy="TodosCounter">
+        {activeTodosCount} items left
+      </span>
+
+      <Filter filter={filter} onFilterChange={onFilterChange} />
+
+      <button
+        type="button"
+        className="todoapp__clear-completed"
+        data-cy="ClearCompletedButton"
+        disabled={!hasCompletedTodos}
+        onClick={onClearCompleted}
+      >
+        Clear completed
+      </button>
+    </footer>
+  );
+};