From 664333d647d34423ecd0947110b18a9eeb7e435c Mon Sep 17 00:00:00 2001
From: Sidach Ruslan <flashangel4600@gmail.com>
Date: Tue, 21 Apr 2026 14:08:05 +0300
Subject: [PATCH] add solution

---
 README.md                            |   2 +-
 src/App.tsx                          | 406 +++++++++++++++++++++++++--
 src/api/todos.ts                     |  21 ++
 src/components/ErrorNotification.tsx |  29 ++
 src/components/Footer.tsx            |  59 ++++
 src/components/Header.tsx            |  59 ++++
 src/components/TodoItem.tsx          | 123 ++++++++
 src/components/TodosList.tsx         |  72 +++++
 src/types/FilterStatus.ts            |   5 +
 src/types/Todo.ts                    |   6 +
 src/types/UserId.ts                  |   1 +
 src/utils/fetchClient.ts             |  46 +++
 12 files changed, 810 insertions(+), 19 deletions(-)
 create mode 100644 src/api/todos.ts
 create mode 100644 src/components/ErrorNotification.tsx
 create mode 100644 src/components/Footer.tsx
 create mode 100644 src/components/Header.tsx
 create mode 100644 src/components/TodoItem.tsx
 create mode 100644 src/components/TodosList.tsx
 create mode 100644 src/types/FilterStatus.ts
 create mode 100644 src/types/Todo.ts
 create mode 100644 src/types/UserId.ts
 create mode 100644 src/utils/fetchClient.ts

diff --git a/README.md b/README.md
index 47a1add059..3ca786f4ea 100644
--- a/README.md
+++ b/README.md
@@ -47,4 +47,4 @@ Implement the ability to edit a todo title on double click:
 
 - Implement a solution following the [React task guideline](https://github.com/mate-academy/react_task-guideline#react-tasks-guideline).
 - Use the [React TypeScript cheat sheet](https://mate-academy.github.io/fe-program/js/extra/react-typescript).
-- Replace `<your_account>` with your Github username in the [DEMO LINK](https://<your_account>.github.io/react_todo-app-with-api/) and add it to the PR description.
+- Replace `<your_account>` with your Github username in the [DEMO LINK](https://RuslanV23.github.io/react_todo-app-with-api/) and add it to the PR description.
diff --git a/src/App.tsx b/src/App.tsx
index 81e011f432..07ce43d6da 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -1,26 +1,396 @@
-/* eslint-disable max-len */
+/* eslint-disable jsx-a11y/label-has-associated-control */
 /* eslint-disable jsx-a11y/control-has-associated-label */
-import React from 'react';
-import { UserWarning } from './UserWarning';
+import React, {
+  useCallback,
+  useEffect,
+  useMemo,
+  useRef,
+  useState,
+} from 'react';
 
-const USER_ID = 0;
+import * as todoService from './api/todos';
+import { Todo } from './types/Todo';
+import { TodosList } from './components/TodosList';
+import { FilterStatus } from './types/FilterStatus';
+import { Footer } from './components/Footer';
+// eslint-disable-next-line max-len
+import { ErrorNotification } from './components/ErrorNotification';
+import { Header } from './components/Header';
+import { USER_ID } from './types/UserId';
 
 export const App: React.FC = () => {
-  if (!USER_ID) {
-    return <UserWarning />;
-  }
+  const [todos, setTodos] = useState<Todo[]>([]);
+  const [filter, setFilter] = useState<FilterStatus>(FilterStatus.All);
+  const [titleInput, setTitleInput] = useState('');
+  const [tempTodo, setTempTodo] = useState<Todo | null>(null);
+  const [error, setError] = useState('');
+
+  const [editTodo, setEditTodo] = useState<Todo | null>(null);
+  const [editTitleInput, setEditTitleInput] = useState('');
+
+  const [isProssesingId, setIsProssesingId] = useState<number[]>([]);
+
+  const [disabledHeaderInput, setDisabledHeaderInput] = useState(false);
+
+  // #region focus
+  const headerInputRef = useRef<HTMLInputElement | null>(null);
+
+  const headerFocus = useCallback(() => {
+    headerInputRef.current?.focus();
+  }, []);
+
+  useEffect(() => {
+    headerFocus();
+  }, [headerFocus]);
+
+  useEffect(() => {
+    if (!disabledHeaderInput) {
+      headerInputRef.current?.focus();
+    }
+  }, [disabledHeaderInput]);
+
+  const timerId = useRef(0);
+
+  const handleSetError = useCallback((newError: string) => {
+    window.clearTimeout(timerId.current);
+
+    timerId.current = window.setTimeout(() => {
+      setError('');
+    }, 3000);
+
+    setError(newError);
+  }, []);
+  // #endregion
+
+  // #region useMemo variable
+  const filteredTodos: Todo[] = useMemo(() => {
+    if (filter === FilterStatus.All) {
+      return todos;
+    }
+
+    return todos.filter(todo =>
+      filter === FilterStatus.Active ? !todo.completed : todo.completed,
+    );
+  }, [todos, filter]);
+
+  const hasCompletedTodo: boolean = useMemo(() => {
+    return todos.some(todo => todo.completed);
+  }, [todos]);
+
+  const hasTodo: boolean = useMemo(() => {
+    return todos.length !== 0;
+  }, [todos]);
+
+  const isEveryCompletedTodo: boolean = useMemo(() => {
+    return todos.every(todo => todo.completed);
+  }, [todos]);
+
+  const itemsLeft: number = useMemo(() => {
+    return todos.filter(todo => !todo.completed).length;
+  }, [todos]);
+
+  // #endregion
+
+  const setProssesingTodo = useCallback(
+    (todoIds: number[], isProsess: boolean) => {
+      if (isProsess) {
+        setIsProssesingId(prev => [...prev, ...todoIds]);
+
+        return;
+      }
+
+      setIsProssesingId(prev => prev.filter(id => !todoIds.includes(id)));
+    },
+    [],
+  );
+
+  const deleteTodo = useCallback(
+    async (todoId: number) => {
+      try {
+        setProssesingTodo([todoId], true);
+        await todoService.deleteTodo(todoId);
+        setTodos(current => current.filter(todo => todo.id !== todoId));
+      } catch {
+        handleSetError('Unable to delete a todo');
+        throw new Error('Unable to delete a todo');
+      } finally {
+        setProssesingTodo([todoId], false);
+        headerFocus();
+      }
+    },
+    [headerFocus, setProssesingTodo, handleSetError],
+  );
+
+  const updateTodo = useCallback(
+    async (todo: Partial<Todo> & Pick<Todo, 'id'>) => {
+      const currentTodo = todos.find(todofind => todofind.id === todo.id);
+
+      if (!currentTodo) {
+        handleSetError('Unable to update a todo');
+
+        return;
+      }
+
+      const isDifferent = (Object.keys(todo) as (keyof Todo)[]).some(
+        todoKey => todo[todoKey] !== currentTodo[todoKey],
+      );
+
+      if (!isDifferent) {
+        return;
+      }
+
+      return todoService.updateTodo(todo);
+    },
+    [todos, handleSetError],
+  );
+
+  const handleToggleCompleleTodo = useCallback(
+    ({ id, completed }: Pick<Todo, 'id' | 'completed'>) => {
+      setProssesingTodo([id], true);
+
+      updateTodo({ id, completed: !completed })
+        .then(updatedTodo => {
+          if (!updatedTodo) {
+            return;
+          }
+
+          setTodos(prevTodos => {
+            const newTodos = [...prevTodos];
+            const index = newTodos.findIndex(
+              todo => todo.id === updatedTodo.id,
+            );
+
+            newTodos.splice(index, 1, updatedTodo);
+
+            return newTodos;
+          });
+        })
+        .catch(() => {
+          handleSetError('Unable to update a todo');
+        })
+        .finally(() => {
+          setProssesingTodo([id], false);
+        });
+    },
+    [setProssesingTodo, updateTodo, handleSetError],
+  );
+
+  const handleEditSubmit = useCallback(
+    ({ title, id }: Todo) => {
+      if (title === editTitleInput) {
+        setEditTodo(null);
+
+        return;
+      }
+
+      const trimmedTitle = editTitleInput.trim();
+
+      if (trimmedTitle.length === 0) {
+        deleteTodo(id);
+
+        return;
+      }
+
+      setEditTitleInput(trimmedTitle);
+      setProssesingTodo([id], true);
+
+      updateTodo({ title: trimmedTitle, id: id })
+        .then(updatedTodo => {
+          if (!updatedTodo) {
+            return;
+          }
+
+          setTodos(prev => {
+            const newTodos = [...prev];
+            const index = newTodos.findIndex(
+              todo => todo.id === updatedTodo.id,
+            );
+
+            newTodos[index].title = trimmedTitle;
+
+            return newTodos;
+          });
+          setEditTodo(null);
+        })
+        .catch(() => {
+          handleSetError('Unable to update a todo');
+        })
+        .finally(() => {
+          setProssesingTodo([id], false);
+        });
+    },
+    [deleteTodo, editTitleInput, setProssesingTodo, updateTodo, handleSetError],
+  );
+
+  const toggleAll = useCallback(async () => {
+    const needToggleTodos = todos.filter(todo =>
+      isEveryCompletedTodo ? true : !todo.completed,
+    );
+
+    const ids = needToggleTodos.map(todo => todo.id);
+
+    setProssesingTodo(ids, true);
+
+    try {
+      const results = await Promise.allSettled(
+        needToggleTodos.map(todo =>
+          updateTodo({ id: todo.id, completed: !isEveryCompletedTodo }),
+        ),
+      );
+
+      const fulfilledTodos = results
+        .filter(
+          (result): result is PromiseFulfilledResult<Todo> =>
+            result.status === 'fulfilled' && result.value !== undefined,
+        )
+        .map(result => result.value);
+
+      if (results.some(result => result.status === 'rejected')) {
+        handleSetError('Unable to update todos');
+      }
+
+      setTodos(prevTodos =>
+        prevTodos.map(todo => {
+          const updatedTodo = fulfilledTodos.find(item => item.id === todo.id);
+
+          return updatedTodo ?? todo;
+        }),
+      );
+    } finally {
+      setProssesingTodo(ids, false);
+    }
+  }, [
+    todos,
+    isEveryCompletedTodo,
+    updateTodo,
+    handleSetError,
+    setProssesingTodo,
+  ]);
+
+  const clearCompletedTodos = useCallback(async () => {
+    try {
+      const idsComplited = todos
+        .filter(todo => todo.completed)
+        .map(todo => todo.id);
+
+      setIsProssesingId((currentIsDeleting: number[]) => [
+        ...currentIsDeleting,
+        ...idsComplited,
+      ]);
+
+      const promiseDeletingTodos = await Promise.allSettled(
+        idsComplited.map(id => todoService.deleteTodo(id)),
+      );
+
+      const succeeded = promiseDeletingTodos
+        .map((r, i) => (r.status === 'fulfilled' ? idsComplited[i] : null))
+        .filter(Boolean) as number[];
+
+      setTodos(prev => prev.filter(t => !succeeded.includes(t.id)));
+
+      if (promiseDeletingTodos.some(r => r.status === 'rejected')) {
+        handleSetError('Unable to delete a todo');
+      }
+
+      setIsProssesingId((currentIsDeleting: number[]) =>
+        currentIsDeleting.filter(id => !idsComplited.includes(id)),
+      );
+
+      headerFocus();
+    } catch {
+      handleSetError('Unable to delete a todo');
+    }
+  }, [todos, headerFocus, handleSetError]);
+
+  const addTodo = useCallback(
+    async (title: string) => {
+      const trimmedTitle = title.trim();
+
+      if (trimmedTitle.length === 0) {
+        handleSetError('Title should not be empty');
+
+        return;
+      }
+
+      setDisabledHeaderInput(true);
+      setTempTodo({
+        title: trimmedTitle,
+        completed: false,
+        userId: USER_ID,
+      } as Todo);
+
+      try {
+        const newTodo = await todoService.createTodo({
+          title: trimmedTitle,
+          completed: false,
+          userId: USER_ID,
+        });
+
+        setTitleInput('');
+        setTodos(currentTodos => [...currentTodos, newTodo]);
+      } catch {
+        handleSetError('Unable to add a todo');
+      } finally {
+        setTempTodo(null);
+        setDisabledHeaderInput(false);
+      }
+    },
+    [handleSetError],
+  );
+
+  useEffect(() => {
+    todoService
+      .getTodos()
+      .then(todo => {
+        window.clearTimeout(timerId.current);
+        setTodos(todo);
+      })
+      .catch(() => {
+        handleSetError('Unable to load todos');
+      });
+  }, [handleSetError]);
 
   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
+          hasTodo={hasTodo}
+          onToggleAll={toggleAll}
+          isEveryCompletedTodo={isEveryCompletedTodo}
+          headerInputRef={headerInputRef}
+          title={titleInput}
+          setTitle={setTitleInput}
+          addTodo={addTodo}
+          disabledInput={disabledHeaderInput}
+        />
+
+        <TodosList
+          editTitleInput={editTitleInput}
+          setEditTitleInput={setEditTitleInput}
+          onEditSubmit={handleEditSubmit}
+          editTodo={editTodo}
+          setEditTodo={setEditTodo}
+          handleToggleCompleleTodo={handleToggleCompleleTodo}
+          todos={filteredTodos}
+          onDelete={deleteTodo}
+          tempTodo={tempTodo}
+          isProssesingId={isProssesingId}
+        />
+
+        {todos.length !== 0 && (
+          <Footer
+            itemsLeft={itemsLeft}
+            setFilter={setFilter}
+            filter={filter}
+            hasCompletedTodo={hasCompletedTodo}
+            onClearCompletedTodos={clearCompletedTodos}
+          />
+        )}
+      </div>
+
+      <ErrorNotification error={error} setError={setError} />
+    </div>
   );
 };
diff --git a/src/api/todos.ts b/src/api/todos.ts
new file mode 100644
index 0000000000..480024ec9e
--- /dev/null
+++ b/src/api/todos.ts
@@ -0,0 +1,21 @@
+import { Todo } from '../types/Todo';
+import { USER_ID } from '../types/UserId';
+import { client } from '../utils/fetchClient';
+
+export const getTodos = () => {
+  return client.get<Todo[]>(`/todos?userId=${USER_ID}`);
+};
+
+export const createTodo = (todo: Omit<Todo, 'id'>) => {
+  return client.post<Todo>(`/todos`, todo);
+};
+
+export const deleteTodo = (todoId: number) => {
+  return client.delete(`/todos/${todoId}`);
+};
+
+export const updateTodo = (todo: Partial<Todo>): Promise<Todo> => {
+  return client.patch(`/todos/${todo.id}`, todo);
+};
+
+// Add more methods here
diff --git a/src/components/ErrorNotification.tsx b/src/components/ErrorNotification.tsx
new file mode 100644
index 0000000000..d87c8e8ca3
--- /dev/null
+++ b/src/components/ErrorNotification.tsx
@@ -0,0 +1,29 @@
+import classNames from 'classnames';
+import React from 'react';
+
+type Props = {
+  error: string;
+  setError: (er: string) => void;
+};
+
+const ErrorNotificationComponent: React.FC<Props> = ({ error, setError }) => {
+  return (
+    <div
+      data-cy="ErrorNotification"
+      className={classNames(
+        'notification is-danger is-light has-text-weight-normal',
+        { hidden: !error },
+      )}
+    >
+      <button
+        data-cy="HideErrorButton"
+        type="button"
+        className="delete"
+        onClick={() => setError('')}
+      />
+      {error}
+    </div>
+  );
+};
+
+export const ErrorNotification = React.memo(ErrorNotificationComponent);
diff --git a/src/components/Footer.tsx b/src/components/Footer.tsx
new file mode 100644
index 0000000000..3b12272d94
--- /dev/null
+++ b/src/components/Footer.tsx
@@ -0,0 +1,59 @@
+import React from 'react';
+import { FilterStatus } from '../types/FilterStatus';
+import classNames from 'classnames';
+
+type Props = {
+  filter: FilterStatus;
+  setFilter: (filter: FilterStatus) => void;
+  hasCompletedTodo: boolean;
+  itemsLeft: number;
+  onClearCompletedTodos: () => Promise<void>;
+};
+
+const FooterComponent: React.FC<Props> = ({
+  itemsLeft,
+  setFilter,
+  filter,
+  hasCompletedTodo,
+  onClearCompletedTodos,
+}) => {
+  return (
+    <footer className="todoapp__footer" data-cy="Footer">
+      <span className="todo-count" data-cy="TodosCounter">
+        {itemsLeft} items left
+      </span>
+
+      <nav className="filter" data-cy="Filter">
+        {Object.values(FilterStatus).map(filterValue => (
+          <a
+            key={filterValue}
+            onClick={() => setFilter(filterValue)}
+            href={
+              filterValue === FilterStatus.All
+                ? '#/'
+                : `#/${filterValue.toLowerCase()}`
+            }
+            className={classNames('filter__link', {
+              selected: filter === filterValue,
+            })}
+            data-cy={`FilterLink${filterValue}`}
+          >
+            {filterValue}
+          </a>
+        ))}
+      </nav>
+
+      <button
+        disabled={!hasCompletedTodo}
+        type="button"
+        className="todoapp__clear-completed"
+        data-cy="ClearCompletedButton"
+        onClick={() => onClearCompletedTodos()}
+      >
+        Clear completed
+      </button>
+    </footer>
+  );
+};
+
+export const Footer = React.memo(FooterComponent);
diff --git a/src/components/Header.tsx b/src/components/Header.tsx
new file mode 100644
index 0000000000..7985f06c61
--- /dev/null
+++ b/src/components/Header.tsx
@@ -0,0 +1,59 @@
+import classNames from 'classnames';
+import React from 'react';
+
+type Props = {
+  hasTodo: boolean;
+  onToggleAll: () => void;
+  isEveryCompletedTodo: boolean;
+  headerInputRef: React.MutableRefObject<HTMLInputElement | null>;
+  title: string;
+  setTitle: (title: string) => void;
+  addTodo: (title: string) => Promise<void>;
+  disabledInput: boolean;
+};
+
+const HeaderComponent: React.FC<Props> = ({
+  hasTodo,
+  onToggleAll,
+  isEveryCompletedTodo,
+  headerInputRef,
+  title,
+  setTitle,
+  addTodo,
+  disabledInput,
+}) => {
+  const handleSubmit = async (event: React.FormEvent<HTMLFormElement>) => {
+    event.preventDefault();
+    addTodo(title);
+  };
+
+  return (
+    <header className="todoapp__header">
+      {hasTodo && (
+        <button
+          type="button"
+          onClick={() => onToggleAll()}
+          className={classNames('todoapp__toggle-all', {
+            active: isEveryCompletedTodo,
+          })}
+          data-cy="ToggleAllButton"
+        />
+      )}
+
+      <form onSubmit={handleSubmit}>
+        <input
+          ref={headerInputRef}
+          data-cy="NewTodoField"
+          type="text"
+          className="todoapp__new-todo"
+          placeholder="What needs to be done?"
+          disabled={disabledInput}
+          value={title}
+          onChange={event => setTitle(event.target.value)}
+        />
+      </form>
+    </header>
+  );
+};
+
+export const Header = React.memo(HeaderComponent);
diff --git a/src/components/TodoItem.tsx b/src/components/TodoItem.tsx
new file mode 100644
index 0000000000..972460cbbc
--- /dev/null
+++ b/src/components/TodoItem.tsx
@@ -0,0 +1,123 @@
+/* eslint-disable jsx-a11y/label-has-associated-control */
+/* eslint-disable jsx-a11y/control-has-associated-label */
+
+import classNames from 'classnames';
+import React, { useEffect, useRef } from 'react';
+import { Todo } from '../types/Todo';
+
+type Props = {
+  todo: Todo;
+  onDelete: (todoid: number) => Promise<void>;
+  handleToggleCompleleTodo: (todo: Pick<Todo, 'id' | 'completed'>) => void;
+  isProssesing: boolean;
+  titleInput: string;
+  setTitleInput: (str: string) => void;
+  editTodo: Todo | null;
+  setEditTodo: (todo: Todo | null) => void;
+  onEditSubmit: (todo: Todo) => void;
+};
+
+const TodoItemComponent: React.FC<Props> = ({
+  todo,
+  onDelete,
+  isProssesing,
+  handleToggleCompleleTodo,
+  titleInput,
+  setTitleInput,
+  editTodo,
+  setEditTodo,
+  onEditSubmit,
+}) => {
+  const inputTitleRef = useRef<HTMLInputElement | null>(null);
+
+  const isEditing = editTodo?.id === todo.id;
+
+  const handleEditSubmit = (event: React.FormEvent<HTMLFormElement>) => {
+    event.preventDefault();
+    onEditSubmit(todo);
+  };
+
+  const handleEditOnBlur = () => {
+    onEditSubmit(todo);
+  };
+
+  useEffect(() => {
+    if (isEditing) {
+      inputTitleRef.current?.focus();
+    }
+  }, [isEditing]);
+
+  return (
+    <div
+      data-cy="Todo"
+      className={classNames('todo', { completed: todo.completed })}
+    >
+      <label className="todo__status-label">
+        <input
+          data-cy="TodoStatus"
+          type="checkbox"
+          className="todo__status"
+          onChange={() => handleToggleCompleleTodo(todo)}
+          checked={todo.completed}
+        />
+      </label>
+
+      {isEditing && !isProssesing ? (
+        <form
+          onKeyUp={event => {
+            if (event.key === 'Escape') {
+              setEditTodo(null);
+              setTitleInput(todo.title);
+            }
+          }}
+          onSubmit={handleEditSubmit}
+        >
+          <input
+            ref={inputTitleRef}
+            data-cy="TodoTitleField"
+            type="text"
+            className="todo__title-field"
+            placeholder="Empty todo will be deleted"
+            value={titleInput}
+            onChange={event => setTitleInput(event.target.value)}
+            onBlur={handleEditOnBlur}
+          />
+        </form>
+      ) : (
+        <>
+          <span
+            data-cy="TodoTitle"
+            className="todo__title"
+            onDoubleClick={() => {
+              setTitleInput(todo.title);
+              setEditTodo(todo);
+            }}
+          >
+            {todo.title}
+          </span>
+
+          <button
+            type="button"
+            className="todo__remove"
+            data-cy="TodoDelete"
+            onClick={() => (!isProssesing ? onDelete(todo.id) : undefined)}
+          >
+            ×
+          </button>
+        </>
+      )}
+
+      <div
+        data-cy="TodoLoader"
+        className={classNames('modal overlay', {
+          'is-active': isProssesing,
+        })}
+      >
+        <div className="modal-background has-background-white-ter" />
+        <div className="loader" />
+      </div>
+    </div>
+  );
+};
+
+export const TodoItem = React.memo(TodoItemComponent);
diff --git a/src/components/TodosList.tsx b/src/components/TodosList.tsx
new file mode 100644
index 0000000000..71733d1102
--- /dev/null
+++ b/src/components/TodosList.tsx
@@ -0,0 +1,72 @@
+/* eslint-disable jsx-a11y/label-has-associated-control */
+/* eslint-disable jsx-a11y/control-has-associated-label */
+
+import React from 'react';
+
+import { Todo as TypeTodo } from '../types/Todo';
+import { TodoItem } from './TodoItem';
+
+type Props = {
+  todos: TypeTodo[];
+  onDelete: (todoid: number) => Promise<void>;
+  tempTodo: TypeTodo | null;
+  isProssesingId: number[];
+  handleToggleCompleleTodo: (todo: Pick<TypeTodo, 'id' | 'completed'>) => void;
+  editTitleInput: string;
+  setEditTitleInput: (str: string) => void;
+  editTodo: TypeTodo | null;
+  setEditTodo: (todo: TypeTodo | null) => void;
+  onEditSubmit: (todo: TypeTodo) => void;
+};
+
+const TodosListComponent: React.FC<Props> = ({
+  todos,
+  onDelete,
+  tempTodo,
+  isProssesingId,
+  handleToggleCompleleTodo,
+  editTitleInput,
+  setEditTitleInput,
+  editTodo,
+  setEditTodo,
+  onEditSubmit,
+}) => {
+  return (
+    <section className="todoapp__main" data-cy="TodoList">
+      {todos.map(todo => {
+        const isProssesing = isProssesingId.includes(todo.id);
+
+        return (
+          <TodoItem
+            todo={todo}
+            key={todo.id}
+            onDelete={onDelete}
+            handleToggleCompleleTodo={handleToggleCompleleTodo}
+            isProssesing={isProssesing}
+            titleInput={editTitleInput}
+            setTitleInput={setEditTitleInput}
+            editTodo={editTodo}
+            setEditTodo={setEditTodo}
+            onEditSubmit={onEditSubmit}
+          />
+        );
+      })}
+
+      {tempTodo && (
+        <TodoItem
+          todo={tempTodo}
+          isProssesing={true}
+          onDelete={onDelete}
+          handleToggleCompleleTodo={handleToggleCompleleTodo}
+          titleInput={editTitleInput}
+          setTitleInput={setEditTitleInput}
+          editTodo={editTodo}
+          setEditTodo={setEditTodo}
+          onEditSubmit={onEditSubmit}
+        />
+      )}
+    </section>
+  );
+};
+
+export const TodosList = React.memo(TodosListComponent);
diff --git a/src/types/FilterStatus.ts b/src/types/FilterStatus.ts
new file mode 100644
index 0000000000..7ca17f289b
--- /dev/null
+++ b/src/types/FilterStatus.ts
@@ -0,0 +1,5 @@
+export enum FilterStatus {
+  All = 'All',
+  Active = 'Active',
+  Completed = 'Completed',
+}
diff --git a/src/types/Todo.ts b/src/types/Todo.ts
new file mode 100644
index 0000000000..3f52a5fdde
--- /dev/null
+++ b/src/types/Todo.ts
@@ -0,0 +1,6 @@
+export interface Todo {
+  id: number;
+  userId: number;
+  title: string;
+  completed: boolean;
+}
diff --git a/src/types/UserId.ts b/src/types/UserId.ts
new file mode 100644
index 0000000000..e9af16120f
--- /dev/null
+++ b/src/types/UserId.ts
@@ -0,0 +1 @@
+export const USER_ID = 4140;
diff --git a/src/utils/fetchClient.ts b/src/utils/fetchClient.ts
new file mode 100644
index 0000000000..28c946e7f6
--- /dev/null
+++ b/src/utils/fetchClient.ts
@@ -0,0 +1,46 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+const BASE_URL = 'https://mate.academy/students-api';
+
+// returns a promise resolved after a given delay
+function wait(delay: number) {
+  return new Promise(resolve => {
+    setTimeout(resolve, delay);
+  });
+}
+
+// To have autocompletion and avoid mistypes
+type RequestMethod = 'GET' | 'POST' | 'PATCH' | 'DELETE';
+
+function request<T>(
+  url: string,
+  method: RequestMethod = 'GET',
+  data: any = null, // we can send any data to the server
+): Promise<T> {
+  const options: RequestInit = { method };
+
+  if (data) {
+    // We add body and Content-Type only for the requests with data
+    options.body = JSON.stringify(data);
+    options.headers = {
+      'Content-Type': 'application/json; charset=UTF-8',
+    };
+  }
+
+  // DON'T change the delay it is required for tests
+  return wait(100)
+    .then(() => fetch(BASE_URL + url, options))
+    .then(response => {
+      if (!response.ok) {
+        throw new Error(`${response.status} ${response.statusText}`);
+      }
+
+      return response.json();
+    });
+}
+
+export const client = {
+  get: <T>(url: string) => request<T>(url),
+  post: <T>(url: string, data: any) => request<T>(url, 'POST', data),
+  patch: <T>(url: string, data: any) => request<T>(url, 'PATCH', data),
+  delete: (url: string) => request(url, 'DELETE'),
+};