Що таке REST API · fullstack.org.ua

fullstack.org.ua

Що таке REST API · fullstack.org.ua

javascript

const http = require('node:http');
const { URL } = require('node:url');

let tasks = [
  { id: 1, title: 'Вивчити REST', completed: false },
  { id: 2, title: 'Створити API', completed: false }
];

let nextId = 3;

function sendJson(response, statusCode, data) {
  response.writeHead(statusCode, {
    'Content-Type': 'application/json; charset=utf-8'
  });

  response.end(data === undefined ? '' : JSON.stringify(data));
}

function readJsonBody(request) {
  return new Promise((resolve, reject) => {
    let body = '';

    request.on('data', (chunk) => {
      body += chunk;
    });

    request.on('end', () => {
      if (body.trim() === '') {
        resolve({});
        return;
      }

      try {
        resolve(JSON.parse(body));
      } catch {
        reject(new Error('Некоректний JSON'));
      }
    });

    request.on('error', reject);
  });
}

const server = http.createServer(async (request, response) => {
  const requestUrl = new URL(
    request.url,
    `http://${request.headers.host}`
  );

  const pathParts = requestUrl.pathname.split('/').filter(Boolean);
  const isTasksRoute = pathParts[0] === 'tasks';
  const taskId = pathParts.length === 2 ? Number(pathParts[1]) : null;

  if (!isTasksRoute || (pathParts.length === 2 && !Number.isInteger(taskId))) {
    sendJson(response, 404, { error: 'Маршрут не знайдено' });
    return;
  }

  if (request.method === 'GET' && pathParts.length === 1) {
    sendJson(response, 200, tasks);
    return;
  }

  if (request.method === 'GET' && pathParts.length === 2) {
    const task = tasks.find((item) => item.id === taskId);

    if (!task) {
      sendJson(response, 404, { error: 'Завдання не знайдено' });
      return;
    }

    sendJson(response, 200, task);
    return;
  }

  if (request.method === 'POST' && pathParts.length === 1) {
    try {
      const data = await readJsonBody(request);

      if (typeof data.title !== 'string' || data.title.trim() === '') {
        sendJson(response, 400, {
          error: 'Поле title має бути непорожнім рядком'
        });
        return;
      }

      const task = {
        id: nextId++,
        title: data.title.trim(),
        completed: Boolean(data.completed)
      };

      tasks.push(task);
      sendJson(response, 201, task);
    } catch (error) {
      sendJson(response, 400, { error: error.message });
    }

    return;
  }

  if (request.method === 'PUT' && pathParts.length === 2) {
    const taskIndex = tasks.findIndex((item) => item.id === taskId);

    if (taskIndex === -1) {
      sendJson(response, 404, { error: 'Завдання не знайдено' });
      return;
    }

    try {
      const data = await readJsonBody(request);

      if (typeof data.title !== 'string' || data.title.trim() === '') {
        sendJson(response, 400, {
          error: 'Поле title має бути непорожнім рядком'
        });
        return;
      }

      tasks[taskIndex] = {
        id: taskId,
        title: data.title.trim(),
        completed: Boolean(data.completed)
      };

      sendJson(response, 200, tasks[taskIndex]);
    } catch (error) {
      sendJson(response, 400, { error: error.message });
    }

    return;
  }

  if (request.method === 'DELETE' && pathParts.length === 2) {
    const taskIndex = tasks.findIndex((item) => item.id === taskId);

    if (taskIndex === -1) {
      sendJson(response, 404, { error: 'Завдання не знайдено' });
      return;
    }

    tasks.splice(taskIndex, 1);
    sendJson(response, 204);
    return;
  }

  sendJson(response, 405, { error: 'Метод не підтримується' });
});

server.listen(3000, () => {
  console.log('REST API запущено на http://localhost:3000');
});