const express = require('express');
const cors = require('cors');
const bodyParser = require('body-parser');
const sqlite3 = require('sqlite3').verbose();

const app = express();
app.use(cors());
app.use(bodyParser.json());

const PORT = 4000;
const ADMIN_LOGIN = 'admin';
const ADMIN_PASSWORD = 'admin123';

const db = new sqlite3.Database('./donations.db', (err) => {
  if (err) {
    console.error('Błąd otwarcia bazy danych', err);
  } else {
    console.log('Połączono z bazą SQLite.');
  }
});

// Tworzenie tabel: campaigns oraz donations
db.serialize(() => {
  db.run(`
    CREATE TABLE IF NOT EXISTS campaigns (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      title TEXT NOT NULL,
      description TEXT NOT NULL,
      target REAL NOT NULL
    )
  `);

  db.run(`
    CREATE TABLE IF NOT EXISTS donations (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      campaign_id INTEGER NOT NULL,
      amount REAL NOT NULL,
      description TEXT NOT NULL,
      date TEXT NOT NULL,
      FOREIGN KEY (campaign_id) REFERENCES campaigns(id)
    )
  `);
});

// -----------------------
// Endpointy publiczne
// -----------------------

// Lista wszystkich kampanii
app.get('/api/campaigns', (req, res) => {
  db.all("SELECT * FROM campaigns", (err, rows) => {
    if (err) return res.status(500).json({ error: 'Błąd bazy danych' });
    res.json(rows);
  });
});

// Pobranie szczegółów kampanii (razem z sumą wpłat)
app.get('/api/campaigns/:id', (req, res) => {
  const campaignId = req.params.id;
  db.get("SELECT * FROM campaigns WHERE id = ?", [campaignId], (err, campaign) => {
    if (err) return res.status(500).json({ error: 'Błąd bazy danych' });
    if (!campaign) return res.status(404).json({ error: 'Kampania nie znaleziona' });
    
    db.get(
      "SELECT SUM(amount) as totalDonations FROM donations WHERE campaign_id = ?",
      [campaignId],
      (err, row) => {
        if (err) return res.status(500).json({ error: 'Błąd bazy danych' });
        const totalDonations = row.totalDonations || 0;
        res.json({ ...campaign, totalDonations });
      }
    );
  });
});

// Lista wpłat dla kampanii
app.get('/api/campaigns/:id/donations', (req, res) => {
  const campaignId = req.params.id;
  db.all("SELECT * FROM donations WHERE campaign_id = ? ORDER BY date DESC", [campaignId], (err, rows) => {
    if (err) return res.status(500).json({ error: 'Błąd bazy danych' });
    res.json(rows);
  });
});

// -----------------------
// Endpointy chronione – panel administratora
// -----------------------

// Logowanie – bardzo uproszczone
app.post('/api/login', (req, res) => {
  const { login, password } = req.body;
  if (login === ADMIN_LOGIN && password === ADMIN_PASSWORD) {
    res.json({ token: 'admin-session-token-abc123' });
  } else {
    res.status(401).json({ error: 'Błędne dane logowania' });
  }
});

// Tworzenie nowej kampanii (admin)
app.post('/api/campaigns', (req, res) => {
  const { title, description, target, token } = req.body;
  if (!token) return res.status(401).json({ error: 'Brak uprawnień' });
  const stmt = db.prepare("INSERT INTO campaigns (title, description, target) VALUES (?, ?, ?)");
  stmt.run(title, description, target, function(err) {
    if (err) return res.status(500).json({ error: 'Błąd bazy danych' });
    const newCampaign = { id: this.lastID, title, description, target };
    res.status(201).json(newCampaign);
  });
  stmt.finalize();
});

// Aktualizacja celu kampanii (admin)
app.post('/api/campaigns/:id/target', (req, res) => {
  const campaignId = req.params.id;
  const { newTarget, token } = req.body;
  if (!token) return res.status(401).json({ error: 'Brak uprawnień' });
  db.run("UPDATE campaigns SET target = ? WHERE id = ?", [newTarget, campaignId], function(err) {
    if (err) return res.status(500).json({ error: 'Błąd bazy danych' });
    res.json({ target: newTarget });
  });
});

// Dodawanie wpłaty do kampanii (admin)
app.post('/api/campaigns/:id/donations', (req, res) => {
  const campaignId = req.params.id;
  const { amount, description, token } = req.body;
  if (!token) return res.status(401).json({ error: 'Brak uprawnień' });
  const date = new Date().toISOString();
  const stmt = db.prepare("INSERT INTO donations (campaign_id, amount, description, date) VALUES (?, ?, ?, ?)");
  stmt.run(campaignId, amount, description, date, function(err) {
    if (err) return res.status(500).json({ error: 'Błąd bazy danych' });
    const newDonation = { id: this.lastID, campaign_id: campaignId, amount, description, date };
    res.status(201).json(newDonation);
  });
  stmt.finalize();
});

app.listen(PORT, () => {
  console.log(`Server działa na porcie ${PORT}`);
});