const express = require('express');
const cors    = require('cors');
const helmet  = require('helmet');
const path    = require('path');
const fs      = require('fs');
const { runMigrations } = require('./db/migrations');
const { initDatabase } = require('./db/init');
const { logStartupBanner } = require('./utils/startupLog');

const app  = express();
const PORT = process.env.PORT || 3000;

// Ensure required directories exist
const UPLOAD_PATH = process.env.UPLOAD_PATH || path.join(__dirname, '../uploads');
const STATIC_PATH = process.env.STATIC_PATH || path.join(__dirname, '../static');
const DATA_DIR    = process.env.DATA_DIR    || path.join(__dirname, '../data');

[DATA_DIR, UPLOAD_PATH, STATIC_PATH].forEach(dir => {
  if (!fs.existsSync(dir)) fs.mkdirSync(dir, { recursive: true });
});

// Run migrations BEFORE initializing the DB connection used by routes
const DB_PATH = process.env.DB_PATH || path.join(__dirname, '../data/breedr.db');
console.log('Running database migrations...');
try {
  runMigrations(DB_PATH);
} catch (err) {
  console.error('Migration failed — aborting startup:', err.message);
  process.exit(1);
}

// Init DB (path is managed internally by db/init.js)
console.log('Initializing database...');
initDatabase();
const dbStatus = '✓ Connected';
console.log('✓ Database ready!\n');

// ── Middleware ─────────────────────────────────────────────────────────
app.use(helmet({ contentSecurityPolicy: false }));
app.use(cors());
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

// ── Static file serving ──────────────────────────────────────────────
app.use('/uploads', express.static(UPLOAD_PATH));
app.use('/static',  express.static(STATIC_PATH));
app.use('/uploads', (_req, res) => res.status(404).json({ error: 'Upload not found' }));
app.use('/static',  (_req, res) => res.status(404).json({ error: 'Static asset not found' }));

// ── API Routes ──────────────────────────────────────────────────────────
app.use('/api/dogs',    require('./routes/dogs'));
app.use('/api/litters',  require('./routes/litters'));
app.use('/api/health',   require('./routes/health'));
app.use('/api/genetics', require('./routes/genetics'));
app.use('/api/pedigree', require('./routes/pedigree'));
app.use('/api/breeding', require('./routes/breeding'));
app.use('/api/settings', require('./routes/settings'));

// ── Production SPA fallback ────────────────────────────────────────────────
if (process.env.NODE_ENV === 'production') {
  const clientBuild = path.join(__dirname, '../client/dist');
  app.use(express.static(clientBuild));
  app.get(/^(?!\/(?:api|static|uploads)\/).*$/, (_req, res) => {
    res.sendFile(path.join(clientBuild, 'index.html'));
  });
}

// ── Global error handler ──────────────────────────────────────────────────
app.use((err, _req, res, _next) => {
  console.error('Error:', err);
  res.status(err.status || 500).json({
    error: err.message || 'Internal server error',
    ...(process.env.NODE_ENV === 'development' && { stack: err.stack })
  });
});

app.listen(PORT, '0.0.0.0', () => {
  logStartupBanner({
    appName: 'BREEDR',
    port: PORT,
    environment: process.env.NODE_ENV || 'development',
    dataDir: DATA_DIR,
    uploadPath: UPLOAD_PATH,
    staticPath: STATIC_PATH,
    dbStatus: dbStatus
  });
});

module.exports = app;