const express      = require('express');
const cors         = require('cors');
const path         = require('path');
const db           = require('./db/database');
const generatePdf  = require('./pdf/generator');

const app  = express();
const PORT = process.env.PORT || 3001;

app.use(cors());
app.use(express.json());
app.use(express.static(path.join(__dirname, 'client', 'dist')));

// Health
app.get('/api/health', (req, res) => res.json({ status: 'ok', timestamp: new Date().toISOString() }));

// Employees
app.get('/api/employees', (req, res) => {
  const rows = db.prepare('SELECT id, name, department, supervisor FROM employees ORDER BY name ASC').all();
  res.json(rows);
});

app.post('/api/employees', (req, res) => {
  const { name, department, supervisor } = req.body;
  if (!name) return res.status(400).json({ error: 'name is required' });
  const existing = db.prepare('SELECT * FROM employees WHERE LOWER(name) = LOWER(?)').get(name);
  if (existing) {
    if (department || supervisor) {
      db.prepare('UPDATE employees SET department = COALESCE(?, department), supervisor = COALESCE(?, supervisor) WHERE id = ?')
        .run(department || null, supervisor || null, existing.id);
    }
    return res.json({ ...existing, department, supervisor });
  }
  const result = db.prepare('INSERT INTO employees (name, department, supervisor) VALUES (?, ?, ?)')
    .run(name, department || null, supervisor || null);
  res.status(201).json({ id: result.lastInsertRowid, name, department, supervisor });
});

// Employee score (current snapshot)
app.get('/api/employees/:id/score', (req, res) => {
  const row = db.prepare('SELECT * FROM active_cpas_scores WHERE employee_id = ?').get(req.params.id);
  res.json(row || { employee_id: req.params.id, active_points: 0, violation_count: 0 });
});

// Dashboard
app.get('/api/dashboard', (req, res) => {
  const rows = db.prepare(`
    SELECT e.id, e.name, e.department, e.supervisor,
           COALESCE(s.active_points, 0)  AS active_points,
           COALESCE(s.violation_count,0) AS violation_count
    FROM employees e
    LEFT JOIN active_cpas_scores s ON s.employee_id = e.id
    ORDER BY active_points DESC, e.name ASC
  `).all();
  res.json(rows);
});

// Violation history (per employee) with resolutions
app.get('/api/violations/employee/:id', (req, res) => {
  const limit = parseInt(req.query.limit) || 50;
  const rows  = db.prepare(`
    SELECT v.*, r.resolution_type, r.details AS resolution_details,
           r.resolved_by, r.created_at AS resolved_at
    FROM violations v
    LEFT JOIN violation_resolutions r ON r.violation_id = v.id
    WHERE v.employee_id = ?
    ORDER BY v.incident_date DESC, v.created_at DESC
    LIMIT ?
  `).all(req.params.id, limit);
  res.json(rows);
});

// Helper: compute prior_active_points at time of insert
function getPriorActivePoints(employeeId, incidentDate) {
  const row = db.prepare(
    `SELECT COALESCE(SUM(points),0) AS pts
     FROM violations
     WHERE employee_id = ?
       AND negated = 0
       AND incident_date >= DATE(?, '-90 days')
       AND incident_date < ?`
  ).get(employeeId, incidentDate, incidentDate);
  return row ? row.pts : 0;
}

// POST new violation
app.post('/api/violations', (req, res) => {
  const {
    employee_id, violation_type, violation_name, category,
    points, incident_date, incident_time, location,
    details, submitted_by, witness_name
  } = req.body;

  if (!employee_id || !violation_type || !points || !incident_date) {
    return res.status(400).json({ error: 'Missing required fields' });
  }

  const ptsInt   = parseInt(points);
  const priorPts = getPriorActivePoints(employee_id, incident_date);

  const result = db.prepare(`
    INSERT INTO violations (
      employee_id, violation_type, violation_name, category,
      points, incident_date, incident_time, location,
      details, submitted_by, witness_name,
      prior_active_points
    ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
  `).run(
    employee_id, violation_type, violation_name || violation_type,
    category || 'General', ptsInt, incident_date,
    incident_time || null, location || null,
    details || null, submitted_by || null, witness_name || null,
    priorPts
  );

  res.status(201).json({ id: result.lastInsertRowid });
});

// ── Negate a violation ──────────────────────────────────────────────────────
app.patch('/api/violations/:id/negate', (req, res) => {
  const { resolution_type, details, resolved_by } = req.body;
  const id = req.params.id;

  const violation = db.prepare('SELECT * FROM violations WHERE id = ?').get(id);
  if (!violation) return res.status(404).json({ error: 'Violation not found' });

  // Mark negated
  db.prepare('UPDATE violations SET negated = 1 WHERE id = ?').run(id);

  // Upsert resolution record
  const existing = db.prepare('SELECT id FROM violation_resolutions WHERE violation_id = ?').get(id);
  if (existing) {
    db.prepare(`
      UPDATE violation_resolutions
      SET resolution_type = ?, details = ?, resolved_by = ?, created_at = datetime('now')
      WHERE violation_id = ?
    `).run(resolution_type || 'Resolved', details || null, resolved_by || null, id);
  } else {
    db.prepare(`
      INSERT INTO violation_resolutions (violation_id, resolution_type, details, resolved_by)
      VALUES (?, ?, ?, ?)
    `).run(id, resolution_type || 'Resolved', details || null, resolved_by || null);
  }

  res.json({ success: true });
});

// ── Restore a negated violation ─────────────────────────────────────────────
app.patch('/api/violations/:id/restore', (req, res) => {
  const id = req.params.id;

  const violation = db.prepare('SELECT * FROM violations WHERE id = ?').get(id);
  if (!violation) return res.status(404).json({ error: 'Violation not found' });

  db.prepare('UPDATE violations SET negated = 0 WHERE id = ?').run(id);
  db.prepare('DELETE FROM violation_resolutions WHERE violation_id = ?').run(id);

  res.json({ success: true });
});

// ── Hard delete a violation ─────────────────────────────────────────────────
app.delete('/api/violations/:id', (req, res) => {
  const id = req.params.id;

  const violation = db.prepare('SELECT * FROM violations WHERE id = ?').get(id);
  if (!violation) return res.status(404).json({ error: 'Violation not found' });

  // Delete resolution first (FK safety)
  db.prepare('DELETE FROM violation_resolutions WHERE violation_id = ?').run(id);
  db.prepare('DELETE FROM violations WHERE id = ?').run(id);

  res.json({ success: true });
});

// ── PDF endpoint ─────────────────────────────────────────────────────────────
app.get('/api/violations/:id/pdf', async (req, res) => {
  try {
    const violation = db.prepare(`
      SELECT v.*, e.name as employee_name, e.department, e.supervisor
      FROM violations v
      JOIN employees e ON e.id = v.employee_id
      WHERE v.id = ?
    `).get(req.params.id);

    if (!violation) return res.status(404).json({ error: 'Violation not found' });

    const active = db.prepare('SELECT * FROM active_cpas_scores WHERE employee_id = ?')
      .get(violation.employee_id) || { active_points: 0, violation_count: 0 };

    const scoreForPdf = {
      employee_id:     violation.employee_id,
      active_points:   violation.prior_active_points != null ? violation.prior_active_points : active.active_points,
      violation_count: active.violation_count,
    };

    const pdfBuffer = await generatePdf(violation, scoreForPdf);
    const safeName  = violation.employee_name.replace(/[^a-z0-9]/gi, '_');

    res.set({
      'Content-Type':        'application/pdf',
      'Content-Disposition': `attachment; filename="CPAS_${safeName}_${violation.incident_date}.pdf"`,
      'Content-Length':      pdfBuffer.length,
    });
    res.end(pdfBuffer);
  } catch (err) {
    console.error('[PDF]', err);
    res.status(500).json({ error: 'PDF generation failed', detail: err.message });
  }
});

// SPA fallback
app.get('*', (req, res) => res.sendFile(path.join(__dirname, 'client', 'dist', 'index.html')));

app.listen(PORT, '0.0.0.0', () => console.log(`[CPAS] Server running on port ${PORT}`));