import express from 'express';
import { pool } from '../db.js';
import { getSettings } from '../lib/settings.js';
import { loadProjects } from '../lib/projects.js';
import { loadEntries } from '../lib/entries.js';
import { addDays, today } from '../lib/dates.js';

const router = express.Router();
const str = (v, max) => (v == null ? null : String(v).trim().slice(0, max) || null);

function normalize(body, creating) {
  const errors = [];
  const out = {};
  if (creating || body.name !== undefined) {
    out.name = str(body.name, 190);
    if (!out.name) errors.push('Kundenname fehlt.');
  }
  if (creating || body.short_name !== undefined) {
    out.short_name = str(body.short_name, 16)?.toUpperCase().replace(/[^A-Z0-9ÄÖÜ_-]/g, '') || null;
    if (!out.short_name) errors.push('Kürzel fehlt (z. B. KUKA) - es steht im Projektcode.');
  }
  for (const [key, max] of [
    ['contact_person', 160],
    ['email', 190],
    ['phone', 60],
    ['street', 190],
    ['zip', 20],
    ['city', 120],
    ['country', 80],
    ['notes', 5000],
  ]) {
    if (body[key] !== undefined) out[key] = str(body[key], max);
  }
  if (body.color !== undefined) out.color = /^#[0-9a-f]{6}$/i.test(body.color || '') ? body.color : null;
  if (body.is_active !== undefined) out.is_active = body.is_active ? 1 : 0;
  return { out, errors };
}

router.get('/', async (req, res, next) => {
  try {
    const [rows] = await pool.query(
      `SELECT c.*, (SELECT COUNT(*) FROM pulse_projects p WHERE p.customer_id = c.id) AS project_count
         FROM pulse_customers c ORDER BY c.name`
    );
    res.json(rows.map((r) => ({ ...r, is_active: Boolean(r.is_active), project_count: Number(r.project_count) })));
  } catch (err) {
    next(err);
  }
});

/**
 * Uebersicht: welche Kunden haben welche Projekte mit welchen Mitarbeitern,
 * wie viel Umsatz ist erbracht und wie viel noch offen - plus die letzten 12
 * Monate Umsatz fuer die Verlaufslinie.
 */
router.get('/overview', async (req, res, next) => {
  try {
    const settings = await getSettings();
    const [customers] = await pool.query('SELECT * FROM pulse_customers ORDER BY name');
    const projects = await loadProjects(settings);
    const from = `${addDays(today(), -365).slice(0, 7)}-01`;
    const entries = await loadEntries(settings, { from });

    const months = [];
    const cursor = new Date(`${from}T00:00:00Z`);
    for (let i = 0; i < 13; i++) {
      months.push(cursor.toISOString().slice(0, 7));
      cursor.setUTCMonth(cursor.getUTCMonth() + 1);
    }

    const result = customers.map((customer) => {
      const own = projects.filter((p) => p.customer_id === customer.id);
      const memberMap = new Map();
      for (const project of own) for (const m of project.members) memberMap.set(m.id, m);
      const monthly = months.map((month) =>
        entries
          .filter((e) => e.customer_id === customer.id && e.entry_date.startsWith(month))
          .reduce((sum, e) => sum + e.amount + e.fixed_amount, 0)
      );
      return {
        ...customer,
        is_active: Boolean(customer.is_active),
        projects: own.map((p) => ({
          id: p.id,
          code: p.code,
          name: p.name,
          display_name: p.display_name,
          type: p.type,
          is_active: p.is_active,
          used_minutes: p.used_minutes,
          budget_hours: p.budget_hours,
          earned: p.earned,
          open: p.open,
          budget_value: p.budget_value,
          members: p.members,
          end_date: p.end_date,
        })),
        members: [...memberMap.values()],
        used_minutes: own.reduce((s, p) => s + p.used_minutes, 0),
        earned: Math.round(own.reduce((s, p) => s + p.earned, 0) * 100) / 100,
        open: Math.round(own.reduce((s, p) => s + p.open, 0) * 100) / 100,
        monthly: monthly.map((v) => Math.round(v * 100) / 100),
      };
    });
    res.json({ months, customers: result });
  } catch (err) {
    next(err);
  }
});

router.post('/', async (req, res, next) => {
  const { out, errors } = normalize(req.body || {}, true);
  if (errors.length) return res.status(400).json({ error: errors.join(' ') });
  try {
    const keys = Object.keys(out);
    const [result] = await pool.query(
      `INSERT INTO pulse_customers (${keys.join(', ')}) VALUES (${keys.map(() => '?').join(', ')})`,
      keys.map((k) => out[k])
    );
    const [[row]] = await pool.query('SELECT * FROM pulse_customers WHERE id = ?', [result.insertId]);
    res.status(201).json(row);
  } catch (err) {
    if (err.code === 'ER_DUP_ENTRY') return res.status(409).json({ error: 'Dieses Kürzel ist schon vergeben.' });
    next(err);
  }
});

router.put('/:id', async (req, res, next) => {
  const { out, errors } = normalize(req.body || {}, false);
  if (errors.length) return res.status(400).json({ error: errors.join(' ') });
  try {
    const keys = Object.keys(out);
    if (keys.length) {
      const [result] = await pool.query(`UPDATE pulse_customers SET ${keys.map((k) => `${k} = ?`).join(', ')} WHERE id = ?`, [
        ...keys.map((k) => out[k]),
        Number(req.params.id),
      ]);
      if (!result.affectedRows) return res.status(404).json({ error: 'Kunde nicht gefunden.' });
    }
    const [[row]] = await pool.query('SELECT * FROM pulse_customers WHERE id = ?', [Number(req.params.id)]);
    res.json(row);
  } catch (err) {
    if (err.code === 'ER_DUP_ENTRY') return res.status(409).json({ error: 'Dieses Kürzel ist schon vergeben.' });
    next(err);
  }
});

router.delete('/:id', async (req, res, next) => {
  try {
    const [[{ n }]] = await pool.query('SELECT COUNT(*) AS n FROM pulse_projects WHERE customer_id = ?', [Number(req.params.id)]);
    if (Number(n) > 0) {
      return res.status(409).json({ error: `Dem Kunden sind ${n} Projekte zugeordnet. Bitte deaktivieren statt löschen.` });
    }
    await pool.query('DELETE FROM pulse_customers WHERE id = ?', [Number(req.params.id)]);
    res.json({ ok: true });
  } catch (err) {
    next(err);
  }
});

export default router;