const express = require('express');
const router = express.Router();
const { getDb } = require('../db');
const { generateAdvice } = require('../advice');

router.get('/', (req, res) => {
  const db = getDb();
  const tab = req.query.tab || 'overview';

  const clients = db.prepare(`
    SELECT c.*,
      (SELECT COUNT(*) FROM engagements e WHERE e.client_id = c.id) as engagement_count,
      (SELECT COUNT(*) FROM engagements e WHERE e.client_id = c.id AND e.status = 'in_progress') as active_engagements,
      (SELECT MAX(a.created_at) FROM assessments a WHERE a.client_id = c.id) as last_assessment
    FROM clients c ORDER BY c.updated_at DESC
  `).all();

  const stats = {
    total: clients.length,
    active: clients.filter(c => c.status === 'active').length,
    leads: clients.filter(c => c.status === 'lead').length,
    paused: clients.filter(c => c.status === 'paused').length,
    archived: clients.filter(c => c.status === 'archived').length,
    activeEngagements: clients.reduce((s, c) => s + c.active_engagements, 0),
    totalEngagements: clients.reduce((s, c) => s + c.engagement_count, 0)
  };

  const totalDiagrams = db.prepare('SELECT COUNT(*) as cnt FROM data_diagrams').get().cnt;
  const totalRacks = db.prepare('SELECT COUNT(*) as cnt FROM racks').get().cnt;
  const totalRackDevices = db.prepare('SELECT COUNT(*) as cnt FROM rack_devices').get().cnt;
  const totalNetworkDevices = db.prepare('SELECT COUNT(*) as cnt FROM network_devices').get().cnt;

  const overdueTasks = db.prepare('SELECT COUNT(*) as cnt FROM tasks WHERE status IN (\'todo\',\'in_progress\') AND due_date < date(\'now\')').get().cnt;
  const totalTasks = db.prepare('SELECT COUNT(*) as cnt FROM tasks').get().cnt;
  const completedTasks = db.prepare('SELECT COUNT(*) as cnt FROM tasks WHERE status = \'done\'').get().cnt;
  const assessmentsCount = db.prepare('SELECT COUNT(*) as cnt FROM assessments').get().cnt;

  const recentEngagements = db.prepare(`
    SELECT e.*, c.name as client_name FROM engagements e JOIN clients c ON c.id = e.client_id
    WHERE e.status = 'in_progress' ORDER BY e.updated_at DESC LIMIT 8
  `).all();

  const allEngagements = db.prepare(`
    SELECT e.*, c.name as client_name FROM engagements e JOIN clients c ON c.id = e.client_id ORDER BY e.updated_at DESC
  `).all();

  const recentAssessments = db.prepare(`
    SELECT a.id, a.created_at, c.name as client_name FROM assessments a JOIN clients c ON c.id = a.client_id ORDER BY a.created_at DESC LIMIT 5
  `).all();

  const engagementByType = db.prepare('SELECT type, COUNT(*) as cnt FROM engagements GROUP BY type ORDER BY cnt DESC').all();
  const engagementByStatus = db.prepare('SELECT status, COUNT(*) as cnt FROM engagements GROUP BY status ORDER BY cnt DESC').all();
  const clientsByIndustry = db.prepare("SELECT industry, COUNT(*) as cnt FROM clients WHERE industry IS NOT NULL AND industry != '' GROUP BY industry ORDER BY cnt DESC LIMIT 6").all();

  const allAdvice = [];
  for (const client of clients) allAdvice.push(...generateAdvice(client.id));
  const activeAdvice = allAdvice.filter(a => !a.dismissed).sort((a, b) => {
    const prio = { critical: 0, high: 1, medium: 2, low: 3 };
    return (prio[a.priority] || 99) - (prio[b.priority] || 99);
  }).slice(0, 8);

  // Finance
  const timeEntries = db.prepare('SELECT t.*, c.name as client_name, e.title as engagement_title, u.username FROM time_entries t LEFT JOIN clients c ON c.id = t.client_id LEFT JOIN engagements e ON e.id = t.engagement_id LEFT JOIN users u ON u.id = t.user_id ORDER BY t.date DESC LIMIT 20').all();
  const totalHours = db.prepare('SELECT COALESCE(SUM(hours),0) as h FROM time_entries').get().h;
  const billableHours = db.prepare('SELECT COALESCE(SUM(hours),0) as h FROM time_entries WHERE billable=1').get().h;
  const invoices = db.prepare('SELECT i.*, c.name as client_name FROM invoices i JOIN clients c ON c.id = i.client_id ORDER BY i.created_at DESC LIMIT 10').all();
  const totalInvoiced = db.prepare("SELECT COALESCE(SUM(total),0) as t FROM invoices WHERE status != 'draft'").get().t;
  const totalPaid = db.prepare("SELECT COALESCE(SUM(total),0) as t FROM invoices WHERE status='paid'").get().t;
  const totalOutstanding = db.prepare("SELECT COALESCE(SUM(total),0) as t FROM invoices WHERE status IN ('sent','overdue')").get().t;

  // Infrastructure
  const racks = db.prepare('SELECT r.*, c.name as client_name, (SELECT COUNT(*) FROM rack_devices d WHERE d.rack_id = r.id) as device_count FROM racks r JOIN clients c ON c.id = r.client_id ORDER BY r.updated_at DESC LIMIT 6').all();
  const netDevices = db.prepare('SELECT nd.*, c.name as client_name FROM network_devices nd JOIN clients c ON c.id = nd.client_id ORDER BY nd.updated_at DESC LIMIT 10').all();
  const diagrams = db.prepare('SELECT d.*, c.name as client_name FROM data_diagrams d JOIN clients c ON c.id = d.client_id ORDER BY d.updated_at DESC LIMIT 6').all();

  // Tasks
  const allTasks = db.prepare(`
    SELECT t.*, e.title as engagement_title, e.id as eid, c.name as client_name
    FROM tasks t JOIN engagements e ON e.id = t.engagement_id JOIN clients c ON c.id = e.client_id
    ORDER BY CASE t.status WHEN 'todo' THEN 0 WHEN 'in_progress' THEN 1 WHEN 'done' THEN 2 WHEN 'cancelled' THEN 3 END,
    CASE t.priority WHEN 'critical' THEN 0 WHEN 'high' THEN 1 WHEN 'medium' THEN 2 WHEN 'low' THEN 3 END,
    t.due_date ASC
  `).all();

  res.render('dashboard', {
    tab, clients, stats,
    totalDiagrams, totalRacks, totalRackDevices, totalNetworkDevices,
    overdueTasks, totalTasks, completedTasks, assessmentsCount,
    recentEngagements, allEngagements, recentAssessments,
    engagementByType, engagementByStatus, clientsByIndustry,
    activeAdvice,
    timeEntries, totalHours, billableHours, invoices, totalInvoiced, totalPaid, totalOutstanding,
    racks, netDevices, diagrams,
    allTasks
  });
});

module.exports = router;