export const dynamic = 'force-dynamic'

import { asAdmin } from '@/lib/db/with-user'
import { redirect } from 'next/navigation'
import { getSession } from '@/lib/auth/get-session'
import { incidents, sites, capaActions } from '@/lib/db/schema'
import { eq, gte, lt, and, inArray } from 'drizzle-orm'
import { StatCard } from '@/components/dashboard/stat-card'
import { RiskFlagsPanel } from '@/components/dashboard/risk-flags-panel'

export default async function ManagementPage() {
  const session = await getSession()
  if (!session) redirect('/login')
  if (!['management', 'admin'].includes(session.role)) redirect('/')

  const now = new Date()
  const today = now.toISOString().slice(0, 10)
  const thisMonthStart = new Date(now.getFullYear(), now.getMonth(), 1).toISOString()
  const lastMonthStart = new Date(now.getFullYear(), now.getMonth() - 1, 1).toISOString()
  const thirtyDaysAgo = new Date(now.getTime() - 30 * 24 * 60 * 60 * 1000).toISOString()

  const [allIncidents, thisMonthIncidents, lastMonthIncidents, recentIncidents, overdueCapas] = await Promise.all([
    asAdmin(db =>
      db.select({
        id: incidents.id,
        severity: incidents.severity,
        status: incidents.status,
        incidentType: incidents.incidentType,
        medicalStatus: incidents.medicalStatus,
        siteName: sites.name,
      })
      .from(incidents)
      .leftJoin(sites, eq(incidents.siteId, sites.id))
    ),
    asAdmin(db =>
      db.select({ id: incidents.id })
      .from(incidents)
      .where(gte(incidents.reportedAt, new Date(thisMonthStart)))
    ),
    asAdmin(db =>
      db.select({ id: incidents.id })
      .from(incidents)
      .where(and(gte(incidents.reportedAt, new Date(lastMonthStart)), lt(incidents.reportedAt, new Date(thisMonthStart))))
    ),
    asAdmin(db =>
      db.select({ incidentType: incidents.incidentType })
      .from(incidents)
      .where(gte(incidents.reportedAt, new Date(thirtyDaysAgo)))
    ),
    asAdmin(db =>
      db.select({ id: capaActions.id })
      .from(capaActions)
      .where(and(
        inArray(capaActions.status, ['open', 'in_progress']),
        lt(capaActions.dueDate, today)
      ))
    ),
  ])

  const rows = allIncidents
  const totalThisMonth = thisMonthIncidents.length
  const totalLastMonth = lastMonthIncidents.length
  const monthDelta = totalThisMonth - totalLastMonth

  const ltiCount = rows.filter(r => r.medicalStatus === 'lti').length
  const overdueCount = overdueCapas.length

  // Severity distribution
  const severityDist: Record<number, number> = { 1: 0, 2: 0, 3: 0, 4: 0, 5: 0 }
  for (const r of rows) {
    if (r.severity && r.severity >= 1 && r.severity <= 5) {
      severityDist[r.severity] = (severityDist[r.severity] ?? 0) + 1
    }
  }
  const severityMax = Math.max(...Object.values(severityDist), 1)

  // Leading vs lagging (last 30 days)
  const leadingCount = recentIncidents.filter(r => ['hazard', 'near_miss'].includes(r.incidentType)).length
  const laggingCount = recentIncidents.filter(r => r.incidentType === 'injury').length

  // Site comparison
  const siteMap: Record<string, number> = {}
  for (const r of rows) {
    const name = r.siteName ?? 'Unknown'
    siteMap[name] = (siteMap[name] ?? 0) + 1
  }
  const by_site = Object.entries(siteMap).map(([name, count]) => ({ name, count })).sort((a, b) => b.count - a.count)

  const SEVERITY_LABELS: Record<number, string> = { 1: 'Minor', 2: 'Low', 3: 'Moderate', 4: 'Serious', 5: 'Critical' }
  const SEVERITY_COLORS: Record<number, string> = {
    1: 'bg-green-400', 2: 'bg-yellow-400', 3: 'bg-orange-400', 4: 'bg-red-500', 5: 'bg-red-700',
  }

  return (
    <main className="max-w-4xl mx-auto px-4 py-6">
      <div className="flex items-center justify-between mb-6">
        <h1 className="text-2xl font-bold text-gray-900">Management Dashboard</h1>
        <a
          href="/api/dashboard/export?role=management"
          className="text-sm text-gray-500 hover:text-gray-700 border border-gray-200 rounded-lg px-3 py-1.5"
        >
          Export CSV
        </a>
      </div>

      <RiskFlagsPanel />

      {/* Summary stats */}
      <div className="grid grid-cols-2 gap-4 sm:grid-cols-4 mb-6">
        <StatCard
          label="This Month"
          value={totalThisMonth}
          sub={monthDelta >= 0 ? `+${monthDelta} vs last month` : `${monthDelta} vs last month`}
          accent={monthDelta > 0 ? 'yellow' : 'green'}
        />
        <StatCard label="LTI Count" value={ltiCount} accent={ltiCount > 0 ? 'red' : 'green'} sub="lost-time injuries" />
        <StatCard label="CAPA Overdue" value={overdueCount} accent={overdueCount > 0 ? 'red' : 'green'} sub="past due date" />
        <StatCard label="Total (All Time)" value={rows.length} />
      </div>

      {/* Leading vs lagging */}
      <div className="bg-white rounded-xl shadow-sm p-5 mb-4">
        <h2 className="text-sm font-semibold text-gray-700 uppercase tracking-wide mb-1">Leading vs Lagging — Last 30 Days</h2>
        <p className="text-xs text-gray-400 mb-4">Leading: hazard + near-miss · Lagging: injuries</p>
        <div className="flex gap-6">
          <div className="flex-1 text-center bg-blue-50 rounded-lg p-4">
            <p className="text-3xl font-bold text-blue-600">{leadingCount}</p>
            <p className="text-xs text-blue-700 mt-1">Leading (Hazards + Near Misses)</p>
          </div>
          <div className="flex-1 text-center bg-red-50 rounded-lg p-4">
            <p className="text-3xl font-bold text-red-600">{laggingCount}</p>
            <p className="text-xs text-red-700 mt-1">Lagging (Injuries)</p>
          </div>
        </div>
      </div>

      {/* Severity distribution */}
      <div className="bg-white rounded-xl shadow-sm p-5 mb-4">
        <h2 className="text-sm font-semibold text-gray-700 uppercase tracking-wide mb-4">Severity Distribution (All Time)</h2>
        <div className="space-y-2">
          {([5, 4, 3, 2, 1] as const).map(sev => (
            <div key={sev} className="flex items-center gap-3">
              <span className="text-sm text-gray-600 w-24 shrink-0">{SEVERITY_LABELS[sev]}</span>
              <div className="flex-1 bg-gray-100 rounded-full h-3">
                <div
                  className={`h-3 rounded-full ${SEVERITY_COLORS[sev]}`}
                  style={{ width: severityMax > 0 ? `${(severityDist[sev] / severityMax) * 100}%` : '0%' }}
                />
              </div>
              <span className="text-sm font-semibold text-gray-900 w-6 text-right">{severityDist[sev]}</span>
            </div>
          ))}
        </div>
      </div>

      {/* Site comparison */}
      <div className="bg-white rounded-xl shadow-sm p-5">
        <h2 className="text-sm font-semibold text-gray-700 uppercase tracking-wide mb-4">Incidents by Site</h2>
        {by_site.length === 0 ? (
          <p className="text-sm text-gray-400">No data</p>
        ) : (
          <div className="space-y-2">
            {by_site.map(({ name, count }) => (
              <div key={name} className="flex items-center justify-between py-1 border-b border-gray-50 last:border-0">
                <span className="text-sm text-gray-700">{name}</span>
                <span className="text-sm font-semibold text-gray-900">{count}</span>
              </div>
            ))}
          </div>
        )}
      </div>
    </main>
  )
}