export const dynamic = 'force-dynamic'

import Link from 'next/link'
import { createClient } from '@/lib/supabase/server'
import { StatCard } from '@/components/dashboard/stat-card'

const TYPE_LABELS: Record<string, string> = {
  injury: 'Injury',
  near_miss: 'Near Miss',
  hazard: 'Hazard',
  asset_damage: 'Asset Damage',
  environmental: 'Environmental',
  security: 'Security',
  fire: 'Fire',
}

export default async function HseDashboardPage() {
  const supabase = await createClient()

  const now = new Date()
  const thirtyDaysAgo = new Date(now)
  thirtyDaysAgo.setDate(now.getDate() - 30)
  const ninetyDaysAgo = new Date(now)
  ninetyDaysAgo.setDate(now.getDate() - 90)

  const [
    { data: incidents },
    { data: recentIncidents },
    { data: zoneIncidents },
    { data: completedCapas },
    { data: doshPendingRows },
  ] = await Promise.all([
    supabase.from('incidents').select('id, status, incident_type, sites (name)'),
    supabase
      .from('incidents')
      .select('incident_type')
      .gte('reported_at', thirtyDaysAgo.toISOString()),
    supabase
      .from('incidents')
      .select('zones (name)')
      .gte('reported_at', ninetyDaysAgo.toISOString())
      .not('zone_id', 'is', null),
    supabase
      .from('capa_actions')
      .select('due_date, completed_at, verified_at')
      .not('completed_at', 'is', null),
    supabase
      .from('dosh_reports')
      .select('id')
      .eq('status', 'pending'),
  ])

  // --- Existing metrics ---
  const rows = incidents ?? []
  const total = rows.length
  const closed = rows.filter(r => r.status === 'closed').length
  const open = total - closed

  const by_type: Record<string, number> = {}
  for (const r of rows) {
    by_type[r.incident_type] = (by_type[r.incident_type] ?? 0) + 1
  }

  const siteMap: Record<string, number> = {}
  for (const r of rows) {
    const name = (r.sites as unknown as { name: string } | null)?.name ?? '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)

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

  // --- Zone heatmap (last 90 days) ---
  const zoneMap: Record<string, number> = {}
  for (const r of zoneIncidents ?? []) {
    const name = (r.zones as unknown as { name: string } | null)?.name ?? 'Unknown'
    zoneMap[name] = (zoneMap[name] ?? 0) + 1
  }
  const by_zone = Object.entries(zoneMap)
    .map(([name, count]) => ({ name, count }))
    .sort((a, b) => b.count - a.count)
    .slice(0, 10)
  const zoneMax = by_zone[0]?.count ?? 1

  // --- CAPA on-time rate ---
  const capas = completedCapas ?? []
  const onTime = capas.filter(c => {
    const due = new Date(c.due_date)
    const done = c.verified_at
      ? new Date(c.verified_at as string)
      : c.completed_at
        ? new Date(c.completed_at as string)
        : null
    return done !== null && done <= due
  })
  const capaOnTimeRate = capas.length > 0
    ? Math.round((onTime.length / capas.length) * 100)
    : null

  // --- DOSH pending filings ---
  const doshPendingCount = doshPendingRows?.length ?? 0

  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">Dashboard</h1>
        <div className="flex gap-3">
          <a
            href="/api/dashboard/export?role=hse"
            className="text-sm text-gray-500 hover:text-gray-700 border border-gray-200 rounded-lg px-3 py-1.5"
          >
            Export CSV
          </a>
          <Link href="/hse/incidents" className="text-sm text-blue-600 hover:underline">
            View all incidents →
          </Link>
        </div>
      </div>

      {/* Summary stats */}
      <div className="grid grid-cols-2 gap-4 sm:grid-cols-4 mb-6">
        <StatCard label="Total Incidents" value={total} />
        <StatCard label="Open" value={open} accent="yellow" sub="awaiting action" />
        <StatCard label="Closed" value={closed} accent="green" sub="resolved" />
        <StatCard
          label="DOSH Pending"
          value={doshPendingCount}
          accent={doshPendingCount > 0 ? 'yellow' : 'green'}
          sub="filings outstanding"
        />
      </div>

      {/* Leading vs lagging — last 30 days */}
      <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 reports (predict risk) · Lagging: injuries (past harm)
        </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>
          {capaOnTimeRate !== null && (
            <div className="flex-1 text-center bg-green-50 rounded-lg p-4">
              <p className="text-3xl font-bold text-green-600">{capaOnTimeRate}%</p>
              <p className="text-xs text-green-700 mt-1">CAPA On-Time Rate</p>
            </div>
          )}
        </div>
      </div>

      {/* Zone heatmap — last 90 days */}
      {by_zone.length > 0 && (
        <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">
            Zone Incident Heatmap — Last 90 Days
          </h2>
          <div className="space-y-2">
            {by_zone.map(({ name, count }) => (
              <div key={name} className="flex items-center gap-3">
                <span className="text-sm text-gray-600 w-36 shrink-0 truncate">{name}</span>
                <div className="flex-1 bg-gray-100 rounded-full h-3">
                  <div
                    className="h-3 rounded-full"
                    style={{
                      width: `${(count / zoneMax) * 100}%`,
                      backgroundColor: `hsl(${Math.round((1 - count / zoneMax) * 120)}, 70%, 50%)`,
                    }}
                  />
                </div>
                <span className="text-sm font-semibold text-gray-900 w-6 text-right">{count}</span>
              </div>
            ))}
          </div>
        </div>
      )}

      {/* Incident type breakdown */}
      <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">By Incident Type</h2>
        <div className="space-y-2">
          {Object.entries(by_type).sort((a, b) => b[1] - a[1]).map(([type, count]) => (
            <div key={type} className="flex items-center gap-3">
              <span className="text-sm text-gray-600 w-32 shrink-0">{TYPE_LABELS[type] ?? type}</span>
              <div className="flex-1 bg-gray-100 rounded-full h-2">
                <div
                  className="bg-blue-500 h-2 rounded-full"
                  style={{ width: total > 0 ? `${(count / total) * 100}%` : '0%' }}
                />
              </div>
              <span className="text-sm font-semibold text-gray-900 w-6 text-right">{count}</span>
            </div>
          ))}
          {Object.keys(by_type).length === 0 && (
            <p className="text-sm text-gray-400">No incidents yet</p>
          )}
        </div>
      </div>

      {/* By site */}
      <div className="bg-white rounded-xl shadow-sm p-5">
        <h2 className="text-sm font-semibold text-gray-700 uppercase tracking-wide mb-4">By Site</h2>
        <div className="space-y-2">
          {by_site.map(({ name, count }) => (
            <div key={name} className="flex items-center justify-between">
              <span className="text-sm text-gray-600">{name}</span>
              <span className="text-sm font-semibold text-gray-900">{count}</span>
            </div>
          ))}
          {by_site.length === 0 && <p className="text-sm text-gray-400">No data</p>}
        </div>
      </div>
    </main>
  )
}