import { useParams, Link } from '@tanstack/react-router'
import { ArrowLeft, ExternalLink, Package, Loader2, AlertCircle } from 'lucide-react'
import { AppShell } from '@/components/layout/AppShell'
import { StatusBadge } from '@/components/inventory/StatusBadge'
import { Button } from '@/components/ui/button'
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card'
import { useInventoryItem } from '@/hooks/useInventory'

function FieldRow({ label, value }: { label: string; value?: string }) {
  if (!value) return null
  return (
    <div className="flex gap-3 py-2 border-b border-charcoal/40 last:border-0">
      <span className="label-upper text-[#a0a0a0] w-36 flex-shrink-0">{label}</span>
      <span className="text-white text-sm flex-1 break-all">{value}</span>
    </div>
  )
}

export function ItemDetailPage() {
  const { id } = useParams({ from: '/item/$id' })
  const numericId = parseInt(id, 10)
  const { data: item, isLoading, error } = useInventoryItem(numericId)

  if (isLoading) {
    return (
      <AppShell>
        <div className="flex items-center justify-center py-24 text-[#a0a0a0]">
          <Loader2 className="w-6 h-6 animate-spin mr-2" />
          Loading item…
        </div>
      </AppShell>
    )
  }

  if (error || !item) {
    return (
      <AppShell>
        <div className="flex items-center gap-3 p-4 border border-red-500/40 rounded-card bg-red-500/10 text-red-400">
          <AlertCircle className="w-5 h-5 flex-shrink-0" />
          <span className="text-sm">{(error as Error)?.message ?? 'Item not found'}</span>
        </div>
      </AppShell>
    )
  }

  const netboxUrl = `http://netbox.local/dcim/devices/${item.id}/`

  return (
    <AppShell>
      {/* Back nav */}
      <div className="mb-4">
        <Button variant="ghost" size="sm" asChild>
          <Link to="/">
            <ArrowLeft className="w-4 h-4 mr-1.5" />
            Inventory
          </Link>
        </Button>
      </div>

      {/* Header */}
      <div className="flex flex-wrap items-start gap-4 mb-6">
        <div className="flex-1 min-w-0">
          <p className="font-code text-volt text-sm label-upper mb-1">{item.hw_id || item.asset_tag}</p>
          <h1 className="font-display font-black text-2xl text-white leading-tight">{item.name}</h1>
        </div>
        <div className="flex items-center gap-2 flex-shrink-0">
          <StatusBadge status={item.catalog_status} />
          <Button variant="outline" size="sm" asChild>
            <a href={netboxUrl} target="_blank" rel="noopener noreferrer">
              <ExternalLink className="w-3.5 h-3.5 mr-1.5" />
              NetBox
            </a>
          </Button>
        </div>
      </div>

      {/* Two-column layout: photos (left on lg+) / fields (right or below) */}
      <div className="grid grid-cols-1 lg:grid-cols-2 gap-6">
        {/* Photos */}
        <Card>
          <CardHeader>
            <CardTitle className="text-sm label-upper text-[#a0a0a0]">Photos</CardTitle>
          </CardHeader>
          <CardContent>
            {item.photo_urls.length > 0 ? (
              <div className="grid grid-cols-2 gap-2">
                {item.photo_urls.map((url, i) => (
                  <a key={i} href={url} target="_blank" rel="noopener noreferrer">
                    <img
                      src={url}
                      alt={`${item.name} photo ${i + 1}`}
                      className="w-full rounded-sharp object-cover aspect-square hover:opacity-80 transition-opacity"
                      loading="lazy"
                    />
                  </a>
                ))}
              </div>
            ) : (
              <div className="flex flex-col items-center justify-center py-12 text-[#585858]">
                <Package className="w-12 h-12 mb-2" />
                <p className="text-sm">No photos</p>
              </div>
            )}
          </CardContent>
        </Card>

        {/* Fields */}
        <div className="space-y-4">
          <Card>
            <CardHeader>
              <CardTitle className="text-sm label-upper text-[#a0a0a0]">Details</CardTitle>
            </CardHeader>
            <CardContent>
              <FieldRow label="HW ID" value={item.hw_id || item.asset_tag} />
              <FieldRow label="Status" value={item.catalog_status} />
              <FieldRow label="Firmware" value={item.firmware_version} />
              <FieldRow label="Test Date" value={item.test_date} />
              <FieldRow label="Product URL" value={item.product_url} />
            </CardContent>
          </Card>

          {item.ai_notes && (
            <Card>
              <CardHeader>
                <CardTitle className="text-sm label-upper text-[#a0a0a0]">AI Notes</CardTitle>
              </CardHeader>
              <CardContent>
                <p className="text-sm text-white whitespace-pre-wrap">{item.ai_notes}</p>
              </CardContent>
            </Card>
          )}

          {item.test_data && (
            <Card>
              <CardHeader>
                <CardTitle className="text-sm label-upper text-[#a0a0a0]">Test Data</CardTitle>
              </CardHeader>
              <CardContent>
                <pre className="font-code text-xs text-[#a0a0a0] bg-near-black p-3 rounded-sharp overflow-x-auto whitespace-pre-wrap break-words">
                  {(() => {
                    try { return JSON.stringify(JSON.parse(item.test_data!), null, 2) }
                    catch { return item.test_data }
                  })()}
                </pre>
              </CardContent>
            </Card>
          )}
        </div>
      </div>
    </AppShell>
  )
}