'use client';

import Link from 'next/link';
import { useParams } from 'next/navigation';
import { useQuery } from '@tanstack/react-query';

import { PageHeader } from '@/components/shared/page-header';
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
import { apiFetch } from '@/lib/api/client';
import { PIPELINE_STAGES, STAGE_LABELS, type PipelineStage } from '@/lib/constants';

interface DashboardStats {
  totals: { totalClients: number; totalInterests: number; totalBerths: number };
  recent: { newInquiries7d: number; completed30d: number };
  pipeline: Record<string, number>;
  berthStatus: { available: number; under_offer: number; sold: number };
  conversion: { closedTotal: number; openTotal: number; conversionPct: number };
}

const BERTH_STATUS_COLORS: Record<string, string> = {
  available: 'bg-green-500',
  under_offer: 'bg-amber-500',
  sold: 'bg-slate-500',
};

const BERTH_STATUS_LABELS: Record<string, string> = {
  available: 'Available',
  under_offer: 'Under offer',
  sold: 'Sold',
};

export function ReportsDashboard() {
  const params = useParams<{ portSlug: string }>();
  const portSlug = params?.portSlug ?? '';
  const { data, isLoading, error } = useQuery({
    queryKey: ['admin-dashboard-stats'],
    queryFn: () => apiFetch<{ data: DashboardStats }>('/api/v1/admin/dashboard-stats'),
    refetchInterval: 60_000,
  });

  if (isLoading) {
    return (
      <div>
        <PageHeader title="Reports" description="Pipeline, occupancy, and recent activity." />
        <p className="text-sm text-muted-foreground py-6">Loading…</p>
      </div>
    );
  }
  if (error || !data) {
    return (
      <div>
        <PageHeader title="Reports" description="Pipeline, occupancy, and recent activity." />
        <p className="text-sm text-red-600 py-6">
          Failed to load stats: {error instanceof Error ? error.message : 'unknown error'}
        </p>
      </div>
    );
  }

  const stats = data.data;
  const maxStageCount = Math.max(1, ...Object.values(stats.pipeline));
  const totalBerths =
    stats.berthStatus.available + stats.berthStatus.under_offer + stats.berthStatus.sold;

  return (
    <div>
      <PageHeader
        title="Reports"
        description="Live snapshot of clients, pipeline, and berth occupancy. Refreshes every minute."
      />

      {/* KPI tiles */}
      <div className="grid grid-cols-2 lg:grid-cols-4 gap-4 mt-6">
        <KpiTile label="Clients" value={stats.totals.totalClients} href={`/${portSlug}/clients`} />
        <KpiTile
          label="Open interests"
          value={stats.conversion.openTotal}
          href={`/${portSlug}/interests`}
        />
        <KpiTile
          label="Inquiries (7 days)"
          value={stats.recent.newInquiries7d}
          href={`/${portSlug}/admin/inquiries`}
        />
        <KpiTile
          label="Completed (30 days)"
          value={stats.recent.completed30d}
          accent={stats.recent.completed30d > 0 ? 'success' : undefined}
        />
      </div>

      <div className="grid grid-cols-1 lg:grid-cols-2 gap-4 mt-6">
        {/* Pipeline funnel */}
        <Card>
          <CardHeader>
            <CardTitle>Pipeline funnel</CardTitle>
            <CardDescription>Open interests by stage (excludes archived).</CardDescription>
          </CardHeader>
          <CardContent>
            <ul className="space-y-2">
              {PIPELINE_STAGES.map((stage) => {
                const n = stats.pipeline[stage] ?? 0;
                const pct = (n / maxStageCount) * 100;
                return (
                  <li key={stage} className="text-sm">
                    <div className="flex items-center justify-between mb-1">
                      <span>{STAGE_LABELS[stage as PipelineStage]}</span>
                      <span className="font-medium">{n}</span>
                    </div>
                    <div className="h-2 rounded-full bg-muted overflow-hidden">
                      <div
                        className="h-full bg-primary transition-all"
                        style={{ width: `${pct}%` }}
                      />
                    </div>
                  </li>
                );
              })}
            </ul>
            <div className="mt-4 pt-4 border-t text-sm">
              <span className="text-muted-foreground">Conversion (completed / total):</span>{' '}
              <span className="font-medium">{stats.conversion.conversionPct}%</span>
            </div>
          </CardContent>
        </Card>

        {/* Berth occupancy */}
        <Card>
          <CardHeader>
            <CardTitle>Berth occupancy</CardTitle>
            <CardDescription>
              Current public-status mix for {totalBerths} berths in this port.
            </CardDescription>
          </CardHeader>
          <CardContent>
            <div className="space-y-3">
              {(['available', 'under_offer', 'sold'] as const).map((status) => {
                const n = stats.berthStatus[status];
                const pct = totalBerths === 0 ? 0 : Math.round((n / totalBerths) * 100);
                return (
                  <div key={status} className="text-sm">
                    <div className="flex items-center justify-between mb-1">
                      <div className="flex items-center gap-2">
                        <span
                          className={`inline-block h-2.5 w-2.5 rounded-full ${BERTH_STATUS_COLORS[status]}`}
                        />
                        <span>{BERTH_STATUS_LABELS[status]}</span>
                      </div>
                      <span className="font-medium">
                        {n} <span className="text-muted-foreground">· {pct}%</span>
                      </span>
                    </div>
                    <div className="h-2 rounded-full bg-muted overflow-hidden">
                      <div
                        className={`h-full ${BERTH_STATUS_COLORS[status]}`}
                        style={{ width: `${pct}%` }}
                      />
                    </div>
                  </div>
                );
              })}
            </div>
          </CardContent>
        </Card>
      </div>

      <p className="text-xs text-muted-foreground mt-6">
        Need scheduled or downloadable reports?{' '}
        <Link href={`/${portSlug}/reports` as never} className="underline">
          Open the report generator
        </Link>{' '}
        to produce PDF exports of these views.
      </p>
    </div>
  );
}

function KpiTile({
  label,
  value,
  href,
  accent,
}: {
  label: string;
  value: number;
  href?: string;
  accent?: 'success' | 'danger';
}) {
  const accentClass =
    accent === 'success' ? 'text-green-700' : accent === 'danger' ? 'text-red-700' : '';
  const inner = (
    <Card className="h-full transition hover:border-primary/40">
      <CardContent className="py-5">
        <div className={`text-3xl font-semibold ${accentClass}`}>{value}</div>
        <div className="text-sm text-muted-foreground mt-1">{label}</div>
      </CardContent>
    </Card>
  );
  return href ? (
    <Link href={href as never} className="block">
      {inner}
    </Link>
  ) : (
    inner
  );
}