'use client';

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

import { apiFetch } from '@/lib/api/client';
import { Popover, PopoverContent, PopoverTrigger } from '@/components/ui/popover';
import { stageBadgeClass, stageLabel } from '@/lib/constants';
import { cn } from '@/lib/utils';

interface ActiveInterestRow {
  interestId: string;
  clientName: string;
  pipelineStage: string;
  isPrimary: boolean;
  isInEoiBundle: boolean;
}

interface BerthOccupancyChipProps {
  /** Berth to query. */
  berthId: string;
  /** Port slug for the competing-interest link. */
  portSlug: string;
  /** Optional: hide rows from this interest (so a "competing" chip on
   *  a row inside Interest A doesn't surface A itself). */
  excludeInterestId?: string | null;
  /** Hide the chip entirely when the berth has zero active interests
   *  (default: true). Set false when the parent wants a render even
   *  for available berths — useful for the linked-berth row where the
   *  rep wants explicit "no competing interest" feedback. */
  hideWhenEmpty?: boolean;
  /** Compact variant — single-line chip with truncation. Default
   *  shows on multiple lines when the client name overflows. */
  compact?: boolean;
}

/**
 * Surfaces the competing interest(s) that own a non-available berth.
 * Reuses /api/v1/berths/[id]/active-interests (shipped for the columns
 * popover) so the data path is consistent across:
 *   - LinkedBerthRowItem (per linked berth on the interest detail)
 *   - BerthRecommenderPanel recommendation card body
 *   - InterestBerthStatusBanner (deal-level banner)
 *
 * Renders the highest-priority competing interest (in-EOI-bundle first,
 * then primary, then most-recently-updated). Clicking the chip
 * navigates to the competing interest's detail page.
 */
export function BerthOccupancyChip({
  berthId,
  portSlug,
  excludeInterestId,
  hideWhenEmpty = true,
  compact = false,
}: BerthOccupancyChipProps) {
  const { data, isLoading } = useQuery<{ data: ActiveInterestRow[] }>({
    queryKey: ['berth', berthId, 'active-interests'],
    queryFn: () =>
      apiFetch<{ data: ActiveInterestRow[] }>(`/api/v1/berths/${berthId}/active-interests`),
    staleTime: 30_000,
  });

  const rows = data?.data ?? [];
  const competing = rows.filter((r) =>
    excludeInterestId ? r.interestId !== excludeInterestId : true,
  );

  if (isLoading) return null;
  if (competing.length === 0 && hideWhenEmpty) return null;
  if (competing.length === 0) {
    return (
      <span className="inline-flex items-center text-xs text-muted-foreground">
        No competing interest
      </span>
    );
  }

  // Priority: in-EOI-bundle (committed) > primary (flagged primary) >
  // first by API order (already most-recently-updated server-side).
  const primary =
    competing.find((r) => r.isInEoiBundle) ?? competing.find((r) => r.isPrimary) ?? competing[0]!;
  const extras = competing.length - 1;

  const chipClass = cn(
    'inline-flex items-center gap-1.5 rounded-md border border-amber-300 bg-amber-50 px-2 py-0.5 text-xs text-amber-900 hover:bg-amber-100 transition-colors',
    // Cap tight on narrow viewports, but give the name room on desktop
    // so it isn't truncated to "Philippe Ca…" (UAT 2026-06-03).
    compact && 'max-w-[200px] md:max-w-[460px]',
  );

  const stageChip = (stage: string) => (
    <span className={cn('shrink-0 rounded-full px-1.5 text-xs', stageBadgeClass(stage))}>
      {stageLabel(stage)}
    </span>
  );

  // Single competing interest → the chip is a direct link to it.
  if (competing.length === 1) {
    return (
      <Link
        href={`/${portSlug}/interests/${primary.interestId}` as never}
        onClick={(e) => e.stopPropagation()}
        className={chipClass}
        title={`Open ${primary.clientName} (${stageLabel(primary.pipelineStage)})`}
      >
        <span className="font-medium">Under offer to:</span>
        <span className={cn(compact && 'truncate min-w-0')}>{primary.clientName}</span>
        {stageChip(primary.pipelineStage)}
      </Link>
    );
  }

  // Multiple competing interests → the chip opens a popover that lists
  // every competing deal so no name is hidden behind "+N more" (UAT
  // 2026-06-03). Each row links to its interest.
  return (
    <Popover>
      <PopoverTrigger asChild>
        <button type="button" onClick={(e) => e.stopPropagation()} className={chipClass}>
          <span className="font-medium">Under offer to:</span>
          <span className={cn(compact && 'truncate min-w-0')}>{primary.clientName}</span>
          {stageChip(primary.pipelineStage)}
          <span className="shrink-0 text-amber-700">+{extras} more</span>
        </button>
      </PopoverTrigger>
      <PopoverContent align="start" className="w-72 p-0" onClick={(e) => e.stopPropagation()}>
        <div className="border-b px-3 py-2 text-xs font-medium text-muted-foreground">
          {competing.length} interests competing for this berth
        </div>
        <ul className="max-h-72 divide-y overflow-y-auto">
          {competing.map((r) => (
            <li key={r.interestId}>
              <Link
                href={`/${portSlug}/interests/${r.interestId}` as never}
                onClick={(e) => e.stopPropagation()}
                className="flex items-center justify-between gap-2 px-3 py-2 text-sm hover:bg-muted/60"
              >
                <span className="min-w-0 flex-1 truncate">
                  {r.clientName}
                  {r.isInEoiBundle ? (
                    <span className="ml-1.5 text-xs text-amber-700">· in EOI</span>
                  ) : r.isPrimary ? (
                    <span className="ml-1.5 text-xs text-muted-foreground">· primary</span>
                  ) : null}
                </span>
                {stageChip(r.pipelineStage)}
              </Link>
            </li>
          ))}
        </ul>
      </PopoverContent>
    </Popover>
  );
}