'use client';

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

import { apiFetch } from '@/lib/api/client';
import { useRealtimeInvalidation } from '@/hooks/use-realtime-invalidation';
import { Badge } from '@/components/ui/badge';
import { Button } from '@/components/ui/button';
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from '@/components/ui/select';
import { TableSkeleton } from '@/components/shared/loading-skeleton';
import { EmptyState } from '@/components/shared/empty-state';
import { Bookmark } from 'lucide-react';
import { PIPELINE_STAGES, stageLabel, formatSource } from '@/lib/constants';
import type { InterestRow } from '@/components/interests/interest-columns';

interface BerthInterestsTabProps {
  berthId: string;
}

type StageFilter = 'all' | 'active' | 'lost';
type SortMode = 'newest' | 'stage' | 'category';

function stageRank(stage: string): number {
  const idx = PIPELINE_STAGES.indexOf(stage as (typeof PIPELINE_STAGES)[number]);
  return idx === -1 ? 99 : idx;
}

const CATEGORY_RANK: Record<string, number> = {
  hot_lead: 0,
  specific_qualified: 1,
  general_interest: 2,
};

const CATEGORY_LABELS: Record<string, string> = {
  hot_lead: 'Hot lead',
  specific_qualified: 'Specific qualified',
  general_interest: 'General interest',
};

interface ListResponse {
  data: InterestRow[];
  total: number;
}

export function BerthInterestsTab({ berthId }: BerthInterestsTabProps) {
  const params = useParams<{ portSlug: string }>();
  const portSlug = params?.portSlug ?? '';
  const [stage, setStage] = useState<StageFilter>('all');
  const [sortMode, setSortMode] = useState<SortMode>('newest');

  const { data, isLoading } = useQuery<ListResponse>({
    queryKey: ['interests', 'by-berth', berthId],
    queryFn: () => apiFetch<ListResponse>(`/api/v1/interests?berthId=${berthId}&limit=200`),
    staleTime: 30_000,
  });

  useRealtimeInvalidation({
    'interest:created': [['interests', 'by-berth', berthId]],
    'interest:updated': [['interests', 'by-berth', berthId]],
    'interest:stageChanged': [['interests', 'by-berth', berthId]],
    'interest:archived': [['interests', 'by-berth', berthId]],
    'interest:berthLinked': [['interests', 'by-berth', berthId]],
    'interest:berthUnlinked': [['interests', 'by-berth', berthId]],
  });

  const rows = useMemo<InterestRow[]>(() => {
    const all = data?.data ?? [];
    const filtered = all.filter((i) => {
      // 2026-05-14 sentinel-stage cleanup: an interest is "active" when
      // it has no terminal outcome and isn't archived. The legacy
      // `pipelineStage !== 'completed'` check stopped working after the
      // 7-stage refactor stopped writing 'completed' for terminal rows.
      if (stage === 'active') return !i.outcome && !i.archivedAt;
      if (stage === 'lost') return Boolean(i.archivedAt);
      return true;
    });
    const sorted = [...filtered].sort((a, b) => {
      if (sortMode === 'stage') {
        const sa = stageRank(a.pipelineStage);
        const sb = stageRank(b.pipelineStage);
        if (sa !== sb) return sb - sa; // furthest along first
      }
      if (sortMode === 'category') {
        const ca = CATEGORY_RANK[a.leadCategory ?? ''] ?? 99;
        const cb = CATEGORY_RANK[b.leadCategory ?? ''] ?? 99;
        if (ca !== cb) return ca - cb; // hottest first
      }
      // Default + tiebreaker: newest first.
      return new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime();
    });
    return sorted;
  }, [data?.data, stage, sortMode]);

  if (isLoading) return <TableSkeleton />;

  if ((data?.data ?? []).length === 0) {
    return (
      <EmptyState
        icon={Bookmark}
        title="No interests linked to this berth"
        description="Interests will appear here when prospects express interest in this specific berth."
      />
    );
  }

  return (
    <div className="space-y-3">
      <div className="flex flex-wrap items-center gap-2">
        <div className="text-xs text-muted-foreground">
          {rows.length} of {data?.total ?? 0} interest{(data?.total ?? 0) === 1 ? '' : 's'}
        </div>
        <div className="ml-auto flex items-center gap-2">
          <Select value={stage} onValueChange={(v) => setStage(v as StageFilter)}>
            <SelectTrigger className="h-8 w-[140px]" data-testid="berth-interests-filter">
              <SelectValue />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value="all">All stages</SelectItem>
              <SelectItem value="active">Active only</SelectItem>
              <SelectItem value="lost">Lost / archived</SelectItem>
            </SelectContent>
          </Select>
          <Select value={sortMode} onValueChange={(v) => setSortMode(v as SortMode)}>
            <SelectTrigger className="h-8 w-[160px]" data-testid="berth-interests-sort">
              <SelectValue />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value="newest">Newest</SelectItem>
              <SelectItem value="stage">Stage progress</SelectItem>
              <SelectItem value="category">Lead category</SelectItem>
            </SelectContent>
          </Select>
        </div>
      </div>

      <div className="overflow-hidden rounded-lg border border-border bg-card">
        <table className="w-full text-sm" data-testid="berth-interests-table">
          <thead className="bg-muted/40 text-left text-xs font-medium text-muted-foreground">
            <tr>
              <th scope="col" className="px-3 py-2">
                Client
              </th>
              <th scope="col" className="px-3 py-2">
                Stage
              </th>
              <th scope="col" className="px-3 py-2">
                Category
              </th>
              <th scope="col" className="px-3 py-2">
                Source
              </th>
              <th scope="col" className="px-3 py-2">
                Last activity
              </th>
              <th scope="col" className="px-3 py-2 text-right">
                <span className="sr-only">Actions</span>
              </th>
            </tr>
          </thead>
          <tbody>
            {rows.map((i) => (
              <tr
                key={i.id}
                className="border-t border-border last:border-b-0 hover:bg-gradient-brand-soft/40"
              >
                <td className="px-3 py-2 font-medium text-foreground">
                  <Link
                    href={`/${portSlug}/interests/${i.id}` as never}
                    className="hover:text-brand"
                  >
                    {i.clientName ?? '-'}
                  </Link>
                </td>
                <td className="px-3 py-2">
                  <Badge variant="secondary" className="font-normal">
                    {stageLabel(i.pipelineStage)}
                  </Badge>
                </td>
                <td className="px-3 py-2 text-muted-foreground">
                  {i.leadCategory ? (CATEGORY_LABELS[i.leadCategory] ?? i.leadCategory) : '-'}
                </td>
                <td className="px-3 py-2 text-muted-foreground">{formatSource(i.source) ?? '-'}</td>
                <td className="px-3 py-2 text-xs text-muted-foreground">
                  {new Date(i.createdAt).toLocaleDateString()}
                </td>
                <td className="px-3 py-2 text-right">
                  <Button asChild variant="ghost" size="sm" className="h-7 text-xs">
                    <Link href={`/${portSlug}/interests/${i.id}` as never}>Open</Link>
                  </Button>
                </td>
              </tr>
            ))}
          </tbody>
        </table>
      </div>
    </div>
  );
}