"use client";

// components/OverviewSearch.tsx
// Global tax-number / CK-number search for the Overview tab.
//
// Searches ONLY the company registry — every field we search is a tax
// or registration number, per SJ's rule (verified 2026-09-11).
// Substring, case-insensitive. In-memory; the data ships from the
// server with the rest of the dashboard props.

import { useEffect, useMemo, useRef, useState } from "react";
import Link from "next/link";
import { text } from "@/lib/format";
import type { PBRecord } from "@/lib/pb";

export interface OverviewSearchItem extends PBRecord {
  id: string;
  enterprise_no: string;
  enterprise_name: string;
  sars_tax_number: string | null;
  sars_paye_no: string | null;
  sars_vat_no: string | null;
  uif_registration_number: string | null;
  compensation_fund_registration_number: string | null;
}

interface Props {
  items: OverviewSearchItem[];
}

interface Hit {
  id: string;
  enterprise_no: string;
  enterprise_name: string;
  /** Human label, e.g. "SARS PAYE no". */
  fieldLabel: string;
  /** Actual value that matched (preserves original casing/spacing). */
  fieldValue: string;
  /** Path the row should link to. */
  href: string;
}

// Field definitions: (data key, human label) — order is intentional,
// most-common first.
const SEARCH_FIELDS: Array<{ key: keyof OverviewSearchItem; label: string }> = [
  { key: "enterprise_no", label: "CK number" },
  { key: "sars_tax_number", label: "SARS Income Tax no" },
  { key: "sars_paye_no", label: "SARS PAYE no" },
  { key: "sars_vat_no", label: "SARS VAT no" },
  { key: "uif_registration_number", label: "UIF no" },
  { key: "compensation_fund_registration_number", label: "COID no" },
];

const MAX_RESULTS = 50;
const MIN_QUERY_LEN = 2;

function search(items: OverviewSearchItem[], q: string): Hit[] {
  const needle = q.trim().toLowerCase();
  if (needle.length < MIN_QUERY_LEN) return [];
  const hits: Hit[] = [];
  for (const item of items) {
    for (const { key, label } of SEARCH_FIELDS) {
      const raw = item[key];
      if (typeof raw !== "string" || raw === "") continue;
      if (raw.toLowerCase().includes(needle)) {
        hits.push({
          id: item.id,
          enterprise_no: item.enterprise_no,
          enterprise_name: item.enterprise_name,
          fieldLabel: label,
          fieldValue: raw,
          href: `/companies/${item.id}`,
        });
        // One hit per company is enough — don't double-list the same
        // record under multiple matching fields. If the user wants
        // every match, the CK number itself usually disambiguates.
        break;
      }
    }
  }
  return hits.slice(0, MAX_RESULTS);
}

export default function OverviewSearch({ items }: Props) {
  const [query, setQuery] = useState("");
  const [debounced, setDebounced] = useState("");
  const inputRef = useRef<HTMLInputElement>(null);

  // Debounce 150ms so each keystroke doesn't re-render the list.
  useEffect(() => {
    const handle = setTimeout(() => setDebounced(query), 150);
    return () => clearTimeout(handle);
  }, [query]);

  // Cmd/Ctrl+K focuses the search bar from anywhere on the page.
  useEffect(() => {
    const onKey = (e: KeyboardEvent) => {
      const isMod = e.metaKey || e.ctrlKey;
      if (isMod && e.key.toLowerCase() === "k") {
        e.preventDefault();
        inputRef.current?.focus();
        inputRef.current?.select();
      } else if (e.key === "Escape" && document.activeElement === inputRef.current) {
        setQuery("");
        inputRef.current?.blur();
      }
    };
    window.addEventListener("keydown", onKey);
    return () => window.removeEventListener("keydown", onKey);
  }, []);

  const hits = useMemo(() => search(items, debounced), [items, debounced]);
  const showPanel = debounced.trim().length >= MIN_QUERY_LEN;
  const totalCompanies = items.length;

  const clear = () => {
    setQuery("");
    setDebounced("");
    inputRef.current?.focus();
  };

  return (
    <section className="container-x pt-10 pb-2">
      <div className="bg-surface border border-border rounded-lg overflow-hidden">
        {/* Header / input row */}
        <div className="px-5 py-4 border-b border-border-soft">
          <div className="flex items-baseline justify-between gap-3 mb-2">
            <h2 className="text-base font-semibold text-fg">
              Quick search
            </h2>
            <span className="text-xs text-muted">
              {totalCompanies.toLocaleString()} companies · CK no · SARS Income Tax · PAYE · VAT · UIF · COID
            </span>
          </div>
          <div className="relative">
            <span
              aria-hidden="true"
              className="absolute inset-y-0 left-0 flex items-center pl-3 text-muted pointer-events-none"
            >
              <svg viewBox="0 0 24 24" className="w-4 h-4" fill="none" stroke="currentColor" strokeWidth="2">
                <circle cx="11" cy="11" r="7" />
                <path d="m21 21-4.3-4.3" strokeLinecap="round" />
              </svg>
            </span>
            <input
              ref={inputRef}
              type="text"
              inputMode="search"
              autoComplete="off"
              spellCheck={false}
              value={query}
              onChange={(e) => setQuery(e.target.value)}
              placeholder="Type a CK number or SARS tax number…"
              aria-label="Search companies by CK number or tax number"
              className="w-full bg-bg border border-border rounded-md pl-9 pr-20 py-2.5 text-sm text-fg placeholder:text-muted focus:outline-none focus:border-accent transition-colors font-mono"
            />
            <div className="absolute inset-y-0 right-0 flex items-center pr-2 gap-1">
              {query && (
                <button
                  type="button"
                  onClick={clear}
                  aria-label="Clear search"
                  className="text-muted hover:text-fg p-1 rounded transition-colors"
                >
                  <svg viewBox="0 0 24 24" className="w-4 h-4" fill="none" stroke="currentColor" strokeWidth="2">
                    <path d="M18 6L6 18M6 6l12 12" strokeLinecap="round" />
                  </svg>
                </button>
              )}
              <kbd className="hidden sm:inline-flex items-center gap-0.5 px-1.5 py-0.5 text-[10px] font-medium text-muted bg-surface-warm border border-border rounded">
                Ctrl K
              </kbd>
            </div>
          </div>
        </div>

        {/* Results panel — only renders when query is long enough */}
        {showPanel && (
          <div>
            <div className="px-5 py-2 text-xs text-muted border-b border-border-soft">
              {hits.length === 0
                ? `No matches for "${debounced.trim()}"`
                : `${hits.length}${hits.length === MAX_RESULTS ? "+" : ""} match${hits.length === 1 ? "" : "es"} for "${debounced.trim()}"`}
            </div>
            {hits.length === 0 ? (
              <div className="px-5 py-8 text-center text-sm text-muted">
                Nothing matched. Double-check the number — these are
                the fields we search:{" "}
                <span className="font-mono text-fg-2">
                  enterprise_no, sars_tax_number, sars_paye_no, sars_vat_no, uif_registration_number, compensation_fund_registration_number
                </span>.
              </div>
            ) : (
              <ul>
                {hits.map((hit, idx) => (
                  <li
                    key={`${hit.id}-${idx}`}
                    className="border-b border-border-soft last:border-b-0"
                  >
                    <Link
                      href={hit.href}
                      className="flex items-center gap-3 px-5 py-3 hover:bg-surface-warm transition-colors no-underline"
                    >
                      <span className="inline-flex items-center px-1.5 py-0.5 rounded text-[10px] font-semibold tracking-wide uppercase bg-accent/10 text-accent border border-accent/20 flex-shrink-0">
                        Company
                      </span>
                      <div className="min-w-0 flex-1">
                        <p className="text-sm font-semibold text-fg truncate">
                          {text(hit.enterprise_name) || "—"}
                        </p>
                        <p className="text-xs text-muted mt-0.5">
                          <span className="font-mono">{hit.enterprise_no}</span>
                          <span className="mx-2 text-meta">·</span>
                          <span className="text-fg-2 font-medium">{hit.fieldLabel}:</span>{" "}
                          <span className="font-mono">{hit.fieldValue}</span>
                        </p>
                      </div>
                      <svg
                        aria-hidden="true"
                        viewBox="0 0 24 24"
                        className="w-4 h-4 text-muted flex-shrink-0"
                        fill="none"
                        stroke="currentColor"
                        strokeWidth="2"
                      >
                        <path d="m9 18 6-6-6-6" strokeLinecap="round" strokeLinejoin="round" />
                      </svg>
                    </Link>
                  </li>
                ))}
              </ul>
            )}
          </div>
        )}

        {/* Idle hint when no query */}
        {!showPanel && (
          <div className="px-5 py-3 text-xs text-muted">
            Type at least {MIN_QUERY_LEN} characters. Results open the company detail page in a click.
          </div>
        )}
      </div>
    </section>
  );
}