import { useState, useCallback, useRef, useEffect } from 'react';
import type { PostcodeGeometry } from '../../types';
import { authHeaders } from '../../lib/api';
import { useIsMobile } from '../../hooks/useIsMobile';
import { useLocationSearch, type SearchResult } from '../../hooks/useLocationSearch';
import { PlaceSearchInput } from '../ui/PlaceSearchInput';
import { SearchIcon } from '../ui/icons/SearchIcon';

export interface SearchedLocation {
  postcode: string;
  geometry: PostcodeGeometry;
}

const ZOOM_FOR_TYPE: Record<string, number> = {
  city: 10,
  borough: 12,
  town: 13,
  suburb: 14,
  quarter: 14,
  neighbourhood: 14,
  village: 14,
  station: 15,
  island: 12,
  locality: 14,
  hamlet: 15,
  isolated_dwelling: 16,
};

export default function LocationSearch({
  onFlyTo,
  onLocationSearched,
  onMouseEnter,
}: {
  onFlyTo: (lat: number, lng: number, zoom: number) => void;
  onLocationSearched?: (postcode: SearchedLocation | null) => void;
  onMouseEnter?: () => void;
}) {
  const search = useLocationSearch();
  const [error, setError] = useState<string | null>(null);
  const [loading, setLoading] = useState(false);
  const [expanded, setExpanded] = useState(false);
  const isMobile = useIsMobile();
  const containerRef = useRef<HTMLDivElement>(null);
  const inputRef = useRef<HTMLInputElement>(null);

  // Close on outside click
  useEffect(() => {
    const handler = (e: MouseEvent) => {
      if (containerRef.current && !containerRef.current.contains(e.target as Node)) {
        search.close();
        if (isMobile) setExpanded(false);
      }
    };
    document.addEventListener('mousedown', handler);
    return () => document.removeEventListener('mousedown', handler);
  }, [isMobile, search.close]);

  // Focus input when expanding on mobile
  useEffect(() => {
    if (isMobile && expanded) {
      inputRef.current?.focus();
    }
  }, [isMobile, expanded]);

  const selectResult = useCallback(
    async (result: SearchResult) => {
      if (result.type === 'place') {
        const zoom = ZOOM_FOR_TYPE[result.place_type] ?? 14;
        onFlyTo(result.lat, result.lon, zoom);
        onLocationSearched?.(null);
        search.clear();
        if (isMobile) setExpanded(false);
        return;
      }

      // Postcode — fetch geometry
      setError(null);
      setLoading(true);
      search.close();
      try {
        const res = await fetch(`/api/postcode/${encodeURIComponent(result.label)}`, authHeaders());
        if (!res.ok) {
          setError('Postcode not found');
          return;
        }
        const json: {
          postcode: string;
          latitude: number;
          longitude: number;
          geometry: PostcodeGeometry;
        } = await res.json();
        onFlyTo(json.latitude, json.longitude, 16);
        onLocationSearched?.({ postcode: json.postcode, geometry: json.geometry });
        search.clear();
        if (isMobile) setExpanded(false);
      } catch {
        setError('Lookup failed');
      } finally {
        setLoading(false);
      }
    },
    [onFlyTo, onLocationSearched, isMobile, search]
  );

  // Mobile collapsed state: just a search icon button
  if (isMobile && !expanded) {
    return (
      <button
        type="button"
        onClick={() => setExpanded(true)}
        className="absolute top-3 left-3 z-10 p-2 bg-white dark:bg-warm-800 rounded shadow-lg"
        aria-label="Search places or postcodes"
      >
        <SearchIcon className="w-5 h-5 text-warm-600 dark:text-warm-300" />
      </button>
    );
  }

  return (
    <div
      ref={containerRef}
      data-tutorial="search"
      className="absolute top-3 left-3 z-10 flex flex-col"
      onMouseEnter={onMouseEnter}
    >
      <div className="flex items-center shadow-lg rounded bg-white dark:bg-warm-800">
        <SearchIcon className="w-4 h-4 text-warm-400 dark:text-warm-500 ml-3 shrink-0" />
        <PlaceSearchInput
          search={search}
          onSelect={selectResult}
          loading={loading}
          placeholder="Search places or postcodes..."
          size="sm"
          inputClassName="px-2 py-2 text-sm w-56 border-none outline-none bg-transparent text-warm-700 dark:text-warm-200 placeholder-warm-400 dark:placeholder-warm-500"
          inputRef={inputRef}
          onInputChange={() => setError(null)}
        />
      </div>

      {error && (
        <span className="text-xs text-red-600 dark:text-red-300 bg-white/90 dark:bg-warm-800/90 rounded px-2 py-0.5 shadow mt-1">
          {error}
        </span>
      )}
    </div>
  );
}