import { lazy, Suspense, useEffect, useState } from 'react';
import { useFetcher } from 'react-router';
import type { LatLngTuple } from 'leaflet';
import ClientOnly from '../../../components/ClientOnly';
import useDebouncedValue from '../../../hooks/useDebouncedValue';
import type { SimplifiedBrewery } from '../breweries.server';
import type { loader as nearbyLoader } from '../routes/breweries-nearby';
import { formatDistance, type DistanceUnit } from '../utils/distance';
import type { NearbyMapPin } from './NearbyBreweryMap';

const NearbyBreweryMap = lazy(() => import('./NearbyBreweryMap'));

const MAP_PLACEHOLDER_CLASS = 'skeleton min-h-[30rem] h-full w-full rounded-box';
const DEFAULT_RADIUS_KM = 120;
const MIN_RADIUS_KM = 10;
const MAX_RADIUS_KM = 300;
const RADIUS_STEP_KM = 10;
const RADIUS_DEBOUNCE_MS = 300;

export interface FeaturedPin {
    id: string;
    name: string;
    latitude: number;
    longitude: number;
}

interface FallbackCenter {
    latitude: number;
    longitude: number;
    label: string;
}

interface NearbyBreweriesSectionProps {
    featured: FeaturedPin | null;
    fallbackCenter: FallbackCenter | null;
    selectedId: string | null;
    onSelect: (id: string) => void;
}

// Notes aren't tracked on brewery locations yet - see BREWERY_INDEX_HANDOFF.md.
const FILLER_NOTE = 'A stop worth the detour.';

const cardClassName = (selected: boolean) =>
    `card card-sm card-border bg-base-100 text-left shadow transition-shadow hover:shadow-lg ${
        selected ? 'border-2 border-primary' : ''
    }`;

interface BreweriesNearByHeaderParams {
    center: LatLngTuple | null;
    withDistance: { brewery: SimplifiedBrewery; distanceMetres: number }[];
    radiusKm: number;
    unit: 'km' | 'mi';
    centerLabel: string;
}

const BreweriesNearByHeader = ({
    center,
    centerLabel,
    radiusKm,
    unit,
    withDistance,
}: BreweriesNearByHeaderParams) => {
    return (
        <div className="flex items-baseline justify-between gap-4 flex-wrap mb-3.5">
            <h2 className="font-serif text-2xl m-0">Breweries near you</h2>
            <span className="text-sm text-base-content/60">
                {center
                    ? `${withDistance.length} within ${formatDistance(radiusKm * 1000, unit)} of ${centerLabel}`
                    : 'Finding breweries near you…'}
            </span>
        </div>
    );
};

interface RadiusUnitControlsProps {
    radiusKm: number;
    unit: DistanceUnit;
    onRadiusChange: (event: React.ChangeEvent<HTMLInputElement>) => void;
    onSelectKm: () => void;
    onSelectMi: () => void;
}

const RadiusUnitControls = ({
    radiusKm,
    unit,
    onRadiusChange,
    onSelectKm,
    onSelectMi,
}: RadiusUnitControlsProps) => {
    return (
        <div className="flex items-center justify-between gap-3">
            <label className="flex-1 flex flex-col gap-1 text-sm text-base-content/70">
                <span className="flex justify-between">
                    <span>Search radius</span>
                    <span className="font-semibold">{formatDistance(radiusKm * 1000, unit)}</span>
                </span>
                <input
                    type="range"
                    min={MIN_RADIUS_KM}
                    max={MAX_RADIUS_KM}
                    step={RADIUS_STEP_KM}
                    value={radiusKm}
                    onChange={onRadiusChange}
                    className="range range-primary range-sm"
                />
            </label>
            <div className="join self-end">
                <button
                    type="button"
                    onClick={onSelectKm}
                    className={`btn btn-xs join-item ${unit === 'km' ? 'btn-active' : ''}`}
                >
                    km
                </button>
                <button
                    type="button"
                    onClick={onSelectMi}
                    className={`btn btn-xs join-item ${unit === 'mi' ? 'btn-active' : ''}`}
                >
                    mi
                </button>
            </div>
        </div>
    );
};

interface BreweryWithDistance {
    brewery: SimplifiedBrewery;
    distanceMetres: number;
}

interface NearbyBreweryListProps {
    withDistance: BreweryWithDistance[];
    center: LatLngTuple | null;
    radiusKm: number;
    unit: DistanceUnit;
    renderItem: (item: BreweryWithDistance) => React.JSX.Element;
}

const NearbyBreweryList = ({
    withDistance,
    center,
    radiusKm,
    unit,
    renderItem,
}: NearbyBreweryListProps) => {
    return (
        <>
            {withDistance.length === 0 && center && (
                <p className="text-sm text-base-content/60">
                    No partner breweries within {formatDistance(radiusKm * 1000, unit)}.
                </p>
            )}
            {withDistance.map(renderItem)}
        </>
    );
};

interface ChangeLocationButtonProps {
    onClick: () => void;
}

const ChangeLocationButton = ({ onClick }: ChangeLocationButtonProps) => {
    return (
        <div className="pt-1">
            <button type="button" onClick={onClick} className="btn btn-ghost btn-sm">
                Change location
            </button>
        </div>
    );
};

interface ClientOnlyMapProps {
    render: () => React.JSX.Element;
}

const ClientOnlyMap = ({ render }: ClientOnlyMapProps) => {
    return <ClientOnly fallback={<div className={MAP_PLACEHOLDER_CLASS} />}>{render}</ClientOnly>;
};

const NearbyBreweriesSection = ({
    featured,
    fallbackCenter,
    selectedId,
    onSelect,
}: NearbyBreweriesSectionProps) => {
    const [userLocation, setUserLocation] = useState<LatLngTuple | null>(null);
    const [locationLabel, setLocationLabel] = useState('your location');
    const [geoAttempted, setGeoAttempted] = useState(false);
    const [radiusKm, setRadiusKm] = useState(DEFAULT_RADIUS_KM);
    const debouncedRadiusKm = useDebouncedValue(radiusKm, RADIUS_DEBOUNCE_MS);
    const [unit, setUnit] = useState<DistanceUnit>('km');
    const fetcher = useFetcher<typeof nearbyLoader>();

    const requestGeolocation = () => {
        if (!navigator.geolocation) {
            Promise.resolve().then(() => setGeoAttempted(true));
            return;
        }
        navigator.geolocation.getCurrentPosition(
            (pos) => {
                setUserLocation([pos.coords.latitude, pos.coords.longitude]);
                setLocationLabel('your location');
                setGeoAttempted(true);
            },
            () => setGeoAttempted(true),
            { enableHighAccuracy: true },
        );
    };

    useEffect(() => {
        requestGeolocation();
    }, []);

    const center: LatLngTuple | null =
        userLocation ??
        (geoAttempted && fallbackCenter
            ? [fallbackCenter.latitude, fallbackCenter.longitude]
            : null);
    const centerLabel = userLocation ? locationLabel : (fallbackCenter?.label ?? locationLabel);

    useEffect(() => {
        if (!center) return;
        fetcher.load(
            `/breweries/nearby?latitude=${center[0]}&longitude=${center[1]}&rangeInMetres=${debouncedRadiusKm * 1000}`,
        );
        // eslint-disable-next-line react-hooks/exhaustive-deps
    }, [center?.[0], center?.[1], debouncedRadiusKm]);

    const nearby: SimplifiedBrewery[] = fetcher.data?.breweries ?? [];
    const withDistance = center
        ? nearby
              .filter((b) => b.location?.coordinates && b.distanceMetres !== null)
              .map((b) => ({
                  brewery: b,
                  distanceMetres: b.distanceMetres as number,
              }))
              .sort((a, b) => a.distanceMetres - b.distanceMetres)
        : [];

    const pins: NearbyMapPin[] = withDistance.map(({ brewery }) => ({
        id: brewery.breweryPostId,
        name: brewery.breweryName,
        cityLabel: brewery.location
            ? `${brewery.location.cityName}, ${brewery.location.stateProvinceCode}`
            : null,
        latitude: brewery.location!.coordinates!.latitude,
        longitude: brewery.location!.coordinates!.longitude,
    }));
    if (featured && !pins.some((p) => p.id === featured.id)) {
        pins.push({
            id: featured.id,
            name: featured.name,
            cityLabel: null,
            latitude: featured.latitude,
            longitude: featured.longitude,
        });
    }

    return (
        <section id="breweries-near-you" className="max-w-7xl mx-auto px-5 pt-11">
            <BreweriesNearByHeader
                center={center}
                withDistance={withDistance}
                radiusKm={radiusKm}
                unit={unit}
                centerLabel={centerLabel}
            />

            <div className="grid gap-5 items-stretch md:grid-cols-[22rem_1fr]">
                <div className="flex flex-col gap-3 order-2 md:order-1">
                    <RadiusUnitControls
                        radiusKm={radiusKm}
                        unit={unit}
                        onRadiusChange={(e) => setRadiusKm(Number(e.target.value))}
                        onSelectKm={() => setUnit('km')}
                        onSelectMi={() => setUnit('mi')}
                    />
                    <NearbyBreweryList
                        withDistance={withDistance}
                        center={center}
                        radiusKm={radiusKm}
                        unit={unit}
                        renderItem={({ brewery, distanceMetres }) => (
                            <button
                                key={brewery.breweryPostId}
                                type="button"
                                onClick={() => onSelect(brewery.breweryPostId)}
                                className={cardClassName(selectedId === brewery.breweryPostId)}
                            >
                                <div className="card-body">
                                    <div className="flex justify-between items-baseline gap-3">
                                        <h3 className="card-title font-serif text-lg">
                                            {brewery.breweryName}
                                        </h3>
                                        <span className="text-sm font-semibold text-primary whitespace-nowrap">
                                            {formatDistance(distanceMetres, unit)}
                                        </span>
                                    </div>
                                    {brewery.location && (
                                        <div className="text-sm text-base-content/60">
                                            {brewery.location.cityName},{' '}
                                            {brewery.location.stateProvinceCode}
                                        </div>
                                    )}
                                    <div className="text-sm mt-2">{FILLER_NOTE}</div>
                                </div>
                            </button>
                        )}
                    />
                    <ChangeLocationButton onClick={requestGeolocation} />
                </div>

                <div className="order-1 md:order-2">
                    <ClientOnlyMap
                        render={() =>
                            center ? (
                                <Suspense fallback={<div className={MAP_PLACEHOLDER_CLASS} />}>
                                    <NearbyBreweryMap
                                        pins={pins}
                                        selectedId={selectedId}
                                        onSelect={onSelect}
                                        userLocation={userLocation}
                                        userLocationLabel={centerLabel}
                                    />
                                </Suspense>
                            ) : (
                                <div className={MAP_PLACEHOLDER_CLASS} />
                            )
                        }
                    />
                </div>
            </div>
        </section>
    );
};

export default NearbyBreweriesSection;