perfect-postcode/frontend/src/components/home/HomeDemo.tsx
2026-02-15 22:39:53 +00:00

275 lines
10 KiB
TypeScript

import { useState, useEffect, useCallback, useRef, useMemo } from 'react';
import MapComponent from '../map/Map';
import { Slider } from '../ui/Slider';
import { apiUrl, assertOk, authHeaders, logNonAbortError } from '../../lib/api';
import { formatValue } from '../../lib/format';
import { FEATURE_GRADIENT, DENSITY_GRADIENT, DENSITY_GRADIENT_DARK } from '../../lib/consts';
import { gradientToCss } from '../../lib/utils';
import { TickerValue } from '../ui/TickerValue';
import { SpinnerIcon } from '../ui/icons/SpinnerIcon';
import type { FeatureMeta, HexagonData } from '../../types';
const DEMO_VIEW = { longitude: -1.9, latitude: 52.2, zoom: 5.5, pitch: 0 };
const DEMO_FEATURE_NAMES = ['Estimated current price', 'Good+ primary schools within 5km', 'Number of restaurants within 2km'];
const DEMO_BOUNDS = '49,-9.5,57,5';
const DEMO_RESOLUTION = 5;
const noop = () => {};
const featureGradientStyle = gradientToCss(FEATURE_GRADIENT);
interface HomeDemoProps {
features: FeatureMeta[];
theme: 'light' | 'dark';
}
export default function HomeDemo({ features, theme }: HomeDemoProps) {
const [hexData, setHexData] = useState<HexagonData[]>([]);
const [loading, setLoading] = useState(true);
const [fetching, setFetching] = useState(false);
const [sliderValues, setSliderValues] = useState<Record<string, [number, number]>>({});
const [activeFeature, setActiveFeature] = useState<string | null>(null);
const [dragValue, setDragValue] = useState<[number, number] | null>(null);
const [dragHexData, setDragHexData] = useState<HexagonData[] | null>(null);
const fetchTimeoutRef = useRef<ReturnType<typeof setTimeout>>();
const abortRef = useRef<AbortController>();
const dragAbortRef = useRef<AbortController>();
const activeFeatureRef = useRef<string | null>(null);
activeFeatureRef.current = activeFeature;
const demoFeatures = useMemo(
() =>
DEMO_FEATURE_NAMES.map((name) => features.find((f) => f.name === name)).filter(
Boolean
) as FeatureMeta[],
[features]
);
// Initialize slider values when features arrive
useEffect(() => {
if (demoFeatures.length === 0) return;
const initial: Record<string, [number, number]> = {};
for (const f of demoFeatures) {
if (f.min != null && f.max != null) {
initial[f.name] = [f.min, f.max];
}
}
setSliderValues(initial);
}, [demoFeatures]);
// Feature coloring only during drag; density (property count) otherwise
const viewFeatureName = activeFeature;
const viewMeta = viewFeatureName ? features.find((f) => f.name === viewFeatureName) : null;
const colorRange: [number, number] | null =
viewMeta?.min != null && viewMeta?.max != null ? [viewMeta.min, viewMeta.max] : null;
const filterRange: [number, number] | null = activeFeature && dragValue ? dragValue : null;
const displayData = dragHexData ?? hexData;
// Fetch hexagons (debounced) — skipped while dragging
const fetchHexagons = useCallback(() => {
if (activeFeatureRef.current) return;
if (features.length === 0 || Object.keys(sliderValues).length === 0) return;
const params = new URLSearchParams({
resolution: String(DEMO_RESOLUTION),
bounds: DEMO_BOUNDS,
});
const filterParts: string[] = [];
for (const [name, [min, max]] of Object.entries(sliderValues)) {
const meta = features.find((f) => f.name === name);
if (meta?.min != null && meta?.max != null) {
if (min !== meta.min || max !== meta.max) {
filterParts.push(`${name}:${min}:${max}`);
}
}
}
if (filterParts.length > 0) {
params.set('filters', filterParts.join(','));
}
abortRef.current?.abort();
abortRef.current = new AbortController();
setFetching(true);
fetch(apiUrl('hexagons', params), authHeaders({ signal: abortRef.current.signal }))
.then((res) => {
assertOk(res, 'hexagons');
return res.json();
})
.then((data: { features: HexagonData[] }) => {
setHexData(data.features);
setLoading(false);
setFetching(false);
})
.catch((err) => {
logNonAbortError('Failed to fetch demo hexagons', err);
setFetching(false);
});
}, [features, sliderValues]);
useEffect(() => {
clearTimeout(fetchTimeoutRef.current);
fetchTimeoutRef.current = setTimeout(fetchHexagons, 200);
return () => clearTimeout(fetchTimeoutRef.current);
}, [fetchHexagons]);
useEffect(() => {
return () => {
abortRef.current?.abort();
dragAbortRef.current?.abort();
clearTimeout(fetchTimeoutRef.current);
};
}, []);
// Drag start: fetch preview data with other filters only, fields=dragged feature
const handleDragStart = useCallback(
(name: string) => {
setActiveFeature(name);
const currentVal = sliderValues[name];
const meta = features.find((f) => f.name === name);
setDragValue(currentVal || (meta?.min != null ? [meta.min, meta.max!] : null));
const params = new URLSearchParams({
resolution: String(DEMO_RESOLUTION),
bounds: DEMO_BOUNDS,
});
const otherFilterParts: string[] = [];
for (const [n, [min, max]] of Object.entries(sliderValues)) {
if (n === name) continue;
const m = features.find((f) => f.name === n);
if (m?.min != null && m?.max != null && (min !== m.min || max !== m.max)) {
otherFilterParts.push(`${n}:${min}:${max}`);
}
}
if (otherFilterParts.length > 0) {
params.set('filters', otherFilterParts.join(','));
}
params.set('fields', name);
dragAbortRef.current?.abort();
dragAbortRef.current = new AbortController();
fetch(apiUrl('hexagons', params), authHeaders({ signal: dragAbortRef.current.signal }))
.then((res) => {
assertOk(res, 'hexagons');
return res.json();
})
.then((data: { features: HexagonData[] }) => setDragHexData(data.features))
.catch((err) => logNonAbortError('Failed to fetch demo drag data', err));
},
[features, sliderValues]
);
const handleSliderChange = useCallback(
(name: string, value: [number, number]) => {
setSliderValues((prev) => ({ ...prev, [name]: value }));
if (activeFeatureRef.current === name) {
setDragValue(value);
}
},
[]
);
const handleDragEnd = useCallback(() => {
setActiveFeature(null);
setDragValue(null);
setDragHexData(null);
}, []);
return (
<div className="flex flex-col md:flex-row gap-6">
{/* Map */}
<div className="relative rounded-xl overflow-hidden shadow-sm aspect-[4/3] md:w-3/5">
<div className="absolute inset-0 z-50 cursor-default" />
<div className="absolute inset-0">
<MapComponent
data={displayData}
postcodeData={[]}
usePostcodeView={false}
pois={[]}
onViewChange={noop}
viewFeature={viewFeatureName}
colorRange={colorRange}
filterRange={filterRange}
viewSource={activeFeature ? 'drag' : null}
onCancelPin={noop}
features={features}
selectedHexagonId={null}
hoveredHexagonId={null}
onHexagonClick={noop}
onHexagonHover={noop}
initialViewState={DEMO_VIEW}
theme={theme}
screenshotMode={true}
hideLegend={true}
/>
</div>
{loading && (
<div className="absolute inset-0 z-50 flex items-center justify-center bg-warm-50/80 dark:bg-navy-950/80 backdrop-blur-sm">
<div className="flex flex-col items-center gap-4">
<SpinnerIcon className="w-12 h-12 text-teal-600 dark:text-teal-400 animate-spin" />
<p className="text-warm-600 dark:text-warm-300 text-sm font-medium">
Connecting to server...
</p>
</div>
</div>
)}
{!loading && fetching && (
<div className="absolute top-3 left-3 z-50 bg-white dark:bg-navy-800 dark:text-warm-200 px-2 py-1 rounded shadow text-xs">
Loading...
</div>
)}
{/* Colour spectrum legend */}
<div className="absolute bottom-3 left-3 right-3 z-50 pointer-events-none">
<div className="bg-white/90 dark:bg-warm-800/90 rounded-lg px-3 py-2 backdrop-blur-sm text-xs">
<div className="font-semibold text-navy-950 dark:text-warm-100 mb-1 truncate">
{activeFeature ? viewMeta?.name || activeFeature : 'Property density'}
</div>
<div
className="h-2.5 rounded-full"
style={{
background: activeFeature
? featureGradientStyle
: gradientToCss(theme === 'dark' ? DENSITY_GRADIENT_DARK : DENSITY_GRADIENT),
}}
/>
{colorRange && (
<div className="flex justify-between mt-0.5 text-warm-500 dark:text-warm-400">
<TickerValue text={formatValue(colorRange[0], viewMeta ?? undefined)} />
<TickerValue text={formatValue(colorRange[1], viewMeta ?? undefined)} />
</div>
)}
</div>
</div>
</div>
{/* Sliders */}
<div className="md:w-2/5 flex flex-col justify-center space-y-6">
{demoFeatures.map((feature) => {
const value = sliderValues[feature.name];
if (!value || feature.min == null || feature.max == null) return null;
const isActive = activeFeature === feature.name;
return (
<div
key={feature.name}
className={`rounded-lg p-3 ${isActive ? 'ring-2 ring-teal-400 bg-teal-50 dark:bg-teal-900/30' : ''}`}
>
<div className="flex justify-between mb-2">
<span className="text-sm font-semibold text-navy-950 dark:text-warm-100">
{feature.name}
</span>
<span className="text-sm text-warm-500 dark:text-warm-400">
{formatValue(value[0], feature)} &ndash; {formatValue(value[1], feature)}
</span>
</div>
<Slider
min={feature.min}
max={feature.max}
step={feature.step || 1}
value={[value[0], value[1]]}
onValueChange={([min, max]) => handleSliderChange(feature.name, [min, max])}
onPointerDown={() => handleDragStart(feature.name)}
onPointerUp={() => handleDragEnd()}
/>
</div>
);
})}
</div>
</div>
);
}