From db4375b33089c293684164a9b5a74bf58ee57f93 Mon Sep 17 00:00:00 2001
From: Andre Henn <henn@terrestris.de>
Date: Tue, 20 Feb 2024 18:27:16 +0100
Subject: [PATCH] feat: introduce useNominatim hook

---
 src/Hooks/useNominatim/useNominatim.spec.tsx |   7 +
 src/Hooks/useNominatim/useNominatim.ts       | 172 +++++++++++++++++++
 2 files changed, 179 insertions(+)
 create mode 100644 src/Hooks/useNominatim/useNominatim.spec.tsx
 create mode 100644 src/Hooks/useNominatim/useNominatim.ts

diff --git a/src/Hooks/useNominatim/useNominatim.spec.tsx b/src/Hooks/useNominatim/useNominatim.spec.tsx
new file mode 100644
index 00000000..2ec59da5
--- /dev/null
+++ b/src/Hooks/useNominatim/useNominatim.spec.tsx
@@ -0,0 +1,7 @@
+import { useNominatim } from './useNominatim';
+
+describe('basic test', () => {
+  it('is defined', () => {
+    expect(useNominatim).toBeDefined();
+  });
+});
diff --git a/src/Hooks/useNominatim/useNominatim.ts b/src/Hooks/useNominatim/useNominatim.ts
new file mode 100644
index 00000000..2369db52
--- /dev/null
+++ b/src/Hooks/useNominatim/useNominatim.ts
@@ -0,0 +1,172 @@
+
+
+// See https://nominatim.org/release-docs/develop/api/Output/ for some more information
+import { UrlUtil } from '@terrestris/base-util';
+import Logger from '@terrestris/base-util/dist/Logger';
+import { GeoJSON } from 'geojson';
+import { useEffect, useState } from 'react';
+
+export type NominatimPlace = {
+  // eslint-disable-next-line camelcase
+  place_id: number;
+  // eslint-disable-next-line camelcase
+  osm_type: string;
+  // eslint-disable-next-line camelcase
+  osm_id: number;
+  boundingbox: string[];
+  // eslint-disable-next-line camelcase
+  display_name: string;
+  category: string;
+  type: string;
+  importance: number;
+  icon?: string;
+  address?: any;
+  extratags?: any;
+  namedetails?: any;
+  geojson: GeoJSON;
+  licence: string;
+};
+
+export type UseNominatimArgs = {
+  searchTerm: string;
+  /**
+   * Time in miliseconds that the search waits before doing a request.
+   */
+  debounceTime?: number;
+  /**
+   * The Nominatim Base URL. See https://wiki.openstreetmap.org/wiki/Nominatim
+   */
+  nominatimBaseUrl?: string;
+  /**
+   * Output format.
+   */
+  format?: string;
+  /**
+   * The preferred area to find search results in [left],[top],[right],[bottom].
+   */
+  viewBox?: string;
+  /**
+   * Restrict the results to only items contained with the bounding box.
+   * Restricting the results to the bounding box also enables searching by
+   * amenity only. For example a search query of just "[pub]" would normally be
+   * rejected but with bounded=1 will result in a list of items matching within
+   * the bounding box.
+   */
+  bounded?: number;
+  /**
+   * Output geometry of results in geojson format.
+   */
+  polygonGeoJSON?: number;
+  /**
+   * Include a breakdown of the address into elements.
+   */
+  addressDetails?: number;
+  /**
+   * Limit the number of returned results.
+   */
+  limit?: number;
+  /**
+   * Limit search results to a specific country (or a list of countries).
+   * [countrycode] should be the ISO 3166-1alpha2 code, e.g. gb for the United
+   * Kingdom, de for Germany, etc.
+   */
+  countryCodes?: string;
+  /**
+   * Preferred language order for showing search results, overrides the value
+   * specified in the "Accept-Language" HTTP header. Either use a standard RFC2616
+   * accept-language string or a simple comma-separated list of language codes.
+   */
+  searchResultLanguage?: string;
+  /**
+   * A callback function which gets called if data fetching has failed.
+   */
+  onFetchError?: (error: any) => void;
+  /**
+   * The minimal amount of characters in the input to start a search.
+   */
+  minChars?: number;
+};
+
+export const useNominatim = ({
+  addressDetails = 1,
+  bounded = 1,
+  countryCodes = 'de',
+  debounceTime = 300,
+  format = 'json',
+  limit = 10,
+  minChars = 3,
+  nominatimBaseUrl = 'https://nominatim.openstreetmap.org/search?',
+  onFetchError,
+  polygonGeoJSON = 1,
+  searchResultLanguage,
+  searchTerm,
+  viewBox = '-180,90,180,-90'
+}: UseNominatimArgs): NominatimPlace[] | undefined => {
+
+  const [nominatimResults, setNominatimResults] = useState<NominatimPlace[]>([]);
+
+  const onError = (error: any) => {
+    Logger.error(`Error while requesting Nominatim: ${error}`);
+    onFetchError?.(error);
+  };
+
+  // TODO abort controller
+  const fetchResults = async (baseParams: any) => {
+    const getRequestParams = UrlUtil.objectToRequestString(baseParams);
+    try {
+      let fetchOpts: RequestInit = {};
+      if (searchResultLanguage) {
+        fetchOpts = {
+          headers: {
+            'accept-language': searchResultLanguage
+          }
+        };
+      }
+      const response = await fetch(`${nominatimBaseUrl}${getRequestParams}`, fetchOpts);
+      if (!response.ok) {
+        onError(new Error(`Return code: ${response.status}`));
+      }
+      const responseJson = await response.json();
+      setNominatimResults(responseJson);
+    } catch (error) {
+      onError(error);
+    }
+  };
+
+  /**
+   * Trigger search when searchTerm has changed
+   */
+  useEffect(() => {
+    setNominatimResults([]);
+
+    if (!searchTerm) {
+      setNominatimResults([]);
+    }
+
+    if (!searchTerm || searchTerm.length < minChars) {
+      return () => undefined;
+    }
+
+    const timeout = setTimeout(async () => {
+      await fetchResults({
+        format: format,
+        viewbox: viewBox,
+        bounded: bounded,
+        // eslint-disable-next-line camelcase
+        polygon_geojson: polygonGeoJSON,
+        addressdetails: addressDetails,
+        limit: limit,
+        countrycodes: countryCodes,
+        q: searchTerm
+      });
+    }, debounceTime);
+
+    return () => {
+      clearTimeout(timeout);
+    };
+  }, [searchTerm]);
+
+  return nominatimResults;
+};
+
+export default useNominatim;