MapComplete/src/Logic/Search/GeocodingProvider.ts

import { BBox } from "../BBox"
import { Feature, Geometry } from "geojson"
import { DefaultPinIcon } from "../../Models/Constants"
import { Store } from "../UIEventSource"
import * as search from "../../assets/generated/layers/search.json"
import LayerConfig from "../../Models/ThemeConfig/LayerConfig"
import { LayerConfigJson } from "../../Models/ThemeConfig/Json/LayerConfigJson"
import { GeoOperations } from "../GeoOperations"

export type GeocodingCategory =
    | "coordinate"
    | "city"
    | "house"
    | "street"
    | "locality"
    | "country"
    | "train_station"
    | "county"
    | "airport"
    | "shop"

export type GeocodeResult = {
    /**
     * The name of the feature being displayed
     */
    display_name: string
    /**
     * Some optional, extra information
     */
    description?: string | Promise<string>
    feature?: Feature
    lat: number
    lon: number
    /**
     * Format:
     * [lat, lat, lon, lon]
     */
    boundingbox?: number[]
    osm_type?: "node" | "way" | "relation"
    osm_id: string
    category?: GeocodingCategory
    payload?: object
    source?: string
}

export interface GeocodingOptions {
    bbox?: BBox
}

export default interface GeocodingProvider {
    readonly name: string

    /**
     * Performs search.
     * Note: the result _must_ return an empty list in the case of no results.
     * Undefined might be interpreted by clients as "still running"
     */
    search(query: string, options?: GeocodingOptions): Promise<GeocodeResult[]>

    /**
     * @param query
     * @param options
     */
    suggest?(query: string, options?: GeocodingOptions): Store<GeocodeResult[]>
}

export type ReverseGeocodingResult = Feature<
    Geometry,
    {
        osm_id: number
        osm_type: "node" | "way" | "relation"
        country: string
        city: string
        countrycode: string
        type: GeocodingCategory
        street: string
    }
>

export interface ReverseGeocodingProvider {
    reverseSearch(
        coordinate: { lon: number; lat: number },
        zoom: number,
        language?: string
    ): Promise<ReverseGeocodingResult[]>
}

export class GeocodingUtils {
    public static searchLayer = GeocodingUtils.initSearchLayer()

    private static initSearchLayer(): LayerConfig {
        if (search["id"] === undefined) {
            // We are resetting the layeroverview; trying to parse is useless
            return undefined
        }
        return new LayerConfig(<LayerConfigJson>search, "search")
    }

    public static categoryToZoomLevel: Record<GeocodingCategory, number> = {
        city: 12,
        county: 10,
        coordinate: 16,
        country: 8,
        house: 16,
        locality: 14,
        street: 15,
        train_station: 14,
        airport: 13,
        shop: 16,
    }

    public static mergeSimilarResults(results: GeocodeResult[]) {
        const byName: Record<string, GeocodeResult[]> = {}

        for (const result of results) {
            const nm = result.display_name
            if (!byName[nm]) {
                byName[nm] = []
            }
            byName[nm].push(result)
        }

        const merged: GeocodeResult[] = []
        for (const nm in byName) {
            const options = byName[nm]
            const added = options[0]
            merged.push(added)
            const centers: [number, number][] = [[added.lon, added.lat]]
            for (const other of options) {
                const otherCenter: [number, number] = [other.lon, other.lat]
                const nearbyFound = centers.some(
                    (center) => GeoOperations.distanceBetween(center, otherCenter) < 500
                )
                if (!nearbyFound) {
                    merged.push(other)
                    centers.push(otherCenter)
                }
            }
        }
        return merged
    }

    public static categoryToIcon: Record<GeocodingCategory, DefaultPinIcon> = {
        city: "building_office_2",
        coordinate: "globe_alt",
        country: "globe_alt",
        house: "house",
        locality: "building_office_2",
        street: "globe_alt",
        train_station: "train",
        county: "building_office_2",
        airport: "airport",
        shop: "building_storefront",
    }
}