import colors from "./assets/colors.json"

export class Utils {
    /**
     * In the 'deploy'-step, some code needs to be run by ts-node.
     * However, ts-node crashes when it sees 'document'. When running from console, we flag this and disable all code where document is needed.
     * This is a workaround and yet another hack
     */
    public static runningFromConsole = typeof window === "undefined"
    public static readonly assets_path = "./assets/svg/"
    public static externalDownloadFunction: (
        url: string,
        headers?: any
    ) => Promise<{ content: string } | { redirect: string }>
    public static Special_visualizations_tagsToApplyHelpText = `These can either be a tag to add, such as \`amenity=fast_food\` or can use a substitution, e.g. \`addr:housenumber=$number\`.
This new point will then have the tags \`amenity=fast_food\` and \`addr:housenumber\` with the value that was saved in \`number\` in the original feature.

If a value to substitute is undefined, empty string will be used instead.

This supports multiple values, e.g. \`ref=$source:geometry:type/$source:geometry:ref\`

Remark that the syntax is slightly different then expected; it uses '$' to note a value to copy, followed by a name (matched with \`[a-zA-Z0-9_:]*\`). Sadly, delimiting with \`{}\` as these already mark the boundaries of the special rendering...

Note that these values can be prepare with javascript in the theme by using a [calculatedTag](calculatedTags.md#calculating-tags-with-javascript)
 `
    public static readonly imageExtensions = new Set(["jpg", "png", "svg", "jpeg", ".gif"])

    public static readonly special_visualizations_importRequirementDocs = `#### Importing a dataset into OpenStreetMap: requirements

If you want to import a dataset, make sure that:

1. The dataset to import has a suitable license
2. The community has been informed of the import
3. All other requirements of the [import guidelines](https://wiki.openstreetmap.org/wiki/Import/Guidelines) have been followed

There are also some technicalities in your theme to keep in mind:

1. The new feature will be added and will flow through the program as any other new point as if it came from OSM.
    This means that there should be a layer which will match the new tags and which will display it.
2. The original feature from your geojson layer will gain the tag '_imported=yes'.
    This should be used to change the appearance or even to hide it (eg by changing the icon size to zero)
3. There should be a way for the theme to detect previously imported points, even after reloading.
    A reference number to the original dataset is an excellent way to do this
4. When importing ways, the theme creator is also responsible of avoiding overlapping ways.

#### Disabled in unofficial themes

The import button can be tested in an unofficial theme by adding \`test=true\` or \`backend=osm-test\` as [URL-paramter](URL_Parameters.md).
The import button will show up then. If in testmode, you can read the changeset-XML directly in the web console.
In the case that MapComplete is pointed to the testing grounds, the edit will be made on https://master.apis.dev.openstreetmap.org`
    private static knownKeys = [
        "addExtraTags",
        "and",
        "calculatedTags",
        "changesetmessage",
        "clustering",
        "color",
        "condition",
        "customCss",
        "dashArray",
        "defaultBackgroundId",
        "description",
        "descriptionTail",
        "doNotDownload",
        "enableAddNewPoints",
        "enableBackgroundLayerSelection",
        "enableGeolocation",
        "enableLayers",
        "enableMoreQuests",
        "enableSearch",
        "enableShareScreen",
        "enableUserBadge",
        "freeform",
        "hideFromOverview",
        "hideInAnswer",
        "icon",
        "iconOverlays",
        "iconSize",
        "id",
        "if",
        "ifnot",
        "isShown",
        "key",
        "language",
        "layers",
        "lockLocation",
        "maintainer",
        "mappings",
        "maxzoom",
        "maxZoom",
        "minNeededElements",
        "minzoom",
        "multiAnswer",
        "name",
        "or",
        "osmTags",
        "passAllFeatures",
        "presets",
        "question",
        "render",
        "roaming",
        "roamingRenderings",
        "rotation",
        "shortDescription",
        "socialImage",
        "source",
        "startLat",
        "startLon",
        "startZoom",
        "tagRenderings",
        "tags",
        "then",
        "title",
        "titleIcons",
        "type",
        "version",
        "wayHandling",
        "widenFactor",
        "width",
    ]
    private static extraKeys = [
        "nl",
        "en",
        "fr",
        "de",
        "pt",
        "es",
        "name",
        "phone",
        "email",
        "amenity",
        "leisure",
        "highway",
        "building",
        "yes",
        "no",
        "true",
        "false",
    ]
    private static injectedDownloads = {}
    private static _download_cache = new Map<
        string,
        {
            promise: Promise<any | { error: string; url: string; statuscode?: number }>
            timestamp: number
        }
    >()

    /**
     * Parses the arguments for special visualisations
     */
    public static ParseVisArgs(
        specs: { name: string; defaultValue?: string }[],
        args: string[]
    ): any {
        const parsed = {}
        if (args.length > specs.length) {
            throw (
                "To much arguments for special visualization: got " +
                args.join(",") +
                " but expected only " +
                args.length +
                " arguments"
            )
        }
        for (let i = 0; i < specs.length; i++) {
            const spec = specs[i]
            let arg = args[i]?.trim()
            if (arg === undefined || arg === "") {
                arg = spec.defaultValue
            }
            parsed[spec.name] = arg
        }

        return parsed
    }

    static EncodeXmlValue(str) {
        if (typeof str !== "string") {
            str = "" + str
        }

        return str
            .replace(/&/g, "&amp;")
            .replace(/</g, "&lt;")
            .replace(/>/g, "&gt;")
            .replace(/"/g, "&quot;")
            .replace(/'/g, "&apos;")
    }

    /**
     * Gives a clean float, or undefined if parsing fails
     * @param str
     */
    static asFloat(str): number {
        if (str) {
            const i = parseFloat(str)
            if (isNaN(i)) {
                return undefined
            }
            return i
        }
        return undefined
    }

    public static Upper(str: string) {
        return str.substr(0, 1).toUpperCase() + str.substr(1)
    }

    public static TwoDigits(i: number) {
        if (i < 10) {
            return "0" + i
        }
        return "" + i
    }

    /**
     * Converts a number to a string with one number after the comma
     *
     * Utils.Round(15) // => "15.0"
     * Utils.Round(1) // => "1.0"
     * Utils.Round(1.5) // => "1.5"
     * Utils.Round(0.5) // => "0.5"
     * Utils.Round(1.6) // => "1.6"
     * Utils.Round(-15) // => "-15.0"
     * Utils.Round(-1) // => "-1.0"
     * Utils.Round(-1.5) // => "-1.5"
     * Utils.Round(-0.5) // => "-0.5"
     * Utils.Round(-1.6) // => "-1.6"
     * Utils.Round(-1531.63543) // =>"-1531.6"
     */
    public static Round(i: number): string {
        if (i < 0) {
            return "-" + Utils.Round(-i)
        }
        const j = "" + Math.floor(i * 10)
        if (j.length == 1) {
            return "0." + j
        }
        return j.substr(0, j.length - 1) + "." + j.substr(j.length - 1, j.length)
    }

    public static Times(f: (i: number) => string, count: number): string {
        let res = ""
        for (let i = 0; i < count; i++) {
            res += f(i)
        }
        return res
    }

    public static TimesT<T>(count: number, f: (i: number) => T): T[] {
        let res: T[] = []
        for (let i = 0; i < count; i++) {
            res.push(f(i))
        }
        return res
    }

    public static NoNull<T>(array: T[]): NonNullable<T>[] {
        return <any>array?.filter((o) => o !== undefined && o !== null)
    }

    public static Hist(array: string[]): Map<string, number> {
        const hist = new Map<string, number>()
        for (const s of array) {
            hist.set(s, 1 + (hist.get(s) ?? 0))
        }
        return hist
    }

    /**
     * Removes all empty strings from this list
     * If undefined or null is given, an empty list is returned
     *
     * Utils.NoEmpty(undefined) // => []
     * Utils.NoEmpty(["abc","","def", null]) // => ["abc","def", null]
     *
     */
    public static NoEmpty(array: string[]): string[] {
        const ls: string[] = []
        if (!array) {
            return ls
        }
        for (const t of array) {
            if (t === "") {
                continue
            }
            ls.push(t)
        }
        return ls
    }

    public static EllipsesAfter(str: string, l: number = 100) {
        if (str === undefined || str === null) {
            return undefined
        }
        if (str.length <= l) {
            return str
        }
        return str.substr(0, l - 3) + "..."
    }

    public static FixedLength(str: string, l: number) {
        str = Utils.EllipsesAfter(str, l)
        while (str.length < l) {
            str = " " + str
        }
        return str
    }

    public static Dedup(arr: string[]): string[] {
        if (arr === undefined) {
            return undefined
        }
        const newArr = []
        for (const string of arr) {
            if (newArr.indexOf(string) < 0) {
                newArr.push(string)
            }
        }
        return newArr
    }

    public static Dupiclates(arr: string[]): string[] {
        if (arr === undefined) {
            return undefined
        }
        const newArr = []
        const seen = new Set<string>()
        for (const string of arr) {
            if (seen.has(string)) {
                newArr.push(string)
            }
            seen.add(string)
        }
        return newArr
    }

    /**
     * In the given list, all values which are lists will be merged with the values, e.g.
     *
     * Utils.Flatten([ [1,2], 3, [4, [5 ,6]] ]) // => [1, 2, 3, 4, [5, 6]]
     */
    public static Flatten<T>(list: (T | T[])[]): T[] {
        const result = []
        for (const value of list) {
            if (Array.isArray(value)) {
                result.push(...value)
            } else {
                result.push(value)
            }
        }
        return result
    }

    /**
     * Utils.Identical([1,2], [1,2]) // => true
     * Utils.Identical([1,2,3], [1,2,4}]) // => false
     * Utils.Identical([1,2], [1,2,3]) // => false
     */
    public static Identical<T>(t1: T[], t2: T[], eq?: (t: T, t0: T) => boolean): boolean {
        if (t1.length !== t2.length) {
            return false
        }
        eq = (a, b) => a === b
        for (let i = 0; i < t1.length; i++) {
            if (!eq(t1[i], t2[i])) {
                return false
            }
        }
        return true
    }

    /**
     * Utils.MergeTags({k0:"v0","common":"0"},{k1:"v1", common: "1"}) // => {k0: "v0", k1:"v1", common: "1"}
     */
    public static MergeTags(a: any, b: any) {
        const t = {}
        for (const k in a) {
            t[k] = a[k]
        }
        for (const k in b) {
            t[k] = b[k]
        }
        return t
    }

    public static SplitFirst(a: string, sep: string): string[] {
        const index = a.indexOf(sep)
        if (index < 0) {
            return [a]
        }
        return [a.substr(0, index), a.substr(index + sep.length)]
    }

    /**
     * Given a piece of text, will replace any key occuring in 'tags' by the corresponding value
     * @param txt
     * @param tags
     * @param useLang
     * @constructor
     */
    public static SubstituteKeys(
        txt: string | undefined,
        tags?: Record<string, any>,
        useLang?: string
    ): string | undefined {
        if (txt === undefined) {
            return undefined
        }
        const regex = /.*{([^}]*)}.*/

        let match = txt.match(regex)

        while (match) {
            const key = match[1]
            let v = tags === undefined ? undefined : tags[key]
            if (v !== undefined && v !== null) {
                if (v["toISOString"] != undefined) {
                    // This is a date, probably the timestamp of the object
                    // @ts-ignore
                    const date: Date = el
                    v = date.toISOString()
                }

                if (useLang !== undefined && v?.translations !== undefined) {
                    v =
                        v.translations[useLang] ??
                        v.translations["*"] ??
                        (v.textFor !== undefined ? v.textFor(useLang) : v)
                }

                if (v.InnerConstructElement !== undefined) {
                    console.warn(
                        "SubstituteKeys received a BaseUIElement to substitute in - this is probably a bug and will be downcast to a string\nThe key is",
                        key,
                        "\nThe value is",
                        v
                    )
                    v = (<HTMLElement>v.InnerConstructElement())?.textContent
                }

                if (typeof v !== "string") {
                    v = "" + v
                }
                v = v.replace(/\n/g, "<br/>")
            } else {
                // v === undefined
                v = ""
            }
            txt = txt.replace("{" + key + "}", v)
            match = txt.match(regex)
        }

        return txt
    }

    public static LoadCustomCss(location: string) {
        const head = document.getElementsByTagName("head")[0]
        const link = document.createElement("link")
        link.id = "customCss"
        link.rel = "stylesheet"
        link.type = "text/css"
        link.href = location
        link.media = "all"
        head.appendChild(link)
        console.log("Added custom css file ", location)
    }

    public static PushList<T>(target: T[], source?: T[]) {
        if (source === undefined) {
            return
        }
        target.push(...source)
    }

    /**
     * Copies all key-value pairs of the source into the target. This will change the target
     * If the key starts with a '+', the values of the list will be appended to the target instead of overwritten
     * If the key starts with `=`, the property will be overwritten.
     *
     * 'Source' will not be modified, but 'Target' will be
     *
     * const obj = {someValue: 42};
     * const override = {someValue: null};
     * Utils.Merge(override, obj);
     * obj.someValue // => null
     *
     * const obj = {someValue: 42};
     * const override = {someValue: null};
     * const returned = Utils.Merge(override, obj);
     * returned == obj // => true
     *
     *  const source = {
     *                abc: "def",
     *                foo: "bar",
     *                list0: ["overwritten"],
     *                "list1+": ["appended"]
     *            }
     * const target = {
     *                "xyz": "omega",
     *                "list0": ["should-be-gone"],
     *                "list1": ["should-be-kept"],
     *                "list2": ["should-be-untouched"]
     *            }
     * const result = Utils.Merge(source, target)
     * result.abc // => "def"
     * result.foo // => "bar"
     * result.xyz // => "omega"
     * result.list0.length // =>  1
     * result.list0[0] // =>  "overwritten"
     * result.list1.length // =>  2
     * result.list1[0] // =>  "should-be-kept"
     * result.list1[1] // =>  "appended"
     * result.list2.length // =>  1
     * result.list2[0] // => "should-be-untouched"
     */
    static Merge<T, S>(source: Readonly<S>, target: T): T & S {
        if (target === null) {
            return <T & S>source
        }

        for (const key in source) {
            if (!source.hasOwnProperty(key)) {
                continue
            }
            if (key.startsWith("=")) {
                const trimmedKey = key.substr(1)
                target[trimmedKey] = source[key]
                continue
            }

            if (key.startsWith("+") || key.endsWith("+")) {
                const trimmedKey = key.replace("+", "")
                const sourceV = source[key]
                const targetV = target[trimmedKey] ?? []

                let newList: any[]
                if (key.startsWith("+")) {
                    // @ts-ignore
                    newList = sourceV.concat(targetV)
                } else {
                    newList = targetV.concat(sourceV)
                }

                target[trimmedKey] = newList
                continue
            }

            const sourceV = source[key]
            // @ts-ignore
            const targetV = target[key]
            if (typeof sourceV === "object") {
                if (sourceV === null) {
                    // @ts-ignore
                    target[key] = null
                } else if (targetV === undefined) {
                    // @ts-ignore
                    target[key] = sourceV
                } else {
                    Utils.Merge(sourceV, targetV)
                }
            } else {
                // @ts-ignore
                target[key] = sourceV
            }
        }
        // @ts-ignore
        return target
    }

    /**
     * Walks the specified path into the object till the end.
     *
     * If a list is encountered, this is transparently walked recursively on every object.
     * If 'null' or 'undefined' is encountered, this method stops
     *
     * The leaf objects are replaced in the object itself by the specified function.
     */
    public static WalkPath(
        path: string[],
        object: any,
        replaceLeaf: (leaf: any, travelledPath: string[]) => any,
        travelledPath: string[] = []
    ): void {
        if (object == null) {
            return
        }

        const head = path[0]
        if (path.length === 1) {
            // We have reached the leaf
            const leaf = object[head]
            if (leaf !== undefined) {
                if (Array.isArray(leaf)) {
                    object[head] = leaf.map((o) => replaceLeaf(o, travelledPath))
                } else {
                    object[head] = replaceLeaf(leaf, travelledPath)
                    if (object[head] === undefined) {
                        delete object[head]
                    }
                }
            }
            return
        }
        const sub = object[head]
        if (sub === undefined) {
            return
        }
        if (typeof sub !== "object") {
            return
        }
        if (Array.isArray(sub)) {
            sub.forEach((el, i) =>
                Utils.WalkPath(path.slice(1), el, replaceLeaf, [...travelledPath, head, "" + i])
            )
            return
        }
        Utils.WalkPath(path.slice(1), sub, replaceLeaf, [...travelledPath, head])
    }

    /**
     * Walks the specified path into the object till the end.
     * If a list is encountered, this is tranparently walked recursively on every object.
     *
     * The leaf objects are collected in the list
     */
    public static CollectPath(
        path: string[],
        object: any,
        collectedList: { leaf: any; path: string[] }[] = [],
        travelledPath: string[] = []
    ): { leaf: any; path: string[] }[] {
        if (object === undefined || object === null) {
            return collectedList
        }
        const head = path[0]
        travelledPath = [...travelledPath, head]
        if (path.length === 1) {
            // We have reached the leaf
            const leaf = object[head]
            if (leaf === undefined || leaf === null) {
                return collectedList
            }
            if (Array.isArray(leaf)) {
                for (let i = 0; i < (<any[]>leaf).length; i++) {
                    const l = (<any[]>leaf)[i]
                    collectedList.push({ leaf: l, path: [...travelledPath, "" + i] })
                }
            } else {
                collectedList.push({ leaf, path: travelledPath })
            }
            return collectedList
        }
        const sub = object[head]
        if (sub === undefined || sub === null) {
            return collectedList
        }

        if (Array.isArray(sub)) {
            sub.forEach((el, i) =>
                Utils.CollectPath(path.slice(1), el, collectedList, [...travelledPath, "" + i])
            )
            return collectedList
        }
        if (typeof sub !== "object") {
            return collectedList
        }
        return Utils.CollectPath(path.slice(1), sub, collectedList, travelledPath)
    }

    /**
     * Apply a function on every leaf of the JSON; used to rewrite parts of the JSON.
     * Returns a modified copy of the original object.
     *
     * 'null' and 'undefined' are _always_ considered a leaf, even if 'isLeaf' says it isn't
     *
     * Hangs if the object contains a loop
     *
     * // should walk a json
     * const walked = Utils.WalkJson({
     *     key: "value"
     * }, (x: string) => x + "!")
     * walked // => {key: "value!"}
     *
     * // should preserve undefined and null:
     * const walked = Utils.WalkJson({
     *   u: undefined,
     *   n: null,
     *   v: "value"
     * }, (x) => {if(x !== undefined && x !== null){return x+"!}; return x})
     * walked // => {v: "value!", u: undefined, n: null}
     *
     * // should preserve undefined and null, also with a negative isLeaf:
     * const walked = Utils.WalkJson({
     *   u: undefined,
     *   n: null,
     *   v: "value"
     * }, (x) => return x}, _ => false)
     * walked // => {v: "value", u: undefined, n: null}
     */
    static WalkJson(
        json: any,
        f: (v: object | number | string | boolean | undefined, path: string[]) => any,
        isLeaf: (object) => boolean = undefined,
        path: string[] = []
    ) {
        if (json === undefined || json === null) {
            return f(json, path)
        }
        const jtp = typeof json
        if (isLeaf !== undefined) {
            if (jtp === "object") {
                if (isLeaf(json)) {
                    return f(json, path)
                }
            } else {
                return json
            }
        } else if (jtp === "boolean" || jtp === "string" || jtp === "number") {
            return f(json, path)
        }
        if (Array.isArray(json)) {
            return json.map((sub, i) => {
                return Utils.WalkJson(sub, f, isLeaf, [...path, "" + i])
            })
        }

        const cp = { ...json }
        for (const key in json) {
            cp[key] = Utils.WalkJson(json[key], f, isLeaf, [...path, key])
        }
        return cp
    }

    /**
     * Walks an object recursively, will execute the 'collect'-callback on every leaf.
     *
     * Will hang on objects with loops
     */
    static WalkObject(
        json: any,
        collect: (v: number | string | boolean | undefined, path: string[]) => any,
        isLeaf: (object) => boolean = undefined,
        path = []
    ): void {
        if (json === undefined) {
            return
        }
        const jtp = typeof json
        if (isLeaf !== undefined) {
            if (jtp !== "object") {
                return
            }

            if (isLeaf(json)) {
                return collect(json, path)
            }
        } else if (jtp === "boolean" || jtp === "string" || jtp === "number") {
            collect(json, path)
            return
        }
        if (Array.isArray(json)) {
            json.map((sub, i) => {
                return Utils.WalkObject(sub, collect, isLeaf, [...path, i])
            })
            return
        }

        for (const key in json) {
            Utils.WalkObject(json[key], collect, isLeaf, [...path, key])
        }
    }

    static getOrSetDefault<K, V>(dict: Map<K, V>, k: K, v: () => V) {
        let found = dict.get(k)
        if (found !== undefined) {
            return found
        }
        dict.set(k, v())
        return dict.get(k)
    }

    /**
     * Tries to minify the given JSON by applying some compression
     */
    public static MinifyJSON(stringified: string): string {
        stringified = stringified.replace(/\|/g, "||")

        const keys = Utils.knownKeys.concat(Utils.extraKeys)
        for (let i = 0; i < keys.length; i++) {
            const knownKey = keys[i]
            let code = i
            if (i >= 124) {
                code += 1 // Character 127 is our 'escape' character |
            }
            let replacement = "|" + String.fromCharCode(code)
            stringified = stringified.replace(new RegExp(`\"${knownKey}\":`, "g"), replacement)
        }

        return stringified
    }

    public static UnMinify(minified: string): string {
        if (minified === undefined || minified === null) {
            return undefined
        }

        const parts = minified.split("|")
        let result = parts.shift()
        const keys = Utils.knownKeys.concat(Utils.extraKeys)

        for (const part of parts) {
            if (part == "") {
                // Empty string => this was a || originally
                result += "|"
                continue
            }
            const i = part.charCodeAt(0)
            result += '"' + keys[i] + '":' + part.substring(1)
        }

        return result
    }

    public static injectJsonDownloadForTests(url: string, data) {
        Utils.injectedDownloads[url] = data
    }

    public static async download(url: string, headers?: any): Promise<string | undefined> {
        const result = await Utils.downloadAdvanced(url, headers)
        if (result["error"] !== undefined) {
            throw result["error"]
        }
        return result["content"]
    }

    /**
     * Download function which also indicates advanced options, such as redirects
     * @param url
     * @param headers
     */
    public static downloadAdvanced(
        url: string,
        headers?: any
    ): Promise<
        | { content: string }
        | { redirect: string }
        | { error: string; url: string; statuscode?: number }
    > {
        if (this.externalDownloadFunction !== undefined) {
            return this.externalDownloadFunction(url, headers)
        }

        return new Promise((resolve, reject) => {
            const xhr = new XMLHttpRequest()
            xhr.onload = () => {
                if (xhr.status == 200) {
                    resolve({ content: xhr.response })
                } else if (xhr.status === 302) {
                    resolve({ redirect: xhr.getResponseHeader("location") })
                } else if (xhr.status === 509 || xhr.status === 429) {
                    resolve({ error: "rate limited", url, statuscode: xhr.status })
                } else {
                    resolve({
                        error: "other error: " + xhr.statusText,
                        url,
                        statuscode: xhr.status,
                    })
                }
            }
            xhr.open("GET", url)
            if (headers !== undefined) {
                for (const key in headers) {
                    xhr.setRequestHeader(key, headers[key])
                }
            }

            xhr.send()
            xhr.onerror = reject
        })
    }

    public static upload(url: string, data, headers?: any): Promise<string> {
        return new Promise((resolve, reject) => {
            const xhr = new XMLHttpRequest()
            xhr.onload = () => {
                if (xhr.status == 200) {
                    resolve(xhr.response)
                } else if (xhr.status === 509 || xhr.status === 429) {
                    reject("rate limited")
                } else {
                    reject(xhr.statusText)
                }
            }
            xhr.open("POST", url)
            if (headers !== undefined) {
                for (const key in headers) {
                    xhr.setRequestHeader(key, headers[key])
                }
            }

            xhr.send(data)
            xhr.onerror = reject
        })
    }

    public static async downloadJsonCached(
        url: string,
        maxCacheTimeMs: number,
        headers?: any
    ): Promise<any> {
        const result = await Utils.downloadJsonAdvanced(url, headers)
        if (result["content"]) {
            return result["content"]
        }
        throw result["error"]
    }

    public static async downloadJsonCachedAdvanced(
        url: string,
        maxCacheTimeMs: number,
        headers?: any
    ): Promise<{ content: any } | { error: string; url: string; statuscode?: number }> {
        const cached = Utils._download_cache.get(url)
        if (cached !== undefined) {
            if (new Date().getTime() - cached.timestamp <= maxCacheTimeMs) {
                return cached.promise
            }
        }
        const promise =
            /*NO AWAIT as we work with the promise directly */ Utils.downloadJsonAdvanced(
                url,
                headers
            )
        Utils._download_cache.set(url, { promise, timestamp: new Date().getTime() })
        return await promise
    }

    public static async downloadJson(url: string, headers?: any): Promise<any> {
        const result = await Utils.downloadJsonAdvanced(url, headers)
        if (result["content"]) {
            return result["content"]
        }
        throw result["error"]
    }

    public static async downloadJsonAdvanced(
        url: string,
        headers?: any
    ): Promise<{ content: any } | { error: string; url: string; statuscode?: number }> {
        const injected = Utils.injectedDownloads[url]
        if (injected !== undefined) {
            console.log("Using injected resource for test for URL", url)
            return new Promise((resolve, _) => resolve({ content: injected }))
        }
        const result = await Utils.downloadAdvanced(
            url,
            Utils.Merge({ accept: "application/json" }, headers ?? {})
        )
        if (result["error"] !== undefined) {
            return <{ error: string; url: string; statuscode?: number }>result
        }
        const data = result["content"]
        try {
            if (typeof data === "string") {
                return { content: JSON.parse(data) }
            }
            return { content: data }
        } catch (e) {
            console.error("Could not parse ", data, "due to", e, "\n", e.stack)
            return { error: "malformed", url }
        }
    }

    /**
     * Triggers a 'download file' popup which will download the contents
     */
    public static offerContentsAsDownloadableFile(
        contents: string | Blob,
        fileName: string = "download.txt",
        options?: {
            mimetype:
                | string
                | "text/plain"
                | "text/csv"
                | "application/vnd.geo+json"
                | "{gpx=application/gpx+xml}"
                | "application/json"
        }
    ) {
        const element = document.createElement("a")
        let file
        if (typeof contents === "string") {
            file = new Blob([contents], { type: options?.mimetype ?? "text/plain" })
        } else {
            file = contents
        }
        element.href = URL.createObjectURL(file)
        element.download = fileName
        document.body.appendChild(element) // Required for this to work in FireFox
        element.click()
    }

    public static ColourNameToHex(color: string): string {
        return colors[color.toLowerCase()] ?? color
    }

    public static HexToColourName(hex: string): string {
        hex = hex.toLowerCase()
        if (!hex.startsWith("#")) {
            return hex
        }
        const c = Utils.color(hex)

        let smallestDiff = Number.MAX_VALUE
        let bestColor = undefined
        for (const color in colors) {
            if (!colors.hasOwnProperty(color)) {
                continue
            }
            const foundhex = colors[color]
            if (typeof foundhex !== "string") {
                continue
            }
            if (foundhex === hex) {
                return color
            }
            const diff = this.colorDiff(Utils.color(foundhex), c)
            if (diff > 50) {
                continue
            }
            if (diff < smallestDiff) {
                smallestDiff = diff
                bestColor = color
            }
        }
        return bestColor ?? hex
    }

    /**
     * Reorders an object: creates a new object where the keys have been added alphabetically
     *
     * const sorted = Utils.sortKeys({ x: 'x', abc: {'x': 'x', 'a': 'a'}, def: 'def'})
     * JSON.stringify(sorted) // => '{"abc":{"a":"a","x":"x"},"def":"def","x":"x"}'
     */
    static sortKeys(o: any) {
        const copy = {}
        let keys = Object.keys(o)
        keys = keys.sort()
        for (const key of keys) {
            let v = o[key]
            if (typeof v === "object") {
                v = Utils.sortKeys(v)
            }
            copy[key] = v
        }
        return copy
    }

    public static async waitFor(timeMillis: number): Promise<void> {
        return new Promise((resolve) => {
            window.setTimeout(resolve, timeMillis)
        })
    }

    public static toHumanTime(seconds): string {
        seconds = Math.floor(seconds)
        let minutes = Math.floor(seconds / 60)
        seconds = seconds % 60
        let hours = Math.floor(minutes / 60)
        minutes = minutes % 60
        let days = Math.floor(hours / 24)
        hours = hours % 24
        if (days > 0) {
            return days + "days" + " " + hours + "h"
        }
        return hours + ":" + Utils.TwoDigits(minutes) + ":" + Utils.TwoDigits(seconds)
    }

    public static DisableLongPresses() {
        // Remove all context event listeners on mobile to prevent long presses
        window.addEventListener(
            "contextmenu",
            (e) => {
                // Not compatible with IE < 9

                if (e.target["nodeName"] === "INPUT") {
                    return
                }
                e.preventDefault()
                return false
            },
            false
        )
    }

    public static preventDefaultOnMouseEvent(event: any) {
        event?.originalEvent?.preventDefault()
        event?.originalEvent?.stopPropagation()
        event?.originalEvent?.stopImmediatePropagation()
        if (event?.originalEvent) {
            // This is a total workaround, as 'preventDefault' and everything above seems to be not working
            event.originalEvent["dismissed"] = true
        }
    }

    public static OsmChaLinkFor(daysInThePast, theme = undefined): string {
        const now = new Date()
        const lastWeek = new Date(now.getTime() - daysInThePast * 24 * 60 * 60 * 1000)
        const date =
            lastWeek.getFullYear() +
            "-" +
            Utils.TwoDigits(lastWeek.getMonth() + 1) +
            "-" +
            Utils.TwoDigits(lastWeek.getDate())
        let osmcha_link = `"date__gte":[{"label":"${date}","value":"${date}"}],"editor":[{"label":"mapcomplete","value":"mapcomplete"}]`
        if (theme !== undefined) {
            osmcha_link =
                osmcha_link + "," + `"comment":[{"label":"#${theme}","value":"#${theme}"}]`
        }
        return "https://osmcha.org/?filters=" + encodeURIComponent("{" + osmcha_link + "}")
    }

    /**
     * Deepclone an object by serializing and deserializing it
     * @param x
     * @constructor
     */
    static Clone<T>(x: T): T {
        if (x === undefined) {
            return undefined
        }
        return JSON.parse(JSON.stringify(x))
    }

    public static ParseDate(str: string): Date {
        if (str.endsWith(" UTC")) {
            str = str.replace(" UTC", "+00")
        }
        return new Date(str)
    }

    public static sortedByLevenshteinDistance<T>(
        reference: string,
        ts: T[],
        getName: (t: T) => string
    ): T[] {
        const withDistance: [T, number][] = ts.map((t) => [
            t,
            Utils.levenshteinDistance(getName(t), reference),
        ])
        withDistance.sort(([_, a], [__, b]) => a - b)
        return withDistance.map((n) => n[0])
    }

    public static levenshteinDistance(str1: string, str2: string) {
        const track = Array(str2.length + 1)
            .fill(null)
            .map(() => Array(str1.length + 1).fill(null))
        for (let i = 0; i <= str1.length; i += 1) {
            track[0][i] = i
        }
        for (let j = 0; j <= str2.length; j += 1) {
            track[j][0] = j
        }
        for (let j = 1; j <= str2.length; j += 1) {
            for (let i = 1; i <= str1.length; i += 1) {
                const indicator = str1[i - 1] === str2[j - 1] ? 0 : 1
                track[j][i] = Math.min(
                    track[j][i - 1] + 1, // deletion
                    track[j - 1][i] + 1, // insertion
                    track[j - 1][i - 1] + indicator // substitution
                )
            }
        }
        return track[str2.length][str1.length]
    }

    public static MapToObj<V, T>(
        d: Map<string, V>,
        onValue: (t: V, key: string) => T
    ): Record<string, T> {
        const o = {}
        const keys = Array.from(d.keys())
        keys.sort()
        for (const key of keys) {
            o[key] = onValue(d.get(key), key)
        }
        return o
    }

    /**
     * Switches keys and values around
     *
     * Utils.TransposeMap({"a" : ["b", "c"], "x" : ["b", "y"]}) // => {"b" : ["a", "x"], "c" : ["a"], "y" : ["x"]}
     */
    public static TransposeMap<K extends string, V extends string>(
        d: Record<K, V[]>
    ): Record<V, K[]> {
        const newD: Record<V, K[]> = <any>{}

        for (const k in d) {
            const vs = d[k]
            for (let v of vs) {
                const list = newD[v]
                if (list === undefined) {
                    newD[v] = [k] // Left: indexing; right: list with one element
                } else {
                    list.push(k)
                }
            }
        }
        return newD
    }

    /**
     * Utils.colorAsHex({r: 255, g: 128, b: 0}) // => "#ff8000"
     * Utils.colorAsHex(undefined) // => undefined
     */
    public static colorAsHex(c: { r: number; g: number; b: number }) {
        if (c === undefined) {
            return undefined
        }

        function componentToHex(n) {
            let hex = n.toString(16)
            return hex.length == 1 ? "0" + hex : hex
        }

        return "#" + componentToHex(c.r) + componentToHex(c.g) + componentToHex(c.b)
    }

    /**
     *
     * Utils.color("#ff8000") // => {r: 255, g:128, b: 0}
     * Utils.color(" rgba  (12,34,56) ") // => {r: 12, g:34, b: 56}
     * Utils.color(" rgba  (12,34,56,0.5) ") // => {r: 12, g:34, b: 56}
     * Utils.color(undefined) // => undefined
     */
    public static color(hex: string): { r: number; g: number; b: number } {
        if (hex === undefined) {
            return undefined
        }
        hex = hex.replace(/[ \t]/g, "")
        if (hex.startsWith("rgba(")) {
            const match = hex.match(/rgba\(([0-9.]+),([0-9.]+),([0-9.]+)(,[0-9.]*)?\)/)
            if (match == undefined) {
                return undefined
            }
            return { r: Number(match[1]), g: Number(match[2]), b: Number(match[3]) }
        }

        if (!hex.startsWith("#")) {
            return undefined
        }
        if (hex.length === 4) {
            return {
                r: parseInt(hex.substr(1, 1), 16),
                g: parseInt(hex.substr(2, 1), 16),
                b: parseInt(hex.substr(3, 1), 16),
            }
        }

        return {
            r: parseInt(hex.substr(1, 2), 16),
            g: parseInt(hex.substr(3, 2), 16),
            b: parseInt(hex.substr(5, 2), 16),
        }
    }

    public static asDict(
        tags: { key: string; value: string | number }[]
    ): Map<string, string | number> {
        const d = new Map<string, string | number>()

        for (const tag of tags) {
            d.set(tag.key, tag.value)
        }

        return d
    }

    private static colorDiff(
        c0: { r: number; g: number; b: number },
        c1: { r: number; g: number; b: number }
    ) {
        return Math.abs(c0.r - c1.r) + Math.abs(c0.g - c1.g) + Math.abs(c0.b - c1.b)
    }

    static toIdRecord<T extends { id: string }>(ts: T[]): Record<string, T> {
        const result: Record<string, T> = {}
        for (const t of ts) {
            result[t.id] = t
        }
        return result
    }

    public static SetMidnight(d: Date): void {
        d.setUTCHours(0)
        d.setUTCSeconds(0)
        d.setUTCMilliseconds(0)
        d.setUTCMinutes(0)
    }

    public static findParentWithScrolling(element: HTMLElement): HTMLElement {
        // Check if the element itself has scrolling
        if (element.scrollHeight > element.clientHeight) {
            return element
        }

        // If the element does not have scrolling, check if it has a parent element
        if (!element.parentElement) {
            return null
        }

        // If the element has a parent, repeat the process for the parent element
        return Utils.findParentWithScrolling(element.parentElement)
    }

    /**
     * Returns true if the contents of `a` are the same (and in the same order) as `b`.
     * Might have false negatives in some cases
     * @param a
     * @param b
     */
    public static sameList<T>(a: ReadonlyArray<T>, b: ReadonlyArray<T>) {
        if (a == b) {
            return true
        }
        if (a === undefined || a === null || b === undefined || b === null) {
            return false
        }
        if (a.length !== b.length) {
            return false
        }
        for (let i = 0; i < a.length; i++) {
            let ai = a[i]
            let bi = b[i]
            if (ai == bi) {
                continue
            }
            if (ai === bi) {
                continue
            }
            return false
        }
        return true
    }
}