// cast array x into numbers
// get the content of a text node, if any
function nodeVal(x) {
    if (x && x.normalize) {
        x.normalize();
    }
    return x && x.textContent || "";
}

// one Y child of X, if any, otherwise null
function get1(x, y) {
    const n = x.getElementsByTagName(y);
    return n.length ? n[0] : null;
}

function getLineStyle(extensions) {
    const style = {};
    if (extensions) {
        const lineStyle = get1(extensions, "line");
        if (lineStyle) {
            const color = nodeVal(get1(lineStyle, "color")),
                opacity = parseFloat(nodeVal(get1(lineStyle, "opacity"))),
                width = parseFloat(nodeVal(get1(lineStyle, "width")));
            if (color) style.stroke = color;
            if (!isNaN(opacity)) style["stroke-opacity"] = opacity;
            // GPX width is in mm, convert to px with 96 px per inch
            if (!isNaN(width)) style["stroke-width"] = width * 96 / 25.4;
        }
    }
    return style;
}

// get the contents of multiple text nodes, if present
function getMulti(x, ys) {
    const o = {};
    let n;
    let k;
    for (k = 0; k < ys.length; k++) {
        n = get1(x, ys[k]);
        if (n) o[ys[k]] = nodeVal(n);
    }
    return o;
}
function getProperties(node) {
    const prop = getMulti(node, [
        "name",
        "cmt",
        "desc",
        "type",
        "time",
        "keywords"]);

    // Parse additional data from our Garmin extension(s)
    const extensions = node.getElementsByTagNameNS(
        "http://www.garmin.com/xmlschemas/GpxExtensions/v3",
        "*");

    for (let i = 0; i < extensions.length; i++) {
        const extension = extensions[i];
        // Ignore nested extensions, like those on routepoints or trackpoints
        if (extension.parentNode.parentNode === node) {
            prop[extension.tagName.replace(":", "_")] = nodeVal(extension);
        }
    }
    const links = node.getElementsByTagName("link");
    if (links.length) prop.links = [];
    for (let i = 0; i < links.length; i++) {
        prop.links.push(
            Object.assign(
                { href: links[i].getAttribute("href") },
                getMulti(links[i], ["text", "type"])));


    }
    return prop;
}

function coordPair(x) {
    const ll = [
        parseFloat(x.getAttribute("lon")),
        parseFloat(x.getAttribute("lat"))];

    const ele = get1(x, "ele");
    // handle namespaced attribute in browser
    const heartRate = get1(x, "gpxtpx:hr") || get1(x, "hr");
    const time = get1(x, "time");
    let e;
    if (ele) {
        e = parseFloat(nodeVal(ele));
        if (!isNaN(e)) {
            ll.push(e);
        }
    }
    const result = {
        coordinates: ll,
        time: time ? nodeVal(time) : null,
        extendedValues: [] };


    if (heartRate) {
        result.extendedValues.push(["heartRate", parseFloat(nodeVal(heartRate))]);
    }

    const extensions = get1(x, "extensions");
    if (extensions !== null) {
        for (const name of ["speed", "course", "hAcc", "vAcc"]) {
            const v = parseFloat(nodeVal(get1(extensions, name)));
            if (!isNaN(v)) {
                result.extendedValues.push([name, v]);
            }
        }
    }
    return result;
}
function getRoute(node) {
    const line = getPoints(node, "rtept");
    if (!line) return;
    return {
        type: "Feature",
        properties: Object.assign(
            getProperties(node),
            getLineStyle(get1(node, "extensions")),
            { _gpxType: "rte" }),

        geometry: {
            type: "LineString",
            coordinates: line.line } };


}

function getPoints(node, pointname) {
    const pts = node.getElementsByTagName(pointname);
    if (pts.length < 2) return; // Invalid line in GeoJSON

    const line = [];
    const times = [];
    const extendedValues = {};
    for (let i = 0; i < pts.length; i++) {
        const c = coordPair(pts[i]);
        line.push(c.coordinates);
        if (c.time) times.push(c.time);
        for (let j = 0; j < c.extendedValues.length; j++) {
            const [name, val] = c.extendedValues[j];
            const plural = name + "s";
            if (!extendedValues[plural]) {
                extendedValues[plural] = Array(pts.length).fill(null);
            }
            extendedValues[plural][i] = val;
        }
    }
    return {
        line: line,
        times: times,
        extendedValues: extendedValues };

}

function getTrack(node) {
    const segments = node.getElementsByTagName("trkseg");
    const track = [];
    const times = [];
    const extractedLines = [];

    for (let i = 0; i < segments.length; i++) {
        const line = getPoints(segments[i], "trkpt");
        if (line) {
            extractedLines.push(line);
            if (line.times && line.times.length) times.push(line.times);
        }
    }

    if (extractedLines.length === 0) return;

    const multi = extractedLines.length > 1;

    const properties = Object.assign(
        getProperties(node),
        getLineStyle(get1(node, "extensions")),
        { _gpxType: "trk" },
        times.length ?
            {
                coordTimes: multi ? times : times[0] } :

            {});


    for (let i = 0; i < extractedLines.length; i++) {
        const line = extractedLines[i];
        track.push(line.line);
        for (const [name, val] of Object.entries(line.extendedValues)) {
            if (multi) {
                if (!properties[name])
                    properties[name] = extractedLines.map((line) =>
                        new Array(line.line.length).fill(null));

                properties[name][i] = val;
            } else {
                properties[name] = val;
            }
        }
    }

    return {
        type: "Feature",
        properties: properties,
        geometry: multi ?
            {
                type: "MultiLineString",
                coordinates: track } :

            {
                type: "LineString",
                coordinates: track[0] } };


}

function getPoint(node) {
    return {
        type: "Feature",
        properties: Object.assign(getProperties(node), getMulti(node, ["sym"])),
        geometry: {
            type: "Point",
            coordinates: coordPair(node).coordinates } };


}

function* gpxGen(doc) {
    const tracks = doc.getElementsByTagName("trk");
    const routes = doc.getElementsByTagName("rte");
    const waypoints = doc.getElementsByTagName("wpt");

    for (let i = 0; i < tracks.length; i++) {
        const feature = getTrack(tracks[i]);
        if (feature) yield feature;
    }
    for (let i = 0; i < routes.length; i++) {
        const feature = getRoute(routes[i]);
        if (feature) yield feature;
    }
    for (let i = 0; i < waypoints.length; i++) {
        yield getPoint(waypoints[i]);
    }
}

function gpx(doc) {
    return {
        type: "FeatureCollection",
        features: Array.from(gpxGen(doc)) };

}

const EXTENSIONS_NS = "http://www.garmin.com/xmlschemas/ActivityExtension/v2";

const TRACKPOINT_ATTRIBUTES = [
    ["heartRate", "heartRates"],
    ["Cadence", "cadences"],
// Extended Trackpoint attributes
    ["Speed", "speeds"],
    ["Watts", "watts"]];


const LAP_ATTRIBUTES = [
    ["TotalTimeSeconds", "totalTimeSeconds"],
    ["DistanceMeters", "distanceMeters"],
    ["MaximumSpeed", "maxSpeed"],
    ["AverageHeartRateBpm", "avgHeartRate"],
    ["MaximumHeartRateBpm", "maxHeartRate"],

// Extended Lap attributes
    ["AvgSpeed", "avgSpeed"],
    ["AvgWatts", "avgWatts"],
    ["MaxWatts", "maxWatts"]];


function fromEntries(arr) {
    const obj = {};
    for (const [key, value] of arr) {
        obj[key] = value;
    }
    return obj;
}

function getProperties$1(node, attributeNames) {
    const properties = [];

    for (const [tag, alias] of attributeNames) {
        let elem = get1(node, tag);
        if (!elem) {
            const elements = node.getElementsByTagNameNS(EXTENSIONS_NS, tag);
            if (elements.length) {
                elem = elements[0];
            }
        }
        const val = parseFloat(nodeVal(elem));
        if (!isNaN(val)) {
            properties.push([alias, val]);
        }
    }

    return properties;
}

function coordPair$1(x) {
    const lon = nodeVal(get1(x, "LongitudeDegrees"));
    const lat = nodeVal(get1(x, "LatitudeDegrees"));
    if (!lon.length || !lat.length) {
        return null;
    }
    const ll = [parseFloat(lon), parseFloat(lat)];
    const alt = get1(x, "AltitudeMeters");
    const heartRate = get1(x, "HeartRateBpm");
    const time = get1(x, "Time");
    let a;
    if (alt) {
        a = parseFloat(nodeVal(alt));
        if (!isNaN(a)) {
            ll.push(a);
        }
    }
    return {
        coordinates: ll,
        time: time ? nodeVal(time) : null,
        heartRate: heartRate ? parseFloat(nodeVal(heartRate)) : null,
        extensions: getProperties$1(x, TRACKPOINT_ATTRIBUTES) };

}

function getPoints$1(node, pointname) {
    const pts = node.getElementsByTagName(pointname);
    const line = [];
    const times = [];
    if (pts.length < 2) return null; // Invalid line in GeoJSON
    const result = { extendedProperties: {} };
    for (let i = 0; i < pts.length; i++) {
        const c = coordPair$1(pts[i]);
        if (c === null) continue;
        line.push(c.coordinates);
        if (c.time) times.push(c.time);
        for (const [alias, value] of c.extensions) {
            if (!result.extendedProperties[alias]) {
                result.extendedProperties[alias] = Array(pts.length).fill(null);
            }
            result.extendedProperties[alias][i] = value;
        }
    }
    return Object.assign(result, {
        line: line,
        times: times });

}

function getLap(node) {
    const segments = node.getElementsByTagName("Track");
    const track = [];
    const times = [];
    const allExtendedProperties = [];
    let line;
    const properties = fromEntries(getProperties$1(node, LAP_ATTRIBUTES));
    for (let i = 0; i < segments.length; i++) {
        line = getPoints$1(segments[i], "Trackpoint");
        if (line) {
            track.push(line.line);
            if (line.times.length) times.push(line.times);
            allExtendedProperties.push(line.extendedProperties);
        }
    }
    for (let i = 0; i < allExtendedProperties.length; i++) {
        const extendedProperties = allExtendedProperties[i];
        for (const property in extendedProperties) {
            if (segments.length === 1) {
                properties[property] = line.extendedProperties[property];
            } else {
                if (!properties[property]) {
                    properties[property] = track.map((track) =>
                        Array(track.length).fill(null));

                }
                properties[property][i] = extendedProperties[property];
            }
        }
    }
    if (track.length === 0) return;
    if (times.length)
        properties.coordTimes = track.length === 1 ? times[0] : times;
    return {
        type: "Feature",
        properties: properties,
        geometry: {
            type: track.length === 1 ? "LineString" : "MultiLineString",
            coordinates: track.length === 1 ? track[0] : track } };


}

function* tcxGen(doc) {
    const laps = doc.getElementsByTagName("Lap");

    for (let i = 0; i < laps.length; i++) {
        const feature = getLap(laps[i]);
        if (feature) yield feature;
    }
}

function tcx(doc) {
    return {
        type: "FeatureCollection",
        features: Array.from(tcxGen(doc)) };

}

const removeSpace = /\s*/g;
const trimSpace = /^\s*|\s*$/g;
const splitSpace = /\s+/;

// generate a short, numeric hash of a string
function okhash(x) {
    if (!x || !x.length) return 0;
    let h = 0;
    for (let i = 0; i < x.length; i++) {
        h = (h << 5) - h + x.charCodeAt(i) | 0;
    }
    return h;
}

// get one coordinate from a coordinate array, if any
function coord1(v) {
    return v.replace(removeSpace, "").split(",").map(parseFloat);
}

// get all coordinates from a coordinate array as [[],[]]
function coord(v) {
    return v.replace(trimSpace, "").split(splitSpace).map(coord1);
}

function xml2str(node) {
    if (node.xml !== undefined) return node.xml;
    if (node.tagName) {
        let output = node.tagName;
        for (let i = 0; i < node.attributes.length; i++) {
            output += node.attributes[i].name + node.attributes[i].value;
        }
        for (let i = 0; i < node.childNodes.length; i++) {
            output += xml2str(node.childNodes[i]);
        }
        return output;
    }
    if (node.nodeName === "#text") {
        return (node.nodeValue || node.value || "").trim();
    }
    if (node.nodeName === "#cdata-section") {
        return node.nodeValue;
    }
    return "";
}

const geotypes = ["Polygon", "LineString", "Point", "Track", "gx:Track"];

function kmlColor(properties, elem, prefix) {
    let v = nodeVal(get1(elem, "color")) || "";
    const colorProp =
        prefix == "stroke" || prefix === "fill" ? prefix : prefix + "-color";
    if (v.substr(0, 1) === "#") {
        v = v.substr(1);
    }
    if (v.length === 6 || v.length === 3) {
        properties[colorProp] = v;
    } else if (v.length === 8) {
        properties[prefix + "-opacity"] = parseInt(v.substr(0, 2), 16) / 255;
        properties[colorProp] =
            "#" + v.substr(6, 2) + v.substr(4, 2) + v.substr(2, 2);
    }
}

function numericProperty(properties, elem, source, target) {
    const val = parseFloat(nodeVal(get1(elem, source)));
    if (!isNaN(val)) properties[target] = val;
}

function gxCoords(root) {
    let elems = root.getElementsByTagName("coord");
    const coords = [];
    const times = [];
    if (elems.length === 0) elems = root.getElementsByTagName("gx:coord");
    for (let i = 0; i < elems.length; i++) {
        coords.push(nodeVal(elems[i]).split(" ").map(parseFloat));
    }
    const timeElems = root.getElementsByTagName("when");
    for (let j = 0; j < timeElems.length; j++) times.push(nodeVal(timeElems[j]));
    return {
        coords: coords,
        times: times };

}

function getGeometry(root) {
    let geomNode;
    let geomNodes;
    let i;
    let j;
    let k;
    const geoms = [];
    const coordTimes = [];
    if (get1(root, "MultiGeometry")) {
        return getGeometry(get1(root, "MultiGeometry"));
    }
    if (get1(root, "MultiTrack")) {
        return getGeometry(get1(root, "MultiTrack"));
    }
    if (get1(root, "gx:MultiTrack")) {
        return getGeometry(get1(root, "gx:MultiTrack"));
    }
    for (i = 0; i < geotypes.length; i++) {
        geomNodes = root.getElementsByTagName(geotypes[i]);
        if (geomNodes) {
            for (j = 0; j < geomNodes.length; j++) {
                geomNode = geomNodes[j];
                if (geotypes[i] === "Point") {
                    geoms.push({
                        type: "Point",
                        coordinates: coord1(nodeVal(get1(geomNode, "coordinates"))) });

                } else if (geotypes[i] === "LineString") {
                    geoms.push({
                        type: "LineString",
                        coordinates: coord(nodeVal(get1(geomNode, "coordinates"))) });

                } else if (geotypes[i] === "Polygon") {
                    const rings = geomNode.getElementsByTagName("LinearRing"),
                        coords = [];
                    for (k = 0; k < rings.length; k++) {
                        coords.push(coord(nodeVal(get1(rings[k], "coordinates"))));
                    }
                    geoms.push({
                        type: "Polygon",
                        coordinates: coords });

                } else if (geotypes[i] === "Track" || geotypes[i] === "gx:Track") {
                    const track = gxCoords(geomNode);
                    geoms.push({
                        type: "LineString",
                        coordinates: track.coords });

                    if (track.times.length) coordTimes.push(track.times);
                }
            }
        }
    }
    return {
        geoms: geoms,
        coordTimes: coordTimes };

}

function getPlacemark(root, styleIndex, styleMapIndex, styleByHash) {
    const geomsAndTimes = getGeometry(root);
    let i;
    const properties = {};
    const name = nodeVal(get1(root, "name"));
    const address = nodeVal(get1(root, "address"));
    let styleUrl = nodeVal(get1(root, "styleUrl"));
    const description = nodeVal(get1(root, "description"));
    const timeSpan = get1(root, "TimeSpan");
    const timeStamp = get1(root, "TimeStamp");
    const extendedData = get1(root, "ExtendedData");
    let iconStyle = get1(root, "IconStyle");
    let labelStyle = get1(root, "LabelStyle");
    let lineStyle = get1(root, "LineStyle");
    let polyStyle = get1(root, "PolyStyle");
    const visibility = get1(root, "visibility");

    if (name) properties.name = name;
    if (address) properties.address = address;
    if (styleUrl) {
        if (styleUrl[0] !== "#") {
            styleUrl = "#" + styleUrl;
        }

        properties.styleUrl = styleUrl;
        if (styleIndex[styleUrl]) {
            properties.styleHash = styleIndex[styleUrl];
        }
        if (styleMapIndex[styleUrl]) {
            properties.styleMapHash = styleMapIndex[styleUrl];
            properties.styleHash = styleIndex[styleMapIndex[styleUrl].normal];
        }
        // Try to populate the lineStyle or polyStyle since we got the style hash
        const style = styleByHash[properties.styleHash];
        if (style) {
            if (!iconStyle) iconStyle = get1(style, "IconStyle");
            if (!labelStyle) labelStyle = get1(style, "LabelStyle");
            if (!lineStyle) lineStyle = get1(style, "LineStyle");
            if (!polyStyle) polyStyle = get1(style, "PolyStyle");
        }
    }
    if (description) properties.description = description;
    if (timeSpan) {
        const begin = nodeVal(get1(timeSpan, "begin"));
        const end = nodeVal(get1(timeSpan, "end"));
        properties.timespan = { begin: begin, end: end };
    }
    if (timeStamp) {
        properties.timestamp = nodeVal(get1(timeStamp, "when"));
    }
    if (iconStyle) {
        kmlColor(properties, iconStyle, "icon");
        numericProperty(properties, iconStyle, "scale", "icon-scale");
        numericProperty(properties, iconStyle, "heading", "icon-heading");

        const hotspot = get1(iconStyle, "hotSpot");
        if (hotspot) {
            const left = parseFloat(hotspot.getAttribute("x"));
            const top = parseFloat(hotspot.getAttribute("y"));
            if (!isNaN(left) && !isNaN(top)) properties["icon-offset"] = [left, top];
        }
        const icon = get1(iconStyle, "Icon");
        if (icon) {
            const href = nodeVal(get1(icon, "href"));
            if (href) properties.icon = href;
        }
    }
    if (labelStyle) {
        kmlColor(properties, labelStyle, "label");
        numericProperty(properties, labelStyle, "scale", "label-scale");
    }
    if (lineStyle) {
        kmlColor(properties, lineStyle, "stroke");
        numericProperty(properties, lineStyle, "width", "stroke-width");
    }
    if (polyStyle) {
        kmlColor(properties, polyStyle, "fill");
        const fill = nodeVal(get1(polyStyle, "fill"));
        const outline = nodeVal(get1(polyStyle, "outline"));
        if (fill)
            properties["fill-opacity"] =
                fill === "1" ? properties["fill-opacity"] || 1 : 0;
        if (outline)
            properties["stroke-opacity"] =
                outline === "1" ? properties["stroke-opacity"] || 1 : 0;
    }
    if (extendedData) {
        const datas = extendedData.getElementsByTagName("Data"),
            simpleDatas = extendedData.getElementsByTagName("SimpleData");

        for (i = 0; i < datas.length; i++) {
            properties[datas[i].getAttribute("name")] = nodeVal(
                get1(datas[i], "value"));

        }
        for (i = 0; i < simpleDatas.length; i++) {
            properties[simpleDatas[i].getAttribute("name")] = nodeVal(simpleDatas[i]);
        }
    }
    if (visibility) {
        properties.visibility = nodeVal(visibility);
    }
    if (geomsAndTimes.coordTimes.length) {
        properties.coordTimes =
            geomsAndTimes.coordTimes.length === 1 ?
                geomsAndTimes.coordTimes[0] :
                geomsAndTimes.coordTimes;
    }
    const feature = {
        type: "Feature",
        geometry:
            geomsAndTimes.geoms.length === 0 ?
                null :
                geomsAndTimes.geoms.length === 1 ?
                    geomsAndTimes.geoms[0] :
                    {
                        type: "GeometryCollection",
                        geometries: geomsAndTimes.geoms },

        properties: properties };

    if (root.getAttribute("id")) feature.id = root.getAttribute("id");
    return feature;
}

function* kmlGen(doc) {
    // styleindex keeps track of hashed styles in order to match feature
    const styleIndex = {};
    const styleByHash = {};
    // stylemapindex keeps track of style maps to expose in properties
    const styleMapIndex = {};
    // atomic geospatial types supported by KML - MultiGeometry is
    // handled separately
    // all root placemarks in the file
    const placemarks = doc.getElementsByTagName("Placemark");
    const styles = doc.getElementsByTagName("Style");
    const styleMaps = doc.getElementsByTagName("StyleMap");

    for (let k = 0; k < styles.length; k++) {
        const hash = okhash(xml2str(styles[k])).toString(16);
        styleIndex["#" + styles[k].getAttribute("id")] = hash;
        styleByHash[hash] = styles[k];
    }
    for (let l = 0; l < styleMaps.length; l++) {
        styleIndex["#" + styleMaps[l].getAttribute("id")] = okhash(
            xml2str(styleMaps[l])).
        toString(16);
        const pairs = styleMaps[l].getElementsByTagName("Pair");
        const pairsMap = {};
        for (let m = 0; m < pairs.length; m++) {
            pairsMap[nodeVal(get1(pairs[m], "key"))] = nodeVal(
                get1(pairs[m], "styleUrl"));

        }
        styleMapIndex["#" + styleMaps[l].getAttribute("id")] = pairsMap;
    }
    for (let j = 0; j < placemarks.length; j++) {
        const feature = getPlacemark(
            placemarks[j],
            styleIndex,
            styleMapIndex,
            styleByHash);

        if (feature) yield feature;
    }
}

function kml(doc) {
    return {
        type: "FeatureCollection",
        features: Array.from(kmlGen(doc)) };

}

export { gpx, gpxGen, kml, kmlGen, tcx, tcxGen };