#!/usr/bin/env node

const fs = require("fs");
const path = require("path");
const os = require("os");
const { execFileSync } = require("child_process");
const { JsStreetNetwork } = require("osm2streets-js-node");

const repoRoot = path.resolve(__dirname, "..");
const args = parseArgs(process.argv.slice(2));
const configPath = path.resolve(args.config || path.join(repoRoot, "config", "default.json"));
const config = loadConfig(configPath, args);
const qgisApp = config.qgisApp;
const qgisMacOS = path.join(qgisApp, "Contents", "MacOS");
const qgisPython = path.join(qgisMacOS, "python3.12");
const ogr2ogr = path.join(qgisMacOS, "ogr2ogr");
const inputPath = path.resolve(config.input);
const outDir = path.resolve(config.outDir);
const gpkgPath = path.resolve(config.gpkg);
const projectPath = path.resolve(config.project);
const previewPath = path.resolve(config.preview);
const arrowScale = Number(config.arrowScale);
const clipPad = Number(config.clipPad);
const canvasPad = Number(config.canvasPad);
const previewPad = Number(config.previewPad);

if (!Number.isFinite(arrowScale) || arrowScale <= 0) {
  throw new Error(`Invalid arrowScale: ${config.arrowScale}`);
}
for (const [key, value] of [["clipPad", clipPad], ["canvasPad", canvasPad], ["previewPad", previewPad]]) {
  if (!Number.isFinite(value) || value < 0) {
    throw new Error(`Invalid ${key}: ${config[key]}`);
  }
}
if (!fs.existsSync(inputPath)) {
  throw new Error(`Input OSM XML not found: ${inputPath}`);
}
for (const exe of [ogr2ogr, qgisPython]) {
  if (!fs.existsSync(exe)) {
    throw new Error(`QGIS executable not found: ${exe}`);
  }
}

fs.mkdirSync(outDir, { recursive: true });
fs.mkdirSync(path.dirname(gpkgPath), { recursive: true });
fs.mkdirSync(path.dirname(projectPath), { recursive: true });
fs.mkdirSync(path.dirname(previewPath), { recursive: true });

const xml = fs.readFileSync(inputPath, "utf8");
const bbox = getOsmBounds(xml);
const osm = parseOsm(xml);
const clip = makeClipPolygon(bbox, clipPad);

const network = new JsStreetNetwork(xml, JSON.stringify(clip), config.osm2streets);

writeGeoJson(outDir, "plain.geojson", network.toGeojsonPlain());
writeGeoJson(outDir, "lane_polygons.geojson", network.toLanePolygonsGeojson());
writeGeoJson(outDir, "lane_markings.geojson", network.toLaneMarkingsGeojson());
writeGeoJson(outDir, "intersection_markings.geojson", network.toIntersectionMarkingsGeojson());
fs.writeFileSync(path.join(outDir, "network.json"), network.toJson());

const split = splitLayers(outDir, arrowScale, osm);
writeJson(path.join(outDir, "road_surface.geojson"), split.roadSurface);
writeJson(path.join(outDir, "intersection_surface.geojson"), split.intersectionSurface);
writeJson(path.join(outDir, "sidewalks.geojson"), split.sidewalks);
writeJson(path.join(outDir, "lane_separators.geojson"), split.laneSeparators);
writeJson(path.join(outDir, "center_lines.geojson"), split.centerLines);
writeJson(path.join(outDir, "vehicle_stop_lines.geojson"), split.vehicleStopLines);
writeJson(path.join(outDir, "lane_arrows_webscale.geojson"), split.laneArrows);
writeJson(path.join(outDir, "sidewalk_corners.geojson"), split.sidewalkCorners);
writeJson(path.join(outDir, "crosswalks.geojson"), split.crosswalks);
writeJson(path.join(outDir, "osm2streets_scene.geojson"), mergedScene(split));
fs.writeFileSync(
  path.join(outDir, "osm2streets_scene_style.json"),
  JSON.stringify(sceneStyle(), null, 2),
);

if (fs.existsSync(gpkgPath)) {
  fs.unlinkSync(gpkgPath);
}
const ogrEnv = qgisEnv();
importLayer(gpkgPath, path.join(outDir, "road_surface.geojson"), "road_surface", false, ogrEnv);
importLayer(gpkgPath, path.join(outDir, "intersection_surface.geojson"), "intersection_surface", true, ogrEnv);
importLayer(gpkgPath, path.join(outDir, "sidewalks.geojson"), "sidewalks", true, ogrEnv);
importLayer(gpkgPath, path.join(outDir, "sidewalk_corners.geojson"), "sidewalk_corners", true, ogrEnv);
importLayer(gpkgPath, path.join(outDir, "lane_separators.geojson"), "lane_separators", true, ogrEnv);
importLayer(gpkgPath, path.join(outDir, "center_lines.geojson"), "center_lines", true, ogrEnv);
importLayer(gpkgPath, path.join(outDir, "vehicle_stop_lines.geojson"), "vehicle_stop_lines", true, ogrEnv);
importLayer(gpkgPath, path.join(outDir, "lane_arrows_webscale.geojson"), "lane_arrows_webscale", true, ogrEnv);
importLayer(gpkgPath, path.join(outDir, "crosswalks.geojson"), "crosswalks", true, ogrEnv);

const qgisScript = path.join(outDir, "_create_qgis_project.py");
const previewFeature = split.crosswalks.features[0] || split.laneArrows.features[0] || split.roadSurface.features[0];
const defaultPreviewExtent = extentString(expandBounds(
  featureBounds(previewFeature),
  previewPad,
));
fs.writeFileSync(qgisScript, makeQgisScript({
  qgisMacOS,
  gpkgPath,
  projectPath,
  previewPath,
  canvasExtent: config.canvasExtent || extentString(expandBounds(bbox, canvasPad)),
  previewExtent: config.previewExtent || defaultPreviewExtent,
}));

execFileSync(qgisPython, [qgisScript], {
  stdio: "inherit",
  env: {
    ...process.env,
    ...qgisEnv(),
    QT_QPA_PLATFORM: "offscreen",
    PYTHONHOME: path.join(qgisApp, "Contents", "Frameworks"),
    PYTHONPATH: [
      path.join(qgisApp, "Contents", "Resources", "python"),
      path.join(qgisApp, "Contents", "Resources", "python3.11", "site-packages"),
    ].join(":"),
    DYLD_LIBRARY_PATH: [
      qgisMacOS,
      path.join(qgisApp, "Contents", "Frameworks"),
    ].join(":"),
  },
});
fixCanvas(projectPath, config.canvasExtent || extentString(expandBounds(bbox, canvasPad)));

console.log(`Config: ${configPath}`);
console.log(`GeoPackage: ${gpkgPath}`);
console.log(`QGIS project: ${projectPath}`);
console.log(`Preview PNG: ${previewPath}`);

function parseArgs(argv) {
  const out = {};
  for (let i = 0; i < argv.length; i += 1) {
    const arg = argv[i];
    if (!arg.startsWith("--")) continue;
    const key = arg.slice(2).replace(/-([a-z])/g, (_, c) => c.toUpperCase());
    const next = argv[i + 1];
    if (!next || next.startsWith("--")) {
      out[key] = "true";
    } else {
      out[key] = next;
      i += 1;
    }
  }
  return out;
}

function loadConfig(file, cliArgs) {
  if (!fs.existsSync(file)) {
    throw new Error(`Config file not found: ${file}`);
  }
  const base = JSON.parse(fs.readFileSync(file, "utf8"));
  const overrides = {};
  const mapping = {
    qgisApp: "qgisApp",
    input: "input",
    outDir: "outDir",
    gpkg: "gpkg",
    project: "project",
    preview: "preview",
    arrowScale: "arrowScale",
    clipPad: "clipPad",
    pad: "clipPad",
    canvasPad: "canvasPad",
    previewPad: "previewPad",
    canvasExtent: "canvasExtent",
    previewExtent: "previewExtent",
  };
  for (const [argKey, configKey] of Object.entries(mapping)) {
    if (cliArgs[argKey] !== undefined) {
      overrides[configKey] = cliArgs[argKey];
    }
  }
  if (process.env.QGIS_APP && overrides.qgisApp === undefined) {
    overrides.qgisApp = process.env.QGIS_APP;
  }
  const merged = deepMerge(base, overrides);
  const required = ["qgisApp", "input", "outDir", "gpkg", "project", "preview", "osm2streets"];
  for (const key of required) {
    if (merged[key] === undefined || merged[key] === null || merged[key] === "") {
      throw new Error(`Missing config key: ${key}`);
    }
  }
  return merged;
}

function deepMerge(base, overrides) {
  const out = { ...base };
  for (const [key, value] of Object.entries(overrides)) {
    if (
      value &&
      typeof value === "object" &&
      !Array.isArray(value) &&
      base[key] &&
      typeof base[key] === "object" &&
      !Array.isArray(base[key])
    ) {
      out[key] = deepMerge(base[key], value);
    } else {
      out[key] = value;
    }
  }
  return out;
}

function qgisEnv() {
  return {
    PROJ_LIB: path.join(qgisApp, "Contents", "Resources", "qgis", "proj"),
    GDAL_DATA: path.join(qgisApp, "Contents", "Resources", "qgis", "gdal"),
  };
}

function getOsmBounds(xmlText) {
  // OSM exports may contain distant relation members (for example subway
  // nodes) that are not part of the requested map extent. Prefer the explicit
  // bounds element when present and only fall back to node extents for files
  // that do not provide one.
  const boundsMatch = xmlText.match(/<bounds\b([^>]*)\/?\s*>/);
  if (boundsMatch) {
    const attrs = parseAttrs(boundsMatch[1]);
    const values = {
      minLon: Number(attrs.minlon),
      minLat: Number(attrs.minlat),
      maxLon: Number(attrs.maxlon),
      maxLat: Number(attrs.maxlat),
    };
    if (Object.values(values).every(Number.isFinite)) {
      return values;
    }
  }
  let minLon = Infinity;
  let minLat = Infinity;
  let maxLon = -Infinity;
  let maxLat = -Infinity;
  for (const match of xmlText.matchAll(/<node\b([^>]*)>/g)) {
    const attrs = match[1];
    const latMatch = attrs.match(/\blat=(["'])(.*?)\1/);
    const lonMatch = attrs.match(/\blon=(["'])(.*?)\1/);
    if (!latMatch || !lonMatch) continue;
    const lat = Number(latMatch[2]);
    const lon = Number(lonMatch[2]);
    if (!Number.isFinite(lat) || !Number.isFinite(lon)) continue;
    minLon = Math.min(minLon, lon);
    maxLon = Math.max(maxLon, lon);
    minLat = Math.min(minLat, lat);
    maxLat = Math.max(maxLat, lat);
  }
  if (!Number.isFinite(minLon)) {
    throw new Error("No OSM node coordinates found");
  }
  return { minLon, minLat, maxLon, maxLat };
}

function parseOsm(xmlText) {
  const nodes = new Map();
  const ways = new Map();
  for (const match of xmlText.matchAll(/<node\b([^>]*?)(?:\/>|>([\s\S]*?)<\/node>)/g)) {
    const attrs = parseAttrs(match[1]);
    const id = Number(attrs.id);
    const lat = Number(attrs.lat);
    const lon = Number(attrs.lon);
    if (!Number.isFinite(id) || !Number.isFinite(lat) || !Number.isFinite(lon)) continue;
    nodes.set(id, { id, lat, lon, tags: parseTags(match[2] || "") });
  }
  for (const match of xmlText.matchAll(/<way\b([^>]*)>([\s\S]*?)<\/way>/g)) {
    const attrs = parseAttrs(match[1]);
    const id = Number(attrs.id);
    if (!Number.isFinite(id)) continue;
    const body = match[2] || "";
    const refs = [...body.matchAll(/<nd\b([^>]*)\/>/g)]
      .map((refMatch) => Number(parseAttrs(refMatch[1]).ref))
      .filter(Number.isFinite);
    ways.set(id, { id, refs, tags: parseTags(body) });
  }
  return { nodes, ways };
}

function parseAttrs(text) {
  const attrs = {};
  for (const match of text.matchAll(/([\w:.-]+)=(["'])(.*?)\2/g)) {
    attrs[match[1]] = decodeXml(match[3]);
  }
  return attrs;
}

function parseTags(text) {
  const tags = {};
  for (const match of text.matchAll(/<tag\b([^>]*)\/>/g)) {
    const attrs = parseAttrs(match[1]);
    if (attrs.k !== undefined) tags[attrs.k] = attrs.v ?? "";
  }
  return tags;
}

function decodeXml(value) {
  return value
    .replaceAll("&quot;", "\"")
    .replaceAll("&apos;", "'")
    .replaceAll("&lt;", "<")
    .replaceAll("&gt;", ">")
    .replaceAll("&amp;", "&");
}

function makeClipPolygon(bbox, pad) {
  const b = expandBounds(bbox, pad);
  return {
    type: "FeatureCollection",
    features: [{
      type: "Feature",
      properties: {},
      geometry: {
        type: "Polygon",
        coordinates: [[
          [b.minLon, b.minLat],
          [b.maxLon, b.minLat],
          [b.maxLon, b.maxLat],
          [b.minLon, b.maxLat],
          [b.minLon, b.minLat],
        ]],
      },
    }],
  };
}

function expandBounds(bbox, pad) {
  return {
    minLon: bbox.minLon - pad,
    minLat: bbox.minLat - pad,
    maxLon: bbox.maxLon + pad,
    maxLat: bbox.maxLat + pad,
  };
}

function centeredExtent(bbox, width, height) {
  const cx = (bbox.minLon + bbox.maxLon) / 2;
  const cy = (bbox.minLat + bbox.maxLat) / 2;
  return {
    minLon: cx - width / 2,
    minLat: cy - height / 2,
    maxLon: cx + width / 2,
    maxLat: cy + height / 2,
  };
}

function extentString(bbox) {
  return `${bbox.minLon},${bbox.minLat},${bbox.maxLon},${bbox.maxLat}`;
}

function featureBounds(feature) {
  if (!feature?.geometry?.coordinates) {
    throw new Error("No feature available for preview extent");
  }
  const coords = [];
  collectCoords(feature.geometry.coordinates, coords);
  if (!coords.length) {
    throw new Error("Preview feature has no coordinates");
  }
  return {
    minLon: Math.min(...coords.map((p) => p[0])),
    minLat: Math.min(...coords.map((p) => p[1])),
    maxLon: Math.max(...coords.map((p) => p[0])),
    maxLat: Math.max(...coords.map((p) => p[1])),
  };
}

function writeGeoJson(dir, name, content) {
  const file = path.join(dir, name);
  fs.writeFileSync(file, content);
  const count = JSON.parse(content).features?.length ?? 0;
  console.log(`${file}\tfeatures=${count}`);
}

function writeJson(file, value) {
  fs.writeFileSync(file, JSON.stringify(value));
  console.log(`${file}\tfeatures=${value.features.length}`);
}

function emptyCollection() {
  return { type: "FeatureCollection", features: [] };
}

function mergedScene(split) {
  const layers = [
    ["road_surface", 10, split.roadSurface],
    ["intersection_surface", 20, split.intersectionSurface],
    ["sidewalks", 30, split.sidewalks],
    ["sidewalk_corners", 40, split.sidewalkCorners],
    ["lane_separators", 50, split.laneSeparators],
    ["center_lines", 60, split.centerLines],
    ["crosswalks", 70, split.crosswalks],
    ["vehicle_stop_lines", 80, split.vehicleStopLines],
    ["lane_arrows_webscale", 90, split.laneArrows],
  ];
  return {
    type: "FeatureCollection",
    features: layers.flatMap(([renderLayer, zIndex, collection]) => (
      (collection.features || []).map((feature) => ({
        ...feature,
        properties: {
          ...(feature.properties || {}),
          render_layer: renderLayer,
          z_index: zIndex,
        },
      }))
    )),
  };
}

function sceneStyle() {
  return {
    version: 1,
    geometry: "polygon",
    sortProperty: "z_index",
    layerProperty: "render_layer",
    layers: [
      { id: "road_surface", zIndex: 10, fill: "#2b2b28", outline: "#1e1e1c", outlineWidth: 0.04 },
      { id: "intersection_surface", zIndex: 20, fill: "#2b2b28", outline: "#1e1e1c", outlineWidth: 0.04 },
      { id: "sidewalks", zIndex: 30, fill: "#bebeb6", outline: "#9c9c94", outlineWidth: 0.025 },
      { id: "sidewalk_corners", zIndex: 40, fill: "#bebeb6", outline: "#9c9c94", outlineWidth: 0.025 },
      { id: "lane_separators", zIndex: 50, fill: "#eeeee6", outline: null, outlineWidth: 0 },
      { id: "center_lines", zIndex: 60, fill: "#f5be2a", outline: null, outlineWidth: 0 },
      { id: "crosswalks", zIndex: 70, fill: "#fffff6", outline: null, outlineWidth: 0 },
      { id: "vehicle_stop_lines", zIndex: 80, fill: "#fffff6", outline: null, outlineWidth: 0 },
      { id: "lane_arrows_webscale", zIndex: 90, fill: "#fffff6", outline: "#2b2b28", outlineWidth: 0.015 },
    ],
  };
}

function splitLayers(dir, arrowScaleValue, osm) {
  const plain = JSON.parse(fs.readFileSync(path.join(dir, "plain.geojson"), "utf8"));
  const lanePolygons = JSON.parse(fs.readFileSync(path.join(dir, "lane_polygons.geojson"), "utf8"));
  const markings = JSON.parse(fs.readFileSync(path.join(dir, "lane_markings.geojson"), "utf8"));
  const intersections = JSON.parse(fs.readFileSync(path.join(dir, "intersection_markings.geojson"), "utf8"));
  const crosswalkData = buildCrosswalks(osm);
  const serviceWayIds = new Set([...osm.ways.values()]
    .filter((way) => way.tags.highway === "service")
    .map((way) => way.id));
  const out = {
    roadSurface: emptyCollection(),
    intersectionSurface: emptyCollection(),
    sidewalks: emptyCollection(),
    laneSeparators: emptyCollection(),
    centerLines: emptyCollection(),
    vehicleStopLines: crosswalkData.stopLines,
    laneArrows: emptyCollection(),
    sidewalkCorners: intersections,
    crosswalks: crosswalkData.stripes,
  };
  const serviceDrivingPolygons = [];

  for (const feature of plain.features || []) {
    if (feature.properties?.type === "intersection") {
      out.intersectionSurface.features.push(feature);
    }
  }

  for (const feature of lanePolygons.features || []) {
    const type = feature.properties?.type;
    if (type === "Sidewalk" || type === "Footway") {
      out.sidewalks.features.push(feature);
    } else {
      out.roadSurface.features.push(feature);
      if (type === "Driving" && hasAnyWayId(feature.properties?.osm_way_ids, serviceWayIds)) {
        serviceDrivingPolygons.push({
          bbox: featureBounds(feature),
          rings: polygonRings(feature.geometry),
        });
      }
    }
  }

  for (const feature of markings.features || []) {
    const type = feature.properties?.type;
    const conflictsWithCrosswalk = isInAnyPolygon(feature, crosswalkData.zones, "intersects");
    if (type === "lane separator" && !conflictsWithCrosswalk) out.laneSeparators.features.push(feature);
    if (type === "center line" && !conflictsWithCrosswalk && !isInAnyPolygon(feature, serviceDrivingPolygons)) out.centerLines.features.push(feature);
    if (type === "vehicle stop line" && !isInAnyPolygon(feature, crosswalkData.stopLineExclusionZones, "intersects")) {
      out.vehicleStopLines.features.push(feature);
    }
    if (type === "lane arrow" && !conflictsWithCrosswalk && !isInAnyPolygon(feature, serviceDrivingPolygons)) out.laneArrows.features.push(scaleFeature(feature, arrowScaleValue));
  }

  return out;
}

function hasAnyWayId(value, ids) {
  const values = Array.isArray(value) ? value : [value];
  return values.some((id) => ids.has(Number(id)));
}

function polygonRings(geometry) {
  if (!geometry?.coordinates) return [];
  if (geometry.type === "Polygon") return [geometry.coordinates];
  if (geometry.type === "MultiPolygon") return geometry.coordinates;
  return [];
}

function isInAnyPolygon(feature, polygons, mode = "point") {
  if (!polygons.length) return false;
  const featureBbox = featureBounds(feature);
  const points = mode === "intersects" ? featurePoints(feature) : [representativePoint(feature)].filter(Boolean);
  if (!points.length) return false;
  return polygons.some(({ bbox, rings }) => (
    bboxesOverlap(featureBbox, bbox, 0.00001) &&
    points.some((point) => (
      point[0] >= bbox.minLon - 0.00001 &&
      point[0] <= bbox.maxLon + 0.00001 &&
      point[1] >= bbox.minLat - 0.00001 &&
      point[1] <= bbox.maxLat + 0.00001 &&
      rings.some((polygon) => pointInPolygon(point, polygon))
    ))
  ));
}

function featurePoints(feature) {
  const coords = [];
  collectCoords(feature.geometry?.coordinates, coords);
  if (!coords.length) return [];
  return [
    coords[0],
    coords[Math.floor(coords.length / 2)],
    coords[coords.length - 1],
    ...bboxCorners(featureBounds(feature)),
  ];
}

function bboxCorners(bbox) {
  return [
    [bbox.minLon, bbox.minLat],
    [bbox.maxLon, bbox.minLat],
    [bbox.maxLon, bbox.maxLat],
    [bbox.minLon, bbox.maxLat],
  ];
}

function bboxesOverlap(a, b, pad = 0) {
  return a.minLon <= b.maxLon + pad &&
    a.maxLon >= b.minLon - pad &&
    a.minLat <= b.maxLat + pad &&
    a.maxLat >= b.minLat - pad;
}

function representativePoint(feature) {
  const coords = [];
  collectCoords(feature.geometry?.coordinates, coords);
  if (!coords.length) return null;
  return coords[Math.floor(coords.length / 2)];
}

function pointInPolygon(point, rings) {
  if (!rings?.length || !pointInRing(point, rings[0])) return false;
  return !rings.slice(1).some((ring) => pointInRing(point, ring));
}

function pointInRing([x, y], ring) {
  let inside = false;
  for (let i = 0, j = ring.length - 1; i < ring.length; j = i++) {
    const xi = ring[i][0];
    const yi = ring[i][1];
    const xj = ring[j][0];
    const yj = ring[j][1];
    const intersect = ((yi > y) !== (yj > y)) &&
      x < ((xj - xi) * (y - yi)) / (yj - yi) + xi;
    if (intersect) inside = !inside;
  }
  return inside;
}

function buildCrosswalks(osm) {
  const crossingNodes = markedCrossingNodes(osm);
  const clusterCenters = crossingClusters(crossingNodes);
  const stripes = emptyCollection();
  const stopLines = emptyCollection();
  const zones = [];
  const stopLineExclusionZones = [];
  for (const node of crossingNodes) {
    const way = findCrossingWay(osm, node.id);
    const vector = crossingVector(osm, way, node.id);
    if (!vector) continue;
    const crosswalk = crosswalkGeometry(node, way, vector, clusterCenters.get(node.id));
    if (!crosswalk) continue;
    stripes.features.push(...crosswalk.stripes);
    if (crosswalk.stopLine) stopLines.features.push(crosswalk.stopLine);
    zones.push({
      bbox: featureBounds(crosswalk.zone),
      rings: polygonRings(crosswalk.zone.geometry),
    });
    stopLineExclusionZones.push({
      bbox: featureBounds(crosswalk.stopLineExclusionZone),
      rings: polygonRings(crosswalk.stopLineExclusionZone.geometry),
    });
  }
  return { stripes, stopLines, zones, stopLineExclusionZones };
}

function markedCrossingNodes(osm) {
  return [...osm.nodes.values()].filter((node) => {
    if (node.tags.highway !== "crossing") return false;
    const markings = node.tags["crossing:markings"];
    return !(markings && ["no", "none", "unmarked"].includes(markings));
  });
}

function crossingNodeClusters(nodes) {
  const clusters = [];
  for (const node of nodes) {
    let cluster = clusters.find((candidate) => {
      const center = clusterCenter(candidate);
      return distanceMeters(node, center) <= 45;
    });
    if (!cluster) {
      cluster = [];
      clusters.push(cluster);
    }
    cluster.push(node);
  }
  return clusters;
}

function crossingClusters(nodes) {
  const clusters = crossingNodeClusters(nodes);
  const centers = new Map();
  for (const cluster of clusters) {
    if (cluster.length < 2) continue;
    const center = clusterCenter(cluster);
    for (const node of cluster) centers.set(node.id, center);
  }
  return centers;
}

function clusterCenter(nodes) {
  return {
    lon: nodes.reduce((sum, node) => sum + node.lon, 0) / nodes.length,
    lat: nodes.reduce((sum, node) => sum + node.lat, 0) / nodes.length,
  };
}

function distanceMeters(a, b) {
  const meters = metersForLat((a.lat + b.lat) / 2);
  return Math.hypot((a.lon - b.lon) * meters.lon, (a.lat - b.lat) * meters.lat);
}

function findCrossingWay(osm, nodeId) {
  const candidates = [...osm.ways.values()]
    .filter((way) => way.tags.highway && way.refs.includes(nodeId));
  return candidates.find((way) => way.tags.highway !== "service") || candidates[0] || null;
}

function crossingVector(osm, way, nodeId) {
  if (!way) return null;
  const index = way.refs.indexOf(nodeId);
  const prev = osm.nodes.get(way.refs[index - 1]);
  const next = osm.nodes.get(way.refs[index + 1]);
  const current = osm.nodes.get(nodeId);
  if (prev && next) return [next.lon - prev.lon, next.lat - prev.lat];
  if (prev && current) return [current.lon - prev.lon, current.lat - prev.lat];
  if (next && current) return [next.lon - current.lon, next.lat - current.lat];
  return null;
}

function crosswalkGeometry(node, way, vector, intersectionCenter) {
  const meters = metersForLat(node.lat);
  const stripeLength = crosswalkLengthMeters(way);
  const stripeWidth = 0.45;
  const gap = 0.45;
  const count = 6;
  const total = count * stripeWidth + (count - 1) * gap;
  const roadUnit = normalizeMetersVector(vector, meters);
  if (!roadUnit) return null;
  const acrossUnit = [-roadUnit[1], roadUnit[0]];
  const center = [node.lon, node.lat];
  const zoneCoords = rectangleMeters(center, roadUnit, acrossUnit, stripeLength + 0.8, total + 0.8, meters);
  const stopLineExclusionCoords = rectangleMeters(center, roadUnit, acrossUnit, stripeLength + 5, total + 1.5, meters);
  const zone = {
    type: "Feature",
    properties: {
      type: "crosswalk zone",
      crossing_node_id: node.id,
    },
    geometry: { type: "Polygon", coordinates: [zoneCoords] },
  };
  const stopLineExclusionZone = {
    type: "Feature",
    properties: {
      type: "crosswalk stop line exclusion zone",
      crossing_node_id: node.id,
    },
    geometry: { type: "Polygon", coordinates: [stopLineExclusionCoords] },
  };
  const stripes = [];
  for (let i = 0; i < count; i += 1) {
    const offset = -total / 2 + stripeWidth / 2 + i * (stripeWidth + gap);
    const stripeCenter = addMeters(center, acrossUnit, offset, meters);
    const coords = rectangleMeters(stripeCenter, roadUnit, acrossUnit, stripeLength, stripeWidth, meters);
    stripes.push({
      type: "Feature",
      properties: {
        type: "crosswalk stripe",
        crossing_node_id: node.id,
        highway: way?.tags.highway || null,
      },
      geometry: { type: "Polygon", coordinates: [coords] },
    });
  }
  return {
    stripes,
    zone,
    stopLineExclusionZone,
    stopLine: syntheticStopLine(node, way, roadUnit, acrossUnit, stripeLength, total, intersectionCenter, meters),
  };
}

function syntheticStopLine(node, way, roadUnit, acrossUnit, stripeLength, crosswalkWidth, intersectionCenter, meters) {
  if (!intersectionCenter) return null;
  const offset = stripeLength / 2 + 1.2;
  const candidateA = addMeters([node.lon, node.lat], roadUnit, offset, meters);
  const candidateB = addMeters([node.lon, node.lat], roadUnit, -offset, meters);
  const stopSide = pointDistanceMeters(candidateA, intersectionCenter, meters) >= pointDistanceMeters(candidateB, intersectionCenter, meters)
    ? 1
    : -1;
  const stopCenterOnRoad = stopSide === 1 ? candidateA : candidateB;
  const placement = stopLineLanePlacement(way, stripeLength, stopSide);
  const stopCenter = addMeters(stopCenterOnRoad, acrossUnit, placement.acrossOffset, meters);
  const coords = rectangleMeters(stopCenter, acrossUnit, roadUnit, placement.length, 0.45, meters);
  return {
    type: "Feature",
    properties: {
      type: "vehicle stop line",
      source: "crosswalk",
      crossing_node_id: node.id,
      highway: way?.tags.highway || null,
      stop_side: stopSide === 1 ? "with_way_outside" : "against_way_outside",
    },
    geometry: { type: "Polygon", coordinates: [coords] },
  };
}

function pointDistanceMeters(pointA, point, meters) {
  const [lon, lat] = Array.isArray(pointA) ? pointA : [pointA.lon, pointA.lat];
  const px = Array.isArray(point) ? point[0] : point.lon;
  const py = Array.isArray(point) ? point[1] : point.lat;
  return Math.hypot((lon - px) * meters.lon, (lat - py) * meters.lat);
}

function stopLineLanePlacement(way, roadWidth, stopSide) {
  if (isOneway(way)) {
    return { length: Math.max(2.8, roadWidth - 1.4), acrossOffset: 0 };
  }
  const halfWidth = roadWidth / 2;
  const innerGap = 0.15;
  const outerGap = 0.8;
  const laneWidth = Math.max(2.4, halfWidth - innerGap - outerGap);
  // China uses right-hand traffic. If the stop line is on the +roadUnit side,
  // the approaching traffic direction is -roadUnit, whose right side is +acrossUnit.
  const laneSide = stopSide === 1 ? 1 : -1;
  return {
    length: laneWidth,
    acrossOffset: laneSide * (innerGap + laneWidth / 2),
  };
}

function isOneway(way) {
  const value = String(way?.tags.oneway || "").toLowerCase();
  return ["yes", "true", "1"].includes(value);
}

function crosswalkLengthMeters(way) {
  const lanes = Number(way?.tags.lanes);
  if (Number.isFinite(lanes) && lanes > 0) return Math.max(5, lanes * 3.2 + 1.2);
  if (way?.tags.highway === "secondary") return 8.5;
  if (way?.tags.highway === "service") return 4.5;
  return 7.5;
}

function metersForLat(lat) {
  return {
    lon: 111320 * Math.cos((lat * Math.PI) / 180),
    lat: 110540,
  };
}

function normalizeMetersVector([dxLon, dyLat], meters) {
  const x = dxLon * meters.lon;
  const y = dyLat * meters.lat;
  const length = Math.hypot(x, y);
  if (!Number.isFinite(length) || length === 0) return null;
  return [x / length, y / length];
}

function addMeters([lon, lat], [ux, uy], distance, meters) {
  return [lon + (ux * distance) / meters.lon, lat + (uy * distance) / meters.lat];
}

function rectangleMeters(center, axisUnit, acrossUnit, axisWidth, acrossLength, meters) {
  const halfAxis = axisWidth / 2;
  const halfAcross = acrossLength / 2;
  const corners = [
    [-halfAxis, -halfAcross],
    [halfAxis, -halfAcross],
    [halfAxis, halfAcross],
    [-halfAxis, halfAcross],
    [-halfAxis, -halfAcross],
  ];
  return corners.map(([axis, across]) => {
    const x = axisUnit[0] * axis + acrossUnit[0] * across;
    const y = axisUnit[1] * axis + acrossUnit[1] * across;
    return [center[0] + x / meters.lon, center[1] + y / meters.lat];
  });
}

function scaleFeature(feature, scale) {
  const coords = [];
  collectCoords(feature.geometry.coordinates, coords);
  if (!coords.length) return feature;
  const xs = coords.map((p) => p[0]);
  const ys = coords.map((p) => p[1]);
  const cx = (Math.min(...xs) + Math.max(...xs)) / 2;
  const cy = (Math.min(...ys) + Math.max(...ys)) / 2;
  return {
    type: "Feature",
    properties: { ...feature.properties, render_scale: scale },
    geometry: {
      ...feature.geometry,
      coordinates: scaleCoords(feature.geometry.coordinates, cx, cy, scale),
    },
  };
}

function collectCoords(obj, acc) {
  if (Array.isArray(obj) && obj.length >= 2 && typeof obj[0] === "number" && typeof obj[1] === "number") {
    acc.push([obj[0], obj[1]]);
  } else if (Array.isArray(obj)) {
    for (const item of obj) collectCoords(item, acc);
  }
}

function scaleCoords(obj, cx, cy, scale) {
  if (Array.isArray(obj) && obj.length >= 2 && typeof obj[0] === "number" && typeof obj[1] === "number") {
    return [cx + (obj[0] - cx) * scale, cy + (obj[1] - cy) * scale, ...obj.slice(2)];
  }
  if (Array.isArray(obj)) {
    return obj.map((item) => scaleCoords(item, cx, cy, scale));
  }
  return obj;
}

function importLayer(gpkg, source, layerName, update, env) {
  const args = ["-f", "GPKG"];
  if (update) args.push("-update", "-overwrite");
  args.push(gpkg, source, "-nln", layerName);
  execFileSync(ogr2ogr, args, { stdio: "inherit", env: { ...process.env, ...env } });
}

function makeQgisScript(options) {
  return `
from pathlib import Path

from qgis.PyQt.QtCore import QSize
from qgis.PyQt.QtGui import QColor, QImage, QPainter
from qgis.core import (
    QgsApplication,
    QgsCoordinateReferenceSystem,
    QgsFillSymbol,
    QgsMapRendererCustomPainterJob,
    QgsMapSettings,
    QgsProject,
    QgsRectangle,
    QgsSingleSymbolRenderer,
    QgsVectorLayer,
)

QGIS_PREFIX = ${JSON.stringify(options.qgisMacOS)}
GPKG = ${JSON.stringify(options.gpkgPath)}
PROJECT_PATH = ${JSON.stringify(options.projectPath)}
PREVIEW_PATH = ${JSON.stringify(options.previewPath)}
PREVIEW_EXTENT = [${options.previewExtent.split(",").map(Number).join(", ")}]

def fill_symbol(color, outline="0,0,0,0", outline_width="0"):
    return QgsFillSymbol.createSimple({
        "color": color,
        "outline_color": outline,
        "outline_width": outline_width,
        "outline_width_unit": "MM",
        "joinstyle": "round",
    })

def make_layer(layer_name, title, color, outline="0,0,0,0", outline_width="0"):
    layer = QgsVectorLayer(f"{GPKG}|layername={layer_name}", title, "ogr")
    if not layer.isValid():
        raise RuntimeError(f"Invalid layer: {title}")
    layer.setRenderer(QgsSingleSymbolRenderer(fill_symbol(color, outline, outline_width)))
    return layer

QgsApplication.setPrefixPath(QGIS_PREFIX, True)
app = QgsApplication([], False)
app.initQgis()

project = QgsProject.instance()
project.clear()
project.setFileName(PROJECT_PATH)
project.setCrs(QgsCoordinateReferenceSystem("EPSG:4326"))
project.setPresetHomePath(str(Path(PROJECT_PATH).parent))

layers = {
    "road_surface": make_layer("road_surface", "osm2streets road surface", "43,43,40,255", "30,30,28,255", "0.04"),
    "intersection_surface": make_layer("intersection_surface", "osm2streets intersection surface", "43,43,40,255", "30,30,28,255", "0.04"),
    "sidewalks": make_layer("sidewalks", "osm2streets sidewalks", "190,190,182,255", "156,156,148,255", "0.025"),
    "sidewalk_corners": make_layer("sidewalk_corners", "osm2streets sidewalk corners", "190,190,182,255", "156,156,148,255", "0.025"),
    "crosswalks": make_layer("crosswalks", "osm2streets crosswalks", "255,255,246,255"),
    "lane_separators": make_layer("lane_separators", "osm2streets lane separators", "238,238,230,255"),
    "center_lines": make_layer("center_lines", "osm2streets center lines", "245,190,42,255"),
    "vehicle_stop_lines": make_layer("vehicle_stop_lines", "osm2streets vehicle stop lines", "255,255,246,255"),
    "lane_arrows": make_layer("lane_arrows_webscale", "osm2streets lane arrows", "255,255,246,255", "43,43,40,200", "0.015"),
}
draw_order = ["road_surface", "intersection_surface", "sidewalks", "sidewalk_corners", "lane_separators", "center_lines", "crosswalks", "vehicle_stop_lines", "lane_arrows"]
for key in draw_order:
    project.addMapLayer(layers[key], False)
root = project.layerTreeRoot()
for key in draw_order:
    root.insertLayer(0, layers[key])
if not project.write(PROJECT_PATH):
    raise RuntimeError(f"Failed to write {PROJECT_PATH}")

settings = QgsMapSettings()
settings.setLayers([layers[key] for key in reversed(draw_order)])
settings.setDestinationCrs(QgsCoordinateReferenceSystem("EPSG:4326"))
settings.setExtent(QgsRectangle(*PREVIEW_EXTENT))
settings.setOutputSize(QSize(1600, 1100))
settings.setBackgroundColor(QColor(245, 245, 240))
image = QImage(settings.outputSize(), QImage.Format_ARGB32_Premultiplied)
image.fill(settings.backgroundColor().rgba())
painter = QPainter(image)
job = QgsMapRendererCustomPainterJob(settings, painter)
job.start()
job.waitForFinished()
painter.end()
image.save(PREVIEW_PATH)

print(PROJECT_PATH)
print(PREVIEW_PATH)
app.exitQgis()
`;
}

function fixCanvas(projectFile, extentCsv) {
  const fixScript = path.join(os.tmpdir(), `osm2streets_fix_canvas_${process.pid}.py`);
  const script = `
from pathlib import Path
import shutil
import zipfile
import xml.etree.ElementTree as ET

project_path = Path(${JSON.stringify(projectFile)})
extent_values = [${extentCsv.split(",").map(Number).join(", ")}]
work_dir = Path(${JSON.stringify(path.join(os.tmpdir(), `osm2streets_qgz_fix_${process.pid}`))})
if work_dir.exists():
    shutil.rmtree(work_dir)
work_dir.mkdir(parents=True)
with zipfile.ZipFile(project_path, "r") as zin:
    zin.extractall(work_dir)
qgs_files = list(work_dir.glob("*.qgs"))
if not qgs_files:
    raise RuntimeError("No .qgs file found inside project")
qgs_path = qgs_files[0]
tree = ET.parse(qgs_path)
root = tree.getroot()
old_canvas = root.find("mapcanvas")
if old_canvas is not None:
    root.remove(old_canvas)
project_crs = root.find("projectCrs/spatialrefsys")
canvas = ET.Element("mapcanvas", {"name": "theMapCanvas", "annotationsVisible": "1"})
ET.SubElement(canvas, "units").text = "degrees"
extent = ET.SubElement(canvas, "extent")
for key, value in zip(["xmin", "ymin", "xmax", "ymax"], extent_values):
    ET.SubElement(extent, key).text = str(value)
ET.SubElement(canvas, "rotation").text = "0"
dest = ET.SubElement(canvas, "destinationsrs")
if project_crs is not None:
    dest.append(ET.fromstring(ET.tostring(project_crs, encoding="unicode")))
ET.SubElement(canvas, "rendermaptile").text = "0"
ET.SubElement(canvas, "expressionContextScope")
layer_tree = root.find("layer-tree-group")
insert_at = list(root).index(layer_tree) + 1 if layer_tree is not None else 1
root.insert(insert_at, canvas)
ET.indent(tree, space="  ")
tree.write(qgs_path, encoding="UTF-8", xml_declaration=True)
tmp = project_path.with_suffix(".qgz.tmp")
with zipfile.ZipFile(tmp, "w", compression=zipfile.ZIP_DEFLATED) as zout:
    for f in sorted(work_dir.iterdir()):
        zout.write(f, f.name)
tmp.replace(project_path)
shutil.rmtree(work_dir)
`;
  fs.writeFileSync(fixScript, script);
  execFileSync("python3", [fixScript], { stdio: "inherit" });
  fs.unlinkSync(fixScript);
}