"use strict";

const fs = require("fs");
const path = require("path");
const { arrowRingsAt, normalizeManeuver } = require("./turn-lane-arrows");

const OVERRIDE_SCHEMA = "native-road-overrides/v1";
const MOTOR_HIGHWAYS = new Set(["motorway", "trunk", "primary", "secondary", "tertiary", "unclassified", "residential", "living_street", "service"]);
const DEFAULT_WIDTHS = { motorway: 12, trunk: 10, primary: 10, secondary: 8, tertiary: 7, unclassified: 6, residential: 6, living_street: 5, service: 4 };
const DEFAULT_SIDEWALK_WIDTH_METERS = 2;
const DIRECTION_ARROW_INTERVAL_METERS = 32;
const DIRECTION_ARROW_ENDPOINT_BUFFER_METERS = 14;
const STOP_LINE_OFFSET_METERS = 2.7;
const STOP_LINE_MAX_APPROACH_DISTANCE_METERS = 25;
const CENTER_LINE_DASH_LENGTH_METERS = 2;
const CENTER_LINE_DASH_GAP_METERS = 2;
const CENTER_LINE_WIDTH_METERS = .25;
const CENTER_LINE_SOLID_OVERLAP_METERS = .04;
const CENTER_LINE_CONTROL_CLEARANCE_METERS = 1;
const CENTER_LINE_COLORS = new Set(["yellow", "white"]);
const CENTER_LINE_PATTERNS = new Set(["dashed", "solid"]);

function parseOsmRoads(xml) {
  const nodes = new Map();
  const crossingNodes = [];
  for (const match of xml.matchAll(/<node\b([^>]*?)(?:\/>|>([\s\S]*?)<\/node>)/g)) {
    const attrs = xmlAttrs(match[1]);
    if (attrs.action === "delete" || !attrs.id || attrs.lon === undefined || attrs.lat === undefined) continue;
    const coordinate = [Number(attrs.lon), Number(attrs.lat)];
    if (!coordinate.every(Number.isFinite)) continue;
    const id = String(attrs.id); const tags = parseTags(match[2] || "");
    nodes.set(id, coordinate);
    if (tags.highway === "crossing" && !["no", "none", "unmarked"].includes(tags["crossing:markings"])) crossingNodes.push({ id, coordinate, tags });
  }
  const ways = [];
  for (const match of xml.matchAll(/<way\b([^>]*)>([\s\S]*?)<\/way>/g)) {
    const attrs = xmlAttrs(match[1]);
    const body = match[2];
    const tags = parseTags(body);
    if (attrs.action === "delete" || !MOTOR_HIGHWAYS.has(tags.highway || "")) continue;
    const refs = [...body.matchAll(/<nd\b([^>]*)\/?\s*>/g)].map((item) => xmlAttrs(item[1]).ref).filter(Boolean);
    const coords = refs.map((ref) => nodes.get(String(ref))).filter(Boolean);
    if (coords.length < 2 || coords.length !== refs.length) continue;
    ways.push({ id: String(attrs.id), refs: refs.map(String), coords, tags });
  }
  return { nodes, ways, crossingNodes };
}

function compileRoadModel(xml, overrides) {
  const parsed = parseOsmRoads(xml);
  const diagnostics = [];
  const roads = [];
  const endpoints = [];
  const byNode = new Map();
  const sharedNodeWayIds = new Map();
  for (const way of parsed.ways) for (const nodeId of new Set(way.refs)) {
    if (!sharedNodeWayIds.has(nodeId)) sharedNodeWayIds.set(nodeId, new Set());
    sharedNodeWayIds.get(nodeId).add(way.id);
  }
  for (const sourceWay of parsed.ways) {
    const segments = splitWayAtSharedNodes(sourceWay, sharedNodeWayIds);
    for (const way of segments) {
    const directions = way.tags.oneway === "yes" || way.tags.oneway === "1" || way.tags.junction === "roundabout" ? ["forward"] : ["forward", "backward"];
    for (const direction of directions) {
      const base = roadAttributes(way.tags, direction);
      const id = `road:way/${way.id}${way.segmentIndex === null ? "" : `:segment/${way.segmentIndex}`}:${direction}`;
      const road = { id, osmWayIds: [way.id], segmentId: `segment:way/${way.id}/${way.segmentIndex ?? 0}`, sourceRoadId: `road:way/${way.id}:${direction}`, direction, highway: way.tags.highway, centerline: direction === "forward" ? way.coords : [...way.coords].reverse(), sourceNodeIds: direction === "forward" ? [way.refs[0], way.refs.at(-1)] : [way.refs.at(-1), way.refs[0]], tags: way.tags, ...base, appliedOverrideIds: [], diagnostics: [] };
      applyRoadOverrides(road, overrides, diagnostics);
      roads.push(road);
      for (const side of ["start", "end"]) {
        const nodeId = side === "start" ? road.sourceNodeIds[0] : road.sourceNodeIds[1];
        const endpoint = { id: `endpoint:${road.id}:${side}`, roadId: id, side, nodeId, coordinate: side === "start" ? road.centerline[0] : road.centerline.at(-1), direction };
        endpoints.push(endpoint);
        if (!byNode.has(nodeId)) byNode.set(nodeId, []);
        byNode.get(nodeId).push(endpoint);
      }
    }
    }
  }
  const connections = resolveConnections(endpoints, byNode, overrides, diagnostics);
  const extent = roadExtent(roads);
  for (const [nodeId, items] of byNode) {
    if (items.length === 1 && distanceToExtentEdgeMeters(items[0].coordinate, extent) > 25) {
      const endpoint = items[0];
      diagnostics.push({ ...diagnostic("warning", endpoint.roadId, [nodeId], "unconnected-interior-road-end", "道路在区域内部结束，未连接到其他机动车道路。请确认这是实际断头，还是 OSM 节点尚未连接。", endpoint.coordinate), endpointId: endpoint.id, manualCandidates: nearbyManualCandidates(endpoints, endpoint) });
    }
  }
  const crossings = parsed.crossingNodes.map((crossing) => ({ ...crossing, osmWayIds: parsed.ways.filter((way) => way.refs.includes(crossing.id)).map((way) => way.id) }));
  return { schema: "native-road-model/v1", roads, endpoints, connections, crossings, diagnostics };
}

function splitWayAtSharedNodes(way, sharedNodeWayIds) {
  const splitIndexes = [0];
  for (let index = 1; index < way.refs.length - 1; index += 1) if ((sharedNodeWayIds.get(way.refs[index])?.size || 0) > 1) splitIndexes.push(index);
  splitIndexes.push(way.refs.length - 1);
  if (splitIndexes.length === 2) return [{ ...way, segmentIndex: null }];
  return splitIndexes.slice(1).map((end, index) => {
    const start = splitIndexes[index];
    return { ...way, refs: way.refs.slice(start, end + 1), coords: way.coords.slice(start, end + 1), segmentIndex: index + 1 };
  });
}

function roadExtent(roads) {
  const points = roads.flatMap((road) => road.centerline);
  return { minLon: Math.min(...points.map((point) => point[0])), maxLon: Math.max(...points.map((point) => point[0])), minLat: Math.min(...points.map((point) => point[1])), maxLat: Math.max(...points.map((point) => point[1])) };
}

function distanceToExtentEdgeMeters(point, extent) {
  const lonScale = 111320 * Math.cos(point[1] * Math.PI / 180);
  return Math.min((point[0] - extent.minLon) * lonScale, (extent.maxLon - point[0]) * lonScale, (point[1] - extent.minLat) * 111320, (extent.maxLat - point[1]) * 111320);
}

function roadAttributes(tags, direction) {
  const directional = direction === "forward" ? "forward" : "backward";
  const laneTag = tags[`lanes:${directional}`] ?? (tags.oneway === "yes" ? tags.lanes : null);
  const parsedLanes = positiveInteger(laneTag);
  const totalLanes = positiveInteger(tags.lanes);
  const lanes = parsedLanes || (totalLanes ? Math.max(1, Math.ceil(totalLanes / (tags.oneway === "yes" ? 1 : 2))) : 1);
  const parsedWidth = positiveNumber(tags.width);
  const forwardLanes = positiveInteger(tags["lanes:forward"]);
  const backwardLanes = positiveInteger(tags["lanes:backward"]);
  const directionalLaneTotal = forwardLanes && backwardLanes ? forwardLanes + backwardLanes : totalLanes;
  // `width` describes the whole OSM way. A directional road receives its lane
  // share; absent width falls back to a realistic per-lane carriageway width.
  const width = parsedWidth ? parsedWidth * lanes / (directionalLaneTotal || (tags.oneway === "yes" ? lanes : lanes * 2)) : lanes * 3.25;
  return {
    laneCount: lanes,
    widthMeters: width,
    sidewalkLeft: sidewalkState(tags, direction, "left"),
    sidewalkRight: sidewalkState(tags, direction, "right"),
    provenance: {
      laneCount: parsedLanes || totalLanes ? `tag:${parsedLanes ? `lanes:${directional}` : "lanes"}` : "inferred:default-lanes",
      widthMeters: parsedWidth ? "tag:width (按方向车道数分配)" : "inferred:3.25m-per-lane",
    },
  };
}

function sidewalkState(tags, direction, side) {
  const osmSide = direction === "forward" ? side : side === "left" ? "right" : "left";
  const value = tags[`sidewalk:${osmSide}`] ?? tags.sidewalk;
  return value === "both" || value === "yes" || value === osmSide;
}

function loadOverrides(file) {
  if (!fs.existsSync(file)) return { schema: OVERRIDE_SCHEMA, overrides: [] };
  return validateOverrides(JSON.parse(fs.readFileSync(file, "utf8")));
}

function validateOverrides(value, model) {
  if (!value || value.schema !== OVERRIDE_SCHEMA || !Array.isArray(value.overrides)) throw new Error(`Overrides must use ${OVERRIDE_SCHEMA}.`);
  const ids = new Set();
  const roadIds = model ? new Set(model.roads.flatMap((road) => [road.id, road.sourceRoadId])) : null;
  const endpointIds = model ? new Set(model.endpoints.map((endpoint) => endpoint.id)) : null;
  const laneIds = model ? new Set(model.roads.flatMap((road) => Array.from({ length: road.laneCount }, (_, index) => `lane:${road.id}:${index + 1}`))) : null;
  const segmentIds = model ? new Set(model.roads.map((road) => road.segmentId)) : null;
  for (const item of value.overrides) {
    if (!item || typeof item.id !== "string" || !item.id || ids.has(item.id)) throw new Error("Each override needs a unique id.");
    ids.add(item.id);
    if (item.kind === "road") {
      if (typeof item.roadId !== "string" || roadIds && !roadIds.has(item.roadId)) throw new Error(`Unknown road override target: ${item.roadId}`);
      for (const key of ["widthMeters", "laneCount"]) if (item[key] !== undefined && (!Number.isFinite(item[key]) || item[key] <= 0 || (key === "laneCount" && !Number.isInteger(item[key])))) throw new Error(`Invalid road override ${key}.`);
      for (const key of ["sidewalkLeft", "sidewalkRight"]) if (item[key] !== undefined && typeof item[key] !== "boolean") throw new Error(`Invalid road override ${key}.`);
    } else if (item.kind === "junction-connection") {
      if (typeof item.fromEndpointId !== "string" || typeof item.toEndpointId !== "string" || typeof item.enabled !== "boolean" || (endpointIds && (!endpointIds.has(item.fromEndpointId) || !endpointIds.has(item.toEndpointId)))) throw new Error("Invalid junction connection override.");
      if (model && !connectionEndpointsCompatible(model, item.fromEndpointId, item.toEndpointId)) throw new Error("A manual junction connection must go from a road end to a nearby road start (within 35m).");
    } else if (item.kind === "lane-connection") {
      if (typeof item.fromLaneId !== "string" || typeof item.toLaneId !== "string" || typeof item.enabled !== "boolean" || (laneIds && (!laneIds.has(item.fromLaneId) || !laneIds.has(item.toLaneId)))) throw new Error("Invalid lane connection override.");
    } else if (item.kind === "center-line-style") {
      if (typeof item.segmentId !== "string" || !CENTER_LINE_COLORS.has(item.color) || !CENTER_LINE_PATTERNS.has(item.pattern) || (segmentIds && !segmentIds.has(item.segmentId))) throw new Error("Invalid center line style override.");
    } else if (item.kind === "lane-separator-style") {
      if (typeof item.roadId !== "string" || (roadIds && !roadIds.has(item.roadId)) || !Number.isInteger(item.leftLaneIndex) || item.rightLaneIndex !== item.leftLaneIndex + 1 || !CENTER_LINE_COLORS.has(item.color) || !CENTER_LINE_PATTERNS.has(item.pattern)) throw new Error("Invalid lane separator style override.");
    } else throw new Error(`Unsupported override kind: ${item.kind}`);
  }
  return { schema: OVERRIDE_SCHEMA, overrides: value.overrides };
}

function applyRoadOverrides(road, overrides, diagnostics) {
  const matching = overrides.overrides.filter((entry) => entry.kind === "road" && (entry.roadId === road.sourceRoadId || entry.roadId === road.id));
  // A legacy whole-way edit remains the baseline; a segment-specific edit can
  // deliberately refine it after the compiler has introduced split segments.
  matching.sort((first, second) => Number(first.roadId === road.id) - Number(second.roadId === road.id));
  for (const item of matching) {
    for (const key of ["widthMeters", "laneCount", "sidewalkLeft", "sidewalkRight"]) if (item[key] !== undefined) road[key] = item[key];
    road.appliedOverrideIds.push(item.id);
    for (const key of ["widthMeters", "laneCount"]) if (item[key] !== undefined) road.provenance[key] = `override:${item.id}`;
  }
  if (road.widthMeters < road.laneCount * 2.4) diagnostics.push(diagnostic("warning", road.id, road.osmWayIds, "narrow-lane-width", "Configured road width is narrow for the selected lane count.", road.centerline[0]));
}

function resolveConnections(endpoints, byNode, overrides, diagnostics) {
  const result = [];
  for (const [nodeId, items] of byNode) {
    const arrivals = items.filter((endpoint) => endpoint.side === "end");
    const departures = items.filter((endpoint) => endpoint.side === "start");
    for (const arrival of arrivals) for (const departure of departures) {
      if (arrival.roadId === departure.roadId) continue;
      const arrivalRoad = endpoints.find((endpoint) => endpoint.id === arrival.id)?.roadId;
      const departureRoad = endpoints.find((endpoint) => endpoint.id === departure.id)?.roadId;
      if (sameOsmWay(endpoints, arrivalRoad, departureRoad)) continue;
      const override = overrides.overrides.find((entry) => entry.kind === "junction-connection" && entry.fromEndpointId === arrival.id && entry.toEndpointId === departure.id);
      result.push({ id: `connection:${arrival.id}:${departure.id}`, nodeId, fromEndpointId: arrival.id, toEndpointId: departure.id, enabled: override ? override.enabled : true, provenance: override ? `override:${override.id}` : "osm:shared-node" });
    }
    if (items.length > 8) diagnostics.push(diagnostic("warning", `junction:node/${nodeId}`, [nodeId], "complex-junction", "Junction has more than eight directional endpoints and is not compiled as an ordinary junction.", items[0].coordinate));
  }
  // Overrides can add a deliberate movement omitted by the initial inference.
  // Keep it only when both endpoints still belong to the same OSM junction.
  for (const override of overrides.overrides.filter((item) => item.kind === "junction-connection")) {
    const exists = result.some((connection) => connection.fromEndpointId === override.fromEndpointId && connection.toEndpointId === override.toEndpointId);
    if (exists) continue;
    const from = endpoints.find((endpoint) => endpoint.id === override.fromEndpointId);
    const to = endpoints.find((endpoint) => endpoint.id === override.toEndpointId);
    if (!from || !to || !connectionEndpointsCompatible({ endpoints }, from.id, to.id)) continue;
    result.push({ id: `connection:${from.id}:${to.id}`, nodeId: from.nodeId, fromEndpointId: from.id, toEndpointId: to.id, enabled: override.enabled, provenance: `override:${override.id}` });
  }
  return result;
}

function endpointNode(model, endpointId) { return model.endpoints.find((endpoint) => endpoint.id === endpointId)?.nodeId; }
function sameOsmWay(endpoints, firstRoadId, secondRoadId) {
  const roadFor = (roadId) => endpoints.find((endpoint) => endpoint.roadId === roadId)?.roadId;
  const segmentId = (roadId) => roadId.replace(/:(forward|backward)$/, "");
  return segmentId(roadFor(firstRoadId) || firstRoadId) === segmentId(roadFor(secondRoadId) || secondRoadId);
}
function connectionEndpointsCompatible(model, fromId, toId) {
  const from = model.endpoints.find((endpoint) => endpoint.id === fromId);
  const to = model.endpoints.find((endpoint) => endpoint.id === toId);
  if (!from || !to || from.roadId === to.roadId || sameOsmWay(model.endpoints, from.roadId, to.roadId) || from.side !== "end" || to.side !== "start") return false;
  if (from.nodeId === to.nodeId) return true;
  const dx = (from.coordinate[0] - to.coordinate[0]) * 111320 * Math.cos(from.coordinate[1] * Math.PI / 180);
  const dy = (from.coordinate[1] - to.coordinate[1]) * 111320;
  return Math.hypot(dx, dy) <= 35;
}

function nearbyManualCandidates(endpoints, from) {
  return endpoints.filter((to) => to.side === "start" && to.roadId !== from.roadId && !sameOsmWay(endpoints, from.roadId, to.roadId)).map((to) => ({ to, distanceMeters: distanceMeters(from.coordinate, to.coordinate) })).filter((item) => item.distanceMeters <= 35).sort((a, b) => a.distanceMeters - b.distanceMeters).slice(0, 3).map(({ to, distanceMeters: meters }) => ({ toEndpointId: to.id, roadId: to.roadId, distanceMeters: Math.round(meters * 10) / 10 }));
}

function compileGeometry(model, overrides = { overrides: [] }) {
  const diagnostics = [...model.diagnostics];
  const junctionPlans = compileJunctionPlans(model);
  const features = [];
  const emittedSegments = new Set();
  for (const road of model.roads) {
    const segmentKey = road.segmentId;
    if (emittedSegments.has(segmentKey)) continue;
    emittedSegments.add(segmentKey);
    const directions = model.roads.filter((item) => item.segmentId === segmentKey);
    const totalWidth = directions.reduce((sum, item) => sum + item.widthMeters, 0);
    // Road and junction asphalt share one final material. Keep the carriageway
    // continuous through the semantic junction overlay; cutting it back creates
    // visible wedges/gaps without improving the rendered result.
    const ring = roadRing(road.centerline, totalWidth);
    if (!ring) { diagnostics.push(diagnostic("error", road.id, road.osmWayIds, "unclosed-road-surface", "Could not construct a valid road polygon from this centerline.", road.centerline[0])); continue; }
    const surfaceId = road.segmentId.endsWith("/0") ? `surface:way/${road.osmWayIds.join(",")}` : `surface:${segmentKey}`;
    features.push({ type: "Feature", properties: { native_id: surfaceId, directional_road_ids: directions.map((item) => item.id).join(","), osm_way_ids: road.osmWayIds.join(","), source_road_id: road.sourceRoadId, width_m: totalWidth, lane_count: directions.reduce((sum, item) => item.laneCount + sum, 0), provenance: JSON.stringify(directions.map((item) => item.provenance)), override_ids: directions.flatMap((item) => item.appliedOverrideIds).join(",") }, geometry: { type: "Polygon", coordinates: [ring] } });
  }
  const lanes = compileLaneCenterlines(model, diagnostics, junctionPlans);
  const edgeLines = compileEdgeLines(model, junctionPlans);
  const controls = compileControlMarkings(model, lanes, diagnostics);
  const centerLines = compileCenterLines(model, overrides, junctionPlans, controls, diagnostics);
  const markings = compileLaneMarkings(model, overrides, lanes, diagnostics, junctionPlans, controls);
  const sidewalks = compileSidewalkSurfaces(model, diagnostics, junctionPlans);
  const connectorResult = compileConnectors(model, lanes, diagnostics, overrides);
  const junctionFeatures = compileJunctionSurfaces(model, junctionPlans, connectorResult.features, connectorResult.movements, diagnostics);
  validateConnectorContainment(connectorResult.features, junctionFeatures, diagnostics);
  return { roadSurface: { type: "FeatureCollection", features }, edgeLines: { type: "FeatureCollection", features: edgeLines }, sidewalkSurface: { type: "FeatureCollection", features: sidewalks }, intersectionSurface: { type: "FeatureCollection", features: junctionFeatures }, laneCenterlines: { type: "FeatureCollection", features: lanes.features }, laneSeparators: { type: "FeatureCollection", features: markings.separators }, centerLines: { type: "FeatureCollection", features: centerLines }, directionArrows: { type: "FeatureCollection", features: markings.directionArrows }, turnArrows: { type: "FeatureCollection", features: markings.turnArrows }, crosswalks: { type: "FeatureCollection", features: controls.crosswalks }, vehicleStopLines: { type: "FeatureCollection", features: controls.stopLines }, connectors: { type: "FeatureCollection", features: connectorResult.features }, movements: connectorResult.movements, diagnostics };
}

function compileEdgeLines(model, junctionPlans) { const features=[]; for (const road of model.roads) { const line=trimLineAtJunctions(road.centerline, road.sourceNodeIds, junctionPlans); for (const side of [-1,1]) { const ring=roadRing(offsetLine(line, side * road.widthMeters / 2), .12); if (ring) features.push({type:"Feature",properties:{native_id:`edge-line:${road.id}:${side<0?"right":"left"}`,road_id:road.id,side:side<0?"right":"left",color:"white",pattern:"solid",provenance:"native-road-edge-line/v1"},geometry:{type:"Polygon",coordinates:[ring]}}); } } return features; }

function compileCenterLines(model, overrides, junctionPlans, controls, diagnostics) {
  const features = [];
  const controlFeatures = [...controls.crosswalks, ...controls.stopLines];
  const segments = new Map();
  for (const road of model.roads) {
    if (!segments.has(road.segmentId)) segments.set(road.segmentId, []);
    segments.get(road.segmentId).push(road);
  }
  for (const [segmentId, roads] of segments) {
    const forward = roads.find((road) => road.direction === "forward");
    const backward = roads.find((road) => road.direction === "backward");
    if (roads.length !== 2 || !forward || !backward || forward.highway === "service" || backward.highway === "service") continue;
    const line = trimLineAtJunctions(forward.centerline, forward.sourceNodeIds, junctionPlans);
    const length = lineLengthMeters(line);
    if (line.length < 2 || !Number.isFinite(length)) { diagnostics.push(diagnostic("warning", segmentId, forward.osmWayIds, "invalid-center-line", "双向道路无法生成有效道路中心虚线。", forward.centerline[0])); continue; }
    const style = centerLineStyle(overrides, segmentId);
    const gap = style.pattern === "solid" ? 0 : CENTER_LINE_DASH_GAP_METERS;
    const markLength = CENTER_LINE_DASH_LENGTH_METERS + (style.pattern === "solid" ? CENTER_LINE_SOLID_OVERLAP_METERS : 0);
    for (let start = 0, dashIndex = 1; start + markLength <= length; start += CENTER_LINE_DASH_LENGTH_METERS + gap, dashIndex += 1) {
      const placement = pointAndAxisAlongLine(line, start + markLength / 2);
      if (!placement) continue;
      const ring = rectangleAt(placement.point, placement.axis, [-placement.axis[1], placement.axis[0]], markLength, CENTER_LINE_WIDTH_METERS, 0);
      const clearanceRing = rectangleAt(placement.point, placement.axis, [-placement.axis[1], placement.axis[0]], markLength + CENTER_LINE_CONTROL_CLEARANCE_METERS * 2, CENTER_LINE_WIDTH_METERS + CENTER_LINE_CONTROL_CLEARANCE_METERS * 2, 0);
      if (ringsOverlapControl([clearanceRing], controlFeatures)) continue;
      features.push({ type: "Feature", properties: { native_id: `center-line:${segmentId}:${dashIndex}`, segment_id: segmentId, road_id: forward.id, directional_road_ids: roads.map((road) => road.id).join(","), osm_way_ids: forward.osmWayIds.join(","), dash_index: dashIndex, dash_length_m: markLength, dash_gap_m: gap, color: style.color, pattern: style.pattern, effective_style: `${style.color}-${style.pattern}`, placement_rule: "native-bidirectional-centerline/v1", provenance: "native-road-center-line/v1" }, geometry: { type: "Polygon", coordinates: [ring] } });
    }
  }
  return features;
}

function centerLineStyle(overrides, segmentId) {
  const override = overrides.overrides.find((item) => item.kind === "center-line-style" && item.segmentId === segmentId);
  return override ? { color: override.color, pattern: override.pattern } : { color: "yellow", pattern: "dashed" };
}

function compileControlMarkings(model, lanes, diagnostics) {
  const crosswalks = []; const stopLines = [];
  const arrivalEndpointIds = new Set(model.connections.filter((connection) => connection.enabled).map((connection) => connection.fromEndpointId));
  for (const crossing of model.crossings || []) {
    const candidates = model.roads.filter((road) => crossing.osmWayIds.includes(road.osmWayIds[0])).flatMap((road) => (lanes.byRoadId.get(road.id) || []).map((lane) => ({ road, lane, placement: nearestLanePlacement(lane.coordinates, crossing.coordinate), junctionDistanceMeters: distanceMeters(crossing.coordinate, road.centerline.at(-1)) })).filter((item) => item.placement));
    const candidate = candidates.sort((a, b) => a.placement.distance - b.placement.distance)[0];
    if (!candidate || candidate.placement.distance > 12) { diagnostics.push(diagnostic("warning", `crossing:node/${crossing.id}`, [crossing.id], "crossing-no-native-lane", "人行横道无法匹配到安全的原生车道，未生成标线。", crossing.coordinate)); continue; }
    const approach = candidates.filter((item) => arrivalEndpointIds.has(`endpoint:${item.road.id}:end`) && item.junctionDistanceMeters > STOP_LINE_OFFSET_METERS && item.junctionDistanceMeters <= STOP_LINE_MAX_APPROACH_DISTANCE_METERS).sort((a, b) => a.junctionDistanceMeters - b.junctionDistanceMeters || a.placement.distance - b.placement.distance)[0];
    const crosswalkCandidate = approach || candidate;
    const { axis } = crosswalkCandidate.placement; const across = [-axis[1], axis[0]];
    for (let index = 0; index < 6; index += 1) crosswalks.push(controlFeature("crosswalk", crossing, crosswalkCandidate, index + 1, rectangleAt(crossing.coordinate, axis, across, 3, .45, -2.25 + index * .9)));
    if (!approach) { diagnostics.push(diagnostic("info", `crossing:node/${crossing.id}`, [crossing.id], "crossing-no-safe-stop-line", "人行横道没有可确认的路口进口车道，保留斑马线但未生成停止线。", crossing.coordinate)); continue; }
    const rawRoadPlacement = nearestLanePlacement(approach.road.centerline, crossing.coordinate);
    const laneOffset = rawRoadPlacement ? project(approach.placement.point, rawRoadPlacement.point) : [0, 0];
    const lateralOffset = laneOffset[0] * across[0] + laneOffset[1] * across[1];
    const laneCenterAtCrossing = offsetByMeters(crossing.coordinate, across, lateralOffset);
    const stopCenter = offsetByMeters(laneCenterAtCrossing, approach.placement.axis, -STOP_LINE_OFFSET_METERS);
    stopLines.push(controlFeature("stop-line", crossing, approach, 1, rectangleAt(stopCenter, across, approach.placement.axis, approach.road.widthMeters, .45, 0)));
  }
  return { crosswalks, stopLines };
}

function nearestLanePlacement(line, target) { let best = null; let traversedMeters = 0; for (let index = 1; index < line.length; index += 1) { const a = line[index - 1]; const b = line[index]; const vector = project(b, a); const length = Math.hypot(...vector); if (!length) continue; const relative = project(target, a); const ratio = Math.max(0, Math.min(1, (relative[0] * vector[0] + relative[1] * vector[1]) / (length * length))); const point = interpolate(a, b, ratio); const distance = distanceMeters(point, target); if (!best || distance < best.distance) best = { point, axis: [vector[0] / length, vector[1] / length], distance, distanceToEndMeters: lineLengthMeters(line) - traversedMeters - length * ratio }; traversedMeters += length; } return best; }
function offsetByMeters(point, axis, meters) { return unproject([axis[0] * meters, axis[1] * meters], point); }
function rectangleAt(center, axis, across, length, width, offset) { const shifted = offsetByMeters(center, across, offset); const corners = [[-length / 2, -width / 2], [length / 2, -width / 2], [length / 2, width / 2], [-length / 2, width / 2]].map(([forward, side]) => unproject([axis[0] * forward + across[0] * side, axis[1] * forward + across[1] * side], shifted)); return [...corners, corners[0]]; }
function controlFeature(kind, crossing, candidate, part, ring) { const stop = kind === "stop-line"; return { type: "Feature", properties: { native_id: `${kind}:node/${crossing.id}:${part}`, crossing_node_id: crossing.id, road_id: candidate.road.id, lane_id: candidate.lane.id, osm_way_ids: candidate.road.osmWayIds.join(","), direction: candidate.road.direction, placement_method: "native-lane-nearest-point/v1", provenance: stop ? "native-road-stop-line/v1" : "native-road-crosswalk/v1" }, geometry: { type: "Polygon", coordinates: [ring] } }; }

function compileLaneMarkings(model, overrides, lanes, diagnostics, junctionPlans, controls) {
  const separators = []; const directionArrows = []; const turnArrows = [];
  const controlFeatures = [...controls.crosswalks, ...controls.stopLines];
  for (const road of model.roads) {
    const roadLanes = lanes.byRoadId.get(road.id) || [];
    for (let index = 1; index < roadLanes.length; index += 1) {
      const left = roadLanes[index - 1].coordinates; const right = roadLanes[index].coordinates;
      if (left.length !== right.length) continue;
      const centerline = left.map((point, pointIndex) => [(point[0] + right[pointIndex][0]) / 2, (point[1] + right[pointIndex][1]) / 2]);
      const style = laneSeparatorStyle(overrides, road.id, index, index + 1);
      const properties = { road_id: road.id, left_lane_index: index, right_lane_index: index + 1, osm_way_ids: road.osmWayIds.join(","), color: style.color, pattern: style.pattern, effective_style: `${style.color}-${style.pattern}`, provenance: "native-road-lane-separator/v1" };
      if (style.pattern === "solid") { const ring = roadRing(centerline, 0.12); if (ring) separators.push({ type: "Feature", properties: { native_id: `lane-separator:${road.id}:${index}-${index + 1}`, ...properties }, geometry: { type: "Polygon", coordinates: [ring] } }); }
      else for (let distance = 1, part = 1; distance + 1 <= lineLengthMeters(centerline); distance += 4, part += 1) { const placement = pointAndAxisAlongLine(centerline, distance); if (!placement) continue; const ring = rectangleAt(placement.point, placement.axis, [-placement.axis[1], placement.axis[0]], 2, .12, 0); separators.push({ type: "Feature", properties: { native_id: `lane-separator:${road.id}:${index}-${index + 1}:${part}`, ...properties }, geometry: { type: "Polygon", coordinates: [ring] } }); }
    }
    for (const lane of roadLanes) directionArrows.push(...directionArrowFeatures(road, lane, controlFeatures, diagnostics));
    const turns = road.tags[`turn:lanes:${road.direction}`] ?? road.tags["turn:lanes"];
    const maneuvers = turns ? String(turns).split("|") : [];
    for (let index = 0; index < roadLanes.length; index += 1) {
      const lane = roadLanes[index]; const explicitManeuver = maneuvers[index];
      if (!explicitManeuver) continue;
      const maneuver = normalizeManeuver(explicitManeuver);
      if (!lane) { diagnostics.push(diagnostic("warning", road.id, road.osmWayIds, "turn-arrow-lane-missing", "转向标签引用了不存在的车道，未生成箭头。", road.centerline.at(-1))); continue; }
      if (!arrowRingsAt(maneuver, lane.coordinates.at(-1), [0, 1]).length) { diagnostics.push(diagnostic("info", lane.id, road.osmWayIds, "turn-arrow-unsupported", "转向标签不在当前已测试的箭头集合中，未生成箭头。", lane.coordinates.at(-1))); continue; }
      if (lineLengthMeters(lane.coordinates) < 8) { diagnostics.push(diagnostic("warning", lane.id, road.osmWayIds, "turn-arrow-no-safe-placement", "驶入路口前的车道过短，未生成转向箭头。", lane.coordinates.at(-1))); continue; }
      const previous = lane.coordinates.at(-2); const end = lane.coordinates.at(-1);
      const meters = project(end, end); const vector = project(previous, end); const length = Math.hypot(-vector[0], -vector[1]);
      const axis = length ? [-vector[0] / length, -vector[1] / length] : null;
      const placement = axis ? [6, 10, 14, 18, 22].find((distance) => distance < lineLengthMeters(lane.coordinates) - 2 && !ringsOverlapControl(arrowRingsAt(maneuver, pointAlongLine([...lane.coordinates].reverse(), distance), axis), controlFeatures)) : null;
      if (!placement) { diagnostics.push(diagnostic("info", lane.id, road.osmWayIds, "turn-arrow-control-conflict", "转向箭头会压住斑马线或停止线，未生成该箭头。", lane.coordinates.at(-1))); continue; }
      const center = pointAlongLine([...lane.coordinates].reverse(), placement);
      const rings = arrowRingsAt(maneuver, center, axis);
      if (!rings.length) continue;
      for (let part = 0; part < rings.length; part += 1) turnArrows.push({ type: "Feature", properties: { native_id: `turn-arrow:${lane.id}:${maneuver}:${part}`, road_id: road.id, lane_id: lane.id, osm_way_ids: road.osmWayIds.join(","), direction: road.direction, lane_index: lane.index, maneuver, arrow_part: part, placement_distance_meters: placement, provenance: "native-road-turn-arrow/v1" }, geometry: { type: "Polygon", coordinates: [rings[part]] } });
    }
  }
  return { separators, directionArrows, turnArrows };
}

function laneSeparatorStyle(overrides, roadId, leftLaneIndex, rightLaneIndex) { const value = overrides.overrides.find((item) => item.kind === "lane-separator-style" && item.roadId === roadId && item.leftLaneIndex === leftLaneIndex && item.rightLaneIndex === rightLaneIndex); return value ? { color: value.color, pattern: value.pattern } : { color: "white", pattern: "dashed" }; }

function directionArrowFeatures(road, lane, controlFeatures, diagnostics) {
  const length = lineLengthMeters(lane.coordinates);
  const features = [];
  for (let distance = DIRECTION_ARROW_ENDPOINT_BUFFER_METERS, sequence = 1; distance <= length - DIRECTION_ARROW_ENDPOINT_BUFFER_METERS; distance += DIRECTION_ARROW_INTERVAL_METERS, sequence += 1) {
    const placement = pointAndAxisAlongLine(lane.coordinates, distance);
    if (!placement) continue;
    const rings = arrowRingsAt("through", placement.point, placement.axis);
    if (ringsOverlapControl(rings, controlFeatures)) { diagnostics.push(diagnostic("info", lane.id, road.osmWayIds, "direction-arrow-control-conflict", "默认直行箭头会压住斑马线或停止线，已跳过该位置。", placement.point)); continue; }
    for (let part = 0; part < rings.length; part += 1) features.push({ type: "Feature", properties: { native_id: `direction-arrow:${lane.id}:${sequence}:${part}`, road_id: road.id, lane_id: lane.id, osm_way_ids: road.osmWayIds.join(","), direction: road.direction, lane_index: lane.index, maneuver: "through", sequence, distance_along_lane_meters: Math.round(distance * 10) / 10, placement_interval_meters: DIRECTION_ARROW_INTERVAL_METERS, provenance: "native-road-direction-arrow/v1" }, geometry: { type: "Polygon", coordinates: [rings[part]] } });
  }
  return features;
}

function ringsOverlapControl(rings, controls) {
  return rings.some((ring) => controls.some((feature) => ringsOverlap(ring, feature.geometry.coordinates[0])));
}
function ringsOverlap(first, second) {
  const bounds = (ring) => [Math.min(...ring.map((point) => point[0])), Math.min(...ring.map((point) => point[1])), Math.max(...ring.map((point) => point[0])), Math.max(...ring.map((point) => point[1]))];
  const a = bounds(first); const b = bounds(second);
  if (a[0] > b[2] || a[2] < b[0] || a[1] > b[3] || a[3] < b[1]) return false;
  if (first.some((point) => pointInPolygon(point, second)) || second.some((point) => pointInPolygon(point, first))) return true;
  return first.slice(1).some((point, index) => second.slice(1).some((other, otherIndex) => segmentsIntersect(first[index], point, second[otherIndex], other)));
}

function compileSidewalkSurfaces(model, diagnostics, junctionPlans) {
  const features = [];
  const byWay = new Map();
  for (const road of model.roads) {
    const key = road.segmentId;
    if (!byWay.has(key)) byWay.set(key, []);
    byWay.get(key).push(road);
  }
  for (const [wayKey, directions] of byWay) {
    const forward = directions.find((road) => road.direction === "forward") || directions[0];
    const backward = directions.find((road) => road.id !== forward.id);
    const totalWidth = directions.reduce((sum, road) => sum + road.widthMeters, 0);
    const sides = [
      ["left", forward.sidewalkLeft || Boolean(backward?.sidewalkRight)],
      ["right", forward.sidewalkRight || Boolean(backward?.sidewalkLeft)],
    ];
    for (const [side, enabled] of sides) {
      if (!enabled) continue;
      const centerline = trimLineAtJunctions(forward.centerline, forward.sourceNodeIds, junctionPlans);
      const ring = sidewalkRing(centerline, totalWidth / 2, totalWidth / 2 + DEFAULT_SIDEWALK_WIDTH_METERS, side === "left" ? 1 : -1);
      if (!ring) { diagnostics.push(diagnostic("warning", forward.id, forward.osmWayIds, "invalid-sidewalk-surface", "无法为该道路生成连续人行道面。", forward.centerline[0])); continue; }
      const sidewalkId = forward.segmentId.endsWith("/0") ? `sidewalk:way/${forward.osmWayIds.join(",")}:${side}` : `sidewalk:${wayKey}:${side}`;
      features.push({ type: "Feature", properties: { native_id: sidewalkId, osm_way_ids: forward.osmWayIds.join(","), source_road_id: forward.sourceRoadId, side, width_m: DEFAULT_SIDEWALK_WIDTH_METERS, directional_road_ids: directions.map((road) => road.id).join(","), provenance: "native-road-sidewalk/v1", override_ids: directions.flatMap((road) => road.appliedOverrideIds).join(",") }, geometry: { type: "Polygon", coordinates: [ring] } });
    }
  }
  features.push(...compileSidewalkCorners(model, junctionPlans));
  return features;
}

function compileSidewalkCorners(model, junctionPlans) {
  const result = [];
  for (const [nodeId, plan] of junctionPlans) {
    const candidates = [];
    for (const approach of plan.approaches) {
      const directions = model.roads.filter((road) => road.segmentId === approach.segmentId);
      const forward = directions.find((road) => road.direction === "forward") || directions[0];
      if (!forward) continue;
      const outwardIsForward = forward.sourceNodeIds[0] === nodeId;
      const sideStates = outwardIsForward
        ? { left: forward.sidewalkLeft, right: forward.sidewalkRight }
        : { left: forward.sidewalkRight, right: forward.sidewalkLeft };
      const cutback = pointAlongLine(approach.line, plan.cutbackMeters);
      if (!cutback) continue;
      const heading = headingAtEndpoint(approach.line);
      const halfWidth = approach.widthMeters / 2;
      for (const [side, enabled] of Object.entries(sideStates)) {
        if (!enabled) continue;
        // offsetLine's positive normal is driver's left, which is heading -90
        // in this north-based heading convention.
        const sideHeading = heading + (side === "left" ? -90 : 90);
        candidates.push({
          wayKey: approach.segmentId,
          sourceWayKey: forward.osmWayIds.join(","),
          side,
          normalDegrees: sideHeading,
          curb: offsetCoordinate(cutback, sideHeading, halfWidth),
          outer: offsetCoordinate(cutback, sideHeading, halfWidth + DEFAULT_SIDEWALK_WIDTH_METERS),
        });
      }
    }
    candidates.sort((a, b) => angleAround(plan.node, a.curb) - angleAround(plan.node, b.curb));
    for (let index = 0; index < candidates.length; index += 1) {
      const first = candidates[index];
      const second = candidates[(index + 1) % candidates.length];
      if (first.wayKey === second.wayKey) continue;
      const ring = [first.curb, first.outer, second.outer, second.curb, first.curb];
      if (hasSelfIntersection(ring)) continue;
      if (first.sourceWayKey === second.sourceWayKey && (!samePhysicalSide(first, second) || cornerFallsIntoOtherApproach(ring, first.sourceWayKey, plan.approaches))) continue;
      result.push({
        type: "Feature",
        properties: {
          native_id: `sidewalk-corner:node/${nodeId}:${first.wayKey}:${first.side}->${second.wayKey}:${second.side}`,
          osm_node_id: nodeId,
          kind: "corner",
          width_m: DEFAULT_SIDEWALK_WIDTH_METERS,
          provenance: "native-road-sidewalk-corner/v1",
        },
        geometry: { type: "Polygon", coordinates: [ring] },
      });
    }
  }
  return result;
}

function samePhysicalSide(first, second) {
  const radians = (first.normalDegrees - second.normalDegrees) * Math.PI / 180;
  return Math.cos(radians) >= 0.98;
}

function cornerFallsIntoOtherApproach(ring, sourceWayKey, approaches) {
  const center = ring.slice(0, -1).reduce((sum, point) => [sum[0] + point[0] / 4, sum[1] + point[1] / 4], [0, 0]);
  return approaches.filter((approach) => approach.sourceWayKey !== sourceWayKey).some((approach) => {
    const carriageway = roadRing(approach.line, approach.widthMeters);
    return carriageway && pointInPolygon(center, carriageway);
  });
}

function validateConnectorContainment(connectors, junctionFeatures, diagnostics) {
  const junctionByNode = new Map(junctionFeatures.map((feature) => [feature.properties.osm_node_id, feature]));
  for (const connector of connectors) {
    const junction = junctionByNode.get(connector.properties.node_id);
    if (!junction) continue;
    const ring = junction.geometry.coordinates[0];
    if (!connector.geometry.coordinates.every((point) => pointInPolygon(point, ring))) {
      diagnostics.push(diagnostic("warning", connector.properties.connection_id, [connector.properties.node_id], "connector-outside-junction", "转向路径有部分落在路口面外，请检查道路截面或转向连接。", connector.geometry.coordinates[0]));
    }
  }
}

function pointInPolygon(point, ring) {
  for (let index = 1; index < ring.length; index += 1) if (pointOnSegment(point, ring[index - 1], ring[index])) return true;
  let inside = false;
  for (let index = 0, previous = ring.length - 1; index < ring.length; previous = index++) {
    const a = ring[index]; const b = ring[previous];
    const intersect = a[1] > point[1] !== b[1] > point[1] && point[0] < (b[0] - a[0]) * (point[1] - a[1]) / (b[1] - a[1]) + a[0];
    if (intersect) inside = !inside;
  }
  return inside;
}
function pointOnSegment(point, a, b) {
  const cross = (point[0] - a[0]) * (b[1] - a[1]) - (point[1] - a[1]) * (b[0] - a[0]);
  if (Math.abs(cross) > 1e-12) return false;
  return point[0] >= Math.min(a[0], b[0]) - 1e-12 && point[0] <= Math.max(a[0], b[0]) + 1e-12 && point[1] >= Math.min(a[1], b[1]) - 1e-12 && point[1] <= Math.max(a[1], b[1]) + 1e-12;
}

function compileLaneCenterlines(model, diagnostics, junctionPlans) {
  const features = [];
  const byRoadId = new Map();
  for (const road of model.roads) {
    const lanes = [];
    const laneWidth = road.widthMeters / road.laneCount;
    const siblings = model.roads.filter((item) => item.segmentId === road.segmentId);
    const opposite = siblings.find((item) => item.id !== road.id);
    // OSM centerline is the shared carriageway center. On a two-way road,
    // offset each directed carriageway to its own side before placing lanes.
    const carriagewayOffset = opposite ? (road.direction === "forward" ? -opposite.widthMeters / 2 : -road.widthMeters / 2) : 0;
    for (let index = 0; index < road.laneCount; index += 1) {
      // OSM `turn:lanes` is ordered from left to right. Keep lane 1 on the
      // driver's left so tag positions and generated lane IDs have one meaning.
      const offset = carriagewayOffset + (road.widthMeters / 2 - laneWidth * (index + 0.5));
      const coordinates = offsetLine(trimLineAtJunctions(road.centerline, road.sourceNodeIds, junctionPlans), offset);
      if (!coordinates) { diagnostics.push(diagnostic("error", road.id, road.osmWayIds, "invalid-lane-centerline", "无法为该道路生成车道中心线。", road.centerline[0])); continue; }
      const lane = { id: `lane:${road.id}:${index + 1}`, roadId: road.id, index: index + 1, coordinates };
      lanes.push(lane);
      features.push({ type: "Feature", properties: { native_id: lane.id, road_id: road.id, lane_index: lane.index, source: "native-road-lane-centerline/v1" }, geometry: { type: "LineString", coordinates } });
    }
    byRoadId.set(road.id, lanes);
  }
  return { features, byRoadId };
}

function compileConnectors(model, lanes, diagnostics, overrides) {
  const features = [];
  const movements = [];
  for (const connection of model.connections.filter((item) => item.enabled)) {
    const fromRoad = model.roads.find((road) => road.id === endpointRoadId(model, connection.fromEndpointId));
    const toRoad = model.roads.find((road) => road.id === endpointRoadId(model, connection.toEndpointId));
    const fromLanes = lanes.byRoadId.get(fromRoad?.id) || [];
    const toLanes = lanes.byRoadId.get(endpointRoadId(model, connection.toEndpointId)) || [];
    if (!fromLanes.length || !toLanes.length) { diagnostics.push(diagnostic("warning", connection.id, [connection.nodeId], "connector-missing-lane", "转向连接缺少可用车道中心线。", endpointCoordinate(model, connection.fromEndpointId))); continue; }
    for (let index = 0; index < fromLanes.length; index += 1) {
      const turn = connectionTurn(fromRoad, toRoad);
      const defaultTargetIndex = targetLaneIndex(turn, index, fromLanes.length, toLanes.length);
      const defaultFromLane = fromLanes[index]; const defaultToLane = toLanes[defaultTargetIndex];
      const override = laneOverride(overrides, defaultFromLane.id, defaultToLane.id);
      if ((!laneAllowsTurn(fromRoad, index, turn) && override?.enabled !== true) || override?.enabled === false) continue;
      const from = defaultFromLane.coordinates.at(-1); const to = defaultToLane.coordinates[0];
      const control = connectorControlPoint(model, connection, from, to);
      const coordinates = quadraticCurve(from, control, to, 12);
      const length = lineLengthMeters(coordinates);
      const id = `movement:${connection.id}:${defaultFromLane.id}->${defaultToLane.id}`;
      const provenance = override ? `override:${override.id}` : connection.provenance;
      const connectorId = `connector:${id}`;
      const geometryStatus = length < .4 ? "continuous" : length > 80 ? "deferred-too-long" : "connector";
      const movement = { id, connectorId, connectionId: connection.id, nodeId: connection.nodeId, fromRoadId: fromRoad.id, toRoadId: defaultToLane.roadId, fromLaneId: defaultFromLane.id, toLaneId: defaultToLane.id, turn, provenance, appliedOverrideIds: override ? [override.id] : [], geometryPublished: geometryStatus === "connector", geometryStatus };
      if (length < .4) { movements.push(movement); continue; }
      if (length > 80) { diagnostics.push(diagnostic("warning", connection.id, [connection.nodeId], "connector-too-long", "转向路径超过 80 米，未发布几何；请检查路口拓扑或人工连接。", from)); movements.push(movement); continue; }
      features.push({ type: "Feature", properties: { native_id: connectorId, movement_id: id, connection_id: connection.id, node_id: connection.nodeId, from_lane_id: defaultFromLane.id, to_lane_id: defaultToLane.id, turn, provenance }, geometry: { type: "LineString", coordinates } });
      movements.push(movement);
    }
  }
  return { features, movements };
}
function laneOverride(overrides, fromLaneId, toLaneId) { return overrides.overrides.find((item) => item.kind === "lane-connection" && item.fromLaneId === fromLaneId && item.toLaneId === toLaneId); }

function endpointRoadId(model, endpointId) { return model.endpoints.find((endpoint) => endpoint.id === endpointId)?.roadId; }
function endpointCoordinate(model, endpointId) { return model.endpoints.find((endpoint) => endpoint.id === endpointId)?.coordinate; }
function connectionTurn(fromRoad, toRoad) {
  if (!fromRoad || !toRoad) return "unknown";
  const incoming = headingDegrees(fromRoad.centerline.at(-2), fromRoad.centerline.at(-1));
  const outgoing = headingDegrees(toRoad.centerline[0], toRoad.centerline[1]);
  const delta = ((outgoing - incoming + 540) % 360) - 180;
  if (Math.abs(delta) >= 150) return "uturn";
  if (Math.abs(delta) <= 30) return "through";
  return delta > 0 ? "right" : "left";
}
function laneAllowsTurn(road, zeroIndex, turn) {
  if (!road) return true;
  const tag = road.tags[`turn:lanes:${road.direction}`] ?? road.tags["turn:lanes"];
  if (!tag) return true;
  const lanes = String(tag).split("|").map((lane) => lane.split(";").map((value) => value.trim().replace("slight_", "")).filter(Boolean));
  const allowed = lanes[zeroIndex];
  return !allowed || allowed.includes(turn) || turn === "uturn" && allowed.includes("reverse");
}
function targetLaneIndex(turn, sourceIndex, sourceCount, targetCount) {
  if (turn === "left") return 0;
  if (turn === "right") return targetCount - 1;
  if (turn === "uturn") return 0;
  return Math.min(targetCount - 1, Math.round(sourceIndex / Math.max(1, sourceCount - 1) * Math.max(0, targetCount - 1)));
}
function connectorControlPoint(model, connection, from, to) {
  const node = endpointCoordinate(model, connection.fromEndpointId);
  if (!node) return [(from[0] + to[0]) / 2, (from[1] + to[1]) / 2];
  // Nearby manual joins may not share exactly the same point. The midpoint
  // keeps their curve smooth without rewriting the authoritative OSM geometry.
  return node;
}

function quadraticCurve(a, control, b, segments) {
  const result = [];
  for (let index = 0; index <= segments; index += 1) {
    const t = index / segments; const u = 1 - t;
    result.push([u * u * a[0] + 2 * u * t * control[0] + t * t * b[0], u * u * a[1] + 2 * u * t * control[1] + t * t * b[1]]);
  }
  return result;
}

function offsetLine(line, offsetMeters) {
  if (line.length < 2) return null;
  const origin = line[0]; const points = line.map((point) => project(point, origin)); const result = [];
  for (let index = 0; index < points.length; index += 1) {
    const previous = points[Math.max(0, index - 1)]; const next = points[Math.min(points.length - 1, index + 1)];
    const dx = next[0] - previous[0]; const dy = next[1] - previous[1]; const length = Math.hypot(dx, dy);
    if (length < 0.01) return null;
    result.push(unproject([points[index][0] - dy / length * offsetMeters, points[index][1] + dx / length * offsetMeters], origin));
  }
  return result;
}

function lineLengthMeters(line) { return line.slice(1).reduce((sum, point, index) => { const previous = line[index]; const dx = (point[0] - previous[0]) * 111320 * Math.cos(point[1] * Math.PI / 180); const dy = (point[1] - previous[1]) * 111320; return sum + Math.hypot(dx, dy); }, 0); }
function polygonAreaMeters(ring) {
  if (ring.length < 3) return 0;
  const origin = ring[0];
  const points = ring.map((point) => project(point, origin));
  let twiceArea = 0;
  for (let index = 0; index < points.length; index += 1) {
    const next = points[(index + 1) % points.length];
    twiceArea += points[index][0] * next[1] - next[0] * points[index][1];
  }
  return Math.abs(twiceArea) / 2;
}

function compileJunctionSurfaces(model, junctionPlans, connectors, movements, diagnostics) {
  const result = [];
  for (const [nodeId, plan] of junctionPlans) {
    const { segmentIds, node, approaches, cutbackMeters, boundary } = plan;
    const junctionConnectors = connectors.filter((feature) => feature.properties.node_id === nodeId);
    const junctionMovements = movements.filter((movement) => movement.nodeId === nodeId);
    if (boundary.length < 3 || !junctionMovements.length) {
      diagnostics.push(diagnostic("warning", `junction:node/${nodeId}`, [nodeId], "junction-surface-deferred", "路口缺少足够的截面或转向路径，暂不生成路口面。", node));
      continue;
    }
    const approachAreaMeters = polygonAreaMeters(boundary);
    let ring = [...boundary, boundary[0]];
    let boundaryMode = "approach-envelope";
    if (hasSelfIntersection(ring) || !junctionConnectors.every((feature) => feature.geometry.coordinates.every((point) => pointInPolygon(point, ring)))) {
      const envelope = convexHull([...boundary, ...junctionConnectors.flatMap((feature) => feature.geometry.coordinates)]);
      ring = [...envelope, envelope[0]];
      boundaryMode = "connector-convex-fallback";
    }
    if (hasSelfIntersection(ring)) {
      diagnostics.push(diagnostic("error", `junction:node/${nodeId}`, [nodeId], "invalid-junction-surface", "路口截面边界发生自相交，未发布路口面。请检查道路方向或路口拓扑。", node));
      continue;
    }
    const surfaceAreaMeters = polygonAreaMeters(ring);
    const expansionRatio = approachAreaMeters > 0 ? surfaceAreaMeters / approachAreaMeters : null;
    result.push({ type: "Feature", properties: { native_id: `junction:node/${nodeId}`, osm_node_id: nodeId, kind: segmentIds.size === 3 ? "t" : "cross", source_road_ids: approaches.flatMap((approach) => approach.roadIds).join(","), cutback_m: cutbackMeters, movement_count: junctionMovements.length, connector_count: junctionConnectors.length, boundary_mode: boundaryMode, approach_area_m2: Math.round(approachAreaMeters * 10) / 10, surface_area_m2: Math.round(surfaceAreaMeters * 10) / 10, expansion_ratio: expansionRatio === null ? null : Math.round(expansionRatio * 100) / 100, rule: "junction-shared-cutback/v4-shared-node-split" }, geometry: { type: "Polygon", coordinates: [ring] } });
    if (boundaryMode === "connector-convex-fallback") diagnostics.push(diagnostic("warning", `junction:node/${nodeId}`, [nodeId], "junction-connector-envelope-fallback", "路口面需要按转向路径的凸包兜底生成；请检查外缘和路缘与步行带是否符合实际。", node));
    diagnostics.push(diagnostic("info", `junction:node/${nodeId}`, [nodeId], "ordinary-junction-surface", "已按道路截面与转向路径生成普通路口面。", node));
  }
  return result;
}

function compileJunctionPlans(model) {
  const byNode = new Map();
  for (const endpoint of model.endpoints) {
    if (!byNode.has(endpoint.nodeId)) byNode.set(endpoint.nodeId, []);
    byNode.get(endpoint.nodeId).push(endpoint);
  }
  const plans = new Map();
  for (const [nodeId, endpoints] of byNode) {
    const segmentIds = new Set(endpoints.map((endpoint) => endpoint.roadId.replace(/:(forward|backward)$/, "")));
    if (segmentIds.size < 3 || segmentIds.size > 4) continue;
    const approaches = junctionApproaches(model, endpoints);
    if (approaches.length !== segmentIds.size) continue;
    const cutbackMeters = Math.max(...approaches.map((approach) => approach.widthMeters)) * 1.4;
    const node = endpoints[0].coordinate;
    const boundary = junctionBoundary(approaches, node, cutbackMeters);
    if (boundary.length < 3) continue;
    plans.set(nodeId, { node, segmentIds, approaches, cutbackMeters, boundary });
  }
  return plans;
}

function junctionApproaches(model, endpoints) {
  const groups = new Map();
  for (const endpoint of endpoints) {
    const road = model.roads.find((item) => item.id === endpoint.roadId);
    if (!road) continue;
    const key = road.segmentId;
    if (!groups.has(key)) groups.set(key, []);
    groups.get(key).push({ endpoint, road });
  }
  return [...groups.values()].map((directions) => {
    const { endpoint, road } = directions[0];
    return { segmentId: road.segmentId, sourceWayKey: road.osmWayIds.join(","), line: endpoint.side === "end" ? [...road.centerline].reverse() : road.centerline, roadIds: directions.map((item) => item.road.id), widthMeters: directions.reduce((sum, item) => sum + item.road.widthMeters, 0) };
  });
}

function junctionBoundary(approaches, node, cutbackMeters) {
  const points = [];
  for (const approach of approaches) {
    const cutback = pointAlongLine(approach.line, cutbackMeters);
    if (!cutback) continue;
    const heading = headingAtEndpoint(approach.line);
    const half = approach.widthMeters / 2;
    points.push(offsetCoordinate(cutback, heading + 90, half));
    points.push(offsetCoordinate(cutback, heading - 90, half));
  }
  return sortAround(node, points);
}

function pointAlongLine(line, meters) {
  let remaining = meters;
  for (let index = 1; index < line.length; index += 1) {
    const length = distanceMeters(line[index - 1], line[index]);
    if (length >= remaining) return interpolate(line[index - 1], line[index], remaining / length);
    remaining -= length;
  }
  return line.at(-1);
}

function pointAndAxisAlongLine(line, meters) {
  let remaining = meters;
  for (let index = 1; index < line.length; index += 1) {
    const start = line[index - 1]; const end = line[index];
    const length = distanceMeters(start, end);
    if (length < 0.01) continue;
    if (length >= remaining) {
      const vector = project(end, start);
      return { point: interpolate(start, end, remaining / length), axis: [vector[0] / length, vector[1] / length] };
    }
    remaining -= length;
  }
  return null;
}

function trimLineAtJunctions(line, sourceNodeIds, junctionPlans) {
  const startCutback = junctionPlans.get(sourceNodeIds[0])?.cutbackMeters || 0;
  const endCutback = junctionPlans.get(sourceNodeIds.at(-1))?.cutbackMeters || 0;
  if (!startCutback && !endCutback) return line;
  const total = lineLengthMeters(line);
  // Short OSM fragments cannot safely lose both ends. Keep their source
  // geometry intact and let the junction diagnostic surface the ambiguity.
  if (startCutback + endCutback >= total - 0.5) return line;
  const result = [];
  let traversed = 0;
  const start = pointAlongLine(line, startCutback);
  const end = pointAlongLine(line, total - endCutback);
  result.push(start);
  for (let index = 1; index < line.length - 1; index += 1) {
    traversed += distanceMeters(line[index - 1], line[index]);
    if (traversed > startCutback && traversed < total - endCutback) result.push(line[index]);
  }
  result.push(end);
  return result;
}

function headingAtEndpoint(line) { return headingDegrees(line[0], line[1]); }
function headingDegrees(a, b) { return Math.atan2((b[0] - a[0]) * Math.cos(a[1] * Math.PI / 180), b[1] - a[1]) * 180 / Math.PI; }
function offsetCoordinate(point, degrees, meters) { const radians = degrees * Math.PI / 180; return [point[0] + Math.sin(radians) * meters / (111320 * Math.cos(point[1] * Math.PI / 180)), point[1] + Math.cos(radians) * meters / 111320]; }
function angleAround(center, point) { return Math.atan2(point[1] - center[1], point[0] - center[0]); }
function sortAround(center, points) { return points.sort((a, b) => Math.atan2(a[1] - center[1], a[0] - center[0]) - Math.atan2(b[1] - center[1], b[0] - center[0])); }
function convexHull(points) {
  const unique = [...new Map(points.map((point) => [`${point[0]},${point[1]}`, point])).values()].sort((a, b) => a[0] - b[0] || a[1] - b[1]);
  if (unique.length < 3) return unique;
  const cross = (a, b, c) => (b[0] - a[0]) * (c[1] - a[1]) - (b[1] - a[1]) * (c[0] - a[0]);
  const lower = []; for (const point of unique) { while (lower.length >= 2 && cross(lower.at(-2), lower.at(-1), point) <= 0) lower.pop(); lower.push(point); }
  const upper = []; for (const point of [...unique].reverse()) { while (upper.length >= 2 && cross(upper.at(-2), upper.at(-1), point) <= 0) upper.pop(); upper.push(point); }
  return [...lower.slice(0, -1), ...upper.slice(0, -1)];
}
function interpolate(a, b, ratio) { return [a[0] + (b[0] - a[0]) * ratio, a[1] + (b[1] - a[1]) * ratio]; }
function distanceMeters(a, b) { const dx = (b[0] - a[0]) * 111320 * Math.cos(a[1] * Math.PI / 180); const dy = (b[1] - a[1]) * 111320; return Math.hypot(dx, dy); }
function hasSelfIntersection(ring) {
  for (let first = 0; first < ring.length - 1; first += 1) for (let second = first + 1; second < ring.length - 1; second += 1) {
    if (Math.abs(first - second) <= 1 || first === 0 && second === ring.length - 2) continue;
    if (segmentsIntersect(ring[first], ring[first + 1], ring[second], ring[second + 1])) return true;
  }
  return false;
}
function segmentsIntersect(a, b, c, d) {
  const cross = (p, q, r) => (q[0] - p[0]) * (r[1] - p[1]) - (q[1] - p[1]) * (r[0] - p[0]);
  const abC = cross(a, b, c); const abD = cross(a, b, d); const cdA = cross(c, d, a); const cdB = cross(c, d, b);
  return (abC > 0 && abD < 0 || abC < 0 && abD > 0) && (cdA > 0 && cdB < 0 || cdA < 0 && cdB > 0);
}

function circleRing(center, radius, segments) {
  const origin = center;
  const ring = [];
  for (let index = 0; index <= segments; index += 1) {
    const angle = index / segments * Math.PI * 2;
    ring.push(unproject([Math.cos(angle) * radius, Math.sin(angle) * radius], origin));
  }
  return ring;
}

function roadRing(line, width) {
  if (line.length < 2 || !Number.isFinite(width)) return null;
  const origin = line[0];
  const points = line.map((point) => project(point, origin));
  const left = []; const right = [];
  const half = width / 2;
  for (let i = 0; i < points.length; i += 1) {
    const prior = points[Math.max(0, i - 1)]; const next = points[Math.min(points.length - 1, i + 1)];
    const dx = next[0] - prior[0]; const dy = next[1] - prior[1]; const length = Math.hypot(dx, dy);
    if (length < 0.01) return null;
    const nx = -dy / length * half; const ny = dx / length * half;
    left.push(unproject([points[i][0] + nx, points[i][1] + ny], origin));
    right.push(unproject([points[i][0] - nx, points[i][1] - ny], origin));
  }
  const ring = [...left, ...right.reverse(), left[0]];
  return ring.every((point) => point.every(Number.isFinite)) ? ring : null;
}

function sidewalkRing(line, innerOffset, outerOffset, side) {
  const inner = offsetLine(line, innerOffset * side);
  const outer = offsetLine(line, outerOffset * side);
  if (!inner || !outer) return null;
  const ring = [...inner, ...outer.reverse(), inner[0]];
  return ring.every((point) => point.every(Number.isFinite)) ? ring : null;
}

function project(point, origin) { const scale = 111320; return [(point[0] - origin[0]) * scale * Math.cos(origin[1] * Math.PI / 180), (point[1] - origin[1]) * scale]; }
function unproject(point, origin) { const scale = 111320; return [point[0] / (scale * Math.cos(origin[1] * Math.PI / 180)) + origin[0], point[1] / scale + origin[1]]; }
function diagnostic(severity, subjectId, sourceIds, rule, message, coordinate) { return { id: `diagnostic:${rule}:${subjectId}`, severity, subjectId, sourceIds, rule, message, geometry: coordinate ? { type: "Point", coordinates: coordinate } : null }; }
function xmlAttrs(text) { const attrs = {}; for (const match of text.matchAll(/([:\w-]+)\s*=\s*(?:"([^"]*)"|'([^']*)')/g)) attrs[match[1]] = match[2] ?? match[3]; return attrs; }
function parseTags(body) { const tags = {}; for (const match of body.matchAll(/<tag\b([^>]*)\/?\s*>/g)) { const attrs = xmlAttrs(match[1]); if (attrs.k) tags[attrs.k] = attrs.v || ""; } return tags; }
function positiveInteger(value) { const number = Number(value); return Number.isInteger(number) && number > 0 ? number : null; }
function positiveNumber(value) { const match = String(value ?? "").match(/^\s*(\d+(?:\.\d+)?)/); const number = match ? Number(match[1]) : null; return Number.isFinite(number) && number > 0 ? number : null; }
function writeJsonAtomic(file, data) { fs.mkdirSync(path.dirname(file), { recursive: true }); const temporary = `${file}.${process.pid}.tmp`; fs.writeFileSync(temporary, `${JSON.stringify(data, null, 2)}\n`); fs.renameSync(temporary, file); }

module.exports = { OVERRIDE_SCHEMA, compileRoadModel, compileGeometry, loadOverrides, validateOverrides, writeJsonAtomic };