store/mapStore

Zustand store for all map element state, with undo/redo via zundo temporal middleware.

useMapStore

const useMapStore: UseBoundStore<StoreApi<MapState>>

Primary React hook for accessing map state.

// Read state
const lanes = useMapStore((s) => s.lanes)
const project = useMapStore((s) => s.project)

// Call actions
const { addElement, connectLanes } = useMapStore()

For event handlers (to avoid stale closures):

const state = useMapStore.getState()
state.addElement(newLane)

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State

interface MapState {
  project: ProjectConfig | null

  lanes: Record<string, LaneFeature>
  junctions: Record<string, JunctionFeature>
  signals: Record<string, SignalFeature>
  stopSigns: Record<string, StopSignFeature>
  crosswalks: Record<string, CrosswalkFeature>
  clearAreas: Record<string, ClearAreaFeature>
  speedBumps: Record<string, SpeedBumpFeature>
  parkingSpaces: Record<string, ParkingSpaceFeature>
  roads: Record<string, RoadDefinition>
}

All element collections are keyed by element ID.

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Actions

setProject

setProject(config: ProjectConfig): void

Sets the project metadata (name, origin lat/lon, version, date).

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addElement

addElement(element: MapElement): void

Adds an element to the appropriate collection. For lane type, merges default lane properties before storing:

state.lanes[element.id] = { ...defaultLaneProps, ...element }

Default lane props: width: 3.75, speedLimit: 13.89, laneType: CITY_DRIVING, etc.

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updateElement

updateElement(element: MapElement): void

Merges updated properties into an existing element. Does nothing if the element ID does not exist.

Object.assign(state.lanes[element.id], element)

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removeElement

removeElement(id: string, type: MapElement['type']): void

Deletes the element and cleans up all cross-references:

• For lanes: removes id from every other lane's predecessorIds, successorIds, leftNeighborIds, rightNeighborIds

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connectLanes

connectLanes(fromId: string, toId: string): void

Establishes a successor/predecessor link:

• lanes[fromId].successorIds gains toId
• lanes[toId].predecessorIds gains fromId

Idempotent — duplicate IDs are not added.

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setLaneNeighbor

setLaneNeighbor(laneId: string, neighborId: string, side: 'left' | 'right'): void

Establishes a bilateral neighbor link:

• side = 'left': laneId.leftNeighborIds ← neighborId, neighborId.rightNeighborIds ← laneId
• side = 'right': laneId.rightNeighborIds ← neighborId, neighborId.leftNeighborIds ← laneId

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addRoad

addRoad(road: RoadDefinition): void

Adds a road definition to the roads collection.

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updateRoad

updateRoad(road: RoadDefinition): void

Updates an existing road definition by ID.

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removeRoad

removeRoad(roadId: string): void

Deletes a road definition and unassigns all lanes that referenced it.

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assignLaneToRoad

assignLaneToRoad(laneId: string, roadId: string): void

Sets lane.roadId = roadId for the specified lane.

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unassignLaneFromRoad

unassignLaneFromRoad(laneId: string): void

Clears lane.roadId for the specified lane.

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clear

clear(): void

Resets all element collections to {}. Does not reset project.

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loadState

loadState(state: Partial<MapState>): void

Bulk-assigns state fields. Used by the import flow to restore all collections at once:

loadState({
  lanes: Object.fromEntries(parsed.lanes.map(l => [l.id, l])),
  junctions: Object.fromEntries(...),
  // ...
})

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Undo / Redo

useTemporalMapStore is the temporal store exposed by zundo:

import { useMapStore } from './mapStore'
const useTemporalMapStore = (useMapStore as any).temporal

// In a component:
const { undo, redo, pastStates, futureStates } = useTemporalMapStore()

Each set() call inside any action creates a new history snapshot. The entire MapState is snapshotted — undo/redo is O(n) in state size, not O(diff).