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Diffstat (limited to 'backend/src/simulation/robotMovementSimulator.ts')
| -rw-r--r-- | backend/src/simulation/robotMovementSimulator.ts | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/backend/src/simulation/robotMovementSimulator.ts b/backend/src/simulation/robotMovementSimulator.ts new file mode 100644 index 0000000..2299f43 --- /dev/null +++ b/backend/src/simulation/robotMovementSimulator.ts @@ -0,0 +1,241 @@ +import { QueryResult } from "pg"; +import { Server } from "socket.io"; +import db from "../database/postgres.js"; +import { + Robot, + RobotPosition, + RobotsUpdateBroadcast, + SimulationResponse, +} from "../types/robot.js"; + +// Coordinates for the boundaries of the frontend map +const LEIPZIG_AREA = { + WEST: 12.22, + SOUTH: 51.26, + EAST: 12.54, + NORTH: 51.44, +} as const; + +const LEIPZIG_CENTER = { + LAT: 51.340863, + LON: 12.375919, +} as const; + +const SIMULATION_INTERVAL_MS = 2000; + +// IDs of moving robots +const movingRobots = new Set<number>(); + +// Global simulation timer +let simulationTimer: NodeJS.Timeout | null = null; + +/* + MOVEMENT FUNCTION + generate random position within Leipzig based on current position +*/ + +function generateRandomPosition(currentLat: string, currentLon: string) { + // 0.0005 degrees ca. 50-70 meters + const deltaLat = (Math.random() - 0.5) * 0.0005; + const deltaLon = (Math.random() - 0.5) * 0.0005; + + let newLat = parseFloat(currentLat) + deltaLat; + let newLon = parseFloat(currentLon) + deltaLon; + + // Check if robot's new position would be outside of Leipzig, if yes set back to center + const outsideLatBoundary = + newLat < LEIPZIG_AREA.SOUTH || newLat > LEIPZIG_AREA.NORTH; + const outsideLonBoundary = + newLon < LEIPZIG_AREA.WEST || newLon > LEIPZIG_AREA.EAST; + + if (outsideLatBoundary || outsideLonBoundary) { + newLat = LEIPZIG_CENTER.LAT; + newLon = LEIPZIG_CENTER.LON; + } + + return { + lat: newLat.toFixed(7), + lon: newLon.toFixed(7), + }; +} + +/* + MAIN FUNCTION: + move a robot, update database, websocket broadcast +*/ + +async function updateRobotPositions(io: Server) { + let client; + + try { + client = await db.connect(); + + const allRobotsQuery: QueryResult<Robot> = await client.query( + "SELECT * FROM robots ORDER BY id;" + ); + const allRobots = allRobotsQuery.rows; + + // Update database + await client.query("BEGIN"); + + const updatedRobots: Robot[] = []; + + for (const robot of allRobots) { + // If not moving, keep position & set idle + if (!movingRobots?.has(robot.id)) { + if (robot.status === "moving") { + const idleQuery: QueryResult<Robot> = await client.query( + ` + UPDATE robots + SET status = 'idle', + updated_at = CURRENT_TIMESTAMP + WHERE id = $1 + RETURNING *; + `, + [robot.id] + ); + updatedRobots.push(idleQuery.rows[0]); + } else { + updatedRobots.push(robot); + } + continue; + } + + // If moving, assign new position and add previous to log + const newPos: RobotPosition = generateRandomPosition( + robot.lat, + robot.lon + ); + + const previousPositionsLog: RobotPosition[] = + robot.robot_positions || []; + + previousPositionsLog.push({ lat: robot.lat, lon: robot.lon }); + + // Limit log to 10 entries, remove oldest when more + if (previousPositionsLog.length > 10) { + previousPositionsLog.shift(); + } + + const updateQuery: QueryResult<Robot> = await client.query( + ` + UPDATE robots + SET + lat = $1, + lon = $2, + status = 'moving', + robot_positions = $3::jsonb, + updated_at = CURRENT_TIMESTAMP + WHERE id = $4 + RETURNING *; + `, + [ + newPos.lat, + newPos.lon, + JSON.stringify(previousPositionsLog), + robot.id, + ] + ); + + updatedRobots.push(updateQuery.rows[0]); + } + + await client.query("COMMIT"); + + // Websocket broadcast, make sure robots stay in correct order + updatedRobots.sort((a, b) => a.id - b.id); + + const broadcastPayload: RobotsUpdateBroadcast = { updatedRobots }; + + io.emit("robots_update", broadcastPayload); + + // Check if this was the final update, setting all to idle with no more robots moving + if (movingRobots.size === 0) { + if (simulationTimer) { + clearInterval(simulationTimer); + simulationTimer = null; + } + } + } catch (error) { + console.error("Error in the global simulation timer: ", error); + if (client) await client.query("ROLLBACK"); + + // Stop simulation on error + if (simulationTimer) { + clearInterval(simulationTimer); + simulationTimer = null; + } + } finally { + if (client) client.release(); + } +} + +/* + SIMULATION FUNCTION + Runs the simulation by repeating the main function in intervals +*/ + +async function startSimulation(io: Server) { + if (simulationTimer) return; // Already running + + // Immediate execution right away without delay + await updateRobotPositions(io); + + // Then interval for subsequent updates + simulationTimer = setInterval(async () => { + await updateRobotPositions(io); + }, SIMULATION_INTERVAL_MS); +} + +/* + PUBLIC CONTROLLER FUNCTIONS: + start or stop movement of one or all robots +*/ + +export async function setRobotMoving( + io: Server, + robotId: number +): Promise<SimulationResponse> { + movingRobots.add(Number(robotId)); + await startSimulation(io); + + return { + message: `Robot ID ${robotId} set in motion.`, + status: "moving", + }; +} + +export async function setRobotIdle( + robotId: number +): Promise<SimulationResponse> { + movingRobots.delete(Number(robotId)); + + return { + message: `Robot ID ${robotId} stopped.`, + status: "idle", + }; +} + +export async function setAllRobotsMoving( + io: Server +): Promise<SimulationResponse> { + const allRobotIDsQuery: QueryResult<{ id: Robot["id"] }> = await db.query( + "SELECT id FROM robots;" + ); + allRobotIDsQuery.rows.forEach((queryObject) => + movingRobots.add(queryObject.id) + ); + + await startSimulation(io); + + return { + message: "All robots set in motion.", + }; +} + +export async function setAllRobotsIdle(): Promise<SimulationResponse> { + movingRobots.clear(); + return { + message: "All robots stopped.", + }; +} |