Add property billing policy times and policy-based night calculation

src/main/kotlin/com/android/trisolarisserver/controller/booking/BookingFlow.kt

@@ -1,4 +1,5 @@
 package com.android.trisolarisserver.controller.booking
+import com.android.trisolarisserver.controller.common.billableNights
 import com.android.trisolarisserver.controller.common.computeExpectedPay
 import com.android.trisolarisserver.controller.common.nowForProperty
 import com.android.trisolarisserver.controller.common.parseOffset
@@ -58,6 +59,7 @@ import org.springframework.web.bind.annotation.ResponseStatus
 import org.springframework.web.bind.annotation.RestController
 import org.springframework.web.server.ResponseStatusException
 import java.time.OffsetDateTime
+import kotlin.math.abs
 import java.util.UUID
 
 @RestController
@@ -218,7 +220,12 @@ class BookingFlow(
             val expectedPay = if (stays.isEmpty()) {
                 null
             } else {
-                computeExpectedPay(stays, property.timezone)
+                computeExpectedPay(
+                    stays,
+                    property.timezone,
+                    property.billingCheckinTime,
+                    property.billingCheckoutTime
+                )
             }
             val collected = paymentsByBooking[booking.id] ?: 0L
             val extraCharges = chargesByBooking[booking.id] ?: 0L
@@ -461,6 +468,15 @@ class BookingFlow(
         if (stays.any { !isCheckoutAmountValid(it) || !isMinimumStayDurationValid(it, checkOutAt) }) {
             throw ResponseStatusException(HttpStatus.CONFLICT, "Room stay amount is outside allowed range")
         }
+        ensureLedgerToleranceForCheckout(
+            bookingId = bookingId,
+            timezone = booking.property.timezone,
+            billingCheckinTime = booking.property.billingCheckinTime,
+            billingCheckoutTime = booking.property.billingCheckoutTime,
+            stays = stays,
+            checkOutOverrides = stays.associate { it.id!! to checkOutAt },
+            restrictToClosedStaysOnly = false
+        )
         val oldStates = stays.associate { it.id!! to it.toAt }
         stays.forEach { it.toAt = checkOutAt }
         roomStayRepo.saveAll(stays)
@@ -524,6 +540,15 @@ class BookingFlow(
         if (!isMinimumStayDurationValid(stay, checkOutAt)) {
             throw ResponseStatusException(HttpStatus.CONFLICT, "Minimum stay duration is 1 hour")
         }
+        ensureLedgerToleranceForCheckout(
+            bookingId = bookingId,
+            timezone = booking.property.timezone,
+            billingCheckinTime = booking.property.billingCheckinTime,
+            billingCheckoutTime = booking.property.billingCheckoutTime,
+            stays = staysForBooking,
+            checkOutOverrides = mapOf(stay.id!! to checkOutAt),
+            restrictToClosedStaysOnly = true
+        )
 
         val oldToAt = stay.toAt
         val oldIsVoided = stay.isVoided
@@ -770,6 +795,51 @@ class BookingFlow(
         return java.time.Duration.between(stay.fromAt, checkOutAt).toMinutes() >= 60
     }
 
+    private fun ensureLedgerToleranceForCheckout(
+        bookingId: UUID,
+        timezone: String?,
+        billingCheckinTime: String?,
+        billingCheckoutTime: String?,
+        stays: List<RoomStay>,
+        checkOutOverrides: Map<UUID, OffsetDateTime>,
+        restrictToClosedStaysOnly: Boolean
+    ) {
+        val now = nowForProperty(timezone)
+        val expectedStayAmount = stays
+            .asSequence()
+            .filter { !it.isVoided }
+            .mapNotNull { stay ->
+                val effectiveToAt = checkOutOverrides[stay.id] ?: stay.toAt
+                if (restrictToClosedStaysOnly && effectiveToAt == null) {
+                    return@mapNotNull null
+                }
+                val endAt = effectiveToAt ?: now
+                val rate = stay.nightlyRate ?: 0L
+                if (rate <= 0L) {
+                    return@mapNotNull 0L
+                }
+                rate * billableNights(
+                    stay.fromAt,
+                    endAt,
+                    timezone,
+                    billingCheckinTime,
+                    billingCheckoutTime
+                )
+            }
+            .sum()
+        val extraCharges = chargeRepo.sumAmountByBookingId(bookingId)
+        val collected = paymentRepo.sumAmountByBookingId(bookingId)
+        val expectedTotal = expectedStayAmount + extraCharges
+        val tolerance = (expectedTotal * 20L) / 100L
+        val delta = collected - expectedTotal
+        if (abs(delta) > tolerance) {
+            throw ResponseStatusException(
+                HttpStatus.CONFLICT,
+                "Ledger mismatch: collected amount must be within 20% of expected amount before checkout"
+            )
+        }
+    }
+
     private fun logStayAudit(
         stay: RoomStay,
         action: String,