Return average rate for calendar range

src/main/kotlin/com/android/trisolarisserver/controller/RatePlans.kt

@@ -2,6 +2,7 @@ package com.android.trisolarisserver.controller
 
 import com.android.trisolarisserver.component.PropertyAccess
 import com.android.trisolarisserver.controller.dto.RateCalendarResponse
+import com.android.trisolarisserver.controller.dto.RateCalendarAverageResponse
 import com.android.trisolarisserver.controller.dto.RateCalendarRangeUpsertRequest
 import com.android.trisolarisserver.controller.dto.RatePlanCreateRequest
 import com.android.trisolarisserver.controller.dto.RatePlanResponse
@@ -169,14 +170,32 @@ class RatePlans(
         @AuthenticationPrincipal principal: MyPrincipal?,
         @RequestParam from: String,
         @RequestParam to: String
-    ): List<RateCalendarResponse> {
+    ): RateCalendarAverageResponse {
         requireMember(propertyAccess, propertyId, principal)
         val plan = ratePlanRepo.findByIdAndPropertyId(ratePlanId, propertyId)
             ?: throw ResponseStatusException(HttpStatus.NOT_FOUND, "Rate plan not found")
         val fromDate = parseDate(from)
         val toDate = parseDate(to)
+        if (toDate.isBefore(fromDate)) {
+            throw ResponseStatusException(HttpStatus.BAD_REQUEST, "to must be on/after from")
+        }
         val items = rateCalendarRepo.findByRatePlanIdAndRateDateBetweenOrderByRateDateAsc(plan.id!!, fromDate, toDate)
-        return items.map { it.toResponse() }
+        val overrides = items.associateBy { it.rateDate }
+        var total = 0L
+        var days = 0
+        for (date in datesBetween(fromDate, toDate)) {
+            days += 1
+            total += overrides[date]?.rate ?: plan.baseRate
+        }
+        val average = if (days == 0) 0.0 else total.toDouble() / days
+        return RateCalendarAverageResponse(
+            ratePlanId = plan.id!!,
+            from = fromDate,
+            to = toDate,
+            averageRate = average,
+            days = days,
+            currency = plan.currency
+        )
     }
 
     @DeleteMapping("/{ratePlanId}/calendar/{rateDate}")

src/main/kotlin/com/android/trisolarisserver/controller/dto/RateDtos.kt

@@ -41,6 +41,15 @@ data class RateCalendarResponse(
     val rate: Long
 )
 
+data class RateCalendarAverageResponse(
+    val ratePlanId: UUID,
+    val from: LocalDate,
+    val to: LocalDate,
+    val averageRate: Double,
+    val days: Int,
+    val currency: String
+)
+
 data class RoomStayRateChangeRequest(
     val effectiveAt: String,
     val nightlyRate: Long,