Initial interface design for sanity checks

Part of #137

zummon/src/commonMain/kotlin/companysurvey/Validation.kt

@@ -0,0 +1,42 @@
+package com.zenmo.zummon.companysurvey
+
+fun interface Validator {
+    fun validate(survey: Survey): ValidationResult
+}
+
+data class ValidationResult(
+    val status: Status,
+    val message: String,
+)
+
+enum class Status {
+    VALID,
+    INVALID,
+    MISSING_DATA,
+}
+
+val validateContractedCapacity = Validator { survey: Survey ->
+    val gridConnection = survey.getSingleGridConnection()
+
+    val contractedConnectionCapacity = gridConnection.electricity.getContractedConnectionCapacityKw()
+    val physicalConnectionCapacity = gridConnection.electricity.getPhysicalConnectionCapacityKw()
+
+    return@Validator when {
+        contractedConnectionCapacity == null -> ValidationResult(
+            status = Status.MISSING_DATA,
+            message = "No contracted connection capacity given",
+        )
+        physicalConnectionCapacity == null -> ValidationResult(
+            status = Status.MISSING_DATA,
+            message = "No physical connection capacity given",
+        )
+        contractedConnectionCapacity <= physicalConnectionCapacity -> ValidationResult(
+            status = Status.VALID,
+            message = "Contracted connection capacity fits within physical connection",
+        )
+        else -> ValidationResult(
+            status = Status.INVALID,
+            message = "Contracted connection capacity ${gridConnection.electricity.getContractedConnectionCapacityKw()} kW is too large for physical connection ${gridConnection.electricity.getPhysicalConnectionCapacityKw()}"
+        )
+    }
+}