PRSD-353: Registration Number Service

src/main/kotlin/uk/gov/communities/prsdb/webapp/constants/RegistrationNumberConstants.kt

@@ -0,0 +1,43 @@
+package uk.gov.communities.prsdb.webapp.constants
+
+import kotlin.math.pow
+
+val REG_NUM_CHARSET =
+    listOf(
+        'C',
+        'D',
+        'F',
+        'G',
+        'H',
+        'J',
+        'K',
+        'M',
+        'N',
+        'P',
+        'Q',
+        'R',
+        'S',
+        'T',
+        'V',
+        'W',
+        'X',
+        'Y',
+        'Z',
+        '2',
+        '3',
+        '4',
+        '5',
+        '6',
+        '7',
+        '9',
+    )
+
+val REG_NUM_BASE = REG_NUM_CHARSET.size
+
+const val REG_NUM_LENGTH = 8
+
+const val REG_NUM_SEG_LENGTH = REG_NUM_LENGTH / 2
+
+const val MIN_REG_NUM = 0L
+
+val MAX_REG_NUM = REG_NUM_BASE.toDouble().pow(REG_NUM_LENGTH).toLong() - 1

src/main/kotlin/uk/gov/communities/prsdb/webapp/constants/enums/RegistrationNumberType.kt

@@ -0,0 +1,20 @@
+package uk.gov.communities.prsdb.webapp.constants.enums
+
+enum class RegistrationNumberType {
+    PROPERTY,
+    LANDLORD,
+    AGENT,
+    ;
+
+    fun toInitial(): Char = this.toString()[0]
+
+    companion object {
+        fun initialToType(initial: Char): RegistrationNumberType =
+            when (initial) {
+                'P' -> PROPERTY
+                'L' -> LANDLORD
+                'A' -> AGENT
+                else -> throw IllegalArgumentException("Invalid Initial")
+            }
+    }
+}

src/main/kotlin/uk/gov/communities/prsdb/webapp/controllers/ExampleStartPageController.kt

@@ -5,6 +5,8 @@ import org.springframework.ui.Model
 import org.springframework.web.bind.annotation.GetMapping
 import org.springframework.web.bind.annotation.RequestMapping
 import uk.gov.communities.prsdb.webapp.constants.SERVICE_NAME
+import uk.gov.communities.prsdb.webapp.constants.enums.RegistrationNumberType
+import uk.gov.communities.prsdb.webapp.models.dataModels.RegistrationNumberDataModel
 
 @Controller
 @RequestMapping("/")
@@ -14,6 +16,10 @@ class ExampleStartPageController {
         model.addAttribute("contentHeader", "Welcome to the Private Rental Sector Database")
         model.addAttribute("title", "Private Rental Sector Database")
         model.addAttribute("serviceName", SERVICE_NAME)
+        model.addAttribute(
+            "landlordRegNum",
+            RegistrationNumberDataModel(RegistrationNumberType.LANDLORD, 205498766).toString(),
+        )
         model.addAttribute("startButtonHref", "/registration")
         model.addAttribute("startButtonText", "Start now")
         return "demoStart"

src/main/kotlin/uk/gov/communities/prsdb/webapp/database/entity/AuditableEntity.kt

@@ -5,7 +5,6 @@ import jakarta.persistence.MappedSuperclass
 import jakarta.persistence.Temporal
 import jakarta.persistence.TemporalType
 import org.springframework.data.annotation.CreatedDate
-import org.springframework.data.annotation.LastModifiedDate
 import java.io.Serializable
 import java.time.OffsetDateTime
 
@@ -16,10 +15,4 @@ abstract class AuditableEntity : Serializable {
     @Column(updatable = false)
     lateinit var createdDate: OffsetDateTime
         private set
-
-    @LastModifiedDate
-    @Temporal(TemporalType.TIMESTAMP)
-    @Column(insertable = false)
-    lateinit var lastModifiedDate: OffsetDateTime
-        private set
 }

src/main/kotlin/uk/gov/communities/prsdb/webapp/database/entity/Landlord.kt

@@ -0,0 +1,25 @@
+package uk.gov.communities.prsdb.webapp.database.entity
+
+import jakarta.persistence.Entity
+import jakarta.persistence.ForeignKey
+import jakarta.persistence.GeneratedValue
+import jakarta.persistence.GenerationType
+import jakarta.persistence.Id
+import jakarta.persistence.JoinColumn
+import jakarta.persistence.OneToOne
+
+@Entity
+class Landlord {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private val id: Long? = null
+
+    @OneToOne(optional = false)
+    @JoinColumn(
+        name = "registration_number_id",
+        nullable = false,
+        foreignKey = ForeignKey(name = "FK_LANDLORD_REG_NUM"),
+    )
+    lateinit var registrationNumber: RegistrationNumber
+        private set
+}

src/main/kotlin/uk/gov/communities/prsdb/webapp/database/entity/LandlordUser.kt

@@ -11,7 +11,7 @@ import jakarta.persistence.OneToOne
 import java.util.Date
 
 @Entity
-class LandlordUser : AuditableEntity() {
+class LandlordUser : ModifiableAuditableEntity() {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private val id: Long? = null

src/main/kotlin/uk/gov/communities/prsdb/webapp/database/entity/LocalAuthority.kt

@@ -7,7 +7,7 @@ import jakarta.persistence.GenerationType
 import jakarta.persistence.Id
 
 @Entity
-class LocalAuthority : AuditableEntity() {
+class LocalAuthority : ModifiableAuditableEntity() {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private val id: Int? = null

src/main/kotlin/uk/gov/communities/prsdb/webapp/database/entity/LocalAuthorityUser.kt

@@ -10,7 +10,7 @@ import jakarta.persistence.JoinColumn
 import jakarta.persistence.OneToOne
 
 @Entity
-class LocalAuthorityUser : AuditableEntity() {
+class LocalAuthorityUser : ModifiableAuditableEntity() {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private val id: Long? = null

src/main/kotlin/uk/gov/communities/prsdb/webapp/database/entity/ModifiableAuditableEntity.kt

@@ -0,0 +1,20 @@
+package uk.gov.communities.prsdb.webapp.database.entity
+
+import jakarta.persistence.Column
+import jakarta.persistence.MappedSuperclass
+import jakarta.persistence.Temporal
+import jakarta.persistence.TemporalType
+import org.springframework.data.annotation.LastModifiedDate
+import java.io.Serializable
+import java.time.OffsetDateTime
+
+@MappedSuperclass
+abstract class ModifiableAuditableEntity :
+    AuditableEntity(),
+    Serializable {
+    @LastModifiedDate
+    @Temporal(TemporalType.TIMESTAMP)
+    @Column(insertable = false)
+    lateinit var lastModifiedDate: OffsetDateTime
+        private set
+}

src/main/kotlin/uk/gov/communities/prsdb/webapp/database/entity/OneLoginUser.kt

@@ -5,7 +5,7 @@ import jakarta.persistence.Entity
 import jakarta.persistence.Id
 
 @Entity
-class OneLoginUser : AuditableEntity() {
+class OneLoginUser : ModifiableAuditableEntity() {
     @Id
     private val id: String? = null
 

src/main/kotlin/uk/gov/communities/prsdb/webapp/database/entity/RegistrationNumber.kt

@@ -0,0 +1,28 @@
+package uk.gov.communities.prsdb.webapp.database.entity
+
+import jakarta.persistence.Column
+import jakarta.persistence.Entity
+import jakarta.persistence.GeneratedValue
+import jakarta.persistence.GenerationType
+import jakarta.persistence.Id
+import uk.gov.communities.prsdb.webapp.constants.enums.RegistrationNumberType
+
+@Entity
+class RegistrationNumber() : AuditableEntity() {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private val id: Long? = null
+
+    @Column(nullable = false, unique = true)
+    var number: Long? = null
+        private set
+
+    @Column(nullable = false)
+    lateinit var type: RegistrationNumberType
+        private set
+
+    constructor(type: RegistrationNumberType, number: Long) : this() {
+        this.number = number
+        this.type = type
+    }
+}

src/main/kotlin/uk/gov/communities/prsdb/webapp/database/repository/LandlordRepository.kt

@@ -0,0 +1,10 @@
+package uk.gov.communities.prsdb.webapp.database.repository
+
+import org.springframework.data.jpa.repository.JpaRepository
+import uk.gov.communities.prsdb.webapp.database.entity.Landlord
+
+interface LandlordRepository : JpaRepository<Landlord?, Long?> {
+    // The underscore tells JPA to access fields relating to the referenced table
+    @Suppress("ktlint:standard:function-naming")
+    fun findByRegistrationNumber_Number(registrationNumber: Long): Landlord?
+}

src/main/kotlin/uk/gov/communities/prsdb/webapp/database/repository/RegistrationNumberRepository.kt

@@ -0,0 +1,8 @@
+package uk.gov.communities.prsdb.webapp.database.repository
+
+import org.springframework.data.jpa.repository.JpaRepository
+import uk.gov.communities.prsdb.webapp.database.entity.RegistrationNumber
+
+interface RegistrationNumberRepository : JpaRepository<RegistrationNumber?, Long?> {
+    fun existsByNumber(number: Long): Boolean
+}

src/main/kotlin/uk/gov/communities/prsdb/webapp/models/dataModels/RegistrationNumberDataModel.kt

@@ -0,0 +1,56 @@
+package uk.gov.communities.prsdb.webapp.models.dataModels
+
+import uk.gov.communities.prsdb.webapp.constants.REG_NUM_BASE
+import uk.gov.communities.prsdb.webapp.constants.REG_NUM_CHARSET
+import uk.gov.communities.prsdb.webapp.constants.REG_NUM_LENGTH
+import uk.gov.communities.prsdb.webapp.constants.REG_NUM_SEG_LENGTH
+import uk.gov.communities.prsdb.webapp.constants.enums.RegistrationNumberType
+
+data class RegistrationNumberDataModel(
+    val type: RegistrationNumberType,
+    val number: Long,
+) {
+    companion object {
+        fun parseRegNum(regNumString: String): RegistrationNumberDataModel {
+            val baseRegNumString = getBaseRegNumString(regNumString)
+
+            validateBaseRegNumString(baseRegNumString)
+
+            val regNumType = RegistrationNumberType.initialToType(baseRegNumString[0])
+
+            var regNumNumber = 0L
+            for (char in baseRegNumString.substring(1)) {
+                regNumNumber = REG_NUM_BASE * regNumNumber + REG_NUM_CHARSET.indexOf(char)
+            }
+
+            return RegistrationNumberDataModel(regNumType, regNumNumber)
+        }
+
+        private fun getBaseRegNumString(regNumString: String): String = regNumString.filter { it.isLetterOrDigit() }.uppercase()
+
+        private fun validateBaseRegNumString(baseRegNumString: String) {
+            if (baseRegNumString.length != REG_NUM_LENGTH + 1) {
+                throw IllegalArgumentException("Invalid registration number string length")
+            }
+            if (baseRegNumString.substring(1).any { !REG_NUM_CHARSET.contains(it) }) {
+                throw IllegalArgumentException("Invalid registration number string characters")
+            }
+        }
+    }
+
+    override fun toString(): String {
+        var regNumString = ""
+        var quotient = this.number
+        while (quotient > 0) {
+            regNumString = REG_NUM_CHARSET[(quotient % REG_NUM_BASE).toInt()] + regNumString
+            quotient /= REG_NUM_BASE
+        }
+        regNumString = regNumString.padStart(REG_NUM_LENGTH, REG_NUM_CHARSET[0])
+
+        return this.type.toInitial() +
+            "-" +
+            regNumString.substring(0, REG_NUM_SEG_LENGTH) +
+            "-" +
+            regNumString.substring(REG_NUM_SEG_LENGTH)
+    }
+}

src/main/kotlin/uk/gov/communities/prsdb/webapp/services/LandlordService.kt

@@ -0,0 +1,19 @@
+package uk.gov.communities.prsdb.webapp.services
+
+import org.springframework.stereotype.Service
+import uk.gov.communities.prsdb.webapp.constants.enums.RegistrationNumberType
+import uk.gov.communities.prsdb.webapp.database.entity.Landlord
+import uk.gov.communities.prsdb.webapp.database.repository.LandlordRepository
+import uk.gov.communities.prsdb.webapp.models.dataModels.RegistrationNumberDataModel
+
+@Service
+class LandlordService(
+    val landlordRepository: LandlordRepository,
+) {
+    fun retrieveLandlordByRegNum(regNum: RegistrationNumberDataModel): Landlord? {
+        if (regNum.type != RegistrationNumberType.LANDLORD) {
+            throw IllegalArgumentException("Invalid registration number type")
+        }
+        return landlordRepository.findByRegistrationNumber_Number(regNum.number)
+    }
+}

src/main/kotlin/uk/gov/communities/prsdb/webapp/services/RegistrationNumberService.kt

@@ -0,0 +1,27 @@
+package uk.gov.communities.prsdb.webapp.services
+
+import jakarta.transaction.Transactional
+import org.springframework.stereotype.Service
+import uk.gov.communities.prsdb.webapp.constants.MAX_REG_NUM
+import uk.gov.communities.prsdb.webapp.constants.MIN_REG_NUM
+import uk.gov.communities.prsdb.webapp.constants.enums.RegistrationNumberType
+import uk.gov.communities.prsdb.webapp.database.entity.RegistrationNumber
+import uk.gov.communities.prsdb.webapp.database.repository.RegistrationNumberRepository
+
+@Service
+class RegistrationNumberService(
+    val regNumRepository: RegistrationNumberRepository,
+) {
+    @Transactional
+    fun createRegistrationNumber(type: RegistrationNumberType) {
+        regNumRepository.save(RegistrationNumber(type, generateUniqueRegNum()))
+    }
+
+    private fun generateUniqueRegNum(): Long {
+        var registrationNumber: Long
+        do {
+            registrationNumber = (MIN_REG_NUM..MAX_REG_NUM).random()
+        } while (regNumRepository.existsByNumber(registrationNumber))
+        return registrationNumber
+    }
+}

src/main/resources/db/migrations/V1_1_0__reg_num_and_landlord_skeleton.sql

@@ -0,0 +1,24 @@
+CREATE TABLE landlord
+(
+    id                     BIGINT GENERATED BY DEFAULT AS IDENTITY NOT NULL,
+    registration_number_id BIGINT                                  NOT NULL,
+    CONSTRAINT pk_landlord PRIMARY KEY (id)
+);
+
+CREATE TABLE registration_number
+(
+    id           BIGINT GENERATED BY DEFAULT AS IDENTITY NOT NULL,
+    created_date TIMESTAMPTZ(6),
+    number       BIGINT                                  NOT NULL,
+    type         SMALLINT                                NOT NULL,
+    CONSTRAINT pk_registrationnumber PRIMARY KEY (id)
+);
+
+ALTER TABLE landlord
+    ADD CONSTRAINT uc_landlord_registration_number UNIQUE (registration_number_id);
+
+ALTER TABLE registration_number
+    ADD CONSTRAINT uc_registrationnumber_number UNIQUE (number);
+
+ALTER TABLE landlord
+    ADD CONSTRAINT FK_LANDLORD_REG_NUM FOREIGN KEY (registration_number_id) REFERENCES registration_number (id);

src/main/resources/templates/demoStart.html

@@ -2,6 +2,10 @@
 <html th:replace="~{fragments/layout :: layout(${title}, ${serviceName}, ~{::main})}">
 <main class="govuk-main-wrapper" id="main-content">
     <h1 class="govuk-heading-xl" th:text="${contentHeader}">Default page template</h1>
+    <p class="govuk-body">
+        <span>Example Landlord Registration Number: </span>
+        <span th:text="${landlordRegNum}">Example Landlord Registration Number</span>
+    </p>
     <div th:replace="~{fragments/startButton :: button( ${startButtonHref}, ${startButtonText} )}"></div>
 </main>
 </html>