feat: add loan interest backend functionality

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanproduct/domain/LoanRateRegisterCibilSlab.java

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+/**
+ * Copyright since 2025 Mifos Initiative
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+package org.apache.fineract.portfolio.loanproduct.domain;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+import java.math.BigDecimal;
+import java.time.LocalDateTime;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import org.apache.fineract.infrastructure.core.service.DateUtils;
+
+/**
+ * One CIBIL/credit-score band of a rate register version — e.g. {601..650} tier "Fair" adds +1.00%.
+ * Applied on top of the chart cell at loan sanction. Typically 5 rows per version; ordered on reads
+ * by {@code displayOrder}.
+ */
+@Entity
+@Table(name = "m_loan_rate_register_cibil_slab")
+@Getter
+@Setter
+@NoArgsConstructor
+public class LoanRateRegisterCibilSlab {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @Column(name = "effective_id", nullable = false)
+    private Long effectiveId;
+
+    @Column(name = "score_from", nullable = false)
+    private Integer scoreFrom;
+
+    @Column(name = "score_to", nullable = false)
+    private Integer scoreTo;
+
+    @Column(name = "tier", length = 30, nullable = false)
+    private String tier;
+
+    @Column(name = "slab_type", length = 20, nullable = false)
+    private String slabType;
+
+    @Column(name = "adjustment_pct", nullable = false)
+    private BigDecimal adjustmentPct;
+
+    @Column(name = "display_order", nullable = false)
+    private Integer displayOrder;
+
+    @Column(name = "created_date")
+    private LocalDateTime createdDate;
+
+    public static LoanRateRegisterCibilSlab create(final Long effectiveId, final Integer scoreFrom, final Integer scoreTo, final String tier,
+            final String slabType, final BigDecimal adjustmentPct, final Integer displayOrder) {
+        final LoanRateRegisterCibilSlab s = new LoanRateRegisterCibilSlab();
+        s.effectiveId = effectiveId;
+        s.scoreFrom = scoreFrom;
+        s.scoreTo = scoreTo;
+        s.tier = tier;
+        s.slabType = slabType != null ? slabType : "Flat";
+        s.adjustmentPct = adjustmentPct;
+        s.displayOrder = displayOrder;
+        s.createdDate = LocalDateTime.now(DateUtils.getDateTimeZoneOfTenant());
+        return s;
+    }
+}

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanproduct/domain/LoanRateRegisterCibilSlabRepository.java

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+/**
+ * Copyright since 2025 Mifos Initiative
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+package org.apache.fineract.portfolio.loanproduct.domain;
+
+import java.util.List;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface LoanRateRegisterCibilSlabRepository extends JpaRepository<LoanRateRegisterCibilSlab, Long> {
+
+    /** CIBIL bands for a version, ordered as the UI shows them (ascending score bands). */
+    List<LoanRateRegisterCibilSlab> findByEffectiveIdOrderByDisplayOrderAsc(Long effectiveId);
+}

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanproduct/domain/LoanRateRegisterEffective.java

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+/**
+ * Copyright since 2025 Mifos Initiative
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+package org.apache.fineract.portfolio.loanproduct.domain;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import org.apache.fineract.infrastructure.core.service.DateUtils;
+
+/**
+ * One effective (versioned) copy of the central Loan Interest Rate Register. Mirrors the
+ * {@code FdBaseInterestRateEffective} versioning model: each approved save creates a new row with
+ * {@code isActive=true} and deactivates the previous active row ({@code isActive=false,
+ * effectiveToDate=today}). Reads for "current active" filter on {@code isActive=true}.
+ *
+ * The 34-product × 10-slab rate matrix for this version lives in {@link LoanRateRegisterSlabHistory};
+ * the CIBIL/credit-score bands live in {@link LoanRateRegisterCibilSlab}, both keyed by this row's
+ * id and cascade-deleted with it.
+ */
+@Entity
+@Table(name = "m_loan_rate_register_effective")
+@Getter
+@Setter
+@NoArgsConstructor
+public class LoanRateRegisterEffective {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @Column(name = "name", length = 200, nullable = false)
+    private String name;
+
+    @Column(name = "effective_from_date", nullable = false)
+    private LocalDate effectiveFromDate;
+
+    @Column(name = "effective_to_date")
+    private LocalDate effectiveToDate;
+
+    @Column(name = "currency_code", length = 3, nullable = false)
+    private String currencyCode;
+
+    @Column(name = "is_active", nullable = false)
+    private Boolean isActive;
+
+    @Column(name = "fallback_no_cibil_slab", nullable = false)
+    private Integer fallbackNoCibilSlab;
+
+    @Column(name = "fallback_below_min", length = 20, nullable = false)
+    private String fallbackBelowMin;
+
+    @Column(name = "note", length = 500)
+    private String note;
+
+    @Column(name = "created_by_id")
+    private Long createdById;
+
+    @Column(name = "created_date")
+    private LocalDateTime createdDate;
+
+    public static LoanRateRegisterEffective create(final String name, final LocalDate effectiveFromDate, final String currencyCode,
+            final Integer fallbackNoCibilSlab, final String fallbackBelowMin, final String note, final Long createdById) {
+        final LoanRateRegisterEffective e = new LoanRateRegisterEffective();
+        e.name = name;
+        e.effectiveFromDate = effectiveFromDate;
+        e.currencyCode = currencyCode != null ? currencyCode : "INR";
+        e.isActive = true;
+        e.fallbackNoCibilSlab = fallbackNoCibilSlab != null ? fallbackNoCibilSlab : 2;
+        e.fallbackBelowMin = fallbackBelowMin != null ? fallbackBelowMin : "block";
+        e.note = note;
+        e.createdById = createdById;
+        e.createdDate = LocalDateTime.now(DateUtils.getDateTimeZoneOfTenant());
+        return e;
+    }
+
+    /** Flip this version to inactive and close its effective window. Called when a newer version is approved. */
+    public void deactivate(final LocalDate toDate) {
+        this.isActive = false;
+        this.effectiveToDate = toDate;
+    }
+}

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanproduct/domain/LoanRateRegisterEffectiveRepository.java

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+/**
+ * Copyright since 2025 Mifos Initiative
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+package org.apache.fineract.portfolio.loanproduct.domain;
+
+import java.util.List;
+import java.util.Optional;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface LoanRateRegisterEffectiveRepository extends JpaRepository<LoanRateRegisterEffective, Long> {
+
+    /** All active versions, newest-effective first. At most one row in a healthy system. */
+    List<LoanRateRegisterEffective> findByIsActiveTrueOrderByEffectiveFromDateDesc();
+
+    /** The current active version, if any. */
+    Optional<LoanRateRegisterEffective> findFirstByIsActiveTrueOrderByEffectiveFromDateDesc();
+
+    /** Version history list — all versions, newest first. */
+    List<LoanRateRegisterEffective> findAllByOrderByEffectiveFromDateDesc();
+}

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanproduct/domain/LoanRateRegisterSlabHistory.java

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+/**
+ * Copyright since 2025 Mifos Initiative
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+package org.apache.fineract.portfolio.loanproduct.domain;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+import java.math.BigDecimal;
+import java.time.LocalDateTime;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import org.apache.fineract.infrastructure.core.service.DateUtils;
+
+/**
+ * A single cell of a rate register version — one row per {product × amount-slab}. Product and slab
+ * metadata are denormalised so one query can rebuild the full matrix without a join. The cell holds
+ * either a plain numeric rate, a formula string ({@code "1% + FD"}) resolved at sanction, or
+ * N.A. (both value and formula null, {@code isNa=true}) to mean "slab not offered".
+ */
+@Entity
+@Table(name = "m_loan_rate_register_slab_history")
+@Getter
+@Setter
+@NoArgsConstructor
+public class LoanRateRegisterSlabHistory {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @Column(name = "effective_id", nullable = false)
+    private Long effectiveId;
+
+    // ---- product dimension ----------------------------------------------
+    @Column(name = "product_sr_no", nullable = false)
+    private Integer productSrNo;
+
+    @Column(name = "product_name", length = 200, nullable = false)
+    private String productName;
+
+    // ---- amount-slab dimension ------------------------------------------
+    @Column(name = "slab_order", nullable = false)
+    private Integer slabOrder;
+
+    @Column(name = "slab_label", length = 60, nullable = false)
+    private String slabLabel;
+
+    @Column(name = "amount_upto")
+    private BigDecimal amountUpto;
+
+    // ---- cell value (exactly one of value / formula is populated; both null + isNa=true means N.A.) ----
+    @Column(name = "rate_value")
+    private BigDecimal rateValue;
+
+    @Column(name = "rate_formula", length = 50)
+    private String rateFormula;
+
+    @Column(name = "is_formula", nullable = false)
+    private Boolean isFormula;
+
+    @Column(name = "is_na", nullable = false)
+    private Boolean isNa;
+
+    @Column(name = "created_date")
+    private LocalDateTime createdDate;
+
+    public static LoanRateRegisterSlabHistory create(final Long effectiveId, final Integer productSrNo, final String productName,
+            final Integer slabOrder, final String slabLabel, final BigDecimal amountUpto, final BigDecimal rateValue,
+            final String rateFormula, final boolean isFormula, final boolean isNa) {
+        final LoanRateRegisterSlabHistory s = new LoanRateRegisterSlabHistory();
+        s.effectiveId = effectiveId;
+        s.productSrNo = productSrNo;
+        s.productName = productName;
+        s.slabOrder = slabOrder;
+        s.slabLabel = slabLabel;
+        s.amountUpto = amountUpto;
+        s.rateValue = rateValue;
+        s.rateFormula = rateFormula;
+        s.isFormula = isFormula;
+        s.isNa = isNa;
+        s.createdDate = LocalDateTime.now(DateUtils.getDateTimeZoneOfTenant());
+        return s;
+    }
+}

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanproduct/domain/LoanRateRegisterSlabHistoryRepository.java

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+/**
+ * Copyright since 2025 Mifos Initiative
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+package org.apache.fineract.portfolio.loanproduct.domain;
+
+import java.util.List;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface LoanRateRegisterSlabHistoryRepository extends JpaRepository<LoanRateRegisterSlabHistory, Long> {
+
+    /** All cells of a version, ordered by product then by amount-slab. Rebuilds the full matrix in order. */
+    List<LoanRateRegisterSlabHistory> findByEffectiveIdOrderByProductSrNoAscSlabOrderAsc(Long effectiveId);
+}