feat: buyer ledger report generation (#9)

 - buyer ledger report generation

---------

Signed-off-by: Rajdeep Roy Chowdhury <[email protected]>

Author: Razdeep

build.gradle.kts

@@ -42,6 +42,8 @@ dependencies {
     implementation(libs.spring.boot.starter.data.jpa)
     implementation(libs.postgres.connector)
     implementation(libs.gson)
+    implementation(libs.spring.boot.starter.freemarker)
+    implementation(libs.openhtml)
 
     compileOnly(libs.lombok)
     annotationProcessor(libs.lombok)

gradle/libs.versions.toml

@@ -12,6 +12,7 @@ jackson = "2.15.0"
 micrometer = "1.11.0" # adjust if needed
 testcontainers = "1.17.6"
 rewritespring = "6.21.0"
+openhtml = "1.0.10"
 
 [libraries]
 spring-boot-starter-web = { module = "org.springframework.boot:spring-boot-starter-web" }
@@ -21,6 +22,7 @@ spring-boot-starter-actuator = { module = "org.springframework.boot:spring-boot-
 spring-boot-starter-data-redis = { module = "org.springframework.boot:spring-boot-starter-data-redis", version.ref = "springboot" }
 spring-boot-starter-cache = { module = "org.springframework.boot:spring-boot-starter-cache", version = "2.4.3" }
 spring-boot-starter-test = { module = "org.springframework.boot:spring-boot-starter-test" }
+spring-boot-starter-freemarker = { module = "org.springframework.boot:spring-boot-starter-freemarker" }
 
 jjwt = { module = "io.jsonwebtoken:jjwt", version.ref = "jjwt" }
 jaxb-api = { module = "javax.xml.bind:jaxb-api", version.ref = "jaxb" }
@@ -42,3 +44,5 @@ testcontainers-mysql = { module = "org.testcontainers:mysql", version.ref = "tes
 
 openrewrite-recipe-rewrite-spring = { module = "org.openrewrite.recipe:rewrite-spring", version.ref = "rewritespring" }
 
+openhtml = { module = "com.openhtmltopdf:openhtmltopdf-pdfbox", version.ref = "openhtml"}
+

src/main/java/com/razdeep/konsignapi/controller/ReportController.java

@@ -0,0 +1,37 @@
+package com.razdeep.konsignapi.controller;
+
+import com.razdeep.konsignapi.constant.KonsignConstant;
+import com.razdeep.konsignapi.service.BuyerService;
+import com.razdeep.konsignapi.service.SupplierService;
+import io.micrometer.core.annotation.Timed;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+@CrossOrigin
+@RestController
+@RequestMapping(KonsignConstant.CONTROLLER_API_PREFIX + "/report")
+public class ReportController {
+
+    private final SupplierService supplierService;
+    private final BuyerService buyerService;
+
+    public ReportController(SupplierService supplierService, BuyerService buyerService) {
+        this.supplierService = supplierService;
+        this.buyerService = buyerService;
+    }
+
+    @Timed
+    @GetMapping("/supplier")
+    public ResponseEntity<byte[]> generateSupplierReport(@RequestParam String supplierId) throws Exception {
+        final var bytes = supplierService.generateSupplierLedger(supplierId);
+        return ResponseEntity.ok().contentType(MediaType.APPLICATION_PDF).body(bytes);
+    }
+
+    @Timed
+    @GetMapping("/buyer")
+    public ResponseEntity<byte[]> generateBuyerReport(@RequestParam String buyerId) throws Exception {
+        final var bytes = buyerService.generateBuyerLedger(buyerId);
+        return ResponseEntity.ok().contentType(MediaType.APPLICATION_PDF).body(bytes);
+    }
+}

src/main/java/com/razdeep/konsignapi/repository/BillCollectionDTO.java

@@ -0,0 +1,19 @@
+package com.razdeep.konsignapi.repository;
+
+import java.time.LocalDate;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+
+@Data
+@AllArgsConstructor
+public class BillCollectionDTO {
+    String billNo;
+    LocalDate billDate;
+    String billAmount;
+    String supplierName;
+    String voucherNo;
+    Double amountCollected;
+    String bank;
+    String ddNo;
+    LocalDate ddDate;
+}

src/main/java/com/razdeep/konsignapi/repository/BillCollectionProjection.java

@@ -0,0 +1,24 @@
+package com.razdeep.konsignapi.repository;
+
+import java.time.LocalDate;
+
+public interface BillCollectionProjection {
+
+    String getBillNo();
+
+    LocalDate getBillDate();
+
+    String getBillAmount();
+
+    String getSupplierName();
+
+    String getVoucherNo();
+
+    Double getAmountCollected();
+
+    String getBank();
+
+    String getDdNo();
+
+    LocalDate getDdDate();
+}

src/main/java/com/razdeep/konsignapi/repository/BuyerRepository.java

@@ -5,6 +5,7 @@
 import java.util.Optional;
 import lombok.NonNull;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
 import org.springframework.stereotype.Repository;
 
 @Repository
@@ -14,4 +15,50 @@ public interface BuyerRepository extends JpaRepository<BuyerEntity, String> {
     List<BuyerEntity> findAllByAgencyId(@NonNull String agencyId);
 
     Optional<BuyerEntity> findByBuyerIdAndAgencyId(@NonNull String buyerId, @NonNull String agencyId);
+
+    @Query("""
+        select b.buyerName
+        from BuyerEntity b
+        where b.buyerId = :buyerId
+            and b.agencyId = :agencyId
+    """)
+    String findBuyerNameByBuyerId(String buyerId, String agencyId);
+
+    @Query(value = """
+with collection_joined as (
+select
+	*
+from
+	collection_voucher
+join collection_voucher_item on
+	voucher_no = fk_collection_voucher_id
+where buyer_buyer_id = :buyerId
+and collection_voucher.agency_id = :agencyId),
+bill_joined as (
+select
+	*
+from
+	bill
+join supplier on
+	bill.fk_supplier_id = supplier.supplier_id
+join buyer on
+	bill.fk_buyer_id = buyer.buyer_id
+)
+select
+	bill_joined.bill_no as billNo,
+	bill_joined.bill_date as billDate,
+	bill_joined.bill_amount as billAmount,
+	bill_joined.supplier_name as supplierName,
+	collection_joined.voucher_no as voucherNo,
+	collection_joined.amount_collected as amountCollected,
+	collection_joined.bank as bank,
+	collection_joined.dd_no as ddNo,
+	collection_joined.dd_date as ddDate
+from
+	bill_joined
+join collection_joined
+on
+	bill_joined.bill_no = collection_joined.bill_bill_no;
+            """, nativeQuery = true)
+    List<BillCollectionProjection> computeBuyerLedger(@NonNull String buyerId, @NonNull String agencyId);
 }

src/main/java/com/razdeep/konsignapi/repository/SupplierRepository.java

@@ -4,6 +4,7 @@
 import java.util.List;
 import java.util.Optional;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
 import org.springframework.stereotype.Repository;
 
 @Repository
@@ -14,4 +15,11 @@ public interface SupplierRepository extends JpaRepository<SupplierEntity, String
     List<SupplierEntity> findAllByAgencyId(String supplierName);
 
     Optional<SupplierEntity> findSupplierBySupplierIdAndAgencyId(String supplierId, String agencyId);
+
+    @Query("""
+        select s.supplierName
+        from SupplierEntity s
+        where s.supplierId = :supplierId
+    """)
+    String findSupplierNameBySupplierId(String supplierId);
 }

src/main/java/com/razdeep/konsignapi/service/BuyerService.java

@@ -2,9 +2,13 @@
 
 import com.razdeep.konsignapi.entity.BuyerEntity;
 import com.razdeep.konsignapi.model.Buyer;
+import com.razdeep.konsignapi.repository.BillCollectionDTO;
+import com.razdeep.konsignapi.repository.BillCollectionProjection;
 import com.razdeep.konsignapi.repository.BuyerRepository;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import org.springframework.stereotype.Service;
 
 @Service
@@ -79,4 +83,29 @@ public BuyerEntity getBuyerByBuyerName(String buyerName) {
         final var resultList = buyerRepository.findAllBuyerByBuyerNameAndAgencyId(buyerName, agencyId);
         return resultList == null || resultList.isEmpty() ? null : resultList.get(0);
     }
+
+    public byte[] generateBuyerLedger(String buyerId) throws Exception {
+        String agencyId = commonService.getAgencyId();
+        Map<String, Object> payload = new HashMap<>();
+
+        String buyerName = buyerRepository.findBuyerNameByBuyerId(buyerId, agencyId);
+        payload.put("buyerName", buyerName);
+
+        List<BillCollectionProjection> rows = buyerRepository.computeBuyerLedger(buyerId, agencyId);
+        List<BillCollectionDTO> items = rows.stream()
+                .map(rawRow -> new BillCollectionDTO(
+                        rawRow.getBillNo(),
+                        rawRow.getBillDate(),
+                        rawRow.getBillAmount(),
+                        rawRow.getSupplierName(),
+                        rawRow.getVoucherNo(),
+                        rawRow.getAmountCollected(),
+                        rawRow.getBank(),
+                        rawRow.getDdNo(),
+                        rawRow.getDdDate()))
+                .toList();
+        payload.put("items", items);
+
+        return commonService.generatePdf("buyer.ftl", payload);
+    }
 }

src/main/java/com/razdeep/konsignapi/service/CommonService.java

@@ -1,15 +1,27 @@
 package com.razdeep.konsignapi.service;
 
+import com.openhtmltopdf.pdfboxout.PdfRendererBuilder;
 import com.razdeep.konsignapi.model.KonsignUserDetails;
+import freemarker.template.Template;
+import freemarker.template.TemplateException;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.StringWriter;
+import java.util.Map;
 import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.stereotype.Service;
+import org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer;
 
 @Service
 public class CommonService {
 
     private static final int MAX_INITIAL_SIZE = 4;
 
-    public CommonService() {}
+    private final FreeMarkerConfigurer freemarkerConfigurer;
+
+    public CommonService(FreeMarkerConfigurer freemarkerConfigurer) {
+        this.freemarkerConfigurer = freemarkerConfigurer;
+    }
 
     private boolean isVowel(char c) {
         return c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u' || c == 'A' || c == 'E' || c == 'I' || c == 'O'
@@ -50,4 +62,35 @@ public String getAgencyId() {
         }
         return konsignUserDetails.getAgencyId();
     }
+
+    private byte[] convertHtmlToPdf(String html) throws Exception {
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+
+        PdfRendererBuilder builder = new PdfRendererBuilder();
+        builder.withHtmlContent(html, null);
+        builder.toStream(out);
+
+        // IMPORTANT: Embed font
+        //        builder.useFont(
+        //                new File("fonts/DejaVuSans.ttf"),
+        //                "DejaVu Sans"
+        //        );
+
+        builder.run();
+        return out.toByteArray();
+    }
+
+    private String generateHtml(String templateName, Map<String, Object> payload)
+            throws IOException, TemplateException {
+        Template template = freemarkerConfigurer.getConfiguration().getTemplate(templateName);
+        StringWriter writer = new StringWriter();
+        template.process(payload, writer);
+
+        return writer.toString();
+    }
+
+    public byte[] generatePdf(String templateName, Map<String, Object> payload) throws Exception {
+        String html = generateHtml(templateName, payload);
+        return convertHtmlToPdf(html);
+    }
 }

src/main/java/com/razdeep/konsignapi/service/SupplierService.java

@@ -4,7 +4,9 @@
 import com.razdeep.konsignapi.model.Supplier;
 import com.razdeep.konsignapi.repository.SupplierRepository;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import org.springframework.stereotype.Service;
 
 @Service
@@ -82,4 +84,13 @@ public SupplierEntity getSupplierBySupplierName(String supplierName) {
         final var resultList = supplierRepository.findAllSupplierBySupplierNameAndAgencyId(supplierName, agencyId);
         return resultList == null || resultList.isEmpty() ? null : resultList.get(0);
     }
+
+    // TODO: implement properly later
+    public byte[] generateSupplierLedger(String supplierId) throws Exception {
+        String supplierName = supplierRepository.findSupplierNameBySupplierId(supplierId);
+        Map<String, Object> payload = new HashMap<>();
+        payload.put("supplierName", supplierName);
+
+        return commonService.generatePdf("supplier.ftl", payload);
+    }
 }