feat: Add EML to PDF conversion functionality

common/build.gradle

@@ -43,7 +43,7 @@ dependencies {
     api 'jakarta.servlet:jakarta.servlet-api:6.1.0'
     api 'org.snakeyaml:snakeyaml-engine:2.9'
     api "org.springdoc:springdoc-openapi-starter-webmvc-ui:2.8.8"
-
+    api 'jakarta.mail:jakarta.mail-api:2.1.3'
     compileOnly "org.projectlombok:lombok:$lombokVersion"
     annotationProcessor "org.projectlombok:lombok:$lombokVersion"
 

common/src/main/java/stirling/software/common/model/api/converters/EmlToPdfRequest.java

@@ -0,0 +1,39 @@
+package stirling.software.common.model.api.converters;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import stirling.software.common.model.api.PDFFile;
+
+@Data
+@EqualsAndHashCode(callSuper = true)
+public class EmlToPdfRequest extends PDFFile {
+
+    // fileInput is inherited from PDFFile
+
+    @Schema(
+            description = "Include email attachments in the PDF output",
+            requiredMode = Schema.RequiredMode.NOT_REQUIRED,
+            example = "false")
+    private boolean includeAttachments = false;
+
+    @Schema(
+            description = "Maximum attachment size in MB to include (default 10MB, range: 1-100)",
+            requiredMode = Schema.RequiredMode.NOT_REQUIRED,
+            example = "10",
+            minimum = "1",
+            maximum = "100")
+    private int maxAttachmentSizeMB = 10;
+
+    @Schema(
+            description = "Download HTML intermediate file instead of PDF",
+            requiredMode = Schema.RequiredMode.NOT_REQUIRED,
+            example = "false")
+    private boolean downloadHtml = false;
+
+    @Schema(
+            description = "Include CC and BCC recipients in header (if available)",
+            requiredMode = Schema.RequiredMode.NOT_REQUIRED,
+            example = "true")
+    private boolean includeAllRecipients = true;
+}

src/main/java/stirling/software/SPDF/controller/api/converters/ConvertEmlToPDF.java

@@ -0,0 +1,148 @@
+package stirling.software.SPDF.controller.api.converters;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+
+import org.jetbrains.annotations.NotNull;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ModelAttribute;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.multipart.MultipartFile;
+
+import io.github.pixee.security.Filenames;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import lombok.extern.slf4j.Slf4j;
+import stirling.software.common.model.api.converters.EmlToPdfRequest;
+import stirling.software.common.util.EmlToPdf;
+import stirling.software.common.util.WebResponseUtils;
+
+@RestController
+@RequestMapping("/api/v1/convert")
+@Tag(name = "Convert", description = "Convert APIs")
+@Slf4j
+public class ConvertEmlToPDF {
+
+    @Value("${WEASYPRINT_PATH:weasyprint}")
+    private String weasyprintPath;
+
+    @PostMapping(consumes = "multipart/form-data", value = "/eml/pdf")
+    @Operation(
+            summary = "Convert EML to PDF",
+            description =
+                    "This endpoint converts EML (email) files to PDF format with extensive"
+                        + " customization options. Features include font settings, image constraints, display modes, attachment handling,"
+                        + " and HTML debug output. Input: EML file, Output: PDF"
+                        + " or HTML file. Type: SISO")
+    public ResponseEntity<byte[]> convertEmlToPdf(@ModelAttribute EmlToPdfRequest request) {
+
+        MultipartFile inputFile = request.getFileInput();
+        String originalFilename = inputFile.getOriginalFilename();
+
+        // Validate input
+        if (inputFile == null || inputFile.isEmpty()) {
+            log.error("No file provided for EML to PDF conversion.");
+            return ResponseEntity.badRequest()
+                    .body("No file provided".getBytes(StandardCharsets.UTF_8));
+        }
+
+        if (originalFilename == null || originalFilename.trim().isEmpty()) {
+            log.error("Filename is null or empty.");
+            return ResponseEntity.badRequest()
+                    .body("Please provide a valid filename".getBytes(StandardCharsets.UTF_8));
+        }
+
+        // Validate file type - support EML
+        String lowerFilename = originalFilename.toLowerCase();
+        if (!lowerFilename.endsWith(".eml")) {
+            log.error("Invalid file type for EML to PDF: {}", originalFilename);
+            return ResponseEntity.badRequest()
+                    .body("Please upload a valid EML file".getBytes(StandardCharsets.UTF_8));
+        }
+
+        String baseFilename = Filenames.toSimpleFileName(originalFilename); // Use Filenames utility
+
+        try {
+            byte[] fileBytes = inputFile.getBytes();
+
+            if (request.isDownloadHtml()) {
+                try {
+                    String htmlContent = EmlToPdf.convertEmlToHtml(fileBytes, request);
+                    log.info("Successfully converted EML to HTML: {}", originalFilename);
+                    return WebResponseUtils.bytesToWebResponse(
+                            htmlContent.getBytes(StandardCharsets.UTF_8),
+                            baseFilename + ".html",
+                            MediaType.TEXT_HTML);
+                } catch (Exception e) {
+                    log.error("HTML conversion failed for {}", originalFilename, e);
+                    return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                            .body(
+                                    ("HTML conversion failed: " + e.getMessage())
+                                            .getBytes(StandardCharsets.UTF_8));
+                }
+            }
+
+            // Convert EML to PDF with enhanced options
+            try {
+                byte[] pdfBytes =
+                        EmlToPdf.convertEmlToPdf(
+                                weasyprintPath, // Use configured WeasyPrint path
+                                request,
+                                fileBytes,
+                                originalFilename,
+                                false);
+
+                if (pdfBytes == null || pdfBytes.length == 0) {
+                    log.error("PDF conversion failed - empty output for {}", originalFilename);
+                    return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                            .body(
+                                    "PDF conversion failed - empty output"
+                                            .getBytes(StandardCharsets.UTF_8));
+                }
+                log.info("Successfully converted EML to PDF: {}", originalFilename);
+                return WebResponseUtils.bytesToWebResponse(
+                        pdfBytes, baseFilename + ".pdf", MediaType.APPLICATION_PDF);
+
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                log.error("EML to PDF conversion was interrupted for {}", originalFilename, e);
+                return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                        .body("Conversion was interrupted".getBytes(StandardCharsets.UTF_8));
+            } catch (Exception e) {
+                String errorMessage = buildErrorMessage(e, originalFilename);
+                log.error("EML to PDF conversion failed for {}: {}", originalFilename, errorMessage, e);
+                return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                        .body(errorMessage.getBytes(StandardCharsets.UTF_8));
+            }
+
+        } catch (IOException e) {
+            log.error("File processing error for EML to PDF: {}", originalFilename, e);
+            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                    .body("File processing error".getBytes(StandardCharsets.UTF_8));
+        }
+    }
+
+    private static @NotNull String buildErrorMessage(Exception e, String originalFilename) {
+        String errorMessage;
+        if (e.getMessage() != null && e.getMessage().contains("Invalid EML")) {
+            errorMessage =
+                    "Invalid EML file format. Please ensure you've uploaded a valid email"
+                            + " file ("
+                            + originalFilename
+                            + ").";
+        } else if (e.getMessage() != null && e.getMessage().contains("WeasyPrint")) {
+            errorMessage =
+                    "PDF generation failed for "
+                            + originalFilename
+                            + ". This may be due to complex email formatting.";
+        } else {
+            errorMessage = "Conversion failed for " + originalFilename + ": " + e.getMessage();
+        }
+        return errorMessage;
+    }
+}

src/main/java/stirling/software/SPDF/controller/web/ConverterWebController.java

@@ -7,7 +7,6 @@ import org.springframework.web.servlet.ModelAndView;
 
 import io.swagger.v3.oas.annotations.Hidden;
 import io.swagger.v3.oas.annotations.tags.Tag;
-
 import stirling.software.common.util.CheckProgramInstall;
 
 @Controller
@@ -121,4 +120,11 @@ public class ConverterWebController {
         model.addAttribute("currentPage", "pdf-to-pdfa");
         return "convert/pdf-to-pdfa";
     }
+
+    @GetMapping("/eml-to-pdf")
+    @Hidden
+    public String convertEmlToPdfForm(Model model) {
+        model.addAttribute("currentPage", "eml-to-pdf");
+        return "convert/eml-to-pdf";
+    }
 }

src/main/resources/messages_en_GB.properties

@@ -621,6 +621,22 @@ home.HTMLToPDF.title=HTML to PDF
 home.HTMLToPDF.desc=Converts any HTML file or zip to PDF
 HTMLToPDF.tags=markup,web-content,transformation,convert
 
+#eml-to-pdf
+home.EMLToPDF.title=EML to PDF
+home.EMLToPDF.desc=Converts email (EML) files to PDF format including headers, body, and inline images
+EMLToPDF.tags=email,conversion,eml,message,transformation,convert,mail
+
+EMLToPDF.title=EML To PDF
+EMLToPDF.header=EML To PDF
+EMLToPDF.submit=Convert
+EMLToPDF.downloadHtml=Download HTML intermediate file instead of PDF
+EMLToPDF.downloadHtmlHelp=This allows you to see the HTML version before PDF conversion and can help debug formatting issues
+EMLToPDF.includeAttachments=Include attachments in PDF
+EMLToPDF.maxAttachmentSize=Maximum attachment size (MB)
+EMLToPDF.help=Converts email (EML) files to PDF format including headers, body, and inline images
+EMLToPDF.troubleshootingTip1=EML to HTML is a more reliable process, so with batch-processing it is recommended to save both
+EMLToPDF.troubleshootingTip2=With a small number of EMLs, if the PDF is malformed, you can download HTML and override some of the problematic HTML code.
+EMLToPDF.troubleshootingTip3=Embeddings, however, do not work with HTMLs
 
 home.MarkdownToPDF.title=Markdown to PDF
 home.MarkdownToPDF.desc=Converts any Markdown file to PDF

src/main/resources/templates/convert/eml-to-pdf.html

@@ -0,0 +1,93 @@
+<!DOCTYPE html>
+<html th:lang="${#locale.language}" th:dir="#{language.direction}" th:data-language="${#locale.toString()}"
+  xmlns:th="https://www.thymeleaf.org">
+
+<head>
+  <th:block th:insert="~{fragments/common :: head(title=#{EMLToPDF.title}, header=#{EMLToPDF.header})}"></th:block>
+</head>
+
+<body>
+  <div id="page-container">
+    <div id="content-wrap">
+      <th:block th:insert="~{fragments/navbar.html :: navbar}"></th:block>
+      <div class="container py-4">
+        <div class="row justify-content-center">
+          <div class="col-md-6">
+            <div class="card shadow-sm">
+              <div class="card-body">
+                <div class="tool-header">
+                  <span class="material-symbols-rounded tool-header-icon convertto">email</span>
+                  <span class="tool-header-text" th:text="#{EMLToPDF.header}"></span>
+                </div>
+                <form method="post" enctype="multipart/form-data" th:action="@{'/api/v1/convert/eml/pdf'}" class="mt-4">
+                  <div th:replace="~{fragments/common :: fileSelector(name='fileInput', multipleInputsForSingleRequest=false, accept='.eml,message/rfc822')}">
+                  </div>
+                  
+                  <div class="form-check mb-3">
+                    <input type="checkbox" class="form-check-input" name="downloadHtml" id="downloadHtml">
+                    <label class="form-check-label" for="downloadHtml" th:text="#{EMLToPDF.downloadHtml}"></label>
+                    <div class="form-text" th:text="#{EMLToPDF.downloadHtmlHelp}"></div>
+                  </div>
+                  
+                  <div id="pdfOnlyOptions">
+                    <div class="form-check mb-3">
+                      <input type="checkbox" class="form-check-input" name="includeAttachments" id="includeAttachments" checked>
+                      <label class="form-check-label" for="includeAttachments" th:text="#{EMLToPDF.includeAttachments}"></label>
+                    </div>
+                    
+                    <div class="mb-3">
+                      <label for="maxAttachmentSizeMB" class="form-label" th:text="#{EMLToPDF.maxAttachmentSize}"></label>
+                      <input type="number" class="form-control" id="maxAttachmentSizeMB" name="maxAttachmentSizeMB" value="10" min="1" max="100">
+                    </div>
+                    
+
+                  </div>
+
+                  <div class="mb-4">
+                    <button class="btn btn-outline-primary" type="button" data-bs-toggle="collapse" 
+                            data-bs-target="#info" aria-expanded="false" aria-controls="info" th:text="#{info}">
+                    </button>
+                    <div class="collapse mt-3" id="info">
+                      <div class="card card-body">
+                        <p class="mb-2" th:text="#{EMLToPDF.help}"></p>
+                        <ul class="mb-0">
+                          <li th:text="#{EMLToPDF.troubleshootingTip1}"></li>
+                          <li th:text="#{EMLToPDF.troubleshootingTip2}"></li>
+                          <li th:text="#{EMLToPDF.troubleshootingTip3}"></li>
+                        </ul>
+                      </div>
+                    </div>
+                  </div>
+                  
+                  <button type="submit" id="submitBtn" class="btn btn-primary" th:text="#{EMLToPDF.submit}"></button>
+                </form>
+              </div>
+            </div>
+          </div>
+        </div>
+      </div>
+    </div>
+    <th:block th:insert="~{fragments/footer.html :: footer}"></th:block>
+  </div>
+
+  <script>
+    document.addEventListener('DOMContentLoaded', function() {
+      const downloadHtml = document.getElementById('downloadHtml');
+      const pdfOnlyOptions = document.getElementById('pdfOnlyOptions');
+      const submitBtn = document.getElementById('submitBtn');
+
+      function updateFormState() {
+        if (pdfOnlyOptions && submitBtn) {
+          pdfOnlyOptions.style.display = downloadHtml.checked ? 'none' : 'block';
+          submitBtn.textContent = downloadHtml.checked ? 'Download HTML' : '[[#{EMLToPDF.submit}]]';
+        }
+      }
+
+      if (downloadHtml) {
+        downloadHtml.addEventListener('change', updateFormState);
+        updateFormState();
+      }
+    });
+  </script>
+</body>
+</html>

src/main/resources/templates/fragments/navElements.html

@@ -59,6 +59,9 @@
       <div
         th:replace="~{fragments/navbarEntry :: navbarEntry('markdown-to-pdf', 'markdown', 'home.MarkdownToPDF.title', 'home.MarkdownToPDF.desc', 'MarkdownToPDF.tags', 'convertto')}">
       </div>
+      <div
+        th:replace="~{fragments/navbarEntry :: navbarEntry('eml-to-pdf', 'email', 'home.EMLToPDF.title', 'home.EMLToPDF.desc', 'EMLToPDF.tags', 'convertto')}">
+      </div>
     </div>
   </div>
   <div id="groupConvertFrom" class="feature-group">