adding Marker to parse effectively pdf

backend/src/main/java/com/aiteacher/book/BookController.java

@@ -2,7 +2,9 @@ package com.aiteacher.book;
 
 import com.aiteacher.document.FigureEntity;
 import com.aiteacher.document.FigureRepository;
+import com.aiteacher.document.MarkdownStorageService;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 import org.springframework.web.multipart.MultipartFile;
@@ -18,10 +20,13 @@ public class BookController {
 
     private final BookService bookService;
     private final FigureRepository figureRepository;
+    private final MarkdownStorageService markdownStorageService;
 
-    public BookController(BookService bookService, FigureRepository figureRepository) {
+    public BookController(BookService bookService, FigureRepository figureRepository,
+                          MarkdownStorageService markdownStorageService) {
         this.bookService = bookService;
         this.figureRepository = figureRepository;
+        this.markdownStorageService = markdownStorageService;
     }
 
     @PostMapping(consumes = "multipart/form-data")
@@ -59,6 +64,17 @@ public class BookController {
         ));
     }
 
+    @GetMapping(value = "/{id}/pages/{pageNumber}/markdown", produces = MediaType.TEXT_PLAIN_VALUE)
+    public ResponseEntity<String> getPageMarkdown(@PathVariable UUID id,
+                                                   @PathVariable int pageNumber) {
+        bookService.getById(id); // 404 if not found
+        try {
+            return ResponseEntity.ok(markdownStorageService.getText(id, pageNumber));
+        } catch (Exception e) {
+            return ResponseEntity.notFound().build();
+        }
+    }
+
     @GetMapping("/{id}/figures")
     public ResponseEntity<List<FigureResponse>> figures(@PathVariable UUID id) {
         bookService.getById(id); // 404 if not found