fix: core package

.gitignore

@@ -33,3 +33,4 @@ build/
 .vscode/
 
 .idea/
+.serena

AGENTS.md

@@ -0,0 +1,55 @@
+# AGENTS.md
+
+Spring Boot **4.1.0** / Java 17 REST backend for an LMS (PostgreSQL). Root package `aplp.backend.lms`.
+
+## Commands
+
+- Build: `./mvnw -DskipTests package`
+- Run: `./mvnw spring-boot:run`
+- All tests: `./mvnw test`
+- Single test: `./mvnw test -Dtest=LmsApplicationTests`
+- Requires JDK 17. No linter, formatter, or checkstyle is configured — don't invent one.
+
+## Build gotcha: GitLab Maven registry
+
+`aplp.backend:core:1.0-SNAPSHOT` is not built here; it resolves from the GitLab package registry (repository id `gitlab-maven` in `pom.xml`). A fresh checkout needs a token for server id `gitlab-maven` in `~/.m2/settings.xml` (or the artifact cached in `~/.m2/repository`). Credentials are not in the repo.
+
+## `aplp.backend.core` shared types
+
+Not defined in this repo; import them instead of recreating:
+
+- `BaseEntity` — `@MappedSuperclass` for every entity: `id`, `createdAt/By`, `updatedAt/By`, `deletedAt/By`; timestamps set via `@PrePersist`/`@PreUpdate`.
+- `ApiResponse<T>` — `ok(data)`, `ok(message, data)`, `error(code, message)`.
+- `PagedResponse<T>` — `of(content, page, size, totalElements)`.
+- `ErrorCode`, `DomainException`, `ResourceNotFoundException`, `TokenHasher.sha256Hex`.
+
+## Architecture
+
+Vertical slices per feature under `aplp.backend.lms.<feature>` (currently `course`, `lesson`, `section`); `common/` holds cross-cutting `api`, `config`, `security`. Layers per feature:
+
+- `api/controller` — `@RestController`, returns `ResponseEntity<ApiResponse<...>>`
+- `application/services`, `application/dtos` (Java records), `application/mappers` (MapStruct)
+- `domain/entities`, `domain/enums`, `domain/repositories` (plain interfaces)
+- `infrastructure/persistence` — `*RepositoryImpl` implements the domain repo and delegates to a Spring Data `*JpaRepository`
+
+Conventions:
+
+- Entities extend `BaseEntity`, use Lombok `@Getter/@Setter/@NoArgsConstructor`, `@Table` snake_case.
+- Controllers stay thin; services throw `ResourceNotFoundException`; `GlobalExceptionHandler` maps exceptions to `ApiResponse`.
+- Mappers are interfaces annotated `@Mapper(componentModel = "spring")`; Lombok/MapStruct annotation processing is already wired in `pom.xml`.
+- Add derived queries to `*JpaRepository` and expose them through the domain repo interface.
+
+## Database
+
+- PostgreSQL, Hibernate default schema `lms`; datasource hardcoded in `src/main/resources/application.yaml`.
+- **`spring.flyway.enabled: false` + `spring.jpa.hibernate.ddl-auto: update`**: Hibernate maintains the schema at runtime. Scripts in `db/migration` (`V{n}__desc.sql`) are history only and are NOT applied on startup. A schema change needs both the entity field and a migration; don't assume Flyway runs.
+- jsonb columns use `@JdbcTypeCode(SqlTypes.JSON)` on a `String` field.
+
+## Security
+
+- `SecurityConfig` disables CSRF and `permitAll`s every request — endpoints are currently unauthenticated despite OpenAPI declaring a `bearerAuth` JWT scheme (Swagger UI at `/swagger-ui`).
+- `JpaAuditingConfig` reads the current user from `SecurityContextHolder` and expects `Authentication.getPrincipal()` to be a `Long` userId.
+
+## Testing
+
+Only `LmsApplicationTests` (`@SpringBootTest contextLoads`) exists. There is no `src/test/resources` or test profile, so tests use the real `application.yaml` datasource and require access to the remote DB — `./mvnw test` fails without it.

pom.xml

@@ -108,15 +108,39 @@
             <artifactId>springdoc-openapi-starter-webmvc-ui</artifactId>
             <version>3.1.0</version>
         </dependency>
+        <dependency>
+            <groupId>io.minio</groupId>
+            <artifactId>minio</artifactId>
+            <version>8.5.17</version>
+        </dependency>
 
         <dependency>
             <groupId>aplp.backend</groupId>
             <artifactId>core</artifactId>
-            <version>1.0-SNAPSHOT</version>
+            <version>1.0.0-SNAPSHOT</version>
         </dependency>
 
     </dependencies>
 
+    <repositories>
+        <repository>
+            <id>gitea</id>
+            <url>https://git.koda.id.vn/api/packages/aplp/maven</url>
+        </repository>
+    </repositories>
+
+    <distributionManagement>
+        <repository>
+            <id>gitea</id>
+            <url>https://git.koda.id.vn/api/packages/aplp/maven</url>
+        </repository>
+
+        <snapshotRepository>
+            <id>gitea</id>
+            <url>https://git.koda.id.vn/api/packages/aplp/maven</url>
+        </snapshotRepository>
+    </distributionManagement>
+
     <build>
         <plugins>
             <plugin>

src/main/java/aplp/backend/lms/api/common/exception/GlobalExceptionHandler.java

@@ -1,40 +0,0 @@
-package aplp.backend.lms.api.common.exception;
-
-import aplp.backend.core.common.exception.ResourceNotFoundException;
-import aplp.backend.core.common.response.ErrorResponse;
-import org.springframework.http.HttpStatus;
-import org.springframework.http.ResponseEntity;
-import org.springframework.web.bind.annotation.ExceptionHandler;
-import org.springframework.web.bind.annotation.RestControllerAdvice;
-
-import java.time.LocalDateTime;
-
-@RestControllerAdvice
-public class GlobalExceptionHandler {
-
-    @ExceptionHandler(ResourceNotFoundException.class)
-    public ResponseEntity<ErrorResponse> handleNotFound(
-            ResourceNotFoundException ex
-    ) {
-        return ResponseEntity
-                .status(HttpStatus.NOT_FOUND)
-                .body(new ErrorResponse(
-                        HttpStatus.NOT_FOUND.value(),
-                        ex.getMessage(),
-                        LocalDateTime.now()
-                ));
-    }
-
-    @ExceptionHandler(Exception.class)
-    public ResponseEntity<ErrorResponse> handleException(
-            Exception ex
-    ) {
-        return ResponseEntity
-                .status(HttpStatus.INTERNAL_SERVER_ERROR)
-                .body(new ErrorResponse(
-                        HttpStatus.INTERNAL_SERVER_ERROR.value(),
-                        "Internal server error",
-                        LocalDateTime.now()
-                ));
-    }
-}

src/main/java/aplp/backend/lms/api/controllers/CourseController.java

@@ -1,48 +0,0 @@
-package aplp.backend.lms.api.controllers;
-
-import aplp.backend.lms.application.dtos.CourseReqDto;
-import aplp.backend.lms.application.dtos.CourseResDto;
-import aplp.backend.lms.application.services.CourseService;
-import jakarta.validation.Valid;
-import lombok.RequiredArgsConstructor;
-import org.springframework.http.HttpStatus;
-import org.springframework.web.bind.annotation.*;
-
-import java.util.List;
-
-@RestController
-@RequestMapping("/api/courses")
-@RequiredArgsConstructor
-public class CourseController {
-
-    private final CourseService courseService;
-
-    @GetMapping
-    public List<CourseResDto> getAll() {
-        return courseService.getAll();
-    }
-
-    @GetMapping("/{id}")
-    public CourseResDto getById(@PathVariable Long id) {
-        return courseService.getById(id);
-    }
-
-    @PostMapping
-    @ResponseStatus(HttpStatus.CREATED)
-    public CourseResDto create(@Valid @RequestBody CourseReqDto request) {
-        return courseService.create(request);
-    }
-
-    @PutMapping("/{id}")
-    public CourseResDto update(
-            @PathVariable Long id,
-            @RequestBody CourseReqDto request) {
-        return courseService.update(id, request);
-    }
-
-    @DeleteMapping("/{id}")
-    @ResponseStatus(HttpStatus.NO_CONTENT)
-    public void delete(@PathVariable Long id) {
-        courseService.delete(id);
-    }
-}

src/main/java/aplp/backend/lms/application/dtos/CourseReqDto.java

@@ -1,6 +0,0 @@
-package aplp.backend.lms.application.dtos;
-
-public record CourseReqDto(
-        String title,
-        String description
-) {}

src/main/java/aplp/backend/lms/application/dtos/CourseResDto.java

@@ -1,17 +0,0 @@
-package aplp.backend.lms.application.dtos;
-
-import aplp.backend.lms.domain.entities.Course;
-
-public record CourseResDto(
-        Long id,
-        String title,
-        String description
-) {
-    public static CourseResDto from(Course course) {
-        return new CourseResDto(
-                course.getId(),
-                course.getTitle(),
-                course.getDescription()
-        );
-    }
-}

src/main/java/aplp/backend/lms/application/mappers/CourseMapper.java

@@ -1,20 +0,0 @@
-package aplp.backend.lms.application.mappers;
-
-import aplp.backend.lms.application.dtos.CourseReqDto;
-import aplp.backend.lms.application.dtos.CourseResDto;
-import aplp.backend.lms.domain.entities.Course;
-import org.mapstruct.Mapper;
-import org.mapstruct.MappingTarget;
-
-@Mapper(componentModel = "spring")
-public interface CourseMapper {
-
-    CourseResDto toResponse(Course course);
-
-    Course toEntity(CourseReqDto request);
-
-    void updateEntity(
-            CourseReqDto request,
-            @MappingTarget Course course
-    );
-}

src/main/java/aplp/backend/lms/application/services/CourseService.java

@@ -1,52 +0,0 @@
-package aplp.backend.lms.application.services;
-
-import aplp.backend.core.common.exception.ResourceNotFoundException;
-import aplp.backend.lms.application.dtos.CourseReqDto;
-import aplp.backend.lms.application.dtos.CourseResDto;
-import aplp.backend.lms.application.mappers.CourseMapper;
-import aplp.backend.lms.domain.entities.Course;
-import aplp.backend.lms.domain.repositories.CourseRepository;
-import lombok.RequiredArgsConstructor;
-import org.springframework.stereotype.Service;
-
-import java.util.List;
-
-@Service
-@RequiredArgsConstructor
-public class CourseService {
-
-    private final CourseRepository courseRepository;
-    private final CourseMapper courseMapper;
-
-    public List<CourseResDto> getAll() {
-        return courseRepository.findAll()
-                .stream()
-                .map(CourseResDto::from)
-                .toList();
-    }
-
-    public CourseResDto getById(Long id) {
-        Course course = courseRepository.findById(id)
-                .orElseThrow(() -> new ResourceNotFoundException("Course not found"));
-
-        return CourseResDto.from(course);
-    }
-
-    public CourseResDto create(CourseReqDto request) {
-        Course course = courseMapper.toEntity(request);
-        return courseMapper.toResponse(courseRepository.save(course));
-    }
-
-    public CourseResDto update(Long id, CourseReqDto request) {
-        Course course = courseRepository.findById(id)
-                .orElseThrow(() -> new ResourceNotFoundException("Course not found"));
-
-        courseMapper.updateEntity(request, course);
-
-        return courseMapper.toResponse(courseRepository.save(course));
-    }
-
-    public void delete(Long id) {
-        courseRepository.deleteById(id);
-    }
-}

src/main/java/aplp/backend/lms/common/api/GlobalExceptionHandler.java

@@ -0,0 +1,80 @@
+package aplp.backend.lms.common.api;
+
+import aplp.backend.core.common.exception.DomainException;
+import aplp.backend.core.common.exception.ErrorCode;
+import aplp.backend.core.common.exception.ResourceNotFoundException;
+import aplp.backend.core.common.response.ApiResponse;
+import org.springframework.dao.DataIntegrityViolationException;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+import java.util.stream.Collectors;
+
+@RestControllerAdvice
+public class GlobalExceptionHandler {
+
+    @ExceptionHandler(ResourceNotFoundException.class)
+    public ResponseEntity<ApiResponse<?>> handleNotFound(
+            ResourceNotFoundException ex
+    ) {
+        return ResponseEntity
+                .status(HttpStatus.NOT_FOUND)
+                .body(ApiResponse.error(
+                        HttpStatus.NOT_FOUND.name(),
+                        ex.getMessage()
+                ));
+    }
+
+    @ExceptionHandler(DomainException.class)
+    public ResponseEntity<ApiResponse<?>> handleDomainException(DomainException ex) {
+        return ResponseEntity
+                .status(ex.code().status())
+                .body(ApiResponse.error(
+                        ex.code().name(),
+                        ex.getMessage()
+                ));
+    }
+
+    @ExceptionHandler(Exception.class)
+    public ResponseEntity<ApiResponse<?>> handleException(
+            Exception ex
+    ) {
+        return ResponseEntity
+                .status(HttpStatus.INTERNAL_SERVER_ERROR)
+                .body(ApiResponse.error(
+                        ErrorCode.INTERNAL_ERROR.name(),
+                        "Internal server error"
+                ));
+    }
+
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    public ResponseEntity<ApiResponse<?>> handleValidation(
+            MethodArgumentNotValidException ex
+    ) {
+        String message = ex.getBindingResult().getFieldErrors().stream()
+                .map(e -> e.getField() + ": " + e.getDefaultMessage())
+                .sorted()
+                .collect(Collectors.joining("; "));
+        return ResponseEntity
+                .badRequest()
+                .body(ApiResponse.error(
+                        ErrorCode.VALIDATION_FAILED.name(),
+                        message
+                ));
+    }
+
+    @ExceptionHandler(DataIntegrityViolationException.class)
+    public ResponseEntity<ApiResponse<?>> handleConflict(
+            DataIntegrityViolationException ex
+    ) {
+        return ResponseEntity
+                .status(HttpStatus.CONFLICT)
+                .body(ApiResponse.error(
+                        HttpStatus.CONFLICT.name(),
+                        "Duplicate or invalid data: " + ex.getMostSpecificCause().getMessage()
+                ));
+    }
+}

src/main/java/aplp/backend/lms/common/config/JpaAuditingConfig.java

@@ -0,0 +1,30 @@
+package aplp.backend.lms.common.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.domain.AuditorAware;
+import org.springframework.data.jpa.repository.config.EnableJpaAuditing;
+import org.springframework.security.authentication.AnonymousAuthenticationToken;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.context.SecurityContextHolder;
+
+@Configuration
+@EnableJpaAuditing(auditorAwareRef = "auditorProvider")
+public class JpaAuditingConfig {
+
+    @Bean
+    public AuditorAware<Long> auditorProvider() {
+        return () -> {
+            Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
+            if (authentication == null
+                    || !authentication.isAuthenticated()
+                    || authentication instanceof AnonymousAuthenticationToken) {
+                return java.util.Optional.empty();
+            }
+            if (authentication.getPrincipal() instanceof Long userId) {
+                return java.util.Optional.of(userId);
+            }
+            return java.util.Optional.empty();
+        };
+    }
+}

src/main/java/aplp/backend/lms/common/config/OpenApiConfig.java

@@ -1,4 +1,4 @@
-package aplp.backend.lms.infrastructure.config;
+package aplp.backend.lms.common.config;
 
 import io.swagger.v3.oas.annotations.OpenAPIDefinition;
 import io.swagger.v3.oas.annotations.enums.SecuritySchemeType;

src/main/java/aplp/backend/lms/common/security/SecurityConfig.java

@@ -0,0 +1,47 @@
+package aplp.backend.lms.common.security;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configurers.AbstractHttpConfigurer;
+import org.springframework.security.web.SecurityFilterChain;
+import org.springframework.web.cors.CorsConfiguration;
+import org.springframework.web.cors.CorsConfigurationSource;
+import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
+
+import java.util.List;
+
+@Configuration
+public class SecurityConfig {
+
+    @Bean
+    public CorsConfigurationSource corsConfigurationSource() {
+        CorsConfiguration config = new CorsConfiguration();
+        config.setAllowedOrigins(List.of(
+                "http://localhost:5173",
+                "http://localhost:3000"
+        ));
+        config.setAllowedMethods(List.of("GET", "POST", "PUT", "DELETE", "OPTIONS"));
+        config.setAllowedHeaders(List.of("*"));
+        config.setAllowCredentials(true);
+
+        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
+        source.registerCorsConfiguration("/**", config);
+        return source;
+    }
+
+    @Bean
+    public SecurityFilterChain securityFilterChain(
+            HttpSecurity http
+    ) throws Exception {
+
+        http
+                .cors(cors -> cors.configurationSource(corsConfigurationSource()))
+                .csrf(AbstractHttpConfigurer::disable)
+                .authorizeHttpRequests(auth -> auth
+                        .anyRequest().permitAll()
+                );
+
+        return http.build();
+    }
+}

src/main/java/aplp/backend/lms/common/storage/FileController.java

@@ -0,0 +1,36 @@
+package aplp.backend.lms.common.storage;
+
+import aplp.backend.core.common.response.ApiResponse;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.multipart.MultipartFile;
+
+@RestController
+@RequestMapping("/api/files")
+public class FileController {
+
+    private final FileStorageService fileStorageService;
+
+    public FileController(FileStorageService fileStorageService) {
+        this.fileStorageService = fileStorageService;
+    }
+
+    @PostMapping
+    public ResponseEntity<ApiResponse<FileResDto>> upload(
+            @RequestParam("file") MultipartFile file,
+            @RequestParam(value = "folder", required = false, defaultValue = "general") String folder) {
+        return ResponseEntity.status(HttpStatus.CREATED)
+                .body(ApiResponse.ok(fileStorageService.upload(file, folder)));
+    }
+
+    @DeleteMapping
+    public ResponseEntity<ApiResponse<Void>> delete(@RequestParam("objectKey") String objectKey) {
+        fileStorageService.delete(objectKey);
+        return ResponseEntity.ok(ApiResponse.ok("Deleted successfully", null));
+    }
+}

src/main/java/aplp/backend/lms/common/storage/FileResDto.java

@@ -0,0 +1,8 @@
+package aplp.backend.lms.common.storage;
+
+public record FileResDto(
+        String url,
+        String objectKey,
+        long size,
+        String contentType
+) {}

src/main/java/aplp/backend/lms/common/storage/FileStorageService.java

@@ -0,0 +1,122 @@
+package aplp.backend.lms.common.storage;
+
+import aplp.backend.core.common.exception.DomainException;
+import aplp.backend.core.common.exception.ErrorCode;
+import io.minio.MinioClient;
+import io.minio.PutObjectArgs;
+import io.minio.RemoveObjectArgs;
+import org.springframework.stereotype.Service;
+import org.springframework.web.multipart.MultipartFile;
+
+import java.util.Locale;
+import java.util.UUID;
+
+@Service
+public class FileStorageService {
+
+    private final MinioClient minioClient;
+    private final StorageProperties properties;
+
+    public FileStorageService(MinioClient minioClient, StorageProperties properties) {
+        this.minioClient = minioClient;
+        this.properties = properties;
+    }
+
+    public FileResDto upload(MultipartFile file, String folder) {
+        if (file == null || file.isEmpty()) {
+            throw new DomainException(ErrorCode.INVALID_ARGUMENT, "File is required");
+        }
+
+        String contentType = file.getContentType();
+        if (contentType == null || !contentType.startsWith("image/")) {
+            throw new DomainException(ErrorCode.INVALID_ARGUMENT, "Only image files are allowed");
+        }
+
+        String objectKey = buildObjectKey(folder, contentType, file.getOriginalFilename());
+        try {
+            minioClient.putObject(PutObjectArgs.builder()
+                    .bucket(properties.bucket())
+                    .object(objectKey)
+                    .stream(file.getInputStream(), file.getSize(), -1)
+                    .contentType(contentType)
+                    .build());
+        } catch (Exception e) {
+            throw new DomainException(ErrorCode.INTERNAL_ERROR, "Failed to upload file: " + e.getMessage());
+        }
+
+        return new FileResDto(
+                publicUrl(objectKey),
+                objectKey,
+                file.getSize(),
+                contentType
+        );
+    }
+
+    public String publicUrl(String objectKey) {
+        if (objectKey == null || objectKey.isBlank()) {
+            return null;
+        }
+        if (isAbsoluteUrl(objectKey)) {
+            return objectKey;
+        }
+        return properties.publicUrl() + "/" + properties.bucket() + "/" + objectKey;
+    }
+
+    public void delete(String objectKey) {
+        String key = toObjectKey(objectKey);
+        if (key == null) {
+            throw new DomainException(ErrorCode.INVALID_ARGUMENT, "objectKey is required");
+        }
+        try {
+            minioClient.removeObject(RemoveObjectArgs.builder()
+                    .bucket(properties.bucket())
+                    .object(key)
+                    .build());
+        } catch (Exception e) {
+            throw new DomainException(ErrorCode.INTERNAL_ERROR, "Failed to delete file: " + e.getMessage());
+        }
+    }
+
+    private String toObjectKey(String value) {
+        if (value == null || value.isBlank()) {
+            return null;
+        }
+        String prefix = properties.publicUrl() + "/" + properties.bucket() + "/";
+        if (value.startsWith(prefix)) {
+            return value.substring(prefix.length());
+        }
+        return isAbsoluteUrl(value) ? null : value;
+    }
+
+    private static boolean isAbsoluteUrl(String value) {
+        return value.startsWith("http://") || value.startsWith("https://");
+    }
+
+    static String buildObjectKey(String folder, String contentType, String originalFilename) {
+        return sanitizeFolder(folder) + "/" + UUID.randomUUID() + "." + extensionFor(contentType, originalFilename);
+    }
+
+    static String sanitizeFolder(String folder) {
+        if (folder == null || folder.isBlank()) {
+            return "general";
+        }
+        String clean = folder.trim().toLowerCase(Locale.ROOT).replaceAll("[^a-z0-9_-]", "");
+        return clean.isEmpty() ? "general" : clean;
+    }
+
+    static String extensionFor(String contentType, String originalFilename) {
+        return switch (contentType) {
+            case "image/jpeg", "image/jpg" -> "jpg";
+            case "image/png" -> "png";
+            case "image/gif" -> "gif";
+            case "image/webp" -> "webp";
+            case "image/svg+xml" -> "svg";
+            default -> {
+                String name = originalFilename == null ? "" : originalFilename;
+                int dot = name.lastIndexOf('.');
+                String ext = dot < 0 ? "" : name.substring(dot + 1).toLowerCase(Locale.ROOT).replaceAll("[^a-z0-9]", "");
+                yield ext.isEmpty() ? "img" : ext;
+            }
+        };
+    }
+}

src/main/java/aplp/backend/lms/common/storage/MinioConfig.java

@@ -0,0 +1,61 @@
+package aplp.backend.lms.common.storage;
+
+import io.minio.BucketExistsArgs;
+import io.minio.MakeBucketArgs;
+import io.minio.MinioClient;
+import io.minio.SetBucketPolicyArgs;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@EnableConfigurationProperties(StorageProperties.class)
+public class MinioConfig {
+
+    private static final Logger log = LoggerFactory.getLogger(MinioConfig.class);
+
+    private static final String PUBLIC_READ_POLICY = """
+            {
+              "Version": "2012-10-17",
+              "Statement": [
+                {
+                  "Effect": "Allow",
+                  "Principal": {"AWS": ["*"]},
+                  "Action": ["s3:GetObject"],
+                  "Resource": ["arn:aws:s3:::%s/*"]
+                }
+              ]
+            }
+            """;
+
+    private final StorageProperties properties;
+
+    public MinioConfig(StorageProperties properties) {
+        this.properties = properties;
+    }
+
+    @Bean
+    public MinioClient minioClient() {
+        MinioClient client = MinioClient.builder()
+                .endpoint(properties.endpoint())
+                .credentials(properties.accessKey(), properties.secretKey())
+                .build();
+
+        try {
+            if (!client.bucketExists(BucketExistsArgs.builder().bucket(properties.bucket()).build())) {
+                client.makeBucket(MakeBucketArgs.builder().bucket(properties.bucket()).build());
+                log.info("Created MinIO bucket '{}'", properties.bucket());
+            }
+            client.setBucketPolicy(SetBucketPolicyArgs.builder()
+                    .bucket(properties.bucket())
+                    .config(PUBLIC_READ_POLICY.formatted(properties.bucket()))
+                    .build());
+        } catch (Exception e) {
+            log.warn("MinIO bucket init skipped ({}): {}", properties.endpoint(), e.getMessage());
+        }
+
+        return client;
+    }
+}

src/main/java/aplp/backend/lms/common/storage/StorageProperties.java

@@ -0,0 +1,12 @@
+package aplp.backend.lms.common.storage;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+@ConfigurationProperties(prefix = "minio")
+public record StorageProperties(
+        String endpoint,
+        String accessKey,
+        String secretKey,
+        String bucket,
+        String publicUrl
+) {}

src/main/java/aplp/backend/lms/course/api/controller/CourseController.java

@@ -0,0 +1,51 @@
+package aplp.backend.lms.course.api.controller;
+
+import aplp.backend.core.common.response.ApiResponse;
+import aplp.backend.lms.course.application.dtos.CourseReqDto;
+import aplp.backend.lms.course.application.dtos.CourseResDto;
+import aplp.backend.lms.course.application.services.CourseService;
+import jakarta.validation.Valid;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/courses")
+public class CourseController {
+
+    private final CourseService courseService;
+
+    public CourseController(CourseService courseService) {
+        this.courseService = courseService;
+    }
+
+    @GetMapping
+    public ResponseEntity<ApiResponse<List<CourseResDto>>> getAll() {
+        return ResponseEntity.ok(ApiResponse.ok(courseService.getAll()));
+    }
+
+    @GetMapping("/{id}")
+    public ResponseEntity<ApiResponse<CourseResDto>> getById(@PathVariable Long id) {
+        return ResponseEntity.ok(ApiResponse.ok(courseService.getById(id)));
+    }
+
+    @PostMapping
+    public ResponseEntity<ApiResponse<CourseResDto>> create(@Valid @RequestBody CourseReqDto request) {
+        return ResponseEntity.status(HttpStatus.CREATED).body(ApiResponse.ok(courseService.create(request)));
+    }
+
+    @PutMapping("/{id}")
+    public ResponseEntity<ApiResponse<CourseResDto>> update(
+            @PathVariable Long id,
+            @RequestBody CourseReqDto request) {
+        return ResponseEntity.ok(ApiResponse.ok(courseService.update(id, request)));
+    }
+
+    @DeleteMapping("/{id}")
+    public ResponseEntity<ApiResponse<Void>> delete(@PathVariable Long id) {
+        courseService.delete(id);
+        return ResponseEntity.ok(ApiResponse.ok("Deleted successfully", null));
+    }
+}

src/main/java/aplp/backend/lms/course/application/dtos/CourseReqDto.java

@@ -0,0 +1,25 @@
+package aplp.backend.lms.course.application.dtos;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Size;
+
+public record CourseReqDto(
+        @NotBlank(message = "Course code is required")
+        @Size(max = 50, message = "Course code must not exceed 50 characters")
+        String courseCode,
+
+        @NotBlank(message = "Title is required")
+        @Size(max = 200, message = "Title must not exceed 200 characters")
+        String title,
+
+        @Size(max = 255, message = "Slug must not exceed 255 characters")
+        String slug,
+
+        @Size(max = 1000, message = "Description must not exceed 1000 characters")
+        String description,
+
+        @Size(max = 500, message = "Image URL must not exceed 500 characters")
+        String image,
+
+        Boolean isPublished
+) {}

src/main/java/aplp/backend/lms/course/application/dtos/CourseResDto.java

@@ -0,0 +1,34 @@
+package aplp.backend.lms.course.application.dtos;
+
+import aplp.backend.lms.common.storage.FileStorageService;
+import aplp.backend.lms.course.domain.entities.Course;
+
+import java.time.LocalDateTime;
+
+public record CourseResDto(
+        Long id,
+        String courseCode,
+        String title,
+        String slug,
+        String description,
+        String image,
+        String imageUrl,
+        boolean isPublished,
+        LocalDateTime createdAt,
+        LocalDateTime updatedAt
+) {
+    public static CourseResDto from(Course course, FileStorageService fileStorageService) {
+        return new CourseResDto(
+                course.getId(),
+                course.getCourseCode(),
+                course.getTitle(),
+                course.getSlug(),
+                course.getDescription(),
+                course.getImage(),
+                fileStorageService.publicUrl(course.getImage()),
+                course.isPublished(),
+                course.getCreatedAt(),
+                course.getUpdatedAt()
+        );
+    }
+}

src/main/java/aplp/backend/lms/course/application/mappers/CourseMapper.java

@@ -0,0 +1,20 @@
+package aplp.backend.lms.course.application.mappers;
+
+import aplp.backend.lms.course.application.dtos.CourseReqDto;
+import aplp.backend.lms.course.domain.entities.Course;
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.MappingTarget;
+
+@Mapper(componentModel = "spring")
+public interface CourseMapper {
+
+    @Mapping(target = "published", source = "isPublished")
+    Course toEntity(CourseReqDto request);
+
+    @Mapping(target = "published", source = "isPublished")
+    void updateEntity(
+            CourseReqDto request,
+            @MappingTarget Course course
+    );
+}

src/main/java/aplp/backend/lms/course/application/services/CourseService.java

@@ -0,0 +1,82 @@
+package aplp.backend.lms.course.application.services;
+
+import aplp.backend.core.common.exception.ResourceNotFoundException;
+import aplp.backend.lms.common.storage.FileStorageService;
+import aplp.backend.lms.course.application.dtos.CourseReqDto;
+import aplp.backend.lms.course.application.dtos.CourseResDto;
+import aplp.backend.lms.course.application.mappers.CourseMapper;
+import aplp.backend.lms.course.domain.entities.Course;
+import aplp.backend.lms.course.domain.repositories.CourseRepository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+
+@Service
+public class CourseService {
+
+    private static final Logger log = LoggerFactory.getLogger(CourseService.class);
+
+    private final CourseRepository courseRepository;
+    private final CourseMapper courseMapper;
+    private final FileStorageService fileStorageService;
+
+    public CourseService(
+            CourseRepository courseRepository,
+            CourseMapper courseMapper,
+            FileStorageService fileStorageService) {
+        this.courseRepository = courseRepository;
+        this.courseMapper = courseMapper;
+        this.fileStorageService = fileStorageService;
+    }
+
+    public List<CourseResDto> getAll() {
+        return courseRepository.findAll()
+                .stream()
+                .map(course -> CourseResDto.from(course, fileStorageService))
+                .toList();
+    }
+
+    public CourseResDto getById(Long id) {
+        Course course = courseRepository.findById(id)
+                .orElseThrow(() -> new ResourceNotFoundException("Course not found"));
+
+        return CourseResDto.from(course, fileStorageService);
+    }
+
+    public CourseResDto create(CourseReqDto request) {
+        Course course = courseRepository.save(courseMapper.toEntity(request));
+        return CourseResDto.from(course, fileStorageService);
+    }
+
+    public CourseResDto update(Long id, CourseReqDto request) {
+        Course course = courseRepository.findById(id)
+                .orElseThrow(() -> new ResourceNotFoundException("Course not found"));
+
+        String previousImage = course.getImage();
+        courseMapper.updateEntity(request, course);
+        Course saved = courseRepository.save(course);
+
+        if (previousImage != null && !previousImage.isBlank() && !previousImage.equals(saved.getImage())) {
+            deleteFileQuietly(previousImage);
+        }
+
+        return CourseResDto.from(saved, fileStorageService);
+    }
+
+    public void delete(Long id) {
+        Course course = courseRepository.findById(id)
+                .orElseThrow(() -> new ResourceNotFoundException("Course not found"));
+        courseRepository.deleteById(id);
+        deleteFileQuietly(course.getImage());
+    }
+
+    private void deleteFileQuietly(String objectKey) {
+        try {
+            fileStorageService.delete(objectKey);
+        } catch (Exception e) {
+            log.warn("Failed to delete image '{}': {}", objectKey, e.getMessage());
+        }
+    }
+}

src/main/java/aplp/backend/lms/course/domain/entities/Course.java

@@ -0,0 +1,35 @@
+package aplp.backend.lms.course.domain.entities;
+
+import aplp.backend.core.common.entity.BaseEntity;
+import jakarta.persistence.*;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import org.springframework.data.jpa.domain.support.AuditingEntityListener;
+
+@Entity
+@Table(name = "courses")
+@EntityListeners(AuditingEntityListener.class)
+@Getter
+@Setter
+@NoArgsConstructor
+public class Course extends BaseEntity {
+
+    @Column(name = "course_code", nullable = false, length = 50, unique = true)
+    private String courseCode;
+
+    @Column(nullable = false, length = 200)
+    private String title;
+
+    @Column(nullable = false, unique = true, length = 255)
+    private String slug;
+
+    @Column(length = 1000)
+    private String description;
+
+    @Column(length = 500)
+    private String image;
+
+    @Column(name = "is_published", nullable = false)
+    private boolean isPublished;
+}

src/main/java/aplp/backend/lms/course/domain/repositories/CourseRepository.java

@@ -1,6 +1,6 @@
-package aplp.backend.lms.domain.repositories;
+package aplp.backend.lms.course.domain.repositories;
 
-import aplp.backend.lms.domain.entities.Course;
+import aplp.backend.lms.course.domain.entities.Course;
 import org.springframework.stereotype.Repository;
 
 import java.util.List;

src/main/java/aplp/backend/lms/course/infrastructure/persistence/CourseJpaRepository.java

@@ -1,6 +1,6 @@
-package aplp.backend.lms.infrastructure.persistence.repositories;
+package aplp.backend.lms.course.infrastructure.persistence;
 
-import aplp.backend.lms.domain.entities.Course;
+import aplp.backend.lms.course.domain.entities.Course;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.stereotype.Repository;
 

src/main/java/aplp/backend/lms/course/infrastructure/persistence/CourseRepositoryImpl.java

@@ -1,18 +1,20 @@
-package aplp.backend.lms.infrastructure.persistence.repositories;
+package aplp.backend.lms.course.infrastructure.persistence;
 
-import aplp.backend.lms.domain.entities.Course;
+import aplp.backend.lms.course.domain.entities.Course;
-import aplp.backend.lms.domain.repositories.CourseRepository;
+import aplp.backend.lms.course.domain.repositories.CourseRepository;
-import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Repository;
 
 import java.util.List;
 import java.util.Optional;
 
 @Repository
-@RequiredArgsConstructor
 public class CourseRepositoryImpl implements CourseRepository {
     private final CourseJpaRepository repository;
 
+    public CourseRepositoryImpl(CourseJpaRepository repository) {
+        this.repository = repository;
+    }
+
     @Override
     public Optional<Course> findById(Long id) {
         return repository.findById(id);

src/main/java/aplp/backend/lms/domain/entities/Course.java

@@ -1,24 +0,0 @@
-package aplp.backend.lms.domain.entities;
-
-import jakarta.persistence.*;
-import lombok.Getter;
-import lombok.NoArgsConstructor;
-import lombok.Setter;
-
-@Entity
-@Table(name = "courses")
-@Getter
-@Setter
-@NoArgsConstructor
-public class Course {
-
-    @Id
-    @GeneratedValue(strategy = GenerationType.IDENTITY)
-    private Long id;
-
-    @Column(nullable = false, length = 200)
-    private String title;
-
-    @Column(length = 1000)
-    private String description;
-}

src/main/java/aplp/backend/lms/infrastructure/config/SecurityConfig.java

@@ -1,25 +0,0 @@
-package aplp.backend.lms.infrastructure.config;
-
-import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.Configuration;
-import org.springframework.security.config.annotation.web.builders.HttpSecurity;
-import org.springframework.security.config.annotation.web.configurers.AbstractHttpConfigurer;
-import org.springframework.security.web.SecurityFilterChain;
-
-@Configuration
-public class SecurityConfig {
-
-    @Bean
-    public SecurityFilterChain securityFilterChain(
-            HttpSecurity http
-    ) throws Exception {
-
-        http
-                .csrf(AbstractHttpConfigurer::disable)
-                .authorizeHttpRequests(auth -> auth
-                        .anyRequest().permitAll()
-                );
-
-        return http.build();
-    }
-}

src/main/java/aplp/backend/lms/lesson/api/controller/LessonController.java

@@ -0,0 +1,51 @@
+package aplp.backend.lms.lesson.api.controller;
+
+import aplp.backend.core.common.response.ApiResponse;
+import aplp.backend.lms.lesson.application.dtos.LessonReqDto;
+import aplp.backend.lms.lesson.application.dtos.LessonResDto;
+import aplp.backend.lms.lesson.application.services.LessonService;
+import jakarta.validation.Valid;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/lessons")
+public class LessonController {
+
+    private final LessonService lessonService;
+
+    public LessonController(LessonService lessonService) {
+        this.lessonService = lessonService;
+    }
+
+    @GetMapping
+    public ResponseEntity<ApiResponse<List<LessonResDto>>> getAll() {
+        return ResponseEntity.ok(ApiResponse.ok(lessonService.getAll()));
+    }
+
+    @GetMapping("/{id}")
+    public ResponseEntity<ApiResponse<LessonResDto>> getById(@PathVariable Long id) {
+        return ResponseEntity.ok(ApiResponse.ok(lessonService.getById(id)));
+    }
+
+    @PostMapping
+    public ResponseEntity<ApiResponse<LessonResDto>> create(@Valid @RequestBody LessonReqDto request) {
+        return ResponseEntity.status(HttpStatus.CREATED).body(ApiResponse.ok(lessonService.create(request)));
+    }
+
+    @PutMapping("/{id}")
+    public ResponseEntity<ApiResponse<LessonResDto>> update(
+            @PathVariable Long id,
+            @Valid @RequestBody LessonReqDto request) {
+        return ResponseEntity.ok(ApiResponse.ok(lessonService.update(id, request)));
+    }
+
+    @DeleteMapping("/{id}")
+    public ResponseEntity<ApiResponse<Void>> delete(@PathVariable Long id) {
+        lessonService.delete(id);
+        return ResponseEntity.ok(ApiResponse.ok("Deleted successfully", null));
+    }
+}

src/main/java/aplp/backend/lms/lesson/application/dtos/LessonReqDto.java

@@ -0,0 +1,27 @@
+package aplp.backend.lms.lesson.application.dtos;
+
+import jakarta.validation.constraints.Min;
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Size;
+
+public record LessonReqDto(
+        @NotNull(message = "Course ID is required")
+        Long courseId,
+
+        @NotBlank(message = "Title is required")
+        @Size(max = 200, message = "Title must not exceed 200 characters")
+        String title,
+
+        @Size(max = 255, message = "Slug must not exceed 255 characters")
+        String slug,
+
+        @Size(max = 1000, message = "Description must not exceed 1000 characters")
+        String description,
+
+        @NotNull(message = "Position is required")
+        @Min(value = 1, message = "Position must be at least 1")
+        Integer position,
+
+        Boolean isPublished
+) {}

src/main/java/aplp/backend/lms/lesson/application/dtos/LessonResDto.java

@@ -0,0 +1,31 @@
+package aplp.backend.lms.lesson.application.dtos;
+
+import aplp.backend.lms.lesson.domain.entities.Lesson;
+
+import java.time.LocalDateTime;
+
+public record LessonResDto(
+        Long id,
+        Long courseId,
+        String title,
+        String slug,
+        String description,
+        int position,
+        boolean isPublished,
+        LocalDateTime createdAt,
+        LocalDateTime updatedAt
+) {
+    public static LessonResDto from(Lesson lesson) {
+        return new LessonResDto(
+                lesson.getId(),
+                lesson.getCourse().getId(),
+                lesson.getTitle(),
+                lesson.getSlug(),
+                lesson.getDescription(),
+                lesson.getPosition(),
+                lesson.isPublished(),
+                lesson.getCreatedAt(),
+                lesson.getUpdatedAt()
+        );
+    }
+}

src/main/java/aplp/backend/lms/lesson/application/mappers/LessonMapper.java

@@ -0,0 +1,34 @@
+package aplp.backend.lms.lesson.application.mappers;
+
+import aplp.backend.lms.course.domain.entities.Course;
+import aplp.backend.lms.lesson.application.dtos.LessonReqDto;
+import aplp.backend.lms.lesson.application.dtos.LessonResDto;
+import aplp.backend.lms.lesson.domain.entities.Lesson;
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.MappingTarget;
+
+@Mapper(componentModel = "spring")
+public interface LessonMapper {
+
+    @Mapping(source = "course.id", target = "courseId")
+    @Mapping(target = "isPublished", source = "published")
+    LessonResDto toResponse(Lesson lesson);
+
+    @Mapping(source = "courseId", target = "course")
+    @Mapping(target = "published", source = "isPublished")
+    Lesson toEntity(LessonReqDto request);
+
+    @Mapping(target = "published", source = "isPublished")
+    void updateEntity(
+            LessonReqDto request,
+            @MappingTarget Lesson lesson
+    );
+
+    default Course mapCourse(Long courseId) {
+        if (courseId == null) return null;
+        Course course = new Course();
+        course.setId(courseId);
+        return course;
+    }
+}

src/main/java/aplp/backend/lms/lesson/application/services/LessonService.java

@@ -0,0 +1,57 @@
+package aplp.backend.lms.lesson.application.services;
+
+import aplp.backend.core.common.exception.ResourceNotFoundException;
+import aplp.backend.lms.lesson.application.dtos.LessonReqDto;
+import aplp.backend.lms.lesson.application.dtos.LessonResDto;
+import aplp.backend.lms.lesson.application.mappers.LessonMapper;
+import aplp.backend.lms.lesson.domain.entities.Lesson;
+import aplp.backend.lms.lesson.domain.repositories.LessonRepository;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+
+@Service
+public class LessonService {
+
+    private final LessonRepository lessonRepository;
+    private final LessonMapper lessonMapper;
+
+    public LessonService(LessonRepository lessonRepository, LessonMapper lessonMapper) {
+        this.lessonRepository = lessonRepository;
+        this.lessonMapper = lessonMapper;
+    }
+
+    public List<LessonResDto> getAll() {
+        return lessonRepository.findAll()
+                .stream()
+                .map(LessonResDto::from)
+                .toList();
+    }
+
+    public LessonResDto getById(Long id) {
+        Lesson lesson = lessonRepository.findById(id)
+                .orElseThrow(() -> new ResourceNotFoundException("Lesson not found"));
+
+        return LessonResDto.from(lesson);
+    }
+
+    public LessonResDto create(LessonReqDto request) {
+        Lesson lesson = lessonMapper.toEntity(request);
+        return lessonMapper.toResponse(lessonRepository.save(lesson));
+    }
+
+    public LessonResDto update(Long id, LessonReqDto request) {
+        Lesson lesson = lessonRepository.findById(id)
+                .orElseThrow(() -> new ResourceNotFoundException("Lesson not found"));
+
+        lessonMapper.updateEntity(request, lesson);
+
+        return lessonMapper.toResponse(lessonRepository.save(lesson));
+    }
+
+    public void delete(Long id) {
+        lessonRepository.findById(id)
+                .orElseThrow(() -> new ResourceNotFoundException("Lesson not found"));
+        lessonRepository.deleteById(id);
+    }
+}

src/main/java/aplp/backend/lms/lesson/domain/entities/Lesson.java

@@ -0,0 +1,35 @@
+package aplp.backend.lms.lesson.domain.entities;
+
+import aplp.backend.core.common.entity.BaseEntity;
+import aplp.backend.lms.course.domain.entities.Course;
+import jakarta.persistence.*;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Entity
+@Table(name = "lessons")
+@Getter
+@Setter
+@NoArgsConstructor
+public class Lesson extends BaseEntity {
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "course_id", nullable = false)
+    private Course course;
+
+    @Column(nullable = false, length = 200)
+    private String title;
+
+    @Column(nullable = false, unique = true, length = 255)
+    private String slug;
+
+    @Column(length = 1000)
+    private String description;
+
+    @Column(nullable = false)
+    private int position;
+
+    @Column(name = "is_published", nullable = false)
+    private boolean isPublished;
+}

src/main/java/aplp/backend/lms/lesson/domain/repositories/LessonRepository.java

@@ -0,0 +1,21 @@
+package aplp.backend.lms.lesson.domain.repositories;
+
+import aplp.backend.lms.lesson.domain.entities.Lesson;
+import org.springframework.stereotype.Repository;
+
+import java.util.List;
+import java.util.Optional;
+
+@Repository
+public interface LessonRepository {
+
+    Optional<Lesson> findById(Long id);
+
+    List<Lesson> findAll();
+
+    List<Lesson> findByCourseId(Long courseId);
+
+    Lesson save(Lesson lesson);
+
+    void deleteById(Long id);
+}

src/main/java/aplp/backend/lms/lesson/infrastructure/persistence/LessonJpaRepository.java

@@ -0,0 +1,12 @@
+package aplp.backend.lms.lesson.infrastructure.persistence;
+
+import aplp.backend.lms.lesson.domain.entities.Lesson;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+import java.util.List;
+
+@Repository
+public interface LessonJpaRepository extends JpaRepository<Lesson, Long> {
+    List<Lesson> findByCourseIdOrderByPositionAsc(Long courseId);
+}

src/main/java/aplp/backend/lms/lesson/infrastructure/persistence/LessonRepositoryImpl.java

@@ -0,0 +1,42 @@
+package aplp.backend.lms.lesson.infrastructure.persistence;
+
+import aplp.backend.lms.lesson.domain.entities.Lesson;
+import aplp.backend.lms.lesson.domain.repositories.LessonRepository;
+import org.springframework.stereotype.Repository;
+
+import java.util.List;
+import java.util.Optional;
+
+@Repository
+public class LessonRepositoryImpl implements LessonRepository {
+    private final LessonJpaRepository repository;
+
+    public LessonRepositoryImpl(LessonJpaRepository repository) {
+        this.repository = repository;
+    }
+
+    @Override
+    public Optional<Lesson> findById(Long id) {
+        return repository.findById(id);
+    }
+
+    @Override
+    public List<Lesson> findAll() {
+        return repository.findAll();
+    }
+
+    @Override
+    public List<Lesson> findByCourseId(Long courseId) {
+        return repository.findByCourseIdOrderByPositionAsc(courseId);
+    }
+
+    @Override
+    public Lesson save(Lesson lesson) {
+        return repository.save(lesson);
+    }
+
+    @Override
+    public void deleteById(Long id) {
+        repository.deleteById(id);
+    }
+}

src/main/java/aplp/backend/lms/section/api/controller/SectionController.java

@@ -0,0 +1,56 @@
+package aplp.backend.lms.section.api.controller;
+
+import aplp.backend.core.common.response.ApiResponse;
+import aplp.backend.lms.section.application.dtos.SectionReqDto;
+import aplp.backend.lms.section.application.dtos.SectionResDto;
+import aplp.backend.lms.section.application.services.SectionService;
+import jakarta.validation.Valid;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/sections")
+public class SectionController {
+
+    private final SectionService sectionService;
+
+    public SectionController(SectionService sectionService) {
+        this.sectionService = sectionService;
+    }
+
+    @GetMapping
+    public ResponseEntity<ApiResponse<List<SectionResDto>>> getAll() {
+        return ResponseEntity.ok(ApiResponse.ok(sectionService.getAll()));
+    }
+
+    @GetMapping("/{id}")
+    public ResponseEntity<ApiResponse<SectionResDto>> getById(@PathVariable Long id) {
+        return ResponseEntity.ok(ApiResponse.ok(sectionService.getById(id)));
+    }
+
+    @GetMapping("/by-lesson/{lessonId}")
+    public ResponseEntity<ApiResponse<List<SectionResDto>>> getByLessonId(@PathVariable Long lessonId) {
+        return ResponseEntity.ok(ApiResponse.ok(sectionService.getByLessonId(lessonId)));
+    }
+
+    @PostMapping
+    public ResponseEntity<ApiResponse<SectionResDto>> create(@Valid @RequestBody SectionReqDto request) {
+        return ResponseEntity.status(HttpStatus.CREATED).body(ApiResponse.ok(sectionService.create(request)));
+    }
+
+    @PutMapping("/{id}")
+    public ResponseEntity<ApiResponse<SectionResDto>> update(
+            @PathVariable Long id,
+            @Valid @RequestBody SectionReqDto request) {
+        return ResponseEntity.ok(ApiResponse.ok(sectionService.update(id, request)));
+    }
+
+    @DeleteMapping("/{id}")
+    public ResponseEntity<ApiResponse<Void>> delete(@PathVariable Long id) {
+        sectionService.delete(id);
+        return ResponseEntity.ok(ApiResponse.ok("Deleted successfully", null));
+    }
+}

src/main/java/aplp/backend/lms/section/application/dtos/SectionReqDto.java

@@ -0,0 +1,29 @@
+package aplp.backend.lms.section.application.dtos;
+
+import aplp.backend.lms.section.domain.enums.SectionType;
+import jakarta.validation.constraints.Min;
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Size;
+
+public record SectionReqDto(
+        @NotNull(message = "Lesson ID is required")
+        Long lessonId,
+
+        @NotBlank(message = "Title is required")
+        @Size(max = 255, message = "Title must not exceed 255 characters")
+        String title,
+
+        @NotNull(message = "Type is required")
+        SectionType type,
+
+        @NotNull(message = "Position is required")
+        @Min(value = 1, message = "Position must be at least 1")
+        Integer position,
+
+        String content,
+
+        Integer durationSeconds,
+
+        Boolean isFreePreview
+) {}

src/main/java/aplp/backend/lms/section/application/dtos/SectionResDto.java

@@ -0,0 +1,34 @@
+package aplp.backend.lms.section.application.dtos;
+
+import aplp.backend.lms.section.domain.entities.Section;
+import aplp.backend.lms.section.domain.enums.SectionType;
+
+import java.time.LocalDateTime;
+
+public record SectionResDto(
+        Long id,
+        Long lessonId,
+        String title,
+        SectionType type,
+        int position,
+        String content,
+        int durationSeconds,
+        boolean isFreePreview,
+        LocalDateTime createdAt,
+        LocalDateTime updatedAt
+) {
+    public static SectionResDto from(Section section) {
+        return new SectionResDto(
+                section.getId(),
+                section.getLesson().getId(),
+                section.getTitle(),
+                section.getType(),
+                section.getPosition(),
+                section.getContent(),
+                section.getDurationSeconds(),
+                section.isFreePreview(),
+                section.getCreatedAt(),
+                section.getUpdatedAt()
+        );
+    }
+}

src/main/java/aplp/backend/lms/section/application/mappers/SectionMapper.java

@@ -0,0 +1,31 @@
+package aplp.backend.lms.section.application.mappers;
+
+import aplp.backend.lms.lesson.domain.entities.Lesson;
+import aplp.backend.lms.section.application.dtos.SectionReqDto;
+import aplp.backend.lms.section.application.dtos.SectionResDto;
+import aplp.backend.lms.section.domain.entities.Section;
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.MappingTarget;
+
+@Mapper(componentModel = "spring")
+public interface SectionMapper {
+
+    @Mapping(source = "lesson.id", target = "lessonId")
+    SectionResDto toResponse(Section section);
+
+    @Mapping(source = "lessonId", target = "lesson")
+    Section toEntity(SectionReqDto request);
+
+    void updateEntity(
+            SectionReqDto request,
+            @MappingTarget Section section
+    );
+
+    default Lesson mapLesson(Long lessonId) {
+        if (lessonId == null) return null;
+        Lesson lesson = new Lesson();
+        lesson.setId(lessonId);
+        return lesson;
+    }
+}

src/main/java/aplp/backend/lms/section/application/services/SectionService.java

@@ -0,0 +1,61 @@
+package aplp.backend.lms.section.application.services;
+
+import aplp.backend.core.common.exception.ResourceNotFoundException;
+import aplp.backend.lms.section.application.dtos.SectionReqDto;
+import aplp.backend.lms.section.application.dtos.SectionResDto;
+import aplp.backend.lms.section.application.mappers.SectionMapper;
+import aplp.backend.lms.section.domain.entities.Section;
+import aplp.backend.lms.section.domain.repositories.SectionRepository;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+
+@Service
+public class SectionService {
+
+    private final SectionRepository sectionRepository;
+    private final SectionMapper sectionMapper;
+
+    public SectionService(SectionRepository sectionRepository, SectionMapper sectionMapper) {
+        this.sectionRepository = sectionRepository;
+        this.sectionMapper = sectionMapper;
+    }
+
+    public List<SectionResDto> getAll() {
+        return sectionRepository.findAll()
+                .stream()
+                .map(SectionResDto::from)
+                .toList();
+    }
+
+    public SectionResDto getById(Long id) {
+        Section section = sectionRepository.findById(id)
+                .orElseThrow(() -> new ResourceNotFoundException("Section not found"));
+        return SectionResDto.from(section);
+    }
+
+    public List<SectionResDto> getByLessonId(Long lessonId) {
+        return sectionRepository.findByLessonId(lessonId)
+                .stream()
+                .map(SectionResDto::from)
+                .toList();
+    }
+
+    public SectionResDto create(SectionReqDto request) {
+        Section section = sectionMapper.toEntity(request);
+        return sectionMapper.toResponse(sectionRepository.save(section));
+    }
+
+    public SectionResDto update(Long id, SectionReqDto request) {
+        Section section = sectionRepository.findById(id)
+                .orElseThrow(() -> new ResourceNotFoundException("Section not found"));
+        sectionMapper.updateEntity(request, section);
+        return sectionMapper.toResponse(sectionRepository.save(section));
+    }
+
+    public void delete(Long id) {
+        sectionRepository.findById(id)
+                .orElseThrow(() -> new ResourceNotFoundException("Section not found"));
+        sectionRepository.deleteById(id);
+    }
+}

src/main/java/aplp/backend/lms/section/domain/entities/Section.java

@@ -0,0 +1,43 @@
+package aplp.backend.lms.section.domain.entities;
+
+import aplp.backend.core.common.entity.BaseEntity;
+import aplp.backend.lms.lesson.domain.entities.Lesson;
+import aplp.backend.lms.section.domain.enums.SectionType;
+import jakarta.persistence.*;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import org.hibernate.annotations.JdbcTypeCode;
+import org.hibernate.type.SqlTypes;
+
+@Entity
+@Table(name = "sections")
+@Getter
+@Setter
+@NoArgsConstructor
+public class Section extends BaseEntity {
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "lesson_id", nullable = false)
+    private Lesson lesson;
+
+    @Column(nullable = false, length = 255)
+    private String title;
+
+    @Enumerated(EnumType.STRING)
+    @Column(nullable = false)
+    private SectionType type;
+
+    @Column(nullable = false)
+    private int position;
+
+    @JdbcTypeCode(SqlTypes.JSON)
+    @Column(columnDefinition = "jsonb")
+    private String content;
+
+    @Column(name = "duration_seconds")
+    private int durationSeconds;
+
+    @Column(name = "is_free_preview", nullable = false)
+    private boolean isFreePreview;
+}

src/main/java/aplp/backend/lms/section/domain/enums/SectionType.java

@@ -0,0 +1,21 @@
+package aplp.backend.lms.section.domain.enums;
+
+import com.fasterxml.jackson.annotation.JsonValue;
+
+public enum SectionType {
+    TEXT("text"),
+    VIDEO("video"),
+    QUIZ("quiz"),
+    EMBED("embed");
+
+    private final String value;
+
+    SectionType(String value) {
+        this.value = value;
+    }
+
+    @JsonValue
+    public String getValue() {
+        return value;
+    }
+}

src/main/java/aplp/backend/lms/section/domain/repositories/SectionRepository.java

@@ -0,0 +1,21 @@
+package aplp.backend.lms.section.domain.repositories;
+
+import aplp.backend.lms.section.domain.entities.Section;
+import org.springframework.stereotype.Repository;
+
+import java.util.List;
+import java.util.Optional;
+
+@Repository
+public interface SectionRepository {
+
+    Optional<Section> findById(Long id);
+
+    List<Section> findAll();
+
+    List<Section> findByLessonId(Long lessonId);
+
+    Section save(Section section);
+
+    void deleteById(Long id);
+}

src/main/java/aplp/backend/lms/section/infrastructure/persistence/SectionJpaRepository.java

@@ -0,0 +1,12 @@
+package aplp.backend.lms.section.infrastructure.persistence;
+
+import aplp.backend.lms.section.domain.entities.Section;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+import java.util.List;
+
+@Repository
+public interface SectionJpaRepository extends JpaRepository<Section, Long> {
+    List<Section> findByLessonIdOrderByPositionAsc(Long lessonId);
+}

src/main/java/aplp/backend/lms/section/infrastructure/persistence/SectionRepositoryImpl.java

@@ -0,0 +1,42 @@
+package aplp.backend.lms.section.infrastructure.persistence;
+
+import aplp.backend.lms.section.domain.entities.Section;
+import aplp.backend.lms.section.domain.repositories.SectionRepository;
+import org.springframework.stereotype.Repository;
+
+import java.util.List;
+import java.util.Optional;
+
+@Repository
+public class SectionRepositoryImpl implements SectionRepository {
+    private final SectionJpaRepository repository;
+
+    public SectionRepositoryImpl(SectionJpaRepository repository) {
+        this.repository = repository;
+    }
+
+    @Override
+    public Optional<Section> findById(Long id) {
+        return repository.findById(id);
+    }
+
+    @Override
+    public List<Section> findAll() {
+        return repository.findAll();
+    }
+
+    @Override
+    public List<Section> findByLessonId(Long lessonId) {
+        return repository.findByLessonIdOrderByPositionAsc(lessonId);
+    }
+
+    @Override
+    public Section save(Section section) {
+        return repository.save(section);
+    }
+
+    @Override
+    public void deleteById(Long id) {
+        repository.deleteById(id);
+    }
+}

src/main/resources/application-prod.yaml

@@ -0,0 +1,11 @@
+spring:
+  config:
+    activate:
+      on-profile: prod
+
+minio:
+  endpoint: ${MINIO_ENDPOINT}
+  access-key: ${MINIO_ACCESS_KEY}
+  secret-key: ${MINIO_SECRET_KEY}
+  bucket: ${MINIO_BUCKET}
+  public-url: ${MINIO_PUBLIC_URL}

src/main/resources/application.yaml

@@ -3,9 +3,9 @@ spring:
     name: lms
 
   datasource:
-    url: jdbc:postgresql://localhost:5432/aplp
+    url: jdbc:postgresql://pgsql.koda.id.vn:5432/aplp
     username: postgres
-    password: Pa55w0rd
+    password: xxxx
 
   jpa:
     hibernate:
@@ -16,11 +16,23 @@ spring:
         format_sql: true
     show-sql: true
 
-#  flyway:
+  flyway:
-#    enabled: true
+    enabled: false
-#    default-schema: lms
+    default-schema: lms
-#    schemas: lms
+    schemas: lms
-#    locations: classpath:db/migration
+    locations: classpath:db/migration
+
+  servlet:
+    multipart:
+      max-file-size: 5MB
+      max-request-size: 5MB
+
+minio:
+  endpoint: https://minio.koda.id.vn
+  access-key: CHANGE_ME
+  secret-key: CHANGE_ME
+  bucket: aplp
+  public-url: https://minio.koda.id.vn
 
 springdoc:
   swagger-ui:

src/main/resources/db/migration/V1__course_module.sql

@@ -0,0 +1,8 @@
+-- Flyway Migration V1: Initial schema
+-- Creates courses table
+
+CREATE TABLE IF NOT EXISTS courses (
+    id BIGSERIAL PRIMARY KEY,
+    title VARCHAR(200) NOT NULL,
+    description VARCHAR(1000)
+);

src/main/resources/db/migration/V2__lesson_module.sql

@@ -0,0 +1,14 @@
+-- Flyway Migration V3: Create lessons table
+
+CREATE TABLE IF NOT EXISTS lessons (
+    id BIGSERIAL PRIMARY KEY,
+    lesson_code VARCHAR(50) NOT NULL UNIQUE,
+    lesson_name VARCHAR(200) NOT NULL,
+    description VARCHAR(1000),
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    created_by VARCHAR(255),
+    updated_by VARCHAR(255),
+    deleted_at TIMESTAMPTZ,
+    deleted_by VARCHAR(255)
+);

src/main/resources/db/migration/V3__update_course_add_fields.sql

@@ -0,0 +1,16 @@
+-- Flyway Migration V3: Update courses table
+-- Add course_code, slug, image, is_published
+
+ALTER TABLE courses ADD COLUMN course_code VARCHAR(50);
+ALTER TABLE courses ADD COLUMN slug VARCHAR(255);
+ALTER TABLE courses ADD COLUMN image VARCHAR(500);
+ALTER TABLE courses ADD COLUMN is_published BOOLEAN NOT NULL DEFAULT false;
+
+ALTER TABLE courses ADD CONSTRAINT uq_course_code UNIQUE (course_code);
+ALTER TABLE courses ADD CONSTRAINT uq_course_slug UNIQUE (slug);
+
+UPDATE courses SET slug = LOWER(REPLACE(REPLACE(TRIM(title), ' ', '-'), '.', ''));
+UPDATE courses SET course_code = 'CRS-' || id;
+
+ALTER TABLE courses ALTER COLUMN course_code SET NOT NULL;
+ALTER TABLE courses ALTER COLUMN slug SET NOT NULL;

src/main/resources/db/migration/V4__update_lesson_add_course_fk_and_fields.sql

@@ -0,0 +1,26 @@
+-- Flyway Migration V4: Update lessons table
+-- Add course_id FK, slug, position, is_published; remove lesson_code
+
+ALTER TABLE lessons ADD COLUMN course_id BIGINT;
+ALTER TABLE lessons ADD COLUMN slug VARCHAR(255);
+ALTER TABLE lessons ADD COLUMN position INT;
+ALTER TABLE lessons ADD COLUMN is_published BOOLEAN NOT NULL DEFAULT false;
+
+ALTER TABLE lessons RENAME COLUMN lesson_name TO title;
+
+UPDATE lessons SET slug = LOWER(REPLACE(REPLACE(TRIM(title), ' ', '-'), '.', ''));
+
+ALTER TABLE lessons ALTER COLUMN course_id SET NOT NULL;
+ALTER TABLE lessons ALTER COLUMN slug SET NOT NULL;
+ALTER TABLE lessons ALTER COLUMN position SET NOT NULL;
+
+ALTER TABLE lessons ADD CONSTRAINT fk_lesson_course
+    FOREIGN KEY (course_id) REFERENCES courses(id) ON DELETE CASCADE;
+
+ALTER TABLE lessons ADD CONSTRAINT uq_course_lesson_position UNIQUE (course_id, position);
+ALTER TABLE lessons ADD CONSTRAINT uq_course_lesson_slug UNIQUE (course_id, slug);
+
+ALTER TABLE lessons DROP CONSTRAINT IF EXISTS lessons_lesson_code_key;
+ALTER TABLE lessons DROP COLUMN lesson_code;
+
+CREATE INDEX idx_lessons_course_id ON lessons(course_id);

src/main/resources/db/migration/V5__create_section_module.sql

@@ -0,0 +1,23 @@
+-- Flyway Migration V5: Create sections table
+
+CREATE TYPE section_type AS ENUM ('text', 'video', 'quiz', 'embed');
+
+CREATE TABLE sections (
+    id BIGSERIAL PRIMARY KEY,
+    lesson_id BIGINT NOT NULL REFERENCES lessons(id) ON DELETE CASCADE,
+    title VARCHAR(255) NOT NULL,
+    type section_type NOT NULL DEFAULT 'text',
+    position INT NOT NULL,
+    content JSONB,
+    duration_seconds INT DEFAULT 0,
+    is_free_preview BOOLEAN NOT NULL DEFAULT false,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    created_by VARCHAR(255),
+    updated_by VARCHAR(255),
+    deleted_at TIMESTAMPTZ,
+    deleted_by VARCHAR(255),
+    CONSTRAINT uq_lesson_section_position UNIQUE (lesson_id, position)
+);
+
+CREATE INDEX idx_sections_lesson_id ON sections(lesson_id);

src/test/java/aplp/backend/lms/common/storage/FileStorageServiceTest.java

@@ -0,0 +1,28 @@
+package aplp.backend.lms.common.storage;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class FileStorageServiceTest {
+
+    @Test
+    void sanitizesFolderAndUsesContentTypeExtension() {
+        String key = FileStorageService.buildObjectKey("Course Images!", "image/png", "whatever");
+        assertTrue(key.startsWith("courseimages/"), key);
+        assertTrue(key.endsWith(".png"), key);
+    }
+
+    @Test
+    void blankOrInvalidFolderFallsBackToGeneral() {
+        assertEquals("general", FileStorageService.sanitizeFolder("   "));
+        assertEquals("general", FileStorageService.sanitizeFolder("!!!"));
+    }
+
+    @Test
+    void unknownContentTypeFallsBackToFilenameExtension() {
+        assertEquals("jpg", FileStorageService.extensionFor("application/octet-stream", "photo.JPG"));
+        assertEquals("img", FileStorageService.extensionFor("application/octet-stream", null));
+    }
+}