feat/Estadísticas básicas de aplicación (usuarios, archivos)

gradox2/src/main/java/com/example/gradox2/init/BackfillRunner.java

@@ -0,0 +1,51 @@
+package com.example.gradox2.init;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.core.Ordered;
+import org.springframework.core.annotation.Order;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Transactional;
+
+import com.example.gradox2.persistence.entities.File;
+import com.example.gradox2.persistence.repository.FileRepository;
+import com.example.gradox2.service.implementation.S3StorageService;
+
+import lombok.RequiredArgsConstructor;
+
+/**
+ * One-off: rellena el tamaño (sizeBytes) de archivos publicados antes de que
+ * la columna existiera, consultando S3 (headObject). Es idempotente: solo
+ * procesa registros con tamaño nulo y tolera objetos inaccesibles.
+ */
+@Component
+@Order(Ordered.LOWEST_PRECEDENCE)
+@RequiredArgsConstructor
+public class BackfillRunner implements CommandLineRunner {
+
+    private static final Logger log = LoggerFactory.getLogger(BackfillRunner.class);
+
+    private final FileRepository fileRepository;
+    private final S3StorageService s3StorageService;
+
+    @Override
+    @Transactional
+    public void run(String... args) {
+        var files = fileRepository.findBySizeBytesIsNull();
+        if (files.isEmpty()) {
+            return;
+        }
+
+        int updated = 0;
+        for (File file : files) {
+            Long size = s3StorageService.sizeOf(file.getObjectKey());
+            if (size != null) {
+                file.setSizeBytes(size);
+                updated++;
+            }
+        }
+        fileRepository.saveAll(files);
+        log.info("Backfill de tamaños de archivos completado: {} actualizados de {} pendientes.", updated, files.size());
+    }
+}

gradox2/src/main/java/com/example/gradox2/persistence/entities/File.java

@@ -33,6 +33,13 @@ public class File {
     private String objectKey;
     private String fileHash;
 
+    @Column(name = "size_bytes")
+    private Long sizeBytes;
+
+    @Builder.Default
+    @Column(name = "download_count", nullable = false)
+    private Long downloadCount = 0L;
+
     @Builder.Default
     private Instant uploadAt = Instant.now();
 
@@ -70,6 +77,13 @@ public void removeScore(Score score) {
         this.score = calculateTotalScore();
     }
 
+    public void incrementDownloadCount() {
+        if (this.downloadCount == null) {
+            this.downloadCount = 0L;
+        }
+        this.downloadCount++;
+    }
+
     // El score total ahora se puede calcular dinámicamente
     public Double calculateTotalScore() {
         return scores.stream()

gradox2/src/main/java/com/example/gradox2/persistence/entities/TempFile.java

@@ -30,6 +30,9 @@ public class TempFile {
     private String objectKey;
     private String fileHash;
 
+    @Column(name = "size_bytes")
+    private Long sizeBytes;
+
     @Builder.Default
     private Instant uploadAt = Instant.now();
 

gradox2/src/main/java/com/example/gradox2/persistence/repository/FileRepository.java

@@ -3,6 +3,7 @@
 import java.util.List;
 
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
 
 import com.example.gradox2.persistence.entities.File;
 import com.example.gradox2.persistence.entities.enums.FileType;
@@ -14,4 +15,35 @@ public interface FileRepository extends JpaRepository<File, Long> {
     List<File> findBySubjectId(Long subjectId);
     List<File> findByUploaderId(Long uploaderId);
     List<File> findByUploaderIdAndSubjectId(Long uploaderId, Long subjectId);
+    List<File> findBySizeBytesIsNull();
+
+    //Stats
+    @Query("SELECT COALESCE(SUM(f.sizeBytes), 0) FROM File f")
+    Long sumSizeBytes();
+
+    @Query("SELECT COALESCE(SUM(f.downloadCount), 0) FROM File f")
+    Long sumDownloadCount();
+
+    @Query("SELECT f.type AS type, COUNT(f) AS count FROM File f GROUP BY f.type ORDER BY COUNT(f) DESC")
+    List<FileTypeCount> countByType();
+
+    @Query("SELECT s.code AS code, s.name AS name, c.name AS courseName, COUNT(f) AS count "
+            + "FROM Subject s "
+            + "LEFT JOIN s.resources f "
+            + "LEFT JOIN s.course c "
+            + "GROUP BY s.id, s.code, s.name, c.name "
+            + "ORDER BY COUNT(f) DESC")
+    List<SubjectFileCount> countBySubject();
+
+    interface FileTypeCount {
+        FileType getType();
+        long getCount();
+    }
+
+    interface SubjectFileCount {
+        String getCode();
+        String getName();
+        String getCourseName();
+        long getCount();
+    }
 }

gradox2/src/main/java/com/example/gradox2/presentation/controller/StatsController.java

@@ -0,0 +1,32 @@
+package com.example.gradox2.presentation.controller;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.example.gradox2.presentation.dto.stats.PlatformStatsResponse;
+import com.example.gradox2.service.interfaces.IStatsService;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+@RestController
+@RequestMapping("/stats")
+@Tag(name = "Estadísticas", description = "Métricas colectivas de la plataforma para la comunidad")
+public class StatsController {
+
+    private final IStatsService statsService;
+
+    public StatsController(IStatsService statsService) {
+        this.statsService = statsService;
+    }
+
+    @GetMapping
+    @Operation(summary = "Estadísticas de la plataforma", description = "Métricas globales: total de archivos, usuarios, almacenamiento y descargas, con desglose por tipo y asignatura")
+    @ApiResponse(responseCode = "200", description = "Estadísticas devueltas")
+    public ResponseEntity<PlatformStatsResponse> getPlatformStats() {
+        return ResponseEntity.ok(statsService.getPlatformStats());
+    }
+}

gradox2/src/main/java/com/example/gradox2/presentation/dto/stats/PlatformStatsResponse.java

@@ -0,0 +1,69 @@
+package com.example.gradox2.presentation.dto.stats;
+
+import java.util.List;
+
+import com.example.gradox2.persistence.entities.enums.FileType;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+@Schema(description = "Métricas colectivas de la plataforma para la comunidad")
+public class PlatformStatsResponse {
+
+    @Schema(description = "Número total de archivos publicados", example = "124")
+    private long totalFiles;
+
+    @Schema(description = "Número total de usuarios registrados", example = "532")
+    private long totalUsers;
+
+    @Schema(description = "Tamaño total almacenado en bytes", example = "1536000000")
+    private long totalStorageBytes;
+
+    @Schema(description = "Número total de descargas realizadas", example = "8421")
+    private long totalDownloads;
+
+    @Schema(description = "Desglose de archivos por tipo")
+    private List<TypeStat> byType;
+
+    @Schema(description = "Desglose de archivos por asignatura")
+    private List<SubjectStat> bySubject;
+
+    @Data
+    @Builder
+    @NoArgsConstructor
+    @AllArgsConstructor
+    @Schema(description = "Archivos por tipo")
+    public static class TypeStat {
+        @Schema(description = "Tipo de archivo", example = "APUNTES")
+        private FileType type;
+
+        @Schema(description = "Número de archivos de este tipo", example = "80")
+        private long count;
+    }
+
+    @Data
+    @Builder
+    @NoArgsConstructor
+    @AllArgsConstructor
+    @Schema(description = "Archivos por asignatura")
+    public static class SubjectStat {
+        @Schema(description = "Código de la asignatura", example = "MAT1")
+        private String code;
+
+        @Schema(description = "Nombre de la asignatura", example = "Matemáticas I")
+        private String name;
+
+        @Schema(description = "Nombre del curso al que pertenece", example = "Primer curso")
+        private String courseName;
+
+        @Schema(description = "Número de archivos de esta asignatura", example = "12")
+        private long count;
+    }
+}

gradox2/src/main/java/com/example/gradox2/security/SecurityConfig.java

@@ -60,6 +60,7 @@ public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
                                 .requestMatchers(HttpMethod.GET, "/files/**").permitAll()
                                 .requestMatchers(HttpMethod.GET, "/subjects/**").permitAll()
                                 .requestMatchers(HttpMethod.GET, "/badges/**").permitAll()
+                                .requestMatchers(HttpMethod.GET, "/stats/**").permitAll()
                                 .requestMatchers("/api/auth/**").permitAll()
                                 .requestMatchers("/health**", "/actuator/health/**", "/actuator/info").permitAll()
                                 .requestMatchers("/swagger-ui.html", "/swagger-ui/**", "/v3/api-docs/**").permitAll()

gradox2/src/main/java/com/example/gradox2/service/implementation/FileProposalServiceImpl.java

@@ -90,6 +90,7 @@ public FileProposalResponse uploadFileProposal(UploadFileProposalRequest dto) {
                     .type(dto.getType())
                     .objectKey(objectKey)
                     .fileHash(generateFileHash(fileData)) // Hash seguro
+                    .sizeBytes((long) fileData.length)
                     .subject(subject)
                     .uploader(uploader)
                     .visibilityLevel(dto.getVisibilityLevel() != null ? dto.getVisibilityLevel() : FileVisibility.PUBLIC)

gradox2/src/main/java/com/example/gradox2/service/implementation/FileServiceImpl.java

@@ -59,6 +59,7 @@ public FileServiceImpl(FileRepository fileRepository,
         this.fileUrlSigner = fileUrlSigner;
     }
 
+    @Transactional
     public FileDownloadResponse downloadFile(Long id) {
         File file = fileRepository.findById(id)
                 .orElseThrow(() -> new NotFoundException("File not found"));
@@ -69,6 +70,9 @@ public FileDownloadResponse downloadFile(Long id) {
             throw new NotFoundException("File not found");
         }
 
+        file.incrementDownloadCount();
+        fileRepository.save(file);
+
         String url = fileUrlSigner.presignedGetUrl(file.getObjectKey(),
                 ContentDisposition.attachmentOf(file.getTitle()));
         return FileDownloadResponse.builder().url(url).build();

gradox2/src/main/java/com/example/gradox2/service/implementation/S3StorageService.java

@@ -11,6 +11,7 @@
 import software.amazon.awssdk.services.s3.model.CreateBucketRequest;
 import software.amazon.awssdk.services.s3.model.DeleteObjectRequest;
 import software.amazon.awssdk.services.s3.model.HeadBucketRequest;
+import software.amazon.awssdk.services.s3.model.HeadObjectRequest;
 import software.amazon.awssdk.services.s3.model.NoSuchBucketException;
 import software.amazon.awssdk.services.s3.model.PutObjectRequest;
 import software.amazon.awssdk.services.s3.model.S3Exception;
@@ -60,4 +61,21 @@ public void delete(String key) {
                 .key(key)
                 .build());
     }
+
+    /**
+     * Tamaño en bytes del objeto, o {@code null} si no se puede determinar.
+     */
+    public Long sizeOf(String key) {
+        if (key == null || key.isBlank()) {
+            return null;
+        }
+        try {
+            return s3Client.headObject(HeadObjectRequest.builder()
+                    .bucket(bucketName)
+                    .key(key)
+                    .build()).contentLength();
+        } catch (S3Exception e) {
+            return null;
+        }
+    }
 }

gradox2/src/main/java/com/example/gradox2/service/implementation/StatsServiceImpl.java

@@ -0,0 +1,48 @@
+package com.example.gradox2.service.implementation;
+
+import java.util.stream.Collectors;
+
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import com.example.gradox2.persistence.repository.FileRepository;
+import com.example.gradox2.persistence.repository.UserRepository;
+import com.example.gradox2.presentation.dto.stats.PlatformStatsResponse;
+import com.example.gradox2.service.interfaces.IStatsService;
+
+@Service
+public class StatsServiceImpl implements IStatsService {
+
+    private final FileRepository fileRepository;
+    private final UserRepository userRepository;
+
+    public StatsServiceImpl(FileRepository fileRepository, UserRepository userRepository) {
+        this.fileRepository = fileRepository;
+        this.userRepository = userRepository;
+    }
+
+    @Override
+    @Transactional(readOnly = true)
+    public PlatformStatsResponse getPlatformStats() {
+        return PlatformStatsResponse.builder()
+                .totalFiles(fileRepository.count())
+                .totalUsers(userRepository.count())
+                .totalStorageBytes(fileRepository.sumSizeBytes())
+                .totalDownloads(fileRepository.sumDownloadCount())
+                .byType(fileRepository.countByType().stream()
+                        .map(stat -> PlatformStatsResponse.TypeStat.builder()
+                                .type(stat.getType())
+                                .count(stat.getCount())
+                                .build())
+                        .collect(Collectors.toList()))
+                .bySubject(fileRepository.countBySubject().stream()
+                        .map(stat -> PlatformStatsResponse.SubjectStat.builder()
+                                .code(stat.getCode())
+                                .name(stat.getName())
+                                .courseName(stat.getCourseName())
+                                .count(stat.getCount())
+                                .build())
+                        .collect(Collectors.toList()))
+                .build();
+    }
+}

gradox2/src/main/java/com/example/gradox2/service/implementation/VoteServiceImpl.java

@@ -244,6 +244,7 @@ private void applyFileProposal(FileProposal fileProposal) {
                 .type(tempFile.getType())
                 .objectKey(tempFile.getObjectKey())
                 .fileHash(tempFile.getFileHash())
+                .sizeBytes(tempFile.getSizeBytes())
                 .uploader(tempFile.getUploader())
                 .subject(tempFile.getSubject())
                 .visibilityLevel(tempFile.getVisibilityLevel())

gradox2/src/main/java/com/example/gradox2/service/interfaces/IStatsService.java

@@ -0,0 +1,8 @@
+package com.example.gradox2.service.interfaces;
+
+import com.example.gradox2.presentation.dto.stats.PlatformStatsResponse;
+
+public interface IStatsService {
+
+    PlatformStatsResponse getPlatformStats();
+}

gradox2/src/main/resources/db/migration/V4__file_stats.sql

@@ -0,0 +1,7 @@
+-- V4: métricas comunitarias de archivos.
+-- Guardamos el tamaño (bytes) y el contador de descargas para las estadísticas /stats.
+
+alter table files add column size_bytes bigint;
+alter table files add column download_count bigint not null default 0;
+
+alter table temp_files add column size_bytes bigint;