add file storage: metadata schema, minio upload/download, content-type extension mapping

- add files_metadata and files_metadata_connections tables with CRUD helpers
- add FileMetadata type and Sha256Hash typedef; replace Media struct
- add minio upload, presigned download URL, and key generation
- fix bucket existence check to use FileStorageBucketName instead of hardcoded "main"
- fix files_metadata_connections table name and trailing comma in DDL
- fix column name original -> name in files_metadata schema
- add canonical MIME-to-extension map with .unk fallback
- add FileDownloadLinkTtl constant (24h)

packages/globals/globals.go

@@ -1,6 +1,9 @@
 package globals
 
+import "time"
+
 const (
 	MaxDirectMsgCache     uint32        = 12
 	FileStorageBucketName string        = "communicator"
+	FileDownloadLinkTtl   time.Duration = 24 * time.Hour
 )

packages/minio/minio.go

@@ -2,20 +2,47 @@ package minio
 
 import (
 	"context"
-	"go-socket/packages/globals"
 	"io"
+	"mime"
+	"net/url"
+
+	"go-socket/packages/globals"
 
 	"github.com/minio/minio-go/v7"
 	"github.com/minio/minio-go/v7/pkg/credentials"
 )
 
-var dbConn *minio.Client
+var minClient *minio.Client
+
+var canonicalExt = map[string]string{
+	"image/jpeg":      ".jpg",
+	"image/png":       ".png",
+	"image/gif":       ".gif",
+	"image/webp":      ".webp",
+	"video/mp4":       ".mp4",
+	"application/pdf": ".pdf",
+}
+
+func extensionFromContentType(ct string) string {
+	if ext, ok := canonicalExt[ct]; ok {
+		return ext
+	}
+	exts, err := mime.ExtensionsByType(ct)
+	if err != nil || len(exts) == 0 {
+		return ".unk"
+	}
+	return exts[0]
+}
+
+func getKey(hash string, contentType string) string {
+	return hash + extensionFromContentType(contentType)
+}
 
 func MinInit() {
 	ctx := context.Background()
 
 	var err error
-	dbConn, err = minio.New("localhost:9000", &minio.Options{
+	minClient, err = minio.New("localhost:9000", &minio.Options{
 		Creds:  credentials.NewStaticV4("root", "change_to_env", ""),
 		Secure: false,
 	}) // TODO change in production
@@ -23,22 +50,29 @@ func MinInit() {
 		panic(err)
 	}
 
-	exists, err := dbConn.BucketExists(ctx, "main")
+	exists, err := minClient.BucketExists(ctx, globals.FileStorageBucketName)
 	if err != nil {
 		panic(err)
 	}
 
 	if !exists {
-		err = dbConn.MakeBucket(ctx, globals.FileStorageBucketName, minio.MakeBucketOptions{})
+		err = minClient.MakeBucket(ctx, globals.FileStorageBucketName, minio.MakeBucketOptions{})
 		if err != nil {
 			return
 		}
 	}
+
 }
 
-func putFile(ctx context.Context, key string, reader io.Reader, size uint32, contentType string) error {
+func upload(ctx context.Context, key string, body io.Reader, size int64, contentType string) error {
-	dbConn.PutObject(ctx, globals.FileStorageBucketName, key, reader, int64(size), minio.PutObjectOptions{
+	_, err := minClient.PutObject(ctx, globals.FileStorageBucketName, key, body, size,
+		minio.PutObjectOptions{
 			ContentType: contentType,
 		})
-
+	return err
+}
+
+func getDownloadUrl(ctx context.Context, key string) (*url.URL, error) {
+	u, err := minClient.PresignedGetObject(ctx, globals.FileStorageBucketName, key, globals.FileDownloadLinkTtl, nil)
+	return u, err
 }

packages/postgresql/postgresql.go

@@ -67,6 +67,28 @@ func PgInit(ctx context.Context) {
 		panic(err)
 	}
 
+	_, err = dbConn.Exec(ctx, `
+		CREATE TABLE IF NOT EXISTS files_metadata (
+			id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+			uploader_id UUID NOT NULL REFERENCES users(id),
+			name TEXT,
+			hash TEXT NOT NULL,
+			created_at TIMESTAMP NOT NULL DEFAULT NOW()
+		)
+	`)
+	if err != nil {
+		panic(err)
+	}
+
+	_, err = dbConn.Exec(ctx, `
+		CREATE TABLE IF NOT EXISTS files_metadata_connections (
+			file_metadata_id UUID NOT NULL REFERENCES files_metadata(id) ON DELETE CASCADE,
+			connection_id UUID NOT NULL REFERENCES user_connections(id) ON DELETE CASCADE
+		)
+	`)
+	if err != nil {
+		panic(err)
+	}
 }
 
 func PgUserSave(ctx context.Context, user *types.User) error {
@@ -221,3 +243,57 @@ func PgConnectionGetMessagesBefore(ctx context.Context, before time.Time, connec
 	}
 	return messages, rows.Err()
 }
+
+func PgFileMetadataSave(ctx context.Context, metadata *types.FileMetadata) error {
+	_, err := dbConn.Exec(ctx, `
+		INSERT INTO files_metadata (id, uploader_id, name, hash, created_at) VALUES ($1, $2, $3, $4, $5)
+	`, metadata.Id, metadata.UploaderId, metadata.Name, metadata.Hash, metadata.CreatedAt)
+	return err
+}
+
+func PgFileMetadataGet(ctx context.Context, metadata *types.FileMetadata) error {
+	return dbConn.QueryRow(ctx, `
+		SELECT uploader_id, name, hash, created_at FROM files_metadata WHERE id = $1
+	`, metadata.Id).Scan(&metadata.UploaderId, &metadata.Name, &metadata.Hash, &metadata.CreatedAt)
+}
+
+func PgFileMetadataDelete(ctx context.Context, metadataId *uuid.UUID) error {
+	_, err := dbConn.Exec(ctx, `
+		DELETE FROM files_metadata WHERE id = $1 
+	`, metadataId)
+	return err
+}
+
+func PgFileConnectionsAdd(ctx context.Context, metadataId *uuid.UUID, connectionId *uuid.UUID) error {
+	_, err := dbConn.Exec(ctx, `
+		INSERT INTO files_metadata_connections (file_metadata_id, connection_id) VALUES ($1, $2)
+	`, metadataId, connectionId)
+	return err
+}
+
+func PgFileConnectionsGet(ctx context.Context, metadata *types.FileMetadata) error {
+	rows, err := dbConn.Query(ctx, `
+		SELECT connection_id FROM files_metadata_connections WHERE file_metadata_id = $1
+	`, metadata.Id)
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		connectionId := uuid.UUID{}
+		if err = rows.Scan(&connectionId); err != nil {
+			return err
+		}
+		metadata.Connections = append(metadata.Connections, connectionId)
+	}
+	return rows.Err()
+}
+
+func PgFileMetadataHashExists(ctx context.Context, hash *types.Sha256Hash) (bool, error) {
+	var exists bool
+	err := dbConn.QueryRow(ctx, `
+		SELECT EXISTS (SELECT FROM files_metadata WHERE hash = $1)
+	`, hash).Scan(&exists)
+	return exists, err
+}

packages/types/types.go

@@ -1,6 +1,7 @@
 package types
 
 import (
+	"crypto/sha256"
 	"math/rand/v2"
 	"sync"
 	"time"
@@ -14,6 +15,7 @@ import (
 )
 
 type Rgba [4]uint8
+type Sha256Hash [sha256.Size]byte
 
 func (r Rgba) GetRandom() *Rgba {
 	for i := range r {
@@ -103,8 +105,11 @@ type WsAuthMessage struct {
 	Error   string `json:"error"`
 }
 
-type Media struct {
+type FileMetadata struct {
-	Hash      string
+	CreatedAt   time.Time   `json:"createdAt"`
-	Owner     uint32
+	Connections []uuid.UUID `json:"connections"`
-	CreatedAt time.Time
+	Name        string      `json:"name"`
+	Hash        Sha256Hash  `json:"hash"`
+	Id          uuid.UUID   `json:"id"`
+	UploaderId  uuid.UUID   `json:"uploaderId"`
 }