Refactoring and dashboard state in DB

database/database.go

@@ -2,34 +2,71 @@ package database
 
 import (
 	"encoding/json"
+	"fmt"
+	"io"
 	"log"
 	"os"
 
 	"git.phc.dm.unipi.it/phc/storage/store"
+	"golang.org/x/exp/slices"
 )
 
-type Database interface {
-	Buckets() ([]string, error)
-	CreateBucket(bucket string, options ...any) error
-
-	Bucket(bucket string) (store.Store, error)
+type MonitorWidget struct {
+	Type  string `json:"type"`
+	Value any    `json:"value"`
 }
 
-type bucketInfo struct {
-	Name string `json:"name"`
-	Path string `json:"path"`
+type DashboardState struct {
+	Widgets []MonitorWidget `json:"widgets"`
+}
+
+type Database interface {
+	// Dashboard DashboardState
+
+	GetDashboardState() (DashboardState, error)
+	SetDashboardState(DashboardState) error
+
+	// Bucket Operations
+
+	CreateBucket(bucket string, options ...any) error
+	DeleteBucket(bucket string) error
+
+	AllBuckets() ([]string, error)
+
+	// Bucket Object Operations
+
+	CreateBucketObject(bucket string, r io.Reader) (string, error)
+	DeleteBucketObject(bucket, id string) error
+
+	GetBucketObject(bucket, id string, w io.Writer) error
+	SetBucketObject(bucket, id string, r io.Reader) error
+
+	AllBucketObjects(bucket string) ([]string, error)
+}
+
+type jsonBucket struct {
+	Name    string   `json:"name"`
+	Path    string   `json:"path"`
+	Objects []string `json:"objects"`
 }
 
 type jsonDB struct {
 	file string
 
-	BucketsInfo map[string]bucketInfo `json:"buckets"`
+	PrefixSize int `json:"prefixSize"`
+
+	DashboardState DashboardState         `json:"dashboardState"`
+	Buckets        map[string]*jsonBucket `json:"buckets"`
 }
 
 func NewJSON(file string) Database {
 	db := &jsonDB{
-		file:        file,
-		BucketsInfo: map[string]bucketInfo{},
+		file:       file,
+		PrefixSize: 2,
+		DashboardState: DashboardState{
+			Widgets: []MonitorWidget{},
+		},
+		Buckets: map[string]*jsonBucket{},
 	}
 
 	err := db.load()
@@ -96,37 +133,145 @@ func (db *jsonDB) load() error {
 	return nil
 }
 
-func (db *jsonDB) Buckets() ([]string, error) {
+func (db *jsonDB) GetDashboardState() (DashboardState, error) {
 	db.load()
 
-	buckets := make([]string, 0, len(db.BucketsInfo))
+	return db.DashboardState, nil
+}
 
-	for _, b := range db.BucketsInfo {
+func (db *jsonDB) SetDashboardState(state DashboardState) error {
+	db.load()
+	db.DashboardState = state
+
+	db.store()
+	return nil
+}
+
+func (db *jsonDB) CreateBucket(bucket string, options ...any) error {
+	db.load()
+
+	if _, found := db.Buckets[bucket]; found {
+		return fmt.Errorf("bucket named %q already present", bucket)
+	}
+
+	bi := &jsonBucket{
+		Name:    bucket,
+		Path:    bucket + "/",
+		Objects: []string{},
+	}
+	if len(options) > 0 {
+		bi.Path = options[0].(string)
+	}
+
+	db.Buckets[bucket] = bi
+
+	db.store()
+	return nil
+}
+
+func (db *jsonDB) DeleteBucket(bucket string) error {
+	db.load()
+
+	if _, found := db.Buckets[bucket]; !found {
+		return fmt.Errorf("bucket named %q not found", bucket)
+	}
+
+	delete(db.Buckets, bucket)
+
+	log.Printf("The bucket named %q was removed but its files are still on disk", bucket)
+
+	db.store()
+	return nil
+}
+
+func (db *jsonDB) AllBuckets() ([]string, error) {
+	db.load()
+
+	buckets := make([]string, 0, len(db.Buckets))
+
+	for _, b := range db.Buckets {
 		buckets = append(buckets, b.Name)
 	}
 
 	return buckets, nil
 }
 
-func (db *jsonDB) CreateBucket(bucket string, options ...any) error {
+func (db *jsonDB) CreateBucketObject(bucket string, r io.Reader) (string, error) {
 	db.load()
-	defer db.store()
 
-	bi := bucketInfo{Name: bucket, Path: bucket + "/"}
-	if len(options) > 0 {
-		bi.Path = options[0].(string)
+	b, found := db.Buckets[bucket]
+	if !found {
+		return "", fmt.Errorf("bucket named %q not found", bucket)
 	}
 
-	db.BucketsInfo[bucket] = bi
+	id, err := store.Create(b.Path, db.PrefixSize, r)
+	if err != nil {
+		return "", err
+	}
 
+	b.Objects = append(b.Objects, id)
+
+	db.store()
+	return id, err
+}
+
+func (db *jsonDB) SetBucketObject(bucket, id string, r io.Reader) error {
+	db.load()
+
+	b, found := db.Buckets[bucket]
+	if !found {
+		return fmt.Errorf("bucket named %q not found", bucket)
+	}
+
+	db.store()
+	return store.Update(b.Path, db.PrefixSize, id, r)
+}
+
+func (db *jsonDB) GetBucketObject(bucket, id string, w io.Writer) error {
+	db.load()
+
+	b, found := db.Buckets[bucket]
+	if !found {
+		return fmt.Errorf("bucket named %q not found", bucket)
+	}
+
+	return store.Read(b.Path, db.PrefixSize, id, w)
+}
+
+func (db *jsonDB) DeleteBucketObject(bucket, id string) error {
+	db.load()
+
+	b, found := db.Buckets[bucket]
+	if !found {
+		return fmt.Errorf("bucket named %q not found", bucket)
+	}
+
+	if err := store.Delete(b.Path, db.PrefixSize, id); err != nil {
+		return err
+	}
+
+	i := slices.Index(b.Objects, id)
+	b.Objects = append(b.Objects[:i], b.Objects[i+1:]...)
+
+	db.store()
 	return nil
 }
 
-func (db *jsonDB) Bucket(bucket string) (store.Store, error) {
-	b := db.BucketsInfo[bucket]
+func (db *jsonDB) AllBucketObjects(bucket string) ([]string, error) {
+	db.load()
 
-	return &store.DirStore{
-		BaseDir: b.Path,
-		Prefix:  2,
-	}, nil
+	b, found := db.Buckets[bucket]
+	if !found {
+		return nil, fmt.Errorf("bucket named %q not found", bucket)
+	}
+
+	objects, err := store.All(b.Path)
+	if err != nil {
+		return nil, err
+	}
+
+	b.Objects = objects
+
+	db.store()
+	return b.Objects, nil
 }