feat: add simple reconsiliation capabilities

pkg/collection.go

@@ -2,6 +2,7 @@ package synchronizator
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"slices"
 	"strings"
@@ -35,6 +36,58 @@ type Collection struct {
 	is_default bool
 }
 
+func (collection *Collection) loadNodes() error {
+	sql := `
+		WITH RECURSIVE NodeRelationships AS (
+			SELECT
+				*,
+				relationships._class AS relationship_class,
+				relationships.metadata AS relationship_metadata
+			FROM
+				nodes as src
+				JOIN relationships ON src.id = relationships.node_from
+				WHERE src.id = $1 AND relationships._class = 'COLLECTION_HAS_NODE'
+		)
+		SELECT
+			dst.id,
+			dst.name,
+			dst._class,
+			dst.metadata,
+			dst.original_data
+		FROM
+			NodeRelationships
+			JOIN nodes as dst ON dst.id = NodeRelationships.node_to
+	`
+
+	rows, err := collection._conn.Query(sql, collection.Id)
+	if err != nil {
+		return err
+	}
+
+	defer rows.Close()
+
+	collection._relationships = make([]StandardRelationship, 0)
+	collection.childs = make([]*Node, 0)
+	for rows.Next() {
+		node := &Node{
+			_conn: collection._conn,
+		}
+		if err := rows.Scan(
+			&node.Id,
+			&node.name,
+			&node._class,
+			&node.metadata,
+			&node.originalData,
+		); err != nil {
+			return err
+		}
+
+		collection.childs = append(collection.childs, node)
+	}
+
+	return nil
+}
+
 // NewCollectionObject creates a new Collection instance without persisting it to the database.
 // This is useful when you want to prepare a Collection for later storage.
 func NewCollection(name string, metadata []byte) *Collection {
@@ -145,3 +198,74 @@ func (collection *Collection) FetchNodes(
 
 	return nil
 }
+
+type Reconcilation[T any] func(src *T) (*Node, error)
+
+func ReconciliateCollections[T any](src, dst *Collection, work Reconcilation[T]) error {
+	newNodes := make([]*Node, 0, len(src.childs))
+	updateNodes := make([]*Node, 0, len(src.childs))
+	for _, srcNode := range src.childs {
+		var metadata T
+		err := json.Unmarshal(srcNode.metadata, &metadata)
+		if err != nil {
+			return err
+		}
+
+		dstNode, err := work(&metadata)
+		if err != nil {
+			return err
+		}
+
+		if dstNode == nil {
+			return fmt.Errorf("Node pointer is null")
+		}
+
+		if dstNode.Id == -1 {
+			newNodes = append(newNodes, dstNode)
+		} else {
+			updateNodes = append(updateNodes, dstNode)
+		}
+	}
+
+	BulkCreateNode(src._conn, newNodes)
+	// BulkUpdateNode(src._conn, updateNodes)
+
+	relationships := make([]*Relationship, 0, len(newNodes)+len(updateNodes))
+
+	appendRelationship := func(item *Node) error {
+		relation := &Relationship{
+			_class: "COLLECTION_HAS_NODE",
+			From:   dst.Id,
+			To:     item.Id,
+		}
+
+		err := dst.AddRelationship(relation)
+		if err != nil {
+			return err
+		}
+		relationships = append(relationships, relation)
+
+		return nil
+	}
+
+	for _, item := range newNodes {
+		err := appendRelationship(item)
+		if err != nil {
+			return err
+		}
+	}
+
+	for _, item := range updateNodes {
+		err := appendRelationship(item)
+		if err != nil {
+			return err
+		}
+	}
+
+	err := BulkCreateRelationships(dst._conn, relationships)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

pkg/platform.go

@@ -2,10 +2,33 @@ package synchronizator
 
 import (
 	"context"
+	sql "database/sql"
 	"fmt"
 	"slices"
 )
 
+type platform_has_collection struct {
+	Relationship
+}
+
+func (col_has_node *platform_has_collection) GetClass() string {
+	return "PLATFORM_HAS_COLLECTION"
+}
+
+func (col_has_node *platform_has_collection) GetMetadata() []byte {
+	return nil
+}
+
+func (col_has_node *platform_has_collection) FromRelationship(
+	_class string,
+	metadata []byte,
+) error {
+	if _class != "PLATFORM_HAS_COLLECTION" {
+		return fmt.Errorf("invalid class %s", _class)
+	}
+	return nil
+}
+
 // Platform represents a collection of nodes. It embeds a Node, so all the
 // node's functionality is available.
 type Platform struct {
@@ -17,16 +40,90 @@ func (platform *Platform) AddCollection(
 	name string,
 	metadata, originalData []byte,
 ) (*Collection, error) {
-	collection, err := platform._conn.NewCollection(name, metadata, originalData)
+	var collection *Collection
+
+	err := platform._conn.withTx(func(tx *sql.Tx) error {
+		node, err := platform._conn.newCollectionwithTx(tx, name, metadata, originalData)
+		if err != nil {
+			return err
+		}
+
+		_, err = platform._conn.addRelationwithTx(
+			tx,
+			platform.Id,
+			&platform_has_collection{},
+			node.Id,
+		)
+		if err != nil {
+			return err
+		}
+
+		collection = node
+
+		return nil
+	})
 	if err != nil {
 		return nil, err
 	}
 
 	platform.Collections = append(platform.Collections, collection)
-
 	return collection, nil
 }
 
+func (platform *Platform) loadCollections() error {
+	sql := `
+		WITH RECURSIVE NodeRelationships AS (
+			SELECT
+				*,
+				relationships._class AS relationship_class,
+				relationships.metadata AS relationship_metadata
+			FROM
+				nodes as src
+				JOIN relationships ON src.id = relationships.node_from
+				WHERE src.id = $1 AND relationships._class = 'PLATFORM_HAS_COLLECTION'
+		)
+		SELECT
+			dst.id,
+			dst.name,
+			dst._class,
+			dst.metadata,
+			dst.original_data
+		FROM
+			NodeRelationships
+			JOIN nodes as dst ON dst.id = NodeRelationships.node_to
+	`
+
+	rows, err := platform._conn.Query(sql, platform.Id)
+	if err != nil {
+		return err
+	}
+
+	defer rows.Close()
+
+	platform._relationships = make([]StandardRelationship, 0)
+	platform.Collections = make([]*Collection, 0)
+	for rows.Next() {
+		collection := &Collection{
+			Node: Node{
+				_conn: platform._conn,
+			},
+		}
+		if err := rows.Scan(
+			&collection.Id,
+			&collection.name,
+			&collection._class,
+			&collection.metadata,
+			&collection.originalData,
+		); err != nil {
+			return err
+		}
+
+		platform.Collections = append(platform.Collections, collection)
+	}
+
+	return nil
+}
+
 func (platform *Platform) GetDefaultCollection() (*Collection, error) {
 	for _, collection := range platform.Collections {
 		if collection.IsDefault() {

pkg/synchronizator.go

@@ -195,7 +195,7 @@ func (conn *DB) NewPlatform(name string, metadata []byte, originalData []byte) (
 			Collections: []*Collection{collection},
 		}
 
-		_, err = conn.addRelationwithTx(tx, platform.Id, &collection_has_node{}, collection.Id)
+		_, err = conn.addRelationwithTx(tx, platform.Id, &platform_has_collection{}, collection.Id)
 		if err != nil {
 			return err
 		}
@@ -340,6 +340,60 @@ func (conn *DB) GetNode(id int64) (*Node, error) {
 	return &node, nil
 }
 
+func (conn *DB) GetPlatform(id int64) (*Platform, error) {
+	node := Node{
+		Id:    id,
+		_conn: conn,
+	}
+	sql := "SELECT _class, name, metadata, original_data FROM nodes WHERE id = $1 AND _class = 'PLATFORM';"
+	conn.log(DEBUG, sql)
+
+	err := conn.Connection.QueryRow(sql, id).
+		Scan(&node._class, &node.name, &node.metadata, &node.originalData)
+	if err != nil {
+		conn.log(DEBUG, err)
+		return nil, fmt.Errorf("No row matching id = %v", id)
+	}
+
+	platform := &Platform{
+		Node: node,
+	}
+
+	err = platform.loadCollections()
+	if err != nil {
+		return nil, err
+	}
+
+	return platform, nil
+}
+
+func (conn *DB) GetCollection(id int64) (*Collection, error) {
+	node := Node{
+		Id:    id,
+		_conn: conn,
+	}
+	sql := "SELECT _class, name, metadata, original_data FROM nodes WHERE id = $1 AND _class = 'COLLECTION';"
+	conn.log(DEBUG, sql)
+
+	err := conn.Connection.QueryRow(sql, id).
+		Scan(&node._class, &node.name, &node.metadata, &node.originalData)
+	if err != nil {
+		conn.log(DEBUG, err)
+		return nil, fmt.Errorf("No row matching id = %v", id)
+	}
+
+	collection := &Collection{
+		Node: node,
+	}
+
+	err = collection.loadNodes()
+	if err != nil {
+		return nil, err
+	}
+
+	return collection, nil
+}
+
 // Deletes a node with the provided id
 func (conn *DB) DeleteNode(id int64) error {
 	tx, err := conn.Connection.Begin()