Implement UpdateDataset and UpdateMetadata in GO (#13928)

### What problem does this PR solve?

Implement UpdateDataset and UpdateMetadata in GO

Add cli:
UPDATE CHUNK <chunk_id> OF DATASET <dataset_name> SET <update_fields>
REMOVE TAGS 'tag1', 'tag2' from DATASET 'dataset_name';
SET METADATA OF DOCUMENT <doc_id> TO <meta>


### Type of change

- [ ] Refactoring

internal/cli/user_parser.go

@@ -33,12 +33,8 @@ func (p *Parser) parseLoginUser() (*Command, error) {
 	cmd.Params["email"] = email
 
 	p.nextToken()
-	// Optional: WITH PASSWORD 'password'
-	if p.curToken.Type == TokenWith {
-		p.nextToken()
-		if p.curToken.Type != TokenPassword {
-			return nil, fmt.Errorf("expected PASSWORD after WITH")
-		}
+	// Optional: PASSWORD 'password'
+	if p.curToken.Type == TokenPassword {
 		p.nextToken()
 		password, err := p.parseQuotedString()
 		if err != nil {
@@ -853,6 +849,17 @@ func (p *Parser) parseDeleteCommand() (*Command, error) {
 	}
 }
 
+func (p *Parser) parseRemoveCommand() (*Command, error) {
+	p.nextToken() // consume RM
+
+	switch p.curToken.Type {
+	case TokenTag:
+		return p.parseRemoveTags()
+	default:
+		return nil, fmt.Errorf("unknown REMOVE target: %s", p.curToken.Value)
+	}
+}
+
 func (p *Parser) parseDropToken() (*Command, error) {
 	p.nextToken() // consume TOKEN
 
@@ -1574,6 +1581,9 @@ func (p *Parser) parseSetCommand() (*Command, error) {
 	if p.curToken.Type == TokenToken {
 		return p.parseSetToken()
 	}
+	if p.curToken.Type == TokenMetadata {
+		return p.parseSetMeta()
+	}
 
 	return nil, fmt.Errorf("unknown SET target: %s", p.curToken.Value)
 }
@@ -2229,7 +2239,10 @@ func (p *Parser) parseUserStatement() (*Command, error) {
 		return p.parseInsertCommand()
 	case TokenSearch:
 		return p.parseSearchCommand()
-
+	case TokenUpdate:
+		return p.parseUpdateCommand()
+	case TokenRemove:
+		return p.parseRemoveCommand()
 	default:
 		return nil, fmt.Errorf("invalid user statement: %s", p.curToken.Value)
 	}
@@ -2318,3 +2331,164 @@ func (p *Parser) parseUnsetCommand() (*Command, error) {
 	}
 	return NewCommand("unset_token"), nil
 }
+
+// parseUpdateCommand parses UPDATE CHUNK command
+// UPDATE CHUNK 'chunk_id' OF DATASET 'dataset_name' SET '{"content": "..."}'
+func (p *Parser) parseUpdateCommand() (*Command, error) {
+	p.nextToken() // consume UPDATE
+
+	if p.curToken.Type != TokenChunk {
+		return nil, fmt.Errorf("expected CHUNK after UPDATE")
+	}
+	p.nextToken()
+
+	// Parse chunk_id
+	chunkID, err := p.parseQuotedString()
+	if err != nil {
+		return nil, fmt.Errorf("expected chunk_id: %w", err)
+	}
+
+	cmd := NewCommand("update_chunk")
+	cmd.Params["chunk_id"] = chunkID
+
+	p.nextToken()
+	if p.curToken.Type != TokenOf {
+		return nil, fmt.Errorf("expected OF after chunk_id")
+	}
+	p.nextToken()
+
+	if p.curToken.Type != TokenDataset {
+		return nil, fmt.Errorf("expected DATASET after OF")
+	}
+	p.nextToken()
+
+	// Parse dataset_name
+	datasetName, err := p.parseQuotedString()
+	if err != nil {
+		return nil, fmt.Errorf("expected dataset_name: %w", err)
+	}
+	cmd.Params["dataset_name"] = datasetName
+
+	p.nextToken()
+	if p.curToken.Type != TokenSet {
+		return nil, fmt.Errorf("expected SET after dataset_name")
+	}
+	p.nextToken()
+
+	// Parse JSON body
+	jsonBody, err := p.parseQuotedString()
+	if err != nil {
+		return nil, fmt.Errorf("expected JSON body: %w", err)
+	}
+	cmd.Params["json_body"] = jsonBody
+
+	p.nextToken()
+	// Semicolon is optional
+	if p.curToken.Type == TokenSemicolon {
+		p.nextToken()
+	}
+
+	return cmd, nil
+}
+
+// parseSetMeta parses: SET METADATA OF DOCUMENT 'doc_id' TO '{"key": "value"}'
+func (p *Parser) parseSetMeta() (*Command, error) {
+	p.nextToken() // consume METADATA
+
+	// Expect OF
+	if p.curToken.Type != TokenOf {
+		return nil, fmt.Errorf("expected OF after SET METADATA")
+	}
+	p.nextToken()
+
+	// Expect DOCUMENT
+	if p.curToken.Type != TokenDocument {
+		return nil, fmt.Errorf("expected DOCUMENT after SET METADATA OF")
+	}
+	p.nextToken()
+
+	// Parse doc_id
+	docID, err := p.parseQuotedString()
+	if err != nil {
+		return nil, fmt.Errorf("expected doc_id: %w", err)
+	}
+	cmd := NewCommand("set_meta")
+	cmd.Params["doc_id"] = docID
+
+	p.nextToken()
+	// Expect TO
+	if p.curToken.Type != TokenTo {
+		return nil, fmt.Errorf("expected TO after doc_id")
+	}
+	p.nextToken()
+
+	// Parse meta JSON
+	meta, err := p.parseQuotedString()
+	if err != nil {
+		return nil, fmt.Errorf("expected meta JSON: %w", err)
+	}
+	cmd.Params["meta"] = meta
+
+	p.nextToken()
+	// Semicolon is optional
+	if p.curToken.Type == TokenSemicolon {
+		p.nextToken()
+	}
+
+	return cmd, nil
+}
+
+// parseRemoveTags parses: REMOVE TAGS 'tag1', 'tag2' from DATASET 'dataset_name';
+func (p *Parser) parseRemoveTags() (*Command, error) {
+	p.nextToken() // consume TAGS
+
+	// Parse first tag
+	tag, err := p.parseQuotedString()
+	if err != nil {
+		return nil, fmt.Errorf("expected tag: %w", err)
+	}
+	tags := []string{tag}
+
+	// Parse additional tags separated by commas
+	for {
+		p.nextToken()
+		if p.curToken.Type == TokenComma {
+			p.nextToken()
+			tag, err := p.parseQuotedString()
+			if err != nil {
+				return nil, fmt.Errorf("expected tag after comma: %w", err)
+			}
+			tags = append(tags, tag)
+		} else {
+			break
+		}
+	}
+	cmd := NewCommand("rm_tags")
+	cmd.Params["tags"] = tags
+
+	// Expect from
+	if p.curToken.Type != TokenFrom {
+		return nil, fmt.Errorf("expected FROM after tags")
+	}
+	p.nextToken()
+
+	// Expect DATASET
+	if p.curToken.Type != TokenDataset {
+		return nil, fmt.Errorf("expected DATASET after FROM")
+	}
+	p.nextToken()
+
+	// Parse dataset_name
+	datasetName, err := p.parseQuotedString()
+	if err != nil {
+		return nil, fmt.Errorf("expected dataset_name: %w", err)
+	}
+	cmd.Params["dataset_name"] = datasetName
+
+	// Semicolon is optional
+	if p.curToken.Type == TokenSemicolon {
+		p.nextToken()
+	}
+
+	return cmd, nil
+}