chore: import upstream snapshot with attribution

server/ast/create_database.go

@@ -0,0 +1,136 @@
+// Copyright 2023 Dolthub, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ast
+
+import (
+	"regexp"
+	"strings"
+
+	"github.com/cockroachdb/errors"
+	vitess "github.com/dolthub/vitess/go/vt/sqlparser"
+	"github.com/sirupsen/logrus"
+
+	"github.com/dolthub/doltgresql/postgres/parser/sem/tree"
+)
+
+// nodeCreateDatabase handles *tree.CreateDatabase nodes.
+func nodeCreateDatabase(_ *Context, node *tree.CreateDatabase) (*vitess.DBDDL, error) {
+	var charsets []*vitess.CharsetAndCollate
+
+	if len(node.Template) > 0 {
+		// TODO: special casing "template0", as some tests make use of it and we need them to pass for now
+		if node.Template != "template0" {
+			return nil, errors.Errorf("TEMPLATE clause is not yet supported")
+		}
+	}
+	if len(node.Encoding) > 0 {
+		logrus.Warnf("unsupported clause ENCODING, ignoring")
+	}
+	if len(node.Strategy) > 0 {
+		return nil, errors.Errorf("STRATEGY clause is not yet supported")
+	}
+	if len(node.Locale) > 0 {
+		logrus.Warnf("unsupported clause LC_LOCALE, ignoring")
+	}
+	if len(node.Collate) > 0 {
+		collation, charset, err := parseLocaleString(node.Collate)
+		if err != nil {
+			return nil, err
+		}
+
+		if collation == "" {
+			logrus.Warnf("unsupported LC_COLLATE, ignoring")
+		} else {
+			charsets = append(charsets,
+				&vitess.CharsetAndCollate{
+					Type:  "CHARACTER SET",
+					Value: charset,
+				},
+				&vitess.CharsetAndCollate{
+					Type:  "COLLATE",
+					Value: collation,
+				},
+			)
+		}
+	}
+	if len(node.CType) > 0 {
+		logrus.Warnf("CTYPE clause is not yet supported, ignoring")
+	}
+	if len(node.IcuLocale) > 0 {
+		return nil, errors.Errorf("ICU_LOCALE clause is not yet supported")
+	}
+	if len(node.IcuRules) > 0 {
+		return nil, errors.Errorf("TEMPLATE clause is not yet supported")
+	}
+	if len(node.LocaleProvider) > 0 {
+		return nil, errors.Errorf("LOCALE_PROVIDER clause is not yet supported")
+	}
+	if len(node.CollationVersion) > 0 {
+		return nil, errors.Errorf("COLLATION_VERSION clause is not yet supported")
+	}
+	if len(node.Tablespace) > 0 {
+		return nil, errors.Errorf("TABLESPACE clause is not yet supported")
+	}
+	// TODO: some clauses have default values in case of not being defined.
+	// ALLOW_CONNECTIONS defaults to TRUE
+	if node.AllowConnections != nil {
+		return nil, errors.Errorf("ALLOW_CONNECTIONS clause is not yet supported")
+	}
+	// CONNECTION LIMIT defaults to -1
+	if node.ConnectionLimit != nil {
+		return nil, errors.Errorf("CONNECTION LIMIT clause is not yet supported")
+	}
+	// IS_TEMPLATE defaults to FALSE
+	if node.IsTemplate != nil {
+		return nil, errors.Errorf("IS_TEMPLATE clause is not yet supported")
+	}
+	if node.Oid != nil {
+		return nil, errors.Errorf("OID clause is not yet supported")
+	}
+
+	return &vitess.DBDDL{
+		Action:           vitess.CreateStr,
+		SchemaOrDatabase: "database",
+		DBName:           bareIdentifier(node.Name),
+		IfNotExists:      node.IfNotExists,
+		CharsetCollate:   charsets,
+	}, nil
+}
+
+var collationRegex = regexp.MustCompile(`^(?P<Language>[^_]+)_?(?P<Region>[^.]+)?\.?(?P<CodePage>\d+)?$`)
+
+// parseLocaleString attempts to parse the locale string given to extract a mysql collation we can use
+func parseLocaleString(collation string) (string, string, error) {
+	// FindStringSubmatchIndex returns the indices of the matched elements
+	match := collationRegex.FindStringSubmatch(collation)
+
+	result := make(map[string]string)
+	for i, name := range collationRegex.SubexpNames() {
+		if i > 0 && i <= len(match) {
+			result[name] = match[i]
+		}
+	}
+
+	if result["Language"] == "" {
+		return "", "", errors.Errorf("malformed collation: %s", collation)
+	}
+
+	switch strings.ToLower(result["Language"]) {
+	case "english", "en":
+		return "latin1_general_cs", "latin1", nil
+	}
+
+	return "", "", nil
+}