// 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 (
	vitess "github.com/dolthub/vitess/go/vt/sqlparser"

	"github.com/dolthub/doltgresql/server/auth"

	"github.com/dolthub/doltgresql/postgres/parser/sem/tree"
)

// nodeDropSchema handles *tree.DropSchema nodes.
func nodeDropSchema(ctx *Context, node *tree.DropSchema) (vitess.Statement, error) {
	// TODO: disallow dropping pg_catalog for now
	if node == nil {
		return nil, nil
	}

	if len(node.Names) > 1 {
		return NotYetSupportedError("DROP SCHEMA with multiple schema names is not yet supported.")
	}

	if node.DropBehavior == tree.DropCascade {
		return NotYetSupportedError("DROP SCHEMA with CASCADE behavior is not yet supported.")
	}

	schemaName := node.Names[0]

	return &vitess.DBDDL{
		Action:           vitess.DropStr,
		SchemaOrDatabase: "schema",
		DBName:           schemaName,
		CharsetCollate:   nil,
		IfExists:         node.IfExists,
		Auth: vitess.AuthInformation{
			AuthType:    auth.AuthType_DELETE,
			TargetType:  auth.AuthTargetType_SchemaIdentifiers,
			TargetNames: []string{"", schemaName},
		},
	}, nil
}