// Copyright 2022 RisingWave Labs
//
// 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.

/// Get the prefix from a glob
pub fn get_prefix(glob: &str) -> String {
    let mut escaped = false;
    let mut escaped_filter = false;
    glob.chars()
        .take_while(|c| match (c, &escaped) {
            ('*', false) => false,
            ('[', false) => false,
            ('{', false) => false,
            ('\\', false) => {
                escaped = true;
                true
            }
            (_, false) => true,
            (_, true) => {
                escaped = false;
                true
            }
        })
        .filter(|c| match (c, &escaped_filter) {
            (_, true) => {
                escaped_filter = false;
                true
            }
            ('\\', false) => {
                escaped_filter = true;
                false
            }
            (_, _) => true,
        })
        .collect()
}
