Sources/XCMetricsBackendLib/Common/Utils/String+Utils.swift

// Copyright (c) 2020 Spotify AB.
//
// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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.

import Foundation

extension String {

    func xcm_toSchemaName() -> String {
        let snakeCased = xcm_camelCaseToSnakeCase()

        if snakeCased.last != "s" && snakeCased != "build_metadata" {
            return snakeCased + "s"
        }
        return snakeCased
    }

    func xcm_camelCaseToSnakeCase() -> String {
        let acronymPattern = "([A-Z]+)([A-Z][a-z]|[0-9])"
        let normalPattern = "([a-z0-9])([A-Z])"
        return self.processCamelCaseRegex(pattern: acronymPattern)?
            .processCamelCaseRegex(pattern: normalPattern)?.lowercased() ?? self.lowercased()
    }

    fileprivate func processCamelCaseRegex(pattern: String) -> String? {

        let regex = try? NSRegularExpression(pattern: pattern, options: [])
        let range = NSRange(location: 0, length: count)
        return regex?.stringByReplacingMatches(in: self, options: [], range: range, withTemplate: "$1_$2")
    }

}