//
//  StringExtension.swift
//  SodaLive
//
//  Created by klaus on 2022/06/03.
//

import Foundation

extension Optional where Wrapped == String {
    func isNullOrBlank() -> Bool {
        return self == nil || self!.trimmingCharacters(in: .whitespaces).isEmpty
    }
}

extension String {
    func convertDateFormat(from: String, to: String) -> String {
        let fromFormatter = DateFormatter()
        fromFormatter.dateFormat = from
        fromFormatter.timeZone = TimeZone(identifier: TimeZone.current.identifier)
        
        if let date = fromFormatter.date(from: self) {
            return date.convertDateFormat(dateFormat: to)
        } else {
            return self
        }
    }
    
    func substring(from: Int, to: Int) -> String {
        guard from < count, to >= 0, to - from >= 0 else {
            return ""
        }
        
        // Index 값 획득
        let startIndex = index(self.startIndex, offsetBy: from)
        let endIndex = index(self.startIndex, offsetBy: to + 1) // '+1'이 있는 이유: endIndex는 문자열의 마지막 그 다음을 가리키기 때문
        
        // 파싱
        return String(self[startIndex ..< endIndex])
        
        // 출처 - https://ios-development.tistory.com/379
    }
}