//
//  String+Swifter.swift
//  Swifter
//
//  Copyright (c) 2014 Matt Donnelly.
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.
//

import Foundation

extension String {

    internal func indexOf(_ sub: String) -> Int? {
        guard let range = self.range(of: sub), !range.isEmpty else {
            return nil
        }
        return self.distance(from: self.startIndex, to: range.lowerBound)
    }

    internal subscript (r: Range<Int>) -> Substring {
        get {
            let startIndex = self.index(self.startIndex, offsetBy: r.lowerBound)
            let endIndex = self.index(startIndex, offsetBy: r.upperBound - r.lowerBound)
            return self[startIndex..<endIndex]
        }
    }
    

    func urlEncodedString(_ encodeAll: Bool = false) -> String {
        var allowedCharacterSet: CharacterSet = .urlQueryAllowed
        allowedCharacterSet.remove(charactersIn: "\n:#/?@!$&'()*+,;=")
        if !encodeAll {
            allowedCharacterSet.insert(charactersIn: "[]")
        }
        return self.addingPercentEncoding(withAllowedCharacters: allowedCharacterSet)!
    }

    var queryStringParameters: Dictionary<String, String> {
        var parameters = Dictionary<String, String>()

        let scanner = Scanner(string: self)

        var key: String?
        var value: String?

        while !scanner.isAtEnd {
            key = scanner.scanUpToString("=")
            _ = scanner.scanString("=")

            value = scanner.scanUpToString("&")
            _ = scanner.scanString("&")

            if let key = key, let value = value {
                parameters.updateValue(value, forKey: key)
            }
        }
        
        return parameters
    }
}
