//

// STURL.swift

// STBaseProject

//

// Created by 寒江孤影 on 2019/1/21.

//

import Foundation

public extension URL {

/// 解析查询串为字典；支持无值参数（会得到空字符串）

/// 例如：`https://a.com?x=1&y&z=%E4%B8%AD` -> `["x": "1", "y": "", "z": "中"]`

var queryComponents: [String: String] {

guard let components = URLComponents(url: self, resolvingAgainstBaseURL: false),

let items = components.queryItems, !items.isEmpty

else {

return [:]

}

var result: [String: String] = [:]

for item in items where !item.name.isEmpty {

result[item.name] = item.value ?? ""

}

return result

}

/// 追加查询参数并返回新 URL；已存在的同名参数会追加而不是覆盖

/// - Parameter parameters: 要追加的键值对

/// - Returns: 新 URL，解析失败返回 nil

func appendingQueryParameters(_ parameters: [String: String]) -> URL? {

guard var components = URLComponents(url: self, resolvingAgainstBaseURL: false) else { return nil }

var items = components.queryItems ?? []

for (key, value) in parameters {

items.append(URLQueryItem(name: key, value: value))

}

components.queryItems = items

return components.url

}

/// 返回移除指定参数后的新 URL

/// - Parameter names: 要移除的参数名集合

func removingQueryParameters(named names: [String]) -> URL? {

guard var components = URLComponents(url: self, resolvingAgainstBaseURL: false) else { return nil }

components.queryItems = components.queryItems?.filter { !names.contains($0.name) }

return components.url

}

}