//
//  Malygos.swift
//  Malygos
//
//  Created by xing jian on 11/7/2019.
//  Copyright © 2019 xingjian. All rights reserved.
//

import Foundation

enum JoinType{
  case path
  case query
}
public protocol NetBean {
  static func createBean() -> NetBean?
}
extension NetBean{
  static func createBean() -> NetBean? {
    return nil
  }
}
protocol NetFunction {
  var beanPath:[(String,String?)]{get}
  var beanQuery:[(String,String?)]{get}
  func fillPathAndQuery(_ obj:Any)
  func paras(_ path:String,_ factor:Character)->[(String,String?)]
}
extension NetFunction{
  func paras(_ path:String,_ factor:Character)->[(String,String?)]{
    guard path.count > 0 else{
      return []
    }

    let tuple = path.split(separator: factor).compactMap { item -> String? in
      if item.count > 0 {
        return String(item)
      }
      return nil
      }.map { item -> (String,String?) in
        let pathitem = item.trimmingCharacters(in: .whitespaces)
        let findex = pathitem.firstIndex(of: "{")
        guard findex != nil else{
          return (pathitem,pathitem)
        }
        let lindex = pathitem.lastIndex(of: "}")
        guard lindex != nil else{
          return (pathitem,pathitem)
        }

        let varname =  item[item.index(findex!, offsetBy:1)..<lindex!]
        return (String(varname),nil)
    }
    return tuple
  }
}
extension NetFunction{
  func fillPathAndQuery(_ obj:Any){
    func join(_ items:[(String,String?)],_ variables:[[String:Any]],_ type:JoinType) -> String{
      guard items.count > 0 else {
        return ""
      }
      let result = items.compactMap { item -> String? in
        guard item.1 == nil else{
          return item.0
        }
        var value :Any? = nil
        for varitem in variables{
          if let item = varitem[item.0]{
            value = item
            break;
          }
        }
        if value != nil {
          if  let vstring = value as? String{
            return type == .path ? String(vstring) : String("\(item.0)=\(vstring)")
          }
          if let istring = value as? Int{
            return type == .path ? String(istring) : String("\(item.0)=\(istring)")
          }
          return nil
        }
        return nil
        }.joined(separator: type == .path ? "/":"&")
      return result
    }


    let ref = Mirror(reflecting:obj.self)
    let variables = ref.children.compactMap{ child ->[String:Any]? in
      if let lable = child.label{
        return [lable:child.value]
      }
      return nil
    }
    let newpath = join(beanPath, variables, .path)
    let newquery = join(beanQuery, variables, .query)
  }
}
@propertyDelegate
public struct Get<Bean:NetBean>:NetFunction{
  private var valueInternal:Bean? = nil
  private(set) var beanPath:[(String,String?)] = []
  private(set) var beanQuery:[(String,String?)] = []
  public var value:Bean{
    set(newValue){valueInternal = newValue}
    get{
      let bean = valueInternal ?? Bean.createBean()! as! Bean
      fillPathAndQuery(bean)
      return  bean
    }
  }
  public init(path:String="",query:String=""){
    beanPath = paras(path,"/")
    beanQuery = paras(query,"&")
  }
}
@propertyDelegate
public struct Post<Bean:NetBean> {
  private var valueInternal:Bean? = nil
  public var value:Bean{
    set(newValue){ valueInternal = newValue}
    get{return valueInternal ?? Bean.createBean()! as! Bean}
  }
  public init(){
  }
}
@propertyDelegate
public struct Put<Bean:NetBean> {
  private var valueInternal:Bean? = nil
  public var value:Bean{
    set(newValue){ valueInternal = newValue}
    get{return valueInternal ?? Bean.createBean()! as! Bean}
  }
  public init(){
  }
}
@propertyDelegate
public struct Delete<Bean:NetBean> {
  private var valueInternal:Bean? = nil
  public var value:Bean{
    set(newValue){ valueInternal = newValue}
    get{return valueInternal ?? Bean.createBean()! as! Bean}
  }
  public init(){
  }
}