import "loadResource.yjs"
@LogType("Arg")
contract Incentives{

  export function getMainFrame(arg){
    return "/html/main.html";
  }

  function onCreate(arg) {
    Global.owner = requester;
    Global.bids = [];
    Global.asks = [];
    Global.listFinal = [];
    Global.status = "Bidding";
  }

  export function getOwner(arg) {
    return Global.owner;
  }

  export function isOwner(arg) {
    return requester==Global.owner;
  }

  export function getStatus(arg) {
   return Global.status;
  }
  
  export function getAskListRW(arg) {
    var retList = [];
    for (var i = 0; i < Global.asks.length; i++) {
      var ask = {};
      ask["item"] = Global.asks[i]["item"];
      if (Global.asks[i]["seller"] == requester) {
        ask["seller"] = Global.asks[i]["seller"];
        ask["price"] = Global.asks[i]["price"];
      } else {
        ask["seller"] = "Anonymous";
        ask["price"] = "Unknown";
      }
      retList.push(ask);
    }
    return JSON.stringify(retList);
  }

  export function getAskListRO(arg) {
    if (requester != Global.owner) {
      return "Access Denied";
    }
    return JSON.stringify(Global.asks);
  }

  export function getBidListAll(arg) {
    if (requester != Global.owner) {
      return "Access Denied";
    }
    return JSON.stringify(Global.bids);
  }

  export function getBidListPrivate(arg) {
    var retList = [];
    for (var i = 0; i < Global.bids.length; i++) {
      if (Global.bids[i]["bidder"]==requester) {
        retList.push(Global.bids[i]);
      }
    }
    return JSON.stringify(retList);
  }
  
  export function bid(arg) {//每个args的格式是：{"bidder":"","item":""}  item资源编号，bidder买方
    var args = JSON.parse(arg);
    args["bidder"] = requester;  //从外界引入bidder的编号
    return bidHelper(args);
  }
  
  function bidHelper(args){ 
    if (Global.status != "Bidding") {
      return "Not in bidding status!";
    }
    var asks = findAllElements(Global.asks, "item", args["item"]);
    if (asks.length == 0) {
      return "No such item exists!";
    }
    for (var i = 0; i< Global.bids.length; i++) {	
      if (Global.bids[i]["bidder"]==args["bidder"] && Global.bids[i]["item"]==args["item"]) {
        return "A valid bid already exists";    //这个已经存在买方购买该资源的信息
      }
    }
    Global.bids.push(args);    //没有已存在，就可以将这个信息加入global.bids
    return "Success";    
  }
  
  export function ask(arg) {     //每个args的格式是：{"seller":"","item":""}  item资源编号，seller卖方
    var args = JSON.parse(arg);
    args["seller"] = requester;
    return askHelper(args);
  }
  
  function askHelper(args){
    if (Global.status != "Bidding") {
      return "Not in bidding status";
    }
    for (var i = 0; i< Global.asks.length; i++) {	
      if (Global.asks[i]["item"]==args["item"]) {
        return "A valid ask already exists";  //已经存在卖方提供该资源的信息
      }
    }
    Global.asks.push(args);     //没有已存在，就可以将这个信息加入Global.asks
    return "Success";    
  }
  
  export function match(arg) {
    if (Global.status != "Bidding") {
      return "Not in bidding status";
    }
    if (requester != Global.owner) {
      return "Access Denied";
    }
    if (Global.bids.length == 0 || Global.asks.length == 0) {
      return "Must have at least 1 resource and 1 bid!";
    }
    
    // Algorithm 2 winning candidates determination
    // sort bids and asks
    sortObjectArray(Global.bids,"price",false);   //买方按照价格降序跑列
    sortObjectArray(Global.asks,"price",true);    //卖方升序排列
    // calculate threshold value
    var thrPos = Math.ceil((Global.asks.length+1.0)/2.0);   //取中位数beta
    var askThrValue = Global.asks[thrPos-1]["price"];       //卖方的阈值
    // get candidates according to the threshold value
    var candidateBidsTmp = [];
    for (var i = 0; i < Global.bids.length; i++) {
      if (Global.bids[i]["price"] >= askThrValue) {        //取大于等于卖方阈值的所有买方价格
        candidateBidsTmp.push(Global.bids[i]);     //candidateBidsTmp：大于等于卖方阈值价格的买方价格
      } else {
        break;
      }
    }
    var bidThrValue = candidateBidsTmp[candidateBidsTmp.length-1]["price"];  //取买方的阈值最低价
    // get rid of impossible candidates踢出不可能的candidates  
    var candidateAsks = [];
    var candidateBids = [];
    for (var i=0; i<candidateBidsTmp.length; i++) {
      var askList = findAllElements(Global.asks, "item", candidateBidsTmp[i]["item"]);
	  //在global.asks中的找到提供该资源的所有卖方
      if (askList.length == 1 && askList[0]["price"] < askThrValue) {
	  //如果只有一个卖方提供该资源且卖方提供的资源价格小于卖方阈值
        candidateBids.push(candidateBidsTmp[i]);  //那么这个买方就可能可以拥有这个资源（匹配），加入candidateBids（插入顺序也是按照价格降序排列的）
        var cAskList = findAllElements(candidateAsks, "item", candidateBidsTmp[i]["item"]);
		//在candidateAsks中找到提供这个资源的所有卖方
        if (cAskList.length == 0) {
		//如果还没有加入提供该资源的卖方，那么就加入candidateAsks，就是说这个卖方可能可以卖出这个资源
          candidateAsks.push(askList[0]);
        }
      } 
    }
    
    // Algorithm 3 assignment and pricing
    var matchedList = [];
    for (var i=0; i<candidateAsks.length; i++) {
      var record = {};
      record["used"] = false;
      record["result"] = "N/A";
      record["item"] = candidateAsks[i]["item"];
      record["seller"] = candidateAsks[i]["seller"];
      record["sellerPrice"] = askThrValue;
      var bids = findAllElements(candidateBids, "item", candidateAsks[i]["item"]);
	  //在匹配的买方中找到给该资源报价的所有买方
      record["bidder"] = bids[0]["bidder"];  
      if (bids.length == 1) {
	  //如果只有一个买方报价
        record["bidderPrice"] = bidThrValue;
		//将成交价格设定为买方的阈值价格
      } else {
        record["bidderPrice"] = bids[1]["price"];
		//如果有至少两个报价，那么按照次价格设定成交价
      }
      matchedList.push(record);  
    }
    
    // Algorithm 4 winner elimination  
    var listFinal = [];
    for (var i=0; i<matchedList.length; i++) {
      var finalRecordList = findAllElements(listFinal, "bidder", matchedList[i]["bidder"]);
	  
      if (finalRecordList.length != 0) {
        break;    //如果listFinal中已经存在这个买方了，就break
      }
      var matches = findAllElements(matchedList, "bidder", matchedList[i]["bidder"]);
	  //找到和同个买方的所有情况
      if (matches.length == 1) {  //没有同个买方多个匹配结果，直接加入listFinal
        listFinal.push(matches[0]);
      } else {
	     //如果有同个买方多个匹配结果
        var utilities = [];
        for (var j = 0; j < matches.length; j++) {         
          var bidPrice = findAllElements(
            findAllElements(Global.bids, "bidder", matches[j]["bidder"]), 
            "item", matches[j]["item"])[0]["price"];  
			//同个买方同个资源的最初报价 
          var finalPrice = matches[j]["bidderPrice"];  //成交报价
          utilities.push(bidPrice-finalPrice);  //效用
        }
        var maxU = Number.MIN_VALUE;
        var maxUIndex = -1;
        for (var j = 0; j < utilities.length; j++) {
          if (utilities[j] > maxU) {
            maxU = utilities[j];
            maxUIndex = j;
          }
        }
        listFinal.push(matches[maxUIndex]);
      }
    }
    Global.listFinal = listFinal;
    Global.status = "Finalized";
    return "Success";
  }
  
  @Cost({"countGas":true,"extraGas":"getFinalPrice"})
  export function execute(arg) {
    if (Global.status != "Finalized") {
      return "Bidding has not been finalized!"
    }
    var args = JSON.parse(arg);
    var winningBid = false;
    for (var i=0; i < Global.listFinal.length; i++) {
      if (Global.listFinal[i]["used"]) {
        continue;
      }
      if (Global.listFinal[i]["item"]==args["item"] && Global.listFinal[i]["bidder"]==requester) {
        winningBid = true;
        Global.listFinal[i]["used"] = true;
        Global.listFinal[i]["result"] = "Success";
        break;
      }
    }
    if (!winningBid) {
      return "Access Denied";
    }
    print(args["item"] + " used by " + requester);
    return "Success";
  }
  
  export function getFinalPrice(arg) {
    var args = JSON.parse(arg);
    var winningPrice = 0;
    for (var i=0; i < Global.listFinal.length; i++) {
      if (Global.listFinal[i]["item"]==args["item"] && Global.listFinal[i]["bidder"]==requester) {
        winningPrice = Global.listFinal[i]["bidderPrice"];
        break;
      }
    }
    return winningPrice;
  }  
  
  export function resetStatus(arg) {
    if (requester != Global.owner) {
      return "Access Denied"
    }
    Global.bids = [];
    Global.asks = [];
    Global.listFinal = [];
    Global.status = "Bidding";
    return "Success";
  }

  function sortObjectArray(arr, prop, isAsc) {
  //数组arr按照属性prp的值升序/降序排列
    if (isAsc) {
      for (var a=0; a < arr.length; a++) {
        for (var b=0; b < arr.length-1-a; b++) {
          if (arr[b][prop] > arr[b+1][prop]) {
            var tmp = arr[b];
            arr[b] = arr[b+1];
            arr[b+1] = tmp;
          }
        }
      }
    } else {
      for (var a=0; a < arr.length; a++) {
        for (var b=0; b < arr.length-1-a; b++) {
          if (arr[b][prop] < arr[b+1][prop]) {
            var tmp = arr[b];
            arr[b] = arr[b+1];
            arr[b+1] = tmp;
          }
        }
      }
    }
    return arr;
  }

  function findAllElements(arr, prop, value) {
  //找到arr的prop属性等于value的所有元素
    var newArr = [];
    for (var a = 0; a < arr.length; a++) {
      if (arr[a][prop] == value) {
        newArr.push(arr[a]);
      }
    }
    return newArr;
  }

  export function getFinalListOwner(arg) {
    if (requester != Global.owner) {
      return "Access Denied";
    }
    var retList = [];
    for (var i = 0; i < Global.listFinal.length; i++) {
      var fin = {};
      fin["item"] = Global.listFinal[i]["item"];
      fin["seller"] = Global.listFinal[i]["seller"];
      fin["bidder"] = Global.listFinal[i]["bidder"];
      fin["sellerPrice"] = Global.listFinal[i]["sellerPrice"];
      fin["bidderPrice"] = Global.listFinal[i]["bidderPrice"];
      fin["used"] = Global.listFinal[i]["used"];
      fin["result"] = "Unknown";
      retList.push(fin);
    }
    return JSON.stringify(retList);
  }

  export function getFinalListPrivate(arg) {
    var retList = [];
    for (var i = 0; i < Global.listFinal.length; i++) {
      var fin = {};
      fin["item"] = Global.listFinal[i]["item"];
      fin["used"] = Global.listFinal[i]["used"];
      if (Global.bids[i]["bidder"]==requester && Global.bids[i]["seller"]==requester) {
        fin["seller"] = Global.listFinal[i]["seller"];
        fin["bidder"] = Global.listFinal[i]["bidder"];
        fin["sellerPrice"] = Global.listFinal[i]["sellerPrice"];
        fin["bidderPrice"] = Global.listFinal[i]["bidderPrice"];
        fin["result"] = Global.listFinal[i]["result"];
        fin["canExecute"] = true;
        retList.push(fin);
        fin["result"] = Global.listFinal[i]["result"];
      } else if (Global.bids[i]["bidder"]==requester) {
        fin["seller"] = "Anonymous";
        fin["bidder"] = Global.listFinal[i]["bidder"];
        fin["sellerPrice"] = "Unknown";
        fin["bidderPrice"] = Global.listFinal[i]["bidderPrice"];
        fin["result"] = Global.listFinal[i]["result"];
        fin["canExecute"] = true;
        retList.push(fin);
      } else if (Global.bids[i]["seller"]==requester) {
        fin["seller"] = Global.listFinal[i]["seller"];
        fin["bidder"] = "Anonymous";
        fin["sellerPrice"] = Global.listFinal[i]["sellerPrice"];
        fin["bidderPrice"] = "Unknown";
        fin["result"] = "Unknown";
        fin["canExecute"] = false;
        retList.push(fin);
      }
    }
    return JSON.stringify(retList);
  }
}