loadLibrary("lf:exprParser");


//--------------------------------------------------------------------------
// Web service entry point
//--------------------------------------------------------------------------
function xtk_queryFilter_BuildJS(elemQueryDef)
{
  var strSchema = elemQueryDef.@schema.toString().replace(/.*:/, "");
  var strRes = parseSubCond(elemQueryDef.where, strSchema);
  return strRes;
}

//--------------------------------------------------------------------------
// Web service entry point
//--------------------------------------------------------------------------
function xtk_queryDef_BuildJS(elemWhere, strSchema)
{
  var strRes = parseSubCond(elemWhere, strSchema.toString().replace(/.*:/,""));
  return strRes;
}


//--------------------------------------------------------------------------
// Parses conditions on child elements
//--------------------------------------------------------------------------
function parseSubCond(elem, strBasePath)
{
  var strRes = "";
  var strOp = " && ";

  for each (var elemCond in elem.condition)
  {
    if (elemCond.@setOperator != undefined)
      logError("Feature not supported: set operator " + elemCond.@setOperator)

    var strQueryCond = elemCond.@expr.toString();

    // Nested blocks?
    if (strQueryCond == "")
      var strCond = "(" + parseSubCond(elemCond, strBasePath) + ")";
    else
      strCond = parseCond(strQueryCond, strBasePath);

    strRes += (strRes == "" ? "" : strOp) + strCond;
    if (elemCond.@boolOperator == "OR")
      strOp = " || ";
    else if (elemCond.@boolOperator == "AND NOT")
      strOp = " && ! ";
    else
      strOp = " && ";
  }

  return strRes;
}

//--------------------------------------------------------------------------
// Parses XTK expression and generates matching JS expression
//--------------------------------------------------------------------------
function parseCond(strExpr, strBasePath)
{
  //logVerbose("Type: " + typeof strExpr + "  value: " + strExpr);
  try {
    var tree = vgExprParser.parse(strExpr);
    return jsExpr(tree, strBasePath);
  }
  catch (e)
  {
    if (e instanceof vgExprParser.SyntaxError)
    {
      logVerbose(strExpr);
      logError("Syntax error in expression \"" + strExpr + "\": " + e.message);
    }
    if (e instanceof JsExprException)
    {
      logError("Expression limitation in \"" + strExpr + "\": " + e.strMsg);
    }
    throw e;
  }
}

//--------------------------------------------------------------------------
// Expects an expression tree as input
//--------------------------------------------------------------------------
function jsExpr(tree, strBasePath)
{
  var strMid = "";
  switch (tree.type)
  {
    case "=":
      return jsExpr(tree.left, strBasePath) + "==" + jsExpr(tree.right, strBasePath);

    case ">":
    case "<":
    case ">=":
    case "<=":
      return jsExpr(tree.left, strBasePath) + tree.type + jsExpr(tree.right, strBasePath);

    case "!=":
    case "<>":
      return jsExpr(tree.left, strBasePath) + "!=" + jsExpr(tree.right, strBasePath);

    case "isNull":
     return jsExpr(tree.left, strBasePath) + "==''";

    case "isNotNull":
      return jsExpr(tree.left, strBasePath) + "!=''";

    case "int":
      return tree.left;

    case "str":
      return "'" + tree.left + "'";

    case "xpath":
      return jsXpathExpr(tree, strBasePath);

    case "datetime":
      return "new Date(" + tree.left.substr(0,4) + "," + (parseInt(tree.left.substr(5,2), 10) - 1) + "," + tree.left.substr(8,2) + "," +
        tree.left.substr(11,2) + "," + tree.left.substr(14,2) + "," + tree.left.substr(17,2) + "," +
        tree.left.substr(20,3) + ")";

    case "date":
      return "new Date(" + tree.left.substr(0,4) + "," + (parseInt(tree.left.substr(5,2), 10) - 1) + "," + tree.left.substr(8,2) + ")";

    default:
      throw new JsExprException(tree, strBasePath, "Feature not supported: " + tree.type);
  }
}

//--------------------------------------------------------------------------
// Translate an Xpath to a Javascript expression
// e.g.  @firstName -> recipient.firstName
//--------------------------------------------------------------------------
function jsXpathExpr(tree, strBasePath)
{
  if (strBasePath == undefined)
    var strBase = "";
  else
    strBase = strBasePath + ".";

  if (typeof tree == "undefined" || tree === null)
    return null;

  var strLeft = strBase + tree.left.replace(/^@/, "").replace(/-/g, "_");

  if (typeof tree.right == "string")
    return strLeft + "." + tree.right.replace(/^@/, "").replace(/-/g, "_");

  var strRight = jsXpathExpr(tree.right, strBasePath);
  if (strRight === null)
    return strLeft;

  return  strLeft + "." + strRight;
}

//--------------------------------------------------------------------------
// Exception for JS expression generation
//--------------------------------------------------------------------------
function JsExprException(tree, strBasePath, strMsg)
{
  this.tree = tree;
  this.strBasePath = strBasePath;
  this.strMsg = strMsg;
}