window.onload = init;

function init() {
  removeWhitespace(getSearchCriteriaBodyElement());
}

function addSearchCriterion() {
  var rootElement = getSearchCriteriaBodyElement();
  var criteriaCount = rootElement.childNodes.length;
  
  var row = createNewSearchCriteriumRow(criteriaCount + 1);
  rootElement.appendChild(row);
  resetControls();
}

function deleteSearchCriterium(index) {
  var rootElement = getSearchCriteriaBodyElement();
  var child = rootElement.childNodes[index];
  rootElement.removeChild(child);
  
  resetControls();
}

function getSearchCriteriaBodyElement() {
  return document.getElementById("search_criteria_body");
}

function createNewSearchCriteriumRow(criteriumNr) {
  var row = document.createElement("tr");
  
  row.appendChild(createNewSearchFieldCell(criteriumNr));
  row.appendChild(createNewSearchRelationCell(criteriumNr));
  row.appendChild(createNewSearchTermCell(criteriumNr));
  row.appendChild(createNewSearchCriteriumDeleteCell(criteriumNr));
  
  return row;
}

function createNewSearchFieldCell(criteriumNr) {
  var cell = document.createElement("td");
  cell.appendChild(createNewSearchFieldInput(criteriumNr));

  return cell;
}

function createNewSearchFieldInput(criteriumNr) {
  var input = document.createElement("select");
  
  input.setAttribute("id",   "search_field_" + criteriumNr + "_input");
  input.setAttribute("name", "search_field_" + criteriumNr);
  
  input.appendChild(createSelectOption("1", "Title/Subtitle"));
  input.appendChild(createSelectOption("2", "Author"));
  input.appendChild(createSelectOption("3", "Keywords"));
  input.appendChild(createSelectOption("4", "Abstract"));
  input.appendChild(createSelectOption("5", "Full Text"));
  input.appendChild(createSelectOption("6", "Notes"));
  input.appendChild(createSelectOption("0", "*Any"));
  
  return input;
}

function createNewSearchRelationCell(criteriumNr) {
  var cell = document.createElement("td");
  cell.appendChild(createNewSearchRelationInput(criteriumNr));
  
  return cell;
}

function createNewSearchRelationInput(criteriumNr) {
  var input = document.createElement("select");
  
  input.setAttribute("id",   "search_relation_" + criteriumNr + "_input");
  input.setAttribute("name", "search_relation_" + criteriumNr);
  
  input.appendChild(createSelectOption("2", "Contains"));
  input.appendChild(createSelectOption("3", "Does not contain"));
  input.appendChild(createSelectOption("0", "Matches"));
  input.appendChild(createSelectOption("1", "Does not match"));
  
  return input;
}

function createNewSearchTermCell(criteriumNr) {
  var cell = document.createElement("td");
  cell.appendChild(createNewSearchTermInput(criteriumNr));
  
  return cell;
}

function createNewSearchTermInput(criteriumNr) {
  var input = document.createElement("input");
  
  input.setAttribute("type", "text");
  input.setAttribute("id",   "search_term_" + criteriumNr + "_input");
  input.setAttribute("name", "search_term_" + criteriumNr);
  
  return input;
}

function createNewSearchCriteriumDeleteCell(criteriumNr) {
  var cell = document.createElement("td");
  cell.appendChild(createNewSearchCriteriumDeleteLink(criteriumNr));
  
  return cell;
}

function createNewSearchCriteriumDeleteLink(criteriumNr) {
  var link    = document.createElement("a");
  
  link.setAttribute("href", "#");
  link.onclick = function(){deleteSearchCriterium(criteriumNr - 1);};
  link.innerHTML = "delete";

  return link;
}

function resetControls() {
  var rootElement = getSearchCriteriaBodyElement();
  var criteriaCount = rootElement.childNodes.length;
  
  for(var i = 0; i < criteriaCount; i++) {
    var row = rootElement.childNodes[i];
    setSearchCriteriumControlNames(row, i + 1, criteriaCount > 1);
  }
  
  displayMatchOptions(criteriaCount > 1);
}

function displayMatchOptions(visible) {
  var matchOptions = document.getElementById("match_options");
  
  if(visible) {
    matchOptions.style.visibility = "visible";
  } else {
    matchOptions.style.visibility = "hidden";
  }
}

function setSearchCriteriumControlNames(row, criteriumNr, deleteVisible) {
  var input = row.childNodes[0].childNodes[0];

  input.setAttribute("id",   "search_field_" + criteriumNr + "_input");
  input.setAttribute("name", "search_field_" + criteriumNr);
  
  input = row.childNodes[1].childNodes[0];
  input.setAttribute("id",   "search_relation_" + criteriumNr + "_input");
  input.setAttribute("name", "search_relation_" + criteriumNr);
  
  input = row.childNodes[2].childNodes[0];
  input.setAttribute("id",   "search_term_" + criteriumNr + "_input");
  input.setAttribute("name", "search_term_" + criteriumNr);
  
  var link     = row.childNodes[3].childNodes[0];
  link.onclick = function() {deleteSearchCriterium(criteriumNr - 1)};

  if(deleteVisible) {
    link.style.visibility = "visible";
  } else {
    link.style.visibility = "hidden";
  }
}

function createSelectOption(value, text) {
  var option = document.createElement("option");
  
  option.setAttribute("value", value);
  option.innerHTML = text;
  
  return option;
}

function viewDocument(documentId) {
  var url = "view_document.html?document_id=" + documentId;
  
  window.open(url, "Document", "toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=1,width=800px,height=600px,left=300,top=300");
}

function removeWhitespace(element) {
  for(var i = 0; i < element.childNodes.length; i++) {
    if(!element.childNodes[i].tagName) {
      element.removeChild(element.childNodes[i]);
      i--;
    } else if(element.childNodes[i].childNodes.length > 0 && element.childNodes[i].tagName != "OPTION" && element.childNodes[i].tagName != "INPUT" && element.childNodes[i].tagName != "A") {
      removeWhitespace(element.childNodes[i]);
    }
  }
}

function openHelpPopup() {
  window.open("view_help.html", "Help", "toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=1,width=800px,height=600px,left=300,top=300");
}
function openRequestPopup() {
  window.open("request.html", "Request", "toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=1,width=700px,height=600px,left=300,top=300");
}
function openRequestHelpPopup() {
  window.open("request_help.html", "RequestHelp", "toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=1,width=700px,height=600px,left=300,top=300");
}