// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
/* eslint-disable no-var */

/**
 * This file contains JS functions that implement various navigation
 * features of Monorail.
 */


/**
 * Navigate the browser to the given URL.
 * @param {string} url The URL of the page to browse.
 * @param {boolean} newWindow Open a new tab or window.
 */
function TKR_go(url, newWindow) {
  if (newWindow) {
    window.open(url, '_blank');
  } else {
    document.location = url;
  }
}


/**
 * Tell the browser to scroll to the given anchor on the current page.
 * @param {string} anchor Name of the <a name="xxx"> anchor on the page.
 */
function TKR_goToAnchor(anchor) {
  document.location.hash = anchor;
}


/**
 * Get the user-editable colspec form field.  This text field is normally
 * display:none, but it is shown when the user chooses "Edit columns...".
 * We need a function to get this element because there are multiple form
 * fields on the page with name="colspec", and an IE misfeature sets their
 * id attributes as well, which makes document.getElementById() fail.
 * @return {Element} user editable colspec form field.
 */
function TKR_getColspecElement() {
  const elem = document.getElementById('colspec_field');
  return elem && elem.firstChild;
}


/**
 * Get the artifact search form field.  This is a visible text field where
 * the user enters a query for issues. This function
 * is needed because there is also the project search field on the each page,
 * and it has name="q".  An IE misfeature confuses name="..." with id="...".
 * @return {Element} artifact query form field, or undefined.
 */
function TKR_getArtifactSearchField() {
  const element = _getSearchBarComponent();
  if (!element) return $('searchq');

  return element.shadowRoot.querySelector('#searchq');
}


/**
 * Get the can selector. This function
 * @return {Element} can input element.
 */
function TKR_getArtifactCanField() {
  const element = _getSearchBarComponent();
  if (!element) return $('can');

  return element.shadowRoot.querySelector('#can');
}


function _getSearchBarComponent() {
  const element = document.querySelector('mr-header');
  if (!element) return;

  return element.shadowRoot.querySelector('mr-search-bar');
}


/**
 * Build a query string for all the common contextual values that we use.
 */
function TKR_formatContextQueryArgs() {
  let args = '';
  let colspec = _ctxDefaultColspec;
  const colSpecElem = TKR_getColspecElement();
  if (colSpecElem) {
    colspec = colSpecElem.value;
  }

  if (_ctxHotlistID != '') args += '&hotlist_id=' + _ctxHotlistID;
  if (_ctxCan != 2) args += '&can=' + _ctxCan;
  args += '&q=' + encodeURIComponent(_ctxQuery);
  if (_ctxSortspec != '') args += '&sort=' + _ctxSortspec;
  if (_ctxGroupBy != '') args += '&groupby=' + _ctxGroupBy;
  if (colspec != _ctxDefaultColspec) args += '&colspec=' + colspec;
  if (_ctxStart != 0) args += '&start=' + _ctxStart;
  if (_ctxNum != _ctxResultsPerPage) args += '&num=' + _ctxNum;
  if (!colSpecElem) args += '&mode=grid';
  return args;
}

// Fields that should use ":" when filtering.
const _PRETOKENIZED_FIELDS = [
  'owner', 'reporter', 'cc', 'commentby', 'component'];

/**
 * The user wants to narrow their search results by adding a search term
 * for the given prefix and value. Reload the issue list page with that
 * additional search term.
 * @param {string} prefix Field or label prefix, e.g., "Priority".
 * @param {string} suffix Field or label value, e.g., "High".
 */
function TKR_filterTo(prefix, suffix) {
  let newQuery = TKR_getArtifactSearchField().value;
  if (newQuery != '') newQuery += ' ';

  let op = '=';
  for (let i = 0; i < _PRETOKENIZED_FIELDS.length; i++) {
    if (prefix == _PRETOKENIZED_FIELDS[i]) {
      op = ':';
      break;
    }
  }

  newQuery += prefix + op + suffix;
  let url = 'list?can=' + TKR_getArtifactCanField().value + '&q=' + newQuery;
  if ($('sort') && $('sort').value) url += '&sort=' + $('sort').value;
  url += '&colspec=' + TKR_getColspecElement().value;
  TKR_go(url);
}


/**
 * The user wants to sort their search results by adding a sort spec
 * for the given column. Reload the issue list page with that
 * additional sort spec.
 * @param {string} colname Field or label prefix, e.g., "Priority".
 * @param {boolean} descending True if the values should be reversed.
 */
function TKR_addSort(colname, descending) {
  let existingSortSpec = '';
  if ($('sort')) {
    existingSortSpec = $('sort').value;
  }
  const oldSpecs = existingSortSpec.split(/ +/);
  let sortDirective = colname;
  if (descending) sortDirective = '-' + colname;
  const specs = [sortDirective];
  for (let i = 0; i < oldSpecs.length; i++) {
    if (oldSpecs[i] != '' && oldSpecs[i] != colname &&
        oldSpecs[i] != '-' + colname) {
      specs.push(oldSpecs[i]);
    }
  }

  const isHotlist = window.location.href.includes('/hotlists/');
  let url = isHotlist ? ($('hotlist_name').value + '?') : ('list?');
  url += ('can='+ TKR_getArtifactCanField().value + '&q=' +
      TKR_getArtifactSearchField().value);
  url += '&sort=' + specs.join('+');
  url += '&colspec=' + TKR_getColspecElement().value;
  TKR_go(url);
}

/** Convenience function for sorting in ascending order. */
function TKR_sortUp(colname) {
  TKR_addSort(colname, false);
}

/** Convenience function for sorting in descending order. */
function TKR_sortDown(colname) {
  TKR_addSort(colname, true);
}