//-- copyright
// OpenProject is a project management system.
// Copyright (C) 2012-2018 the OpenProject Foundation (OPF)
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License version 3.
//
// OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
// Copyright (C) 2006-2017 Jean-Philippe Lang
// Copyright (C) 2010-2013 the ChiliProject Team
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
// See docs/COPYRIGHT.rdoc for more details.
//++


// Boilerplate code for remote autocompletion/infinite scrolling.
// Borrows graciously from select2

(function ($, undefined) {
  "use strict";

  function Autocompleter (object, args) {
    this.element = $(object);
    this.opts = null;
    this.fakeInput = null;
    this.initOptions(args);
    this.setupInput();
    this.initSelect2();
  }

  function makeSortable(input) {
    input.select2("container").find("ul.select2-choices").sortable({
      containment: 'parent',
      start: function() {
        input.select2("onSortStart");
      },
      update: function() {
        input.select2("onSortEnd");
      }
    });
  }

  function hasAttribute(element, attributeName) {
    return element.attr(attributeName) && element.attr(attributeName) !== "";
  }

  Autocompleter.prototype = {
    initOptions: function (args) {
      this.opts = $.extend(true, {}, $.fn.autocomplete.defaults, args[0]);

      if (hasAttribute(this.element, "data-ajaxURL")) {
        this.opts.ajax.url = this.element.attr("data-ajaxURL");
      }

      if (hasAttribute(this.element, "data-values")) {
        this.opts.data.results = JSON.parse(this.element.attr('data-values')).map(function (e) {
          e.text = e.text || e.name;
          return e;
        });
        delete this.opts.ajax;
      }
    },

    setupInput: function () {
      if (this.element.is("input")) {
        this.fakeInput = this.element;
      } else {
        $("input[name='" + this.element.attr("name")+"']").remove();

        this.createNewInput();
        this.setInputValue();

        this.element.remove();
      }

      this.fakeInput.data("autocompleter", this);
    },

    createNewInput: function () {
      var attrs_to_copy = {}, currentName, select2id;

      for(var i = 0; i < this.element.get(0).attributes.length; i++) {
        currentName = this.element.get(0).attributes[i].name;
        if(currentName.indexOf("data-") === 0 || $.inArray(currentName, this.opts.allowedAttributes) !== -1) { //only ones starting with data-
          attrs_to_copy[currentName] = this.element.attr(currentName);
        }
      }

      select2id = this.element.attr("id");
      this.fakeInput = this.element.after("<input type='hidden' id='" + select2id + "'></input>").siblings(":input#" + select2id);
      this.fakeInput.attr(attrs_to_copy);
    },

    setInputValue: function () {
      var values = [];
      if (hasAttribute(this.fakeInput, "data-selected")) {
        _.each(JSON.parse(this.fakeInput.attr('data-selected')), function (elem) {
          values.push(elem[1]);
        });

        this.fakeInput.val(values);
      }
    },

    initSelect2: function () {
      $(this.fakeInput).select2(this.opts);

      if (this.opts.sortable) {
        makeSortable($(this.fakeInput));
      }
    }
  };

  $.fn.autocomplete = function () {
    var args = Array.prototype.slice.call(arguments, 0),
        autocompleter;

    $(this).each(function () {
      autocompleter = new Autocompleter($(this), args);
    });
  };

  $.fn.autocomplete.defaults = {
    multiple: false,
    data: {},
    allowedAttributes: ["title", "placeholder", "id", "name"],
    minimumInputLength: 0,
    ajax: {
      null_element: null,
      dataType: 'json',
      quietMillis: 500,
      contentType: "application/json",
      data: function (term, page) {
        return {
          q: term, //search term
          page_limit: 10, // page size
          page: page // current page number
        };
      },
      results: function (data, page) {
        var active_items = [];
        _.each(data.results.items, function (e) {
          active_items.push(e);
        });
        active_items = this.add_null_element(active_items, page);
        return {'results': active_items, 'more': data.results.more};
      },
      add_null_element: function (results, page) {
        if (this.null_element === null || this.null_element === undefined || page !== 1) {
          return results;
        }
        return [this.null_element].concat(results);
      }
    },
    formatResult: function (item, container, query) {
      var match = item.name.toUpperCase().indexOf(query.term.toUpperCase()),
      tl = query.term.length,
      markup = [];

      if (match < 0) {
        return "<span data-value='" + item.id + "'>" +
          _.escape(item.name) + "</span>";
      }

      markup.push(_.escape(
                  item.name.substring(0, match)));
      markup.push("<span class='select2-match' data-value='" + item.id + "'>");
      markup.push(_.escape(
                  item.name.substring(match, match + tl)));
      markup.push("</span>");
      markup.push(_.escape(
                  item.name.substring(match + tl, item.name.length)));
      return markup.join("");
    },
    formatSelection: function (item) {
      return _.escape(item.name);
    },
    initSelection: function (element, callback) {
      var data = [], multiple;

      if (hasAttribute(element, "data-selected")) {
        multiple = element.data("autocompleter").opts.multiple;
        _.each(JSON.parse(element.attr('data-selected')), function (elem) {
          if (multiple) {
            data.push({id: elem[1], name: elem[0]});
          } else {
            data = {id: elem[1], name: elem[0]};
          }
        });
      } else if (element.is("input") && hasAttribute(element, "data-values")) {
        var possible = JSON.parse(element.attr('data-values'));
        var vals = element.val().split(",");
        var byID = {};

        var i;
        for (i = 0; i < possible.length; i += 1) {
          byID[possible[i].id] = possible[i];
        }

        for (i = 0; i < vals.length; i += 1) {
          if (byID[vals[i]]) {
            data.push(byID[vals[i]]);
          } else {
            data.push({ id: vals[i], name: vals[i] });
          }
        }
      }

      callback(data);
    }
  };
}(jQuery));