//-- copyright
// OpenProject is a project management system.
// Copyright (C) 2012-2014 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) 2006-2013 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 doc/COPYRIGHT.rdoc for more details.
//++

// TODO move to UI components
module.exports = function($sce, LABEL_MAX_CHARS, KEY_CODES) {
  return {
    restrict: 'E',
    replace: true,
    scope: {
      selectedTitle: '=',
      groups: '=',
      transitionMethod: '='
    },
    templateUrl: '/templates/components/selectable_title.html',
    link: function(scope) {
      scope.$watch('groups', refreshFilteredGroups);
      scope.$watch('selectedId', selectTitle);

      function refreshFilteredGroups() {
        if(scope.groups){
          initFilteredModels();
        }
      }

      function selectTitle() {
        angular.forEach(scope.filteredGroups, function(group) {
          if(group.models.length) {
            angular.forEach(group.models, function(model){
              model.highlighted = model.id == scope.selectedId;
            });
          }
        });
      }

      function initFilteredModels() {
        scope.filteredGroups = angular.copy(scope.groups);
        angular.forEach(scope.filteredGroups, function(group) {
          group.models = group.models.map(function(model){
            return {
              label: model[0],
              labelHtml: $sce.trustAsHtml(truncate(model[0], LABEL_MAX_CHARS)),
              id: model[1],
              highlighted: false
            };
          });
        });
      }

      function labelHtml(label, filterBy) {
        filterBy = filterBy.toLowerCase();
        label = truncate(label, LABEL_MAX_CHARS);
        if(label.toLowerCase().indexOf(filterBy) >= 0) {
          var labelHtml = label.substr(0, label.toLowerCase().indexOf(filterBy))
            + "<span class='filter-selection'>" + label.substr(label.toLowerCase().indexOf(filterBy), filterBy.length) + "</span>"
            + label.substr(label.toLowerCase().indexOf(filterBy) + filterBy.length);
        } else {
          var labelHtml = label;
        }
        return $sce.trustAsHtml(labelHtml);
      }

      function truncate(text, chars) {
        if (text.length > chars) {
          return text.substr(0, chars) + "...";
        }
        return text;
      }

      function modelIndex(models) {
        return models.map(function(model){
          return model.id;
        }).indexOf(scope.selectedId);
      }

      function performSelect() {
        scope.transitionMethod(scope.selectedId);
      }

      function nextNonEmptyGroup(groups, currentGroupIndex) {
        currentGroupIndex = (currentGroupIndex == undefined) ? -1 : currentGroupIndex;
        while(currentGroupIndex < groups.length - 1) {
          if(groups[currentGroupIndex + 1].models.length) {
            return groups[currentGroupIndex + 1];
          }
          currentGroupIndex = currentGroupIndex + 1;
        }
        return null;
      }

      function previousNonEmptyGroup(groups, currentGroupIndex) {
        while(currentGroupIndex > 0) {
          if(groups[currentGroupIndex - 1].models.length) {
            return groups[currentGroupIndex - 1];
          }
          currentGroupIndex = currentGroupIndex - 1;
        }
        return null;
      }

      function getModelPosition(groups, selectedId) {
        for(var group_index = 0; group_index < groups.length; group_index++) {
          var models = groups[group_index].models;
          var model_index = modelIndex(models);
          if(model_index >= 0) {
            return {
              group: group_index,
              model: model_index
            };
          }
        }
        return false;
      }

      function selectNext() {
        var groups = scope.filteredGroups;
        if(!scope.selectedId) {
          var nextGroup = nextNonEmptyGroup(groups);
          scope.selectedId = nextGroup ? nextGroup.models[0].id : 0;
        } else {
          var position = getModelPosition(groups, scope.selectedId);
          if (!position) return;
          var models = groups[position.group].models;

          if(position.model == models.length - 1){ // It is the last in the group
            var nextGroup = nextNonEmptyGroup(groups, position.group);
            if(nextGroup) {
              scope.selectedId = nextGroup.models[0].id;
            }
          } else {
            scope.selectedId = models[position.model + 1].id;
          }
        }
      }

      function selectPrevious() {
        var groups = scope.filteredGroups;
        if(scope.selectedId) {
          var position = getModelPosition(groups, scope.selectedId);
          if (!position) return;
          var models = groups[position.group].models;

          if(position.model == 0){ // It is the last in the group
            var previousGroup = previousNonEmptyGroup(groups, position.group);
            if(previousGroup) {
              scope.selectedId = previousGroup.models[previousGroup.models.length - 1].id;
            }
          } else {
            scope.selectedId = models[position.model - 1].id;
          }
        }
      }

      function preventDefault(event) {
        event.preventDefault();
        event.stopPropagation();
      }

      angular.element('#title-filter').bind('click', function(event) {
        preventDefault(event);
      });

      scope.handleSelection = function(event) {
        switch(event.which) {
          case KEY_CODES.enter:
            performSelect();
            preventDefault(event);
            break;
          case KEY_CODES.down:
            selectNext();
            preventDefault(event);
            break;
          case KEY_CODES.up:
            selectPrevious();
            preventDefault(event);
            break;
          default:
            break;
        }
      };

      scope.reload = function(modelId, newTitle) {
        scope.selectedTitle = newTitle;
        scope.reloadMethod(modelId);
        scope.$emit('hideAllDropdowns');
      };

      scope.filterModels = function(filterBy) {
        initFilteredModels();

        scope.selectedId = 0;
        angular.forEach(scope.filteredGroups, function(group) {
          if(filterBy.length) {
            group.filterBy = filterBy;
            group.models = group.models.filter(function(model){
              return model.label.toLowerCase().indexOf(filterBy.toLowerCase()) >= 0;
            });

            if(group.models.length) {
              angular.forEach(group.models, function(model){
                model['labelHtml'] = labelHtml(model.label, filterBy);
              });
              if(!scope.selectedId) {
                group.models[0].highlighted = true;
                scope.selectedId = group.models[0].id;
              }
            }
          }
        });
      };
    }
  };
};