angular.module('openproject.workPackages.helpers')

.factory('WorkPackagesTableHelper', ['WorkPackagesHelper', function(WorkPackagesHelper) {
  var WorkPackagesTableHelper = {
    /* builds rows from work packages, see IssuesHelper */
    getRows: function(workPackages, groupBy) {
      var rows = [], ancestors = [];
      var currentGroup, allGroups = [], groupIndex = -1;

      angular.forEach(workPackages, function(workPackage, i) {
        while(ancestors.length > 0 && workPackage.parent_id !== ancestors.last().object.id) {
          // this helper method only reflects hierarchies if nested work packages follow one another
          ancestors.pop();
        }


        // compose row

        var row = {
          level: ancestors.length,
          parent: ancestors.last(),
          ancestors: ancestors.slice(0),
          object: workPackage
        };

        // manage groups

        // this helper method assumes that the work packages are passed in in blocks each of which consisting of work packages which belong to one group

        if (groupBy) {
          currentGroup = WorkPackagesHelper.getRowObjectContent(workPackage, groupBy);

          if(allGroups.indexOf(currentGroup) === -1) {
            allGroups.push(currentGroup);
            groupIndex++;
          }

          angular.extend(row, {
            groupIndex: groupIndex,
            groupName: currentGroup
          });
        }

        rows.push(row);

        if (!workPackage['leaf?']) ancestors.push(row);
      });

      return rows;
    },

    allRowsChecked: function(rows) {
      if( rows.length == 0 ) return false;
      return rows
        .map(function(row) {
          return !!row.checked;
        })
        .reduce(function(a, b){
          return a && b;
        });
    },

    getColumnDifference: function (allColumns, columns) {
      var columnValues = columns.map(function(column){
        return column.name;
      });

      return allColumns.filter(function(column) {
        return !(columnValues.indexOf(column.name) > -1);
      });
    },

    getColumnIndexByName: function(columns, columnName) {
      return columns
        .map(function(column){
          return column.name;
        })
        .indexOf(columnName);
    },

    detectColumnByName: function(columns, columnName) {
      return columns[WorkPackagesTableHelper.getColumnIndexByName(columns, columnName)];
    },

    selectColumnsByName: function(columns, columnNames) {
      return columns.filter(function(column) {
        return columnNames.indexOf(column.name) !== -1;
      });
    },

    moveElementBy: function(array, index, positions) {
      // TODO maybe extend the Array prototype
      var newPosition = index + positions;

      if (newPosition > -1 && newPosition < array.length) {
        var elementToMove = array.splice(index, 1).first();
        array.splice(newPosition, 0, elementToMove);
      }
    },

    moveColumnBy: function(columns, columnName, by) {
      var index = WorkPackagesTableHelper.getColumnIndexByName(columns, columnName);

      WorkPackagesTableHelper.moveElementBy(columns, index, by);
    }

  };

  return WorkPackagesTableHelper;
}]);