'use strict';

var getBusinessObject = require('bpmn-js/lib/util/ModelUtil').getBusinessObject,
    is = require('bpmn-js/lib/util/ModelUtil').is;

var factory = require('../../../../factory/EntryFactory');

var elementHelper = require('../../../../helper/ElementHelper'),
    extensionElementsHelper = require('../../../../helper/ExtensionElementsHelper'),
    cmdHelper = require('../../../../helper/CmdHelper'),
    utils = require('../../../../Utils');

var assign = require('lodash/assign'),
    forEach = require('lodash/forEach'),
    find = require('lodash/find');

function generatePropertyId() {
  return utils.nextId('Property_');
}

/**
 * Get all activiti:property objects for a specific business object
 *
 * @param  {ModdleElement} parent
 *
 * @return {Array<ModdleElement>} a list of activiti:property objects
 */
function getPropertyValues(parent) {
  var properties = parent && getPropertiesElement(parent);
  if (properties && properties.values) {
    return properties.values;
  }
  return [];
}

/**
 * Get all activiti:Properties object for a specific business object
 *
 * @param  {ModdleElement} parent
 *
 * @return {ModdleElement} a activiti:Properties object
 */
function getPropertiesElement(element) {
  if (!isExtensionElements(element)) {
    return element.properties;
  } else {
    return getPropertiesElementInsideExtensionElements(element);
  }
}

/**
 * Get first activiti:Properties object for a specific bpmn:ExtensionElements
 * business object.
 *
 * @param {ModdleElement} extensionElements
 *
 * @return {ModdleElement} a activiti:Properties object
 */
function getPropertiesElementInsideExtensionElements(extensionElements) {
  return find(extensionElements.values, function(elem) {
    return is(elem, 'activiti:Properties');
  });
}

/**
 * Returns true, if the given business object is a bpmn:ExtensionElements.
 *
 * @param {ModdleElement} element
 *
 * @return {boolean} a boolean value
 */
function isExtensionElements(element) {
  return is(element, 'bpmn:ExtensionElements');
}

/**
 * Create a activiti:property entry using tableEntryFactory
 *
 * @param  {djs.model.Base} element
 * @param  {BpmnFactory} bpmnFactory
 * @param  {Object} options
 * @param  {string} options.id
 * @param  {Array<string>} options.modelProperties
 * @param  {Array<string>} options.labels
 * @param  {function} options.getParent Gets the parent business object
 * @param  {function} options.show Indicate when the entry will be shown, should return boolean
 */
module.exports = function(element, bpmnFactory, options, translate) {

  var getParent = options.getParent;

  var modelProperties = options.modelProperties,
      createParent = options.createParent;

  var bo = getBusinessObject(element);
  if (is(element, 'bpmn:Participant')) {
    bo = bo.get('processRef');
  }

  // build properties group only when the participant have a processRef
  if (!bo) {
    return;
  }

  assign(options, {
    addLabel: translate('Add Property'),
    getElements: function(element, node) {
      var parent = getParent(element, node, bo);
      return getPropertyValues(parent);
    },
    addElement: function(element, node) {
      var commands = [],
          parent = getParent(element, node, bo);

      if (!parent && typeof createParent === 'function') {
        var result = createParent(element, bo);
        parent = result.parent;
        commands.push(result.cmd);
      }

      var properties = getPropertiesElement(parent);
      if (!properties) {
        properties = elementHelper.createElement('activiti:Properties', {}, parent, bpmnFactory);

        if (!isExtensionElements(parent)) {
          commands.push(cmdHelper.updateBusinessObject(element, parent, { 'properties': properties }));
        } else {
          commands.push(cmdHelper.addAndRemoveElementsFromList(
            element,
            parent,
            'values',
            'extensionElements',
            [ properties ],
            []
          ));
        }
      }

      var propertyProps = {};
      forEach(modelProperties, function(prop) {
        propertyProps[prop] = undefined;
      });

      // create id if necessary
      if (modelProperties.indexOf('id') >= 0) {
        propertyProps.id = generatePropertyId();
      }

      var property = elementHelper.createElement('activiti:Property', propertyProps, properties, bpmnFactory);
      commands.push(cmdHelper.addElementsTolist(element, properties, 'values', [ property ]));

      return commands;
    },
    updateElement: function(element, value, node, idx) {
      var parent = getParent(element, node, bo),
          property = getPropertyValues(parent)[idx];

      forEach(modelProperties, function(prop) {
        value[prop] = value[prop] || undefined;
      });

      return cmdHelper.updateBusinessObject(element, property, value);
    },
    validate: function(element, value, node, idx) {
      // validate id if necessary
      if (modelProperties.indexOf('id') >= 0) {

        var parent = getParent(element, node, bo),
            properties = getPropertyValues(parent),
            property = properties[idx];

        if (property) {
          // check if id is valid
          var validationError = utils.isIdValid(property, value.id, translate);

          if (validationError) {
            return { id: validationError };
          }
        }
      }
    },
    removeElement: function(element, node, idx) {
      var commands = [],
          parent = getParent(element, node, bo),
          properties = getPropertiesElement(parent),
          propertyValues = getPropertyValues(parent),
          currentProperty = propertyValues[idx];

      commands.push(cmdHelper.removeElementsFromList(element, properties, 'values', null, [ currentProperty ]));

      if (propertyValues.length === 1) {
        // remove activiti:properties if the last existing property has been removed
        if (!isExtensionElements(parent)) {
          commands.push(cmdHelper.updateBusinessObject(element, parent, { properties: undefined }));
        } else {
          forEach(parent.values, function(value) {
            if (is(value, 'activiti:Properties')) {
              commands.push(extensionElementsHelper.removeEntry(bo, element, value));
            }
          });
        }
      }

      return commands;
    }
  });

  return factory.table(options);
};