Orchard/src/Orchard.Web/Modules/Orchard.Widgets/Services/WidgetsService.cs

using System.Collections.Generic;
using System.Linq;
using JetBrains.Annotations;
using Orchard.ContentManagement;
using Orchard.ContentManagement.Aspects;
using Orchard.Themes;
using Orchard.Widgets.Models;

namespace Orchard.Widgets.Services {

    [UsedImplicitly]
    public class WidgetsService : IWidgetsService {
        private readonly IThemeService _themeService;
        private readonly IContentManager _contentManager;

        public WidgetsService(
            IContentManager contentManager,
            IThemeService themeService) {

            _contentManager = contentManager;
            _themeService = themeService;
        }

        public IEnumerable<string> GetWidgetTypes() {
            return _contentManager.GetContentTypeDefinitions()
                .Where(contentTypeDefinition => contentTypeDefinition.Settings.ContainsKey("Stereotype") && contentTypeDefinition.Settings["Stereotype"] == "Widget")
                .Select(contentTypeDefinition => contentTypeDefinition.Name);
        }

        public IEnumerable<LayerPart> GetLayers() {
            return _contentManager
                .Query<LayerPart, LayerPartRecord>()
                .List();
        }

        public IEnumerable<WidgetPart> GetWidgets() {
            return _contentManager
                .Query<WidgetPart, WidgetPartRecord>()
                .List();
        }

        public IEnumerable<string> GetZones() {
            HashSet<string> zones = new HashSet<string>();

            foreach (var theme in _themeService.GetInstalledThemes().Where(theme => theme.Zones != null && !theme.Zones.Trim().Equals(string.Empty))) {
                foreach (string zone in theme.Zones.Split(',').Where(zone => !zones.Contains(zone))) {
                    zones.Add(zone.Trim());
                }
            }

            return zones;
        }

        public IEnumerable<WidgetPart> GetWidgets(int layerId) {
            return GetWidgets().Where(widgetPart => widgetPart.As<ICommonPart>().Container.ContentItem.Id == layerId);
        }

        public LayerPart GetLayer(int layerId) {
            return GetLayers().FirstOrDefault(layer => layer.Id == layerId);
        }

        public LayerPart CreateLayer(string name, string description, string layerRule) {
            LayerPart layerPart = _contentManager.Create<LayerPart>("Layer",
                layer => {
                    layer.Record.Name = name;
                    layer.Record.Description = description;
                    layer.Record.LayerRule = layerRule;
                });

            return layerPart;
        }

        public void UpdateLayer(int layerId, string name, string description, string layerRule) {
            LayerPart layerPart = GetLayer(layerId);
            layerPart.Record.Name = name;
            layerPart.Record.Description = description;
            layerPart.Record.LayerRule = layerRule;
        }

        public void DeleteLayer(int layerId) {
            _contentManager.Remove(GetLayer(layerId).ContentItem);
        }

        public WidgetPart GetWidget(int widgetId) {
            return GetWidgets().FirstOrDefault(widgetPart => widgetPart.Id == widgetId);
        }

        public WidgetPart CreateWidget(int layerId, string widgetType, string title, string position, string zone) {
            LayerPart layerPart = GetLayer(layerId);

            WidgetPart widgetPart = _contentManager.Create<WidgetPart>(widgetType,
                widget => {
                    widget.Record.Title = title;
                    widget.Record.Position = position;
                    widget.Record.Zone = zone;
                    widget.LayerPart = layerPart;
                });

            return widgetPart;
        }

        public void UpdateWidget(int widgetId, string title, string position, string zone) {
            WidgetPart widgetPart = GetWidget(widgetId);
            widgetPart.Record.Title = title;
            widgetPart.Record.Position = position;
            widgetPart.Record.Zone = zone;
        }

        public void DeleteWidget(int widgetId) {
            _contentManager.Remove(GetWidget(widgetId).ContentItem);
        }

        public void MoveWidgetUp(int widgetId) {
            WidgetPart widgetPart = GetWidget(widgetId);
            
            int currentPosition = int.Parse(widgetPart.Record.Position);
            if (currentPosition > 0) {
                WidgetPart widgetBefore = GetWidgets(widgetPart.LayerPart.Id).FirstOrDefault(widgetPartBefore => widgetPartBefore.Record.Position == (currentPosition - 1).ToString());
                widgetBefore.Record.Position = currentPosition.ToString();
                widgetPart.Record.Position = (currentPosition - 1).ToString();
            }
        }

        public void MoveWidgetDown(int widgetId) {
            WidgetPart widgetPart = GetWidget(widgetId);

            int currentPosition = int.Parse(widgetPart.Record.Position);
            if (currentPosition < GetWidgets(widgetPart.LayerPart.Id).Count()) {
                WidgetPart widgetAfter = GetWidgets(widgetPart.LayerPart.Id).FirstOrDefault(widgetPartAfter => widgetPartAfter.Record.Position == (currentPosition + 1).ToString());
                widgetAfter.Record.Position = currentPosition.ToString();
                widgetPart.Record.Position = (currentPosition + 1).ToString();
            }            
        }
    }
}