Orchard/src/Orchard.Web/Modules/Orchard.Localization/Services/LocalizationService.cs

using System.Collections.Generic;
using System.Linq;
using Orchard.ContentManagement;
using Orchard.Localization.Models;

namespace Orchard.Localization.Services {
    public class LocalizationService : ILocalizationService {
        private readonly IContentManager _contentManager;
        private readonly ICultureManager _cultureManager;


        public LocalizationService(IContentManager contentManager, ICultureManager cultureManager) {
            _contentManager = contentManager;
            _cultureManager = cultureManager;
        }


        public LocalizationPart GetLocalizedContentItem(IContent content, string culture) {
            // Warning: Returns only the first of same culture localizations.
            return GetLocalizedContentItem(content, culture, null);
        }

        public LocalizationPart GetLocalizedContentItem(IContent content, string culture, VersionOptions versionOptions) {
            var cultureRecord = _cultureManager.GetCultureByName(culture);

            if (cultureRecord == null) return null;

            var localized = content.As<LocalizationPart>();

            if (localized == null) return null;

            var masterContentItemId = localized.HasTranslationGroup ? localized.Record.MasterContentItemId : localized.Id;

            // Warning: Returns only the first of same culture localizations.
            return _contentManager
                .Query<LocalizationPart>(versionOptions, content.ContentItem.ContentType)
                .Where<LocalizationPartRecord>(l =>
                    (l.Id == masterContentItemId || l.MasterContentItemId == masterContentItemId) &&
                    l.CultureId == cultureRecord.Id)
                .Slice(1)
                .FirstOrDefault();
        }

        public string GetContentCulture(IContent content) {
            var localized = content.As<LocalizationPart>();

            return localized?.Culture == null ?
                _cultureManager.GetSiteCulture() :
                localized.Culture.Culture;
        }

        public void SetContentCulture(IContent content, string culture) {
            var localized = content.As<LocalizationPart>();

            if (localized == null) return;

            localized.Culture = _cultureManager.GetCultureByName(culture);
        }

        public IEnumerable<LocalizationPart> GetLocalizations(IContent content) {
            // Warning: May contain more than one localization of the same culture.
            return GetLocalizations(content, null);
        }

        public IEnumerable<LocalizationPart> GetLocalizations(IContent content, VersionOptions versionOptions) {
            if (content.ContentItem.Id == 0) return Enumerable.Empty<LocalizationPart>();

            var localized = content.As<LocalizationPart>();

            var query = versionOptions == null ?
                _contentManager.Query<LocalizationPart>(localized.ContentItem.ContentType) :
                _contentManager.Query<LocalizationPart>(versionOptions, localized.ContentItem.ContentType);

            int contentItemId = localized.ContentItem.Id;

            if (localized.HasTranslationGroup) {
                int masterContentItemId = localized.MasterContentItem.ContentItem.Id;

                query = query.Where<LocalizationPartRecord>(l =>
                    l.Id != contentItemId && // Exclude the content
                    (l.Id == masterContentItemId || l.MasterContentItemId == masterContentItemId));
            }
            else {
                query = query.Where<LocalizationPartRecord>(l => l.MasterContentItemId == contentItemId);
            }

            // Warning: May contain more than one localization of the same culture.
            return query.List().ToList();
        }
    }
}