using System;
using System.Collections.Generic;
using System.Linq;
using Examine;
using Umbraco.Core;
using Umbraco.Core.Mapping;
using Umbraco.Core.Models;
using Umbraco.Core.Models.Entities;
using Umbraco.Core.Persistence;
using Umbraco.Core.Services;
using Umbraco.Examine;
using Umbraco.Web.Models.ContentEditing;
using Umbraco.Web.Models.Mapping;
using Umbraco.Web.Routing;
using Umbraco.Web.Trees;

namespace Umbraco.Web.Search
{

    /// <summary>
    /// Used for internal Umbraco implementations of <see cref="ISearchableTree"/>
    /// </summary>
    public class UmbracoTreeSearcher
    {
        private readonly ILocalizationService _languageService;
        private readonly IEntityService _entityService;
        private readonly UmbracoMapper _mapper;
        private readonly ISqlContext _sqlContext;
        private readonly IBackOfficeExamineSearcher _backOfficeExamineSearcher;
        private readonly IPublishedUrlProvider _publishedUrlProvider;


        public UmbracoTreeSearcher(
            ILocalizationService languageService,
            IEntityService entityService,
            UmbracoMapper mapper,
            ISqlContext sqlContext,
            IBackOfficeExamineSearcher backOfficeExamineSearcher,
            IPublishedUrlProvider publishedUrlProvider)
        {
            _languageService = languageService;
            _entityService = entityService;
            _mapper = mapper;
            _sqlContext = sqlContext;
            _backOfficeExamineSearcher = backOfficeExamineSearcher;
            _publishedUrlProvider = publishedUrlProvider;
        }

        /// <summary>
        /// Searches Examine for results based on the entity type
        /// </summary>
        /// <param name="query"></param>
        /// <param name="entityType"></param>
        /// <param name="culture"></param>
        /// <param name="totalFound"></param>
        /// <param name="searchFrom">
        /// A starting point for the search, generally a node id, but for members this is a member type alias
        /// </param>
        /// <param name="pageSize"></param>
        /// <param name="pageIndex"></param>
        /// <param name="ignoreUserStartNodes">If set to true, user and group start node permissions will be ignored.</param>
        /// <returns></returns>
        public IEnumerable<SearchResultEntity> ExamineSearch(
            string query,
            UmbracoEntityTypes entityType,
            int pageSize,
            long pageIndex, out long totalFound, string culture = null, string searchFrom = null, bool ignoreUserStartNodes = false)
        {
            var pagedResult = _backOfficeExamineSearcher.Search(query, entityType, pageSize, pageIndex, out totalFound, searchFrom, ignoreUserStartNodes);

            switch (entityType)
            {
                case UmbracoEntityTypes.Member:
                    return MemberFromSearchResults(pagedResult.ToArray());
                case UmbracoEntityTypes.Media:
                    return MediaFromSearchResults(pagedResult);
                case UmbracoEntityTypes.Document:
                    return ContentFromSearchResults(pagedResult, culture);
                default:
                    throw new NotSupportedException("The " + typeof(UmbracoTreeSearcher) + " currently does not support searching against object type " + entityType);
            }
        }

        /// <summary>
        /// Searches with the <see cref="IEntityService"/> for results based on the entity type
        /// </summary>
        /// <param name="objectType"></param>
        /// <param name="query"></param>
        /// <param name="pageSize"></param>
        /// <param name="pageIndex"></param>
        /// <param name="totalFound"></param>
        /// <param name="searchFrom"></param>
        /// <returns></returns>
        public IEnumerable<SearchResultEntity> EntitySearch(UmbracoObjectTypes objectType, string query, int pageSize, long pageIndex, out long totalFound, string searchFrom = null)
        {
            //if it's a GUID, match it
            Guid.TryParse(query, out var g);

            var results = _entityService.GetPagedDescendants(objectType, pageIndex, pageSize, out totalFound,
                filter: _sqlContext.Query<IUmbracoEntity>().Where(x => x.Name.Contains(query) || x.Key == g));
            return _mapper.MapEnumerable<IEntitySlim, SearchResultEntity>(results);
        }

        /// <summary>
        /// Returns a collection of entities for media based on search results
        /// </summary>
        /// <param name="results"></param>
        /// <returns></returns>
        private IEnumerable<SearchResultEntity> MemberFromSearchResults(IEnumerable<ISearchResult> results)
        {
            //add additional data
            foreach (var result in results)
            {
                var m = _mapper.Map<SearchResultEntity>(result);

                //if no icon could be mapped, it will be set to document, so change it to picture
                if (m.Icon == Constants.Icons.DefaultIcon)
                {
                    m.Icon = Constants.Icons.Member;
                }

                if (result.Values.ContainsKey("email") && result.Values["email"] != null)
                {
                    m.AdditionalData["Email"] = result.Values["email"];
                }
                if (result.Values.ContainsKey(UmbracoExamineFieldNames.NodeKeyFieldName) && result.Values[UmbracoExamineFieldNames.NodeKeyFieldName] != null)
                {
                    if (Guid.TryParse(result.Values[UmbracoExamineFieldNames.NodeKeyFieldName], out var key))
                    {
                        m.Key = key;
                    }
                }

                yield return m;
            }
        }

        /// <summary>
        /// Returns a collection of entities for media based on search results
        /// </summary>
        /// <param name="results"></param>
        /// <returns></returns>
        private IEnumerable<SearchResultEntity> MediaFromSearchResults(IEnumerable<ISearchResult> results)
            => _mapper.Map<IEnumerable<SearchResultEntity>>(results);

        /// <summary>
        /// Returns a collection of entities for content based on search results
        /// </summary>
        /// <param name="results"></param>
        /// <param name="culture"></param>
        /// <returns></returns>
        private IEnumerable<SearchResultEntity> ContentFromSearchResults(IEnumerable<ISearchResult> results, string culture = null)
        {
            var defaultLang = _languageService.GetDefaultLanguageIsoCode();

            foreach (var result in results)
            {
                var entity = _mapper.Map<SearchResultEntity>(result, context => {
                        if(culture != null) {
                            context.SetCulture(culture);
                        }
                    }
                );

                var intId = entity.Id.TryConvertTo<int>();
                if (intId.Success)
                {
                    //if it varies by culture, return the default language URL
                    if (result.Values.TryGetValue(UmbracoExamineFieldNames.VariesByCultureFieldName, out var varies) && varies == "y")
                    {
                        entity.AdditionalData["Url"] = _publishedUrlProvider.GetUrl(intId.Result, culture: culture ?? defaultLang);
                    }
                    else
                    {
                        entity.AdditionalData["Url"] = _publishedUrlProvider.GetUrl(intId.Result);
                    }
                }

                yield return entity;
            }
        }

    }
}