using Raven.Client.Documents;
using Raven.Client.Documents.Linq;
using Raven.Client.Documents.Queries;
using Raven.Client.Documents.Session;
using System;
using System.Linq;
using System.Linq.Expressions;

namespace zero.Core.Extensions
{
  public static class QueryableExtensions
  {
    public static IOrderedQueryable<T> OrderBy<T>(this IQueryable<T> source, string path, bool isDescending, OrderingType type = OrderingType.String)
    {
      if (!String.IsNullOrEmpty(path))
      {
        char[] a = path.ToCharArray();
        a[0] = char.ToUpper(a[0]);
        path = new string(a);
      }

      if (isDescending)
      {
        return source.OrderByDescending(path, type);
      }
      return source.OrderBy(path, type);
    }


    public static IOrderedQueryable<T> ThenBy<T>(this IOrderedQueryable<T> source, string path, bool isDescending, OrderingType type = OrderingType.String)
    {
      if (!String.IsNullOrEmpty(path))
      {
        char[] a = path.ToCharArray();
        a[0] = char.ToUpper(a[0]);
        path = new string(a);
      }

      if (isDescending)
      {
        return source.ThenByDescending(path, type);
      }
      return source.ThenBy(path, type);
    }


    public static IQueryable<T> Paging<T>(this IQueryable<T> source, int pageNumber, int pageSize)
    {
      pageNumber = pageNumber.Limit(1, 10_000_000);
      pageSize = pageSize.Limit(1, 1_000);

      if (pageNumber <= 0 || pageSize <= 0)
      {
        throw new NotSupportedException("Both pageNumber and pageSize must be greater than zero");
      }

      return source.Skip((pageNumber - 1) * pageSize).Take(pageSize);
    }


    public static IRavenQueryable<T> WhereIf<T>(this IRavenQueryable<T> source, Expression<Func<T, bool>> predicate, bool condition, Expression<Func<T, bool>> elsePredicate = null)
    {
      if (!condition)
      {
        if (elsePredicate != null)
        {
          return source.Where(elsePredicate);
        }
        return source;
      }

      return source.Where(predicate);
    }


    public static IQueryable<T> SearchIf<T>(this IQueryable<T> source, Expression<Func<T, object>> fieldSelector, string searchTerms, string suffix = null, string prefix = null, SearchOperator @operator = SearchOperator.Or)
    {
      if (String.IsNullOrWhiteSpace(searchTerms))
      {
        return source;
      }

      searchTerms = searchTerms.Trim();

      string[] searchParts = searchTerms.Split(new[] { " " }, StringSplitOptions.RemoveEmptyEntries).Select(x =>
      {
        if (suffix != null)
        {
          x += suffix;
        }
        if (prefix != null)
        {
          x = prefix + x;
        }
        return x;
      }).ToArray();

      if (searchTerms.StartsWith('"') && searchTerms.EndsWith('"'))
      {
        searchParts = new[] { searchTerms };
      }

      return source.Search(fieldSelector, searchParts, @operator: @operator);
    }
  }
}