using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;

using BLToolkit.Data;
using BLToolkit.Data.Linq;

using NUnit.Framework;

namespace Data.Linq
{
	using Model;

	[TestFixture]
	public class Common : TestBase
	{
		[Test]
		public void AsQueryable()
		{
			ForEachProvider(db => AreEqual(
				from p in    Parent from ch in    Child               select p,
				from p in db.Parent from ch in db.Child.AsQueryable() select p));
		}

		[Test]
		public void Convert()
		{
			ForEachProvider(db => AreEqual(
				from p in    Parent from ch in                         Child                select p,
				from p in db.Parent from ch in ((IEnumerable<Child>)db.Child).AsQueryable() select p));
		}

		[Test]
		public void NewCondition()
		{
			ForEachProvider(db => AreEqual(
				from p in    Parent select new { Value = p.Value1 != null ? p.Value1 : 100 },
				from p in db.Parent select new { Value = p.Value1 != null ? p.Value1 : 100 }));
		}

		[Test]
		public void NewCoalesce()
		{
			ForEachProvider(db => AreEqual(
				from p in    Parent select new { Value = p.Value1 ?? 100 },
				from p in db.Parent select new { Value = p.Value1 ?? 100 }));
		}

		[Test]
		public void CoalesceNew()
		{
			Child ch = null;

			ForEachProvider(db => AreEqual(
				from p in    Parent select ch ?? new Child { ParentID = p.ParentID },
				from p in db.Parent select ch ?? new Child { ParentID = p.ParentID }));
		}

		[Test]
		public void ScalarCondition()
		{
			ForEachProvider(db => AreEqual(
				from p in    Parent select p.Value1 != null ? p.Value1 : 100,
				from p in db.Parent select p.Value1 != null ? p.Value1 : 100));
		}

		[Test]
		public void ScalarCoalesce()
		{
			ForEachProvider(db => AreEqual(
				from p in    Parent select p.Value1 ?? 100,
				from p in db.Parent select p.Value1 ?? 100));
		}

		[Test]
		public void ExprCoalesce()
		{
			ForEachProvider(db => AreEqual(
				from p in    Parent select (p.Value1 ?? 100) + 50,
				from p in db.Parent select (p.Value1 ?? 100) + 50));
		}

		static int GetDefault1()
		{
			return 100;
		}

		[Test]
		public void ClientCoalesce1()
		{
			ForEachProvider(db => AreEqual(
				from p in    Parent select p.Value1 ?? GetDefault1(),
				from p in db.Parent select p.Value1 ?? GetDefault1()));
		}

		static int GetDefault2(int n)
		{
			return n;
		}

		[Test]
		public void ClientCoalesce2()
		{
			ForEachProvider(db => AreEqual(
				from p in    Parent select p.Value1 ?? GetDefault2(p.ParentID),
				from p in db.Parent select p.Value1 ?? GetDefault2(p.ParentID)));
		}

		[Test]
		public void CoalesceLike([DataContexts] string context)
		{
			using (var db = GetDataContext(context))
				AreEqual(
					from p in    Person
					where
						(p.FirstName == null ? (bool?)null : (bool?)p.FirstName.StartsWith("Jo")) == null ?
							false :
							(p.FirstName == null ? (bool?)null : p.FirstName.StartsWith("Jo")).Value
					select p,
					from p in db.Person
					where
						(p.FirstName == null ? (bool?)null : (bool?)p.FirstName.StartsWith("Jo")) == null ?
							false :
							(p.FirstName == null ? (bool?)null : p.FirstName.StartsWith("Jo")).Value
					select p);
		}

		[Test]
		public void PreferServerFunc1()
		{
			ForEachProvider(db => AreEqual(
				from p in    Person select p.FirstName.Length,
				from p in db.Person select p.FirstName.Length));
		}

		[Test]
		public void PreferServerFunc2()
		{
			ForEachProvider(db => AreEqual(
				from p in    Person select p.FirstName.Length + "".Length,
				from p in db.Person select p.FirstName.Length + "".Length));
		}

		class Test
		{
			class Entity
			{
				public Test TestField = null;
			}

			public Test TestClosure(ITestDataContext db)
			{
				return db.Person.Select(_ => new Entity { TestField = this }).First().TestField;
			}
		}

		[Test]
		public void ClosureTest()
		{
			ForEachProvider(db => Assert.AreNotEqual(
				new Test().TestClosure(db),
				new Test().TestClosure(db)));
		}

		[Test]
		public void ExecuteTest([IncludeDataContexts("Northwind")] string context)
		{
			using (var db = new NorthwindDB())
			{
				var emp = db.Employee;

				Expression<Func<int>> m = () => emp.Count();

				var exp = Expression.Call(((MethodCallExpression)m.Body).Method, emp.Expression);

				var results = (int)((IQueryable)emp).Provider.Execute(exp);
			}
		}

		class MyClass
		{
			public int ID;

			public override bool Equals(object obj)
			{
				return ((MyClass)obj).ID == ID;
			}

			public override int GetHashCode()
			{
				return ID;
			}
		}

		[Test]
		public void NewObjectTest1()
		{
			ForEachProvider(db => AreEqual(
				from p in Parent
				select new { ID = new MyClass { ID = p.ParentID } } into p1
				where p1.ID.ID == 1
				select p1,
				from p in db.Parent
				select new { ID = new MyClass { ID = p.ParentID } } into p1
				where p1.ID.ID == 1
				select p1));
		}

		[Test]
		public void NewObjectTest2()
		{
			ForEachProvider(db => AreEqual(
				from p in Parent
				select new { ID = new MyClass { ID = p.ParentID } } into p
				join j in
					from c in Child
					select new { ID = new MyClass { ID = c.ParentID } }
				on p.ID.ID equals j.ID.ID
				where p.ID.ID == 1
				select p,
				from p in db.Parent
				select new { ID = new MyClass { ID = p.ParentID } } into p
				join j in
					from c in db.Child
					select new { ID = new MyClass { ID = c.ParentID } }
				on p.ID.ID equals j.ID.ID
				where p.ID.ID == 1
				select p));
		}

		public Table<Person> People2(DbManager db)
		{
			return db.GetTable<Person>();
		}

		[Test]
		public void TableAsMethod()
		{
			using (var db = new TestDbManager())
			{
				var q =
					from d in db.Patient
					from p in People2(db)
					select p;

				q.ToList();

				q =
					from d in db.Patient
					from p in People2(db)
					select p;

				q.ToList();
			}
		}

		[Test]
		public void TableAsExtensionMethod()
		{
			using (var db = new TestDbManager())
			{
				var q =
					from d in db.Patient
					from p in db.People()
					select p;

				q.ToList();
			}
		}

		[Test]
		public void Condition1()
		{
			ForEachProvider(db => AreEqual(
				from p in    Person select new { Name = !string.IsNullOrEmpty(p.FirstName) ? p.FirstName : !string.IsNullOrEmpty(p.MiddleName) ? p.MiddleName : p.LastName },
				from p in db.Person select new { Name = !string.IsNullOrEmpty(p.FirstName) ? p.FirstName : !string.IsNullOrEmpty(p.MiddleName) ? p.MiddleName : p.LastName }));
		}

		[Test]
		public void Condition2()
		{
			ForEachProvider(db => AreEqual(
				from p in    Person select new { Name = !p.FirstName.IsNullOrEmpty() ? p.FirstName : !p.MiddleName.IsNullOrEmpty() ? p.MiddleName : p.LastName },
				from p in db.Person select new { Name = !p.FirstName.IsNullOrEmpty() ? p.FirstName : !p.MiddleName.IsNullOrEmpty() ? p.MiddleName : p.LastName }));
		}

		enum PersonID
		{
			Person1 = 1,
			Person2 = 2
		}

		[Test]
		public void ConvertEnum1()
		{
			ForEachProvider(db => AreEqual(
				from p in    Person where p.ID == (int)PersonID.Person1 select p,
				from p in db.Person where p.ID == (int)PersonID.Person1 select p));
		}

		[Test]
		public void ConvertEnum2()
		{
			var id = PersonID.Person1;

			ForEachProvider(db => AreEqual(
				from p in    Person where p.ID == (int)id select p,
				from p in db.Person where p.ID == (int)id select p));
		}

		[Test]
		public void GroupByUnion1()
		{
			ForEachProvider(db => AreEqual(
				from t in (
					from c in Child
					where c.ParentID < 4
					select new { c.ParentID, ID = c.ChildID })
				.Concat(
					from g in GrandChild
					where g.ParentID >= 4
					select new { ParentID = g.ParentID ?? 0, ID = g.GrandChildID ?? 0 })
				group t by t.ParentID into gr
				select new { ParentID = gr.Key, Sum = gr.Sum(i => i.ID) } into tt
				where tt.Sum != 0
				select tt
				,
				from t in (
					from c in db.Child
					where c.ParentID < 4
					select new { c.ParentID, ID = c.ChildID })
				.Concat(
					from g in db.GrandChild
					where g.ParentID >= 4
					select new { ParentID = g.ParentID ?? 0, ID = g.GrandChildID ?? 0 })
				group t by t.ParentID into gr
				select new { ParentID = gr.Key, Sum = gr.Sum(i => i.ID) } into tt
				where tt.Sum != 0
				select tt
			));
		}

		[Test]
		public void GroupByUnion2()
		{
			ForEachProvider(db =>
			{
				var qe1 =
					from t in (
						from c in Child
						where c.ParentID < 4
						select new { c.ParentID, ID = c.ChildID })
					.Concat(
						from g in GrandChild
						where g.ParentID >= 4
						select new { ParentID = g.ParentID ?? 0, ID = g.GrandChildID ?? 0 })
					group t by t.ParentID into gr
					select new { ParentID = gr.Key, Sum = gr.Sum(i => i.ID) } into tt
					where tt.Sum != 0
					select tt;

				var qe2 =
					from p in Parent
						join tt in qe1 on p.ParentID equals tt.ParentID into gr
						from tt in gr.DefaultIfEmpty()
					select new { p.ParentID };

				var qr1 =
					from t in (
						from c in db.Child
						where c.ParentID < 4
						select new { c.ParentID, ID = c.ChildID })
					.Concat(
						from g in db.GrandChild
						where g.ParentID >= 4
						select new { ParentID = g.ParentID ?? 0, ID = g.GrandChildID ?? 0 })
					group t by t.ParentID into gr
					select new { ParentID = gr.Key, Sum = gr.Sum(i => i.ID) } into tt
					where tt.Sum != 0
					select tt;

				var qr2 =
					from p in db.Parent
						join tt in qr1 on p.ParentID equals tt.ParentID into gr
						from tt in gr.DefaultIfEmpty()
					select new { p.ParentID };

				AreEqual(qe2, qr2);
			});
		}

		[Test]
		public void GroupByLeftJoin1()
		{
			ForEachProvider(db => AreEqual(
				from p in Parent
					join tt in
						from t in Child
						group t by t.ParentID into gr
						select new { ParentID = gr.Key, Sum = gr.Sum(i => i.ChildID) } into tt
						where tt.Sum != 0
						select tt
					on p.ParentID equals tt.ParentID into gr
					from tt in gr.DefaultIfEmpty()
				select p.ParentID,
				from p in db.Parent
					join tt in
						from t in db.Child
						group t by t.ParentID into gr
						select new { ParentID = gr.Key, Sum = gr.Sum(i => i.ChildID) } into tt
						where tt.Sum != 0
						select tt
					on p.ParentID equals tt.ParentID into gr
					from tt in gr.DefaultIfEmpty()
				select p.ParentID));
		}

		void ProcessItem(ITestDataContext db, int id)
		{
			var hashQuery1 = Parent.Where(t => t.ParentID == id);

			var groups1 = Child
				.Where(p => hashQuery1.Any(e => e.ParentID == p.ParentID))
				.GroupBy(e => e.ParentID)
				.Select(g => g.Key);

			var hashQuery2 = db.Parent.Where(t => t.ParentID == id);

			var groups2 = db.Child
				.Where(p => hashQuery2.Any(e => e.ParentID == p.ParentID))
				.GroupBy(e => e.ParentID)
				.Select(g => g.Key);

			AreEqual(groups1, groups2);
		}

		[Test]
		public void ParameterTest1()
		{
			ForEachProvider(db =>
			{
				ProcessItem(db, 1);
				ProcessItem(db, 2);
			});
		}
	}

	static class Extender
	{
		public static Table<Person> People(this DbManager db)
		{
			return db.GetTable<Person>();
		}

		public static bool IsNullOrEmpty(this string value)
		{
			return string.IsNullOrEmpty(value);
		}
	}
}