using System;
using System.Collections.Generic;
using System.Linq;
using Sarand.Net.Standard.Base.Core;
using Sarand.Net.Standard.Base.Utils;

namespace Sarand.Net.Standard.Base.Dbas
{
	//=======================================================================
	//[Serializable()]
	public class DbDfnIndex
	{
		//-------------------------------------------------------------------
		// Definitions.
		public static readonly int SQL_TABLE_STAT = 0;
		public static readonly int SQL_INDEX_CLUSTERED = 1;
		public static readonly int SQL_INDEX_HASHED = 2;
		public static readonly int SQL_INDEX_OTHER = 3;
		//  SQL_INDEX_BTREE     = ???;
		//  SQL_INDEX_CONTENT   = ???;

		//-------------------------------------------------------------------
		// Data members.
		private readonly List<DbDfnIndexColumn> columns = new List<DbDfnIndexColumn>();

		//-------------------------------------------------------------------
		// Construction.
		public DbDfnIndex() { }
		public DbDfnIndex(String schema, String table, String name, bool unique)
		{
			Schema = schema;
			Table = table;
			Name = name;
			Unique = unique;
		}

		//-------------------------------------------------------------------
		// Attributes.
		public String Schema { get; set; } = String.Empty;
		public String Table { get; set; } = String.Empty;
		public String Name { get; set; } = String.Empty;
		public int IndexType { get; set; } = -1;
		public bool Unique { get; set; } = false;
		public bool Primary { get; set; } = false;
		public bool Clustered { get; set; } = false;
		public bool Nullable { get; set; } = false;
		public int Pages { get; set; } = 0;
		public int UniqueValues { get; set; } = 0;
		public bool HasColumns { get; set; } = false;

		//-------------------------------------------------------------------
		// Columns.
		public int ColumnCount
		{
			get
			{
				lock (columns)
					return columns.Count();
			}
		}
		public List<DbDfnIndexColumn> Columns
		{
			get
			{
				lock (columns)
					return columns.ToList();
			}
			set
			{
				lock (columns)
					columns.Clear(); columns.AddRange(value);
			}
		}
		public void CearColumns()
		{
			lock (columns)
				columns.Clear();
		}
		public void AddColumn(DbDfnIndexColumn column)
		{
			lock (columns)
				columns.Add(column);
		}

		//-------------------------------------------------------------------
	}

	//=======================================================================
	// Index list extensions.
	public static class DbDfnIndexList
	{
		// List of index names.
		public static List<String> GetNames(this IEnumerable<DbDfnIndex> indices)
		{
			List<String> names = new List<String>();
			foreach (var index in indices)
				names.Add(index.Name);
			return names;
		}
		// Locate the index in the list.
		public static DbDfnIndex GetIndexByName(this IEnumerable<DbDfnIndex> indices, String name)
		{
			return indices.FirstOrDefault(idx => idx.Name.EqualsCI(name));
		}
		// Retrieve primary index.
		public static DbDfnIndex GetPrimaryIndex(this IEnumerable<DbDfnIndex> indices)
		{
			return indices.FirstOrDefault(idx => idx.Primary);
		}
		// Retrieve clustered index.
		public static DbDfnIndex GetClusteredIndex(this IEnumerable<DbDfnIndex> indices)
		{
			DbDfnIndex index = indices.FirstOrDefault(idx => idx.Clustered);
			if (index == null)
				index = indices.FirstOrDefault(idx => idx.IndexType == DbDfnIndex.SQL_INDEX_CLUSTERED);
			return index;
		}
	}

	//=======================================================================
}