//
//  NpgsqlCircleProvider.cs
//
//  Author:
//       Paul Schneider <paul@pschneider.fr>
//
//  Copyright (c) 2015 GNU GPL
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
using System;
using Yavsc.Model.Circles;
using System.Collections.Specialized;
using System.Configuration;
using Npgsql;
using NpgsqlTypes;
using System.Collections.Generic;

namespace WorkFlowProvider
{
	/// <summary>
	/// Npgsql circle provider.
	/// </summary>
	public class NpgsqlCircleProvider : CircleProvider
	{
		/// <summary>
		/// Initializes a new instance of the <see cref="WorkFlowProvider.NpgsqlCircleProvider"/> class.
		/// </summary>
		public NpgsqlCircleProvider ()
		{
		}

		#region implemented abstract members of CircleProvider

		/// <summary>
		/// Add the specified user.
		/// </summary>
		/// <param name="id">circle Identifier.</param>
		/// <param name="username">User name.</param>
		public override void Add (long id, string username)
		{
			using (NpgsqlConnection cnx = new NpgsqlConnection (connectionString))
			using (NpgsqlCommand cmd = cnx.CreateCommand ()) {
				cmd.CommandText = "insert into circle_members (circle_id, member) values (:cid,:uname)";
				cmd.Parameters.AddWithValue("cid",id);
				cmd.Parameters.AddWithValue("uname",username);
				cnx.Open ();
				cmd.ExecuteNonQuery ();	
				cnx.Close ();
			}
		}

		/// <summary>
		/// Remove the specified user.
		/// </summary>
		/// <param name="id">circle Identifier.</param>
		/// <param name="username">User name.</param>
		public override void Remove (long id, string username)
		{
			using (NpgsqlConnection cnx = new NpgsqlConnection (connectionString))
			using (NpgsqlCommand cmd = cnx.CreateCommand ()) {
				cmd.CommandText = "delete from circle_members where circle_id = :cid and username = :uname";
				cmd.Parameters.AddWithValue("cid",id);
				cmd.Parameters.AddWithValue("uname",username);
				cnx.Open ();
				cmd.ExecuteNonQuery ();	
				cnx.Close ();
			}
		}

		/// <summary>
		/// Get the specified id.
		/// </summary>
		/// <param name="id">Identifier.</param>
		public override Circle Get (long id)
		{
			Circle circ=null;

			using (NpgsqlConnection cnx = new NpgsqlConnection (connectionString)) {
				cnx.Open ();
				using (NpgsqlCommand cmd = cnx.CreateCommand ()) {
					cmd.CommandText = "select title, owner from circle where _id = :cid";
					cmd.Parameters.AddWithValue ("cid", id);
					using (NpgsqlDataReader dr = cmd.ExecuteReader ()) {
						if (dr.Read ()) {
							circ = new Circle ();
							circ.Id = id;
							circ.Title = dr.GetString (
								dr.GetOrdinal ("title"));
							circ.Owner = dr.GetString (
								dr.GetOrdinal ("owner"));
						}
						dr.Close ();
					}
				}

				if (circ != null) {

					using (NpgsqlCommand cmd = cnx.CreateCommand ()) {
						cmd.CommandText = "select member from circle_members where circle_id = :cid";
						cmd.Parameters.AddWithValue ("cid", id);
						cmd.Prepare ();
						List<string> members = new List<string> ();
						using (NpgsqlDataReader dr = cmd.ExecuteReader ()) {
							while (dr.Read ()) 
								members.Add (dr.GetString (0));
							dr.Close ();
							circ.Members = members.ToArray ();
						}
					}
				}
				cnx.Close ();
			}
			return circ;
		}

		/// <summary>
		/// Add the specified owner, title and users.
		/// </summary>
		/// <param name="owner">Owner.</param>
		/// <param name="title">Title.</param>
		/// <param name="users">Users.</param>
		public override long Create (string owner, string title, string[] users)
		{
			long id = 0;
			using (NpgsqlConnection cnx = new NpgsqlConnection (connectionString)) {
				cnx.Open ();
				using (NpgsqlCommand cmd = cnx.CreateCommand ()) {
					cmd.CommandText = "insert into circle (owner,title,applicationname) values (:wnr,:tit,:app) returning _id";
					cmd.Parameters.AddWithValue ("wnr", owner);
					cmd.Parameters.AddWithValue ("tit", title);
					cmd.Parameters.AddWithValue ("app", applicationName);
					id = (long)cmd.ExecuteScalar ();
				}
				using (NpgsqlCommand cmd = cnx.CreateCommand ()) {
					cmd.CommandText = "insert into circle_members (circle_id,member) values (@cid,@mbr)";
					cmd.Parameters.AddWithValue ("cid", id);
					cmd.Parameters.Add ("mbr", NpgsqlDbType.Varchar);
					cmd.Prepare ();
					foreach (string user in users) {
						cmd.Parameters[1].Value = user;
						cmd.ExecuteNonQuery ();
					}
				}
				cnx.Close ();
			}

			throw new NotImplementedException ();
		}

		/// <summary>
		/// Delete the specified owner and title.
		/// </summary>
		/// <param name="id">Identifier.</param>
		public override void Delete (long id)
		{
			using (NpgsqlConnection cnx = new NpgsqlConnection (connectionString))
			using (NpgsqlCommand cmd = cnx.CreateCommand ()) {
				cmd.CommandText = "delete from circle where _id = @cid";
				cmd.Parameters.AddWithValue("cid",id);
				cnx.Open ();
				cmd.ExecuteNonQuery ();	
				cnx.Close ();
			}
		}

		/// <summary>
		/// List user's circles.
		/// </summary>
		/// <param name="user">User.</param>
		public override CircleInfoCollection List (string user)
		{
			CircleInfoCollection cc = null;
			using (NpgsqlConnection cnx = new NpgsqlConnection (connectionString))
			using (NpgsqlCommand cmd = cnx.CreateCommand ()) {
				cmd.CommandText = "select _id, title from circle where owner = :wnr";
				cmd.Parameters.AddWithValue("wnr",user);
				cnx.Open ();
				cmd.Prepare ();
				using (NpgsqlDataReader rdr = cmd.ExecuteReader ()) {
					if (rdr.HasRows) {
						cc = new CircleInfoCollection ();
						while (rdr.Read ()) 
							cc.Add( 
								new CircleInfo (
									rdr.GetInt64 (0),
									rdr.GetString (1)));
					}
					rdr.Close ();
				}
				cnx.Close ();

			}
			return cc;
		}

		#endregion

		string connectionString = null;
		string applicationName = null;
		/// <summary>
		/// Initialize this object using the specified name and config.
		/// </summary>
		/// <param name="name">Name.</param>
		/// <param name="config">Config.</param>
		public override void Initialize (string name, NameValueCollection config)
		{
			if ( string.IsNullOrWhiteSpace(config ["connectionStringName"]))
				throw new ConfigurationErrorsException ("No name for Npgsql connection string found");

			connectionString = ConfigurationManager.ConnectionStrings [config ["connectionStringName"]].ConnectionString;
			applicationName = config["applicationName"] ?? "/";
		}

	}
}