using IOweYou.Backend.Interfaces;
using IOweYou.Backend.Models;
using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Web;

namespace IOweYou.Backend.Classes
{
    public class DebtDataProvider : MySqlDataProvider, IDebtDataProvider
    {
        public IEnumerable<Friend> GetUserFriendsByUserId(User user)
        {
            List<Friend> Friends = null;

            try
            {
                IDbCommand command = _dbConnection.CreateCommand();
                command.CommandText = @"SELECT
                    d.`debt_id`           AS `debt_id`,
	                u.`user_id`           AS `user_id`,
	                u.`username`          AS `user_username`,
	                u.`full_name`         AS `user_full_name`,
	                f.`user_id`           AS `friend_id`,
	                f.`username`          AS `friend_username`,
	                f.`full_name`         AS `friend_full_name`,
	                d.`amount`            AS `amount`,
	                d.`registration_date` AS `registration_date`,
	                d.`expiration_date`   AS `expiration_date`
                FROM `debt` AS d
                LEFT OUTER JOIN `users` AS u ON d.`user_id` = u.`user_id`
                LEFT OUTER JOIN `users` AS f ON d.`friend_id` = f.`user_id`
                WHERE d.`user_id` = @UserId OR d.`friend_id` = @UserId; ";

                IDbDataParameter userIdparam = command.CreateParameter();
                userIdparam.ParameterName = "@UserId";
                userIdparam.Value = user.UserId;
                IDataReader reader = command.ExecuteReader();

                Friends = new List<Friend>();

                while (reader.Read())
                {
                    bool owedDebt = (int)reader["friend_id"] == user.UserId;

                    int friendId = owedDebt ? (int)reader["user_id"] : (int)reader["friend_id"];

                    Friend friend = Friends.Where(f => f.UserId == user.UserId).FirstOrDefault();

                    if (friend == null)
                    {
                        friend = new Friend()
                        {
                            UserId = (int)reader["user_id"],
                            Username = (string)reader["username"],
                            FullName = (string)reader["full_name"],
                            Debts = new List<Debt>(),
                            OwedDebts = new List<Debt>()
                        };
                        Friends.Add(friend);
                    }

                    Debt debt = new Debt()
                    {
                        DebtId = (int)reader["debt_id"],
                        RegistrationDate = (DateTime)reader["registration_date"],
                        ExpirationDate = (DateTime)reader["expiration_date"],
                        Amount = (decimal)reader["amount"]
                    };

                    if (owedDebt)
                    {
                        friend.OwedDebts.Add(debt);
                    }
                    else
                    {
                        friend.Debts.Add(debt);
                    }
                }

            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
            return Friends;
        }

        public bool UpdateUserFriends(User user, IEnumerable<Friend> friends)
        {
            throw new NotImplementedException();
        }
    }
}