using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using Tango.BL.Entities;

namespace Tango.PPC.Shared.SQL
{
    /// <summary>
    /// Represents a <see cref="RemoteSqlDataSet"/> row.
    /// </summary>
    /// <example>
    /// <para>
    /// <i>
    /// The following example demonstrates how to set the connected machine's demo state and query for the connected machine's jobs.
    /// </i>
    /// </para>
    /// <code lang="C#" source="../Tango.FSE.Procedures/Examples/Sql/Program.cs" title="Remote SQL" region="Example" />
    /// </example>
    public class RemoteSqlRow
    {
        private Func<String, Object> _getFuncKey;
        private Func<int, Object> _getFuncIndex;

        /// <summary>
        /// Gets or sets the row values.
        /// </summary>
        public List<Object> Values { get; set; }

        /// <summary>
        /// Initializes a new instance of the <see cref="RemoteSqlRow"/> class.
        /// </summary>
        public RemoteSqlRow()
        {
            Values = new List<object>();
        }

        /// <summary>
        /// Gets a row value by its column name.
        /// </summary>
        /// <param name="columnName">Name of the column.</param>
        /// <returns>The column value.</returns>
        public Object Get(String columnName)
        {
            return _getFuncKey.Invoke(columnName);
        }

        /// <summary>
        /// Gets a row value by its column index.
        /// </summary>
        /// <param name="columnIndex">Index of the column.</param>
        /// <returns>The column value.</returns>
        public Object Get(int columnIndex)
        {
            return _getFuncIndex.Invoke(columnIndex);
        }

        /// <summary>
        /// Gets a row value as type T by its column name.
        /// </summary>
        /// <typeparam name="T">Expected column type.</typeparam>
        /// <param name="columnName">Name of the column.</param>
        /// <returns>The column value.</returns>
        public T Get<T>(String columnName)
        {
            var value = _getFuncKey.Invoke(columnName);

            if (typeof(T) != value.GetType())
            {
                return (T)Convert.ChangeType(value, typeof(T));
            }
            else
            {
                return (T)value;
            }
        }

        /// <summary>
        /// Gets a row value by its column index.
        /// </summary>
        /// <typeparam name="T">Expected column type</typeparam>
        /// <param name="columnIndex">Index of the column.</param>
        /// <returns>The column value.</returns>
        public T Get<T>(int columnIndex)
        {
            var value = _getFuncIndex.Invoke(columnIndex);

            if (typeof(T) != value.GetType())
            {
                return (T)Convert.ChangeType(value, typeof(T));
            }
            else
            {
                return (T)value;
            }
        }

        internal void Init(Func<String, Object> getFuncKey, Func<int, Object> getFuncIndex)
        {
            _getFuncKey = getFuncKey;
            _getFuncIndex = getFuncIndex;
        }

        /// <summary>
        /// Returns a <see cref="System.String" /> that represents this instance.
        /// </summary>
        /// <returns>
        /// A <see cref="System.String" /> that represents this instance.
        /// </returns>
        public override string ToString()
        {
            return String.Join(", ", Values);
        }

        /// <summary>
        /// Creates an object of type T and maps this row to it based on its properties decorated with <see cref="ColumnAttribute"/>.
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <returns></returns>
        public T Map<T>() where T : class, new()
        {
            var obj = Activator.CreateInstance<T>();
            Map<T>(obj);
            return obj;
        }

        /// <summary>
        /// Maps this row to the specified object based on its properties decorated with <see cref="ColumnAttribute"/>.
        /// </summary>
        /// <typeparam name="T">Model type</typeparam>
        /// <param name="obj">The object.</param>
        public void Map<T>(T obj) where T : class
        {
            foreach (var prop in typeof(T).GetPropertiesWithAttribute<ColumnAttribute>())
            {
                try
                {
                    var columnName = prop.GetCustomAttribute<ColumnAttribute>().Name;
                    var value = Get(columnName).ToStringSafe();
                    prop.SetValue(obj, Convert.ChangeType(value, prop.PropertyType));
                }
                catch (Exception ex)
                {
                    Debug.WriteLine(ex);
                }
            }
        }
    }
}