using System;
using System.Collections.Concurrent;
using System.Collections.Generic;

namespace IgniteEngine.IO
{
    /// <summary>
    /// Class that reads data from a <see cref="Script"/> file.
    /// </summary>
    public class ScriptReader : IDisposable
    {
        /// <summary>
        /// Returns true if the script has rows to read.
        /// </summary>
        public bool HasRows => rows.Count > 0;

        /// <summary>
        /// The current row that we are reading.
        /// </summary>
        private ScriptRow currentRow;
        /// <summary>
        /// The queued rows to read.
        /// </summary>
        private readonly ConcurrentQueue<ScriptRow> rows;

        /// <summary>
        /// Creates a new instance of the <see cref="ScriptReader"/> class.
        /// </summary>
        /// <param name="rows">The rows to read.</param>
        public ScriptReader(List<ScriptRow> rows)
        {
            if (rows == null)
            {
                this.rows = new ConcurrentQueue<ScriptRow>();
                return;
            }

            this.rows = new ConcurrentQueue<ScriptRow>(rows);
        }

        /// <summary>
        /// Disposes the reader.
        /// </summary>
        public void Dispose()
        {
            // empty...
        }

        /// <summary>
        /// Gets a boolean from the row.
        /// </summary>
        /// <param name="index">The index to get the value from.</param>
        public bool GetBoolean(int index)
        {
            return bool.Parse(currentRow[index]);
        }

        /// <summary>
        /// Gets a byte from the row.
        /// </summary>
        /// <param name="index">The index to get the value from.</param>
        public byte GetByte(int index)
        {
            return byte.Parse(currentRow[index]);
        }

        /// <summary>
        /// Gets a 16-bit integer from the row.
        /// </summary>
        /// <param name="index">The index to get the value from.</param>
        public short GetInt16(int index)
        {
            return short.Parse(currentRow[index]);
        }

        /// <summary>
        /// Gets a 32-bit integer from the row.
        /// </summary>
        /// <param name="index">The index to get the value from.</param>
        public int GetInt32(int index)
        {
            return int.Parse(currentRow[index]);
        }

        /// <summary>
        /// Gets a 64-bit integer from the row.
        /// </summary>
        /// <param name="index">The index to get the value from.</param>
        public long GetInt64(int index)
        {
            return long.Parse(currentRow[index]);
        }

        /// <summary>
        /// Gets a signed byte from the row.
        /// </summary>
        /// <param name="index">The index to get the value from.</param>
        public sbyte GetSByte(int index)
        {
            return sbyte.Parse(currentRow[index]);
        }

        /// <summary>
        /// Gets an unsigned 16-bit integer from the row.
        /// </summary>
        /// <param name="index">The index to get the value from.</param>
        public ushort GetUInt16(int index)
        {
            return ushort.Parse(currentRow[index]);
        }

        /// <summary>
        /// Gets an unsigned 32-bit integer from the row.
        /// </summary>
        /// <param name="index">The index to get the value from.</param>
        public uint GetUInt32(int index)
        {
            return uint.Parse(currentRow[index]);
        }

        /// <summary>
        /// Gets an unsigned 64-bit integer from the row.
        /// </summary>
        /// <param name="index">The index to get the value from.</param>
        public ulong GetUInt64(int index)
        {
            return ulong.Parse(currentRow[index]);
        }

        /// <summary>
        /// Gets a string from the row.
        /// </summary>
        /// <param name="index">The index to get the value from.</param>
        public string GetString(int index)
        {
            return currentRow[index];
        }

        /// <summary>
        /// Tries to read a row from the file.
        /// </summary>
        /// <returns>True if the row was read successfully.</returns>
        public bool Read()
        {
            return rows.TryDequeue(out currentRow) && currentRow != null;
        }
    }
}