// ****************************************************************

// This is free software licensed under the NUnit license. You may

// obtain a copy of the license at http://nunit.org

// ****************************************************************



using System;

using System.Collections.Generic;

using System.Text;

using System.Collections;



namespace NUnit.UiException

{

    /// <summary>

    /// This is a default implementation of ITextManager interface.

    /// </summary>

    public class DefaultTextManager :

        IEnumerable,

        ITextManager

    {

        /// <summary>

        /// Hold the text to be managed by this instance.

        /// </summary>

        private string _text;



        /// <summary>

        /// Array of strings where each string is a line in this text.

        /// </summary>

        private List<string> _lines;



        /// <summary>

        /// Stores the character count of the longest line in this text.

        /// </summary>

        private int _maxLength;



        /// <summary>

        /// Builds a new instance of TextManager.

        /// </summary>

        public DefaultTextManager()

        {

            _lines = new List<string>();

            Text = "";



            return;

        }



        /// <summary>

        /// Gets the number of lines in the text.

        /// </summary>

        public int LineCount

        {

            get { return (_lines.Count); }

        }



        /// <summary>

        /// Gets or sets the text to be managed by this object.

        /// </summary>

        public string Text

        {

            get { return (_text); }

            set

            {

                if (value == null)

                    value = "";



                _text = value;

                _populateLineCollection(value);

            }

        }



        /// <summary>

        /// Gets the line of text at the specified startingPosition.

        /// (zero based startingPosition).

        /// </summary>

        /// <param name="lineIndex">The startingPosition of the line to get.</param>

        /// <returns>A string that represents the content of the specified line without

        /// the trailing characters.</returns>

        public string GetTextAt(int lineIndex)

        {

            return (_lines[lineIndex]);

        }



        /// <summary>

        /// Gets the character count of the longest line in this text.

        /// </summary>

        public int MaxLength

        {

            get { return (_maxLength); }

        }



        #region private definitions



        /// <summary>

        /// setup member data with the input text.

        /// </summary>

        private void _populateLineCollection(string text)

        {

            string line;

            int textIndex;

            int newIndex;



            textIndex = 0;



            _lines.Clear();

            _maxLength = 0;



            while ((newIndex = text.IndexOf("\n", textIndex, StringComparison.Ordinal)) > textIndex)

            {

                line = text.Substring(textIndex, newIndex - textIndex).TrimEnd();

                _maxLength = Math.Max(_maxLength, line.Length);



                _lines.Add(line);

                textIndex = newIndex + 1;

            }



            if (textIndex < text.Length)

            {

                line = text.Substring(textIndex).TrimEnd();

                _maxLength = Math.Max(_maxLength, line.Length);

                _lines.Add(line);

            }



            return;

        }



        #endregion



        #region IEnumerable Membres



        /// <summary>

        /// Gets an IEnumerator that iterate through each line of the

        /// current text. 

        /// </summary>

        /// <returns>An IEnumerator that iterate through each line of this text.</returns>

        public IEnumerator GetEnumerator()

        {

            return (_lines.GetEnumerator());

        }



        #endregion      

    }

}