using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;

namespace FastReport.Utils
{
    /// <summary>
    /// The helper class used to create unique component names using the fastest method.
    /// </summary>
    /// <remarks>
    /// <para>Note: you can create unique component's name using its <b>CreateUniqueName</b> method.
    /// However, it is very slow and can't be used in some situations (when you create a report 
    /// layout in a code and have a lot of objects on a page).</para>
    /// </remarks>
    /// <example>This example demonstrates how to use this class.
    /// <code>
    /// FastNameCreator nameCreator = new FastNameCreator(Report.AllObjects);
    /// foreach (Base c in Report.AllObjects)
    /// {
    ///   if (c.Name == "")
    ///     nameCreator.CreateUniqueName(c);
    /// }
    /// </code>
    /// </example>
    public class FastNameCreator
    {
        private readonly Hashtable baseNames;

        /// <summary>
        /// Creates the unique name for the given object.
        /// </summary>
        /// <param name="obj">The object to create name for.</param>
        public void CreateUniqueName(Base obj)
        {
            string baseName = obj.BaseName;
            int num = 1;
            if (baseNames.ContainsKey(baseName))
                num = (int)baseNames[baseName] + 1;

            obj.SetName(baseName + num.ToString());
            baseNames[baseName] = num;
        }

        /// <summary>
        /// Initializes a new instance of the <b>FastNameCreator</b> class with collection of 
        /// existing report objects.
        /// </summary>
        /// <param name="objects">The collection of existing report objects.</param>
        public FastNameCreator(ObjectCollection objects)
        {
            baseNames = new Hashtable();

            foreach (Base obj in objects)
            {
                string objName = obj.Name;
                if (!String.IsNullOrEmpty(objName))
                {
                    // find numeric part
                    int i = objName.Length - 1;
                    while (i > 0 && objName[i] >= '0' && objName[i] <= '9')
                    {
                        i--;
                    }

                    if (i >= 0 && i < objName.Length - 1)
                    {
                        // get number
                        string baseName = objName.Substring(0, i + 1);
                        int num;
                        int.TryParse(objName.Substring(i + 1), out num);
                        if (baseNames.ContainsKey(baseName))
                        {
                            int maxNum = (int)baseNames[baseName];
                            if (num < maxNum)
                                num = maxNum;
                        }
                        baseNames[baseName] = num;
                    }
                    else if (!baseNames.ContainsKey(objName))
                    {
                        baseNames[objName] = 0;
                    }
                }
            }
        }
    }
}