using System;
using System.Collections.Generic;
using System.Collections;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.Diagnostics;
using System.Globalization;
using System.IO;

using System.Reflection;
using System.Runtime.CompilerServices;
using System.Security;
using Microsoft.VisualBasic;
using System.Windows;
using System.Xml;
using System.Web;
//using System.Web.Caching;

namespace Traffic
{
    /// <summary>

    /// ''' Provides the functionality related to retrieving the list 

    /// ''' of states for a system; 
    //// reads an xml file
    /// ''' </summary>
    public static class StateManager
    {
        // Cache object that will be used to store and retrieve items from
        // the cache and constants used within this object
        // private static Cache myCache = System.Web.HttpRuntime.Cache();
        private static string stateKey = "StateKey";
        public static string applicationConstantsFileName = AppDomain.CurrentDomain.BaseDirectory + "State.xml"; // = Strings.Replace(System.AppDomain.CurrentDomain.BaseDirectory + "State.xml", "/", @"\");
        // "States.config", "/", "\")
        private static state[] stateArray;
        private static ArrayList errorList;


        // Tells you whether or not any errors have occurred w/in the module
        public static bool hasErrors
        {
            get
            {
                if (errorList == null || errorList.Count == 0)
                    return false;
                else
                    return true;
            }
        }


        // Retrieves an array list of Exception objects
        public static ArrayList getErrors
        {
            get
            {
                return errorList;
            }
        }


        // Private method used to add errors to the errorList
        private static void addError(ref Exception e)
        {
            if (errorList == null)
                errorList = new ArrayList();
            errorList.Add(e);
        }

        /// <summary>
        ///     ''' Gets all the states
        ///     ''' </summary>
        ///     ''' <returns>An array of State objects</returns>
        public static state[] getStates()
        {
            //if (myCache[stateKey] == null)
            PopulateCache();
            return stateArray;
        }


        /// <summary>
        ///     ''' Takes the abbreviation given and returns the full name
        ///     ''' </summary>
        ///     ''' <returns>The full name for the abbreviation in 
        ///     ''' question</returns>
        private static string convertAbbreviationToName(ref string abbreviation)
        {
            XmlDocument xmlFile = new XmlDocument();

            try
            {
                applicationConstantsFileName = applicationConstantsFileName.Replace("/", @"\");
                xmlFile.Load(applicationConstantsFileName);
                XmlNode theNode = xmlFile.SelectSingleNode("descendant::state[@abbreviation='" + abbreviation + "']");

                if (theNode != null)
                    return theNode.Attributes.GetNamedItem("name").Value;
            }
            catch (Exception e)
            {
                addError(ref e);
            }

            return null;
        }


        /// <summary>
        ///     ''' Gets the state object based on the full name
        ///     ''' </summary>
        ///     ''' <param name="name">The full name of the state to 
        ///     ''' retrieve</param>
        ///     ''' <returns>A State object for the name given</returns>
        public static state getStateByName(ref string name)
        {
            // if (myCache[stateKey + name] == null)
            PopulateCache();
            //return state[stateKey + name];

            return (state)Convert.ChangeType(stateKey, typeof(state[]));
        }


        /// <summary>
        ///     ''' Gets the state object based on the abbreviation
        ///     ''' </summary>
        ///     ''' <param name="abbreviation">The abbreviation of the state 
        ///     ''' to retrieve</param>
        ///     ''' <returns>A State object for the abbreviation 
        ///     ''' given</returns>
        public static state getStateByAbbreviation(ref string abbreviation)
        {
            string name = convertAbbreviationToName(ref abbreviation);
            if (name != null)
                return getStateByName(ref name);
            else
                return null/* TODO Change to default(_) if this is not a reference type */;
        }


        /// <summary>The manager attempts to load the XML
        ///     ''' file and store it in the cache with a dependency on the XML 
        ///     ''' file itself.' This means that any time the XML file changes, it 
        ///     ''' is removed from the cache.  When the methods that return State 
        ///     ''' objects are called again, the XML file won't exist in memory 
        ///     ''' and the PopulateCache will be re-called.
        ///     ''' </summary>
        private static void PopulateCache()
        {
            XmlDocument xmlFile = new XmlDocument();
            // Dim theState As State
            XmlNode theNode;
            string theName, theAbbreviation;
            int i = 0;

            try
            {
                applicationConstantsFileName = applicationConstantsFileName.Replace("/", @"\");
                xmlFile.Load(applicationConstantsFileName);

                // Attempt to find the element given the "key" for that tag
                XmlNodeList elementList = xmlFile.GetElementsByTagName("state");

                if (elementList != null)
                {
                    stateArray = (state[])Array.CreateInstance(typeof(state), elementList.Count);

                    // Loop through each element that has the name we're looking for
                    for (i = 0; i <= elementList.Count - 1; i++)
                    {
                        theNode = elementList[i];

                        // Get the name for that tag
                        if (theNode.Attributes.GetNamedItem("name") != null)
                            theName = theNode.Attributes.GetNamedItem("name").Value;
                        else
                            theName = null;

                        // Get the abbreviation for that tag
                        if (theNode.Attributes.GetNamedItem("abbreviation") != null)
                            theAbbreviation = theNode.Attributes.GetNamedItem("abbreviation").Value;
                        else
                            theAbbreviation = null;

                        // Populate that location in the array with the
                        // values for the tag
                        stateArray[i] = new state(ref theName, ref theAbbreviation);

                        // Insert the state into cache
                        //// myCache.Insert(stateKey + theName, stateArray[i], new CacheDependency(applicationConstantsFileName));
                    }

                    // Insert the state array into cache
                    ////  myCache.Insert(stateKey, stateArray, new CacheDependency(applicationConstantsFileName));
                }
            }
            catch (Exception e)
            {
                addError(ref e);
            }
        }
    }

}