using System.Collections.Generic;

/// <summary>
/// A simple static class to get and set globally accessible variables through a key-value approach.
/// </summary>
/// <remarks>
/// <para>Uses a key-value approach (dictionary) for storing and modifying variables.</para>
/// <para>It also uses a lock to ensure consistency between the threads.</para>
/// </remarks>
public static class GlobalVariables
{

    private static readonly object lockObject = new object();
    private static Dictionary<string, object> variablesDictionary = new Dictionary<string, object>();

    /// <summary>
    /// The underlying key-value storage (dictionary).
    /// </summary>
    /// <value>Gets the underlying variables dictionary</value>
    public static Dictionary<string, object> VariablesDictionary => variablesDictionary;

    /// <summary>
    /// Retrieves all global variables.
    /// </summary>
    /// <returns>The global variables dictionary object.</returns>
    public static Dictionary<string, object> GetAll()
    {
        return variablesDictionary;
    }

    /// <summary>
    /// Gets a variable and casts it to the provided type argument.
    /// </summary>
    /// <typeparam name="T">The type of the variable</typeparam>
    /// <param name="key">The variable key</param>
    /// <returns>The casted variable value</returns>
    public static T Get<T>(string key)
    {
        if (variablesDictionary == null || !variablesDictionary.ContainsKey(key))
        {
            return default(T);
        }

        return (T)variablesDictionary[key];
    }

    /// <summary>
    /// Sets the variable, the existing value gets overridden.
    /// </summary>
    /// <remarks>It uses a lock under the hood to ensure consistensy between threads</remarks>
    /// <param name="key">The variable name/key</param>
    /// <param name="value">The variable value</param>
    public static void Set(string key, object value)
    {
        lock (lockObject)
        {
            if (variablesDictionary == null)
            {
                variablesDictionary = new Dictionary<string, object>();
            }
            variablesDictionary[key] = value;
        }
    }

}