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using System;
using System.Collections.Generic;

namespace XenAdmin.Core
{
    /// <summary>
    /// A method for which we might need to run an RBAC test.
    /// </summary>
    public class RbacMethod
    {
        public const string KEY_SPLITTER = "/key:";

        /// <summary>
        /// Creates a new instance of RbacMethod.
        /// </summary>
        /// <param name="method">The method to be checked. In the form "Object.Method",
        /// e.g. "vm.start", "http/get_host_backup", "vm.add_to_other_config".</param>
        /// <param name="key">If the method modifies a hashtable, this is the hash key to be altered by the method.</param>
        public RbacMethod(string method, string key = null)
        {
            Method = method.ToLowerInvariant().Replace("async_", "");
            Key = key?.ToLowerInvariant();
        }

        public string Method { get; }

        public string Key { get; }

        public override string ToString()
        {
            if (Key == null)
                return Method;
            
            return Method + KEY_SPLITTER + Key;
        }
    }

    /// <summary>
    /// Syntactic sugar for making a list of RbacMethods without calling the constructor all the time
    /// </summary>
    public class RbacMethodList : List<RbacMethod>
    {
        public RbacMethodList()
        {
        }

        /// <summary>
        /// Note that this constructor takes simple API calls, or complex ones with hash table edits and keys delimited by a RbacMethod.KEY_SPLITTER
        /// Silently ignores blank methods, blank keys and entries with too many RbacMethod.KEY_SPLITTER
        /// </summary>
        public RbacMethodList(params string[] methods)
        {
            foreach (string entry in methods)
            {
                if (entry == null)
                    continue;

                string[] entrySplit = entry.Split(new string[] { RbacMethod.KEY_SPLITTER }, StringSplitOptions.None);
                string method = entrySplit[0].Trim();
                if (method == "")
                    continue;

                switch (entrySplit.Length)
                {
                    case 1:
                        // no splitters, it's just a method
                        Add(method);
                        break;
                    case 2:
                        // we have a splitter so define it as a key
                        string key = entrySplit[1].Trim();
                        if (key == "")
                            continue;
                        AddWithKey(method, key);
                        break;
                    default:
                        // ignore lengths of longer than 2, too many splitters
                        continue;
                }
                
            }
        }

        public RbacMethodList(params RbacMethod[] methods)
        {
            AddRange(methods);
        }

        /// <summary>
        /// Add a simple API call
        /// </summary>
        /// <param name="method">The method to be checked. In the form "Object.Method" (e.g., "vm.start")
        /// or "http/get_host_backup"</param>
        public void Add(string method)
        {
            Add(new RbacMethod(method));
        }

        /// <summary>
        /// Add a hash table API call with key to be edited
        /// </summary>
        /// <param name="method">The method to be checked. In the form "Object.Method" (e.g., "vm.add_to_other_config").</param>
        /// <param name="key">The hash key to be altered by the call.</param>
        public void AddWithKey(string method, string key)
        {
            Add(new RbacMethod(method, key));
        }

        public void AddRange(params string[] methods)
        {
            foreach (var method in methods)
                Add(method);
        }

        public string[] ToStringArray()
        {
            string[] ans = new string[this.Count];
            int i = 0;
            foreach (RbacMethod method in this)
                ans[i++] = method.ToString();
            return ans;
        }
    }
}