C# code to parse an asterisk voicemail.conf configuration file in the asterisk telephony toolkit. NOTE: depends on "IniParser" available from : https://github.com/rickyah/ini-parser

MailboxConfig.cs

namespace TelephonyServices.DataModels;

public class MailboxConfig
{
  public string MailboxNumber { get; set; } = "";
  public string MailboxSecret { get; set; } = "";
  public string MailboxName { get; set; } = "";
  public string MailboxEmail { get; set; } = "";
  public string MailboxPager { get; set; } = "";
  public string MailboxOptions { get; set; } = "";
}

VoicemailConfig.cs

using IniParser;
using IniParser.Model;

namespace DataModels;

public class VoicemailConfig
{
  public Dictionary<string, string> Options { get; set; } = new();
  public Dictionary<string, Dictionary<string, MailboxConfig?>> Mailboxes { get; set; } = new();

  public MailboxConfig? FindMailbox (string mailbox, string context = "default")
  {
    if (!Mailboxes.ContainsKey(context)) return null;
    return !Mailboxes[context].ContainsKey(mailbox) ? null : Mailboxes[context][mailbox];
  }

  public void LoadVoicemailConf(string voicemailConfigurationFileName)
  {
    // Use IniParser to load our voicemail.config file
    // NOTE: the config is MOSTLY like a 1995 era windows.ini file but not exactly
    // regular options in a section will parse just fine, but lines such as the mailbox
    // definition line WILl STILL parse, but always begin with ">"
    // EG:
    // [general]
    // sendvoicemail=yes
    // ----- Will give ["general"]["sendvoicemail"] with a value "yes"
    //
    // [default]
    // 100 => 1234,vm box,foo@bar
    // ----- Will give ["default"]["100"] with a value "> 1234,vm box,foo@bar"
    //
    // So for lines such as VM specs and dialplan extensions, the file will still parse correctly
    // but the value will need to be tidied up and/or transformed
    //
    var parser = new FileIniDataParser();
    IniData data = parser.ReadFile(voicemailConfigurationFileName);

    // Initialise our VM config and load in the options
    Options = new Dictionary<string, string>();
    Mailboxes = new Dictionary<string, Dictionary<string, MailboxConfig?>>();
    foreach (KeyData key in data["general"])
    {
      Options.Add(key.KeyName, key.Value);
    }

    // Now build a list of mailbox numbers associated with each context
    // and fill in the mail box details in our VM config
    var contextNames = data
      .Sections.Select(s => s.SectionName)
      .Where(s => s != "general" && s != "zonemessages")
      .ToList();
    
    foreach (var contextName in contextNames)
    {
      if (!Mailboxes.ContainsKey(contextName))
      {
        Mailboxes.Add(contextName, new Dictionary<string, MailboxConfig?>());
      }

      foreach (var key in data[contextName])
      {
        var rawVmConfig = key.Value;
        rawVmConfig = rawVmConfig.Trim('>', ' ');
        var rawVmConfigParts = rawVmConfig.Split(',');

        var newConfig = new MailboxConfig();
        newConfig.MailboxNumber = key.KeyName.Trim();
        switch (rawVmConfigParts.Length)
        {
          case 2:
            // we have secret & name
            newConfig.MailboxSecret = rawVmConfigParts[0].Trim();
            newConfig.MailboxName = rawVmConfigParts[1].Trim();
            break;
          case 3:
            // we have secret, name & email
            newConfig.MailboxSecret = rawVmConfigParts[0].Trim();
            newConfig.MailboxName = rawVmConfigParts[1].Trim();
            newConfig.MailboxEmail = rawVmConfigParts[2].Trim();
            break;
          case 4:
            // we have secret, name, email & pager
            newConfig.MailboxSecret = rawVmConfigParts[0].Trim();
            newConfig.MailboxName = rawVmConfigParts[1].Trim();
            newConfig.MailboxEmail = rawVmConfigParts[2].Trim();
            newConfig.MailboxPager = rawVmConfigParts[3].Trim();
            break;
          case 5:
            // we have secret, name, email, pager and options
            newConfig.MailboxSecret = rawVmConfigParts[0].Trim();
            newConfig.MailboxName = rawVmConfigParts[1].Trim();
            newConfig.MailboxEmail = rawVmConfigParts[2].Trim();
            newConfig.MailboxPager = rawVmConfigParts[3].Trim();
            newConfig.MailboxOptions = rawVmConfigParts[4].Trim();
            break;
          default:
            // we have too few or too many VM config options
            // TODO: maybe a custom exception should be thrown here
            break;
        }
        
        Mailboxes[contextName].Add(key.KeyName.Trim(), newConfig);
      }
      
    }

    
    
  }
  
}