/// <summary>
/// Retrieves the help text for the given options container type.
/// </summary>
/// <param name="containerType">
/// The type of options container to retrieve the help text for.
/// </param>
/// <returns>
/// A collection of text lines, the help text.
/// </returns>
/// <exception cref="ArgumentNullException">
/// <para><paramref name="containerType"/> is <c>null</c>.</para>
/// </exception>
public static IEnumerable <string> GetHelp(Type containerType)
{
if (containerType == null)
{
throw new ArgumentNullException("containerType");
}
var map = new PropertyMap(containerType);
// Command line help
var parts = new List <string>();
int argumentIndex = 1;
foreach (PropertyInfo prop in map.ArgumentProperties)
{
var attr = (ArgumentAttribute)prop.GetCustomAttributes(typeof(ArgumentAttribute), true)[0];
string name = attr.Name;
if (StringEx.IsNullOrWhiteSpace(name))
{
name = "ARG" + argumentIndex;
}
if (attr.Optional)
{
parts.Add("[" + name + "]");
}
else
{
parts.Add(name);
}
argumentIndex++;
}
if (map.ArgumentsProperty != null)
{
parts.Add("[ARG]...");
}
if (map.MappedProperties.Any())
{
parts.Add("[OPTIONS]...");
}
yield return(Path.GetFileNameWithoutExtension(Assembly.GetEntryAssembly().Location).ToLower() + " " + string.Join(" ", parts.ToArray()));
yield return(string.Empty);
string[] containerHelp = GetHelpTextFor(containerType).ToArray();
if (containerHelp.Length > 0)
{
foreach (string line in containerHelp)
{
yield return(line);
}
yield return(string.Empty);
}
var argumentsWithDescription =
(from entry in map.ArgumentProperties.Select((property, index) => new { property, index })
let descriptionAttr = entry.property.GetCustomAttributes(typeof(DescriptionAttribute), true).FirstOrDefault() as DescriptionAttribute
where descriptionAttr != null
let attr = (ArgumentAttribute)entry.property.GetCustomAttributes(typeof(ArgumentAttribute), true)[0]
let argName = !StringEx.IsNullOrWhiteSpace(attr.Name) ? attr.Name : ("ARG" + (entry.index + 1))
select new { argName, text = StringEx.SplitLines(descriptionAttr.Description).ToArray() }).ToArray();
if (argumentsWithDescription.Length > 0)
{
yield return("arguments:");
yield return(string.Empty);
int maxLongLength = argumentsWithDescription.Max(p => p.argName.Length);
foreach (var arg in argumentsWithDescription)
{
int lines = arg.text.Length;
if (arg.argName.Length > 20)
{
yield return(" " + arg.argName);
var indent = new string(' ', maxLongLength + 3);
foreach (string line in arg.text)
{
yield return(indent + line);
}
}
else
{
yield return(" " + arg.argName.PadRight(maxLongLength, ' ') + " " + arg.text[0]);
var indent = new string(' ', maxLongLength + 3);
foreach (string line in arg.text.Skip(1))
{
yield return(indent + line);
}
}
}
yield return(string.Empty);
}
var propertiesWithHelpText =
(from propMap in map.MappedProperties
let text = GetHelpTextFor(propMap.Key).ToArray()
where text.Length > 0
select new
{
prop = propMap.Key, option = propMap.Value.Option, parameter = propMap.Value.ParameterName, text
}
into entry
group entry by entry.prop
into g
select new
{
options = g.Select(e => e.option).OrderBy(o => o.Length).ToArray(), g.First().text, g.First().parameter
}
into entry2
orderby(entry2.options.First() == "-h" || entry2.options.First() == "--help") ? 0 : 1, entry2.options.First()
let shortOption = entry2.options.Where(o => o.Length == 2).FirstOrDefault() ?? string.Empty
let longOption = entry2.options.Where(o => o.Length > 2).FirstOrDefault() ?? string.Empty
select new
{
shortOption, longOption, entry2.options, entry2.parameter, entry2.text
}).ToArray();
if (propertiesWithHelpText.Length > 0)
{
yield return("options:");
yield return(string.Empty);
int maxLongLength = propertiesWithHelpText.Max(p => p.longOption.Length + p.parameter.Length);
foreach (var prop in propertiesWithHelpText)
{
int lines = prop.text.Length;
if (prop.longOption.Length > 20)
{
yield return(" " + (prop.shortOption.PadRight(2, ' ') + " " + prop.longOption + " " + prop.parameter).Trim());
var indent = new string(' ', 27);
foreach (string line in prop.text)
{
yield return(indent + line);
}
}
else
{
yield return(" " + prop.shortOption.PadRight(2, ' ') + " " + (prop.longOption + " " + prop.parameter).PadRight(20, ' ') + " " + prop.text[0]);
var indent = new string(' ', 27);
foreach (string line in prop.text.Skip(1))
{
yield return(indent + line);
}
}
}
}
}