Files
Discord.Net/src/Discord.Net.Commands/CommandInfo.cs
2016-10-10 21:34:45 -03:00

279 lines
11 KiB
C#

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks;
namespace Discord.Commands
{
[DebuggerDisplay(@"{DebuggerDisplay,nq}")]
public class CommandInfo
{
private static readonly MethodInfo _convertParamsMethod = typeof(CommandInfo).GetTypeInfo().GetDeclaredMethod(nameof(ConvertParamsList));
private static readonly ConcurrentDictionary<Type, Func<IEnumerable<object>, object>> _arrayConverters = new ConcurrentDictionary<Type, Func<IEnumerable<object>, object>>();
private readonly Func<CommandContext, object[], Task> _action;
public MethodInfo Source { get; }
public ModuleInfo Module { get; }
public string Name { get; }
public string Summary { get; }
public string Remarks { get; }
public string Text { get; }
public int Priority { get; }
public bool HasVarArgs { get; }
public RunMode RunMode { get; }
public IReadOnlyList<string> Aliases { get; }
public IReadOnlyList<CommandParameter> Parameters { get; }
public IReadOnlyList<PreconditionAttribute> Preconditions { get; }
internal CommandInfo(MethodInfo source, ModuleInfo module, CommandAttribute attribute, string groupPrefix)
{
try
{
Source = source;
Module = module;
Name = source.Name;
if (attribute.Text == null)
Text = groupPrefix;
RunMode = attribute.RunMode;
if (groupPrefix != "")
groupPrefix += " ";
if (attribute.Text != null)
Text = groupPrefix + attribute.Text;
var aliasesBuilder = ImmutableArray.CreateBuilder<string>();
aliasesBuilder.Add(Text);
var aliasesAttr = source.GetCustomAttribute<AliasAttribute>();
if (aliasesAttr != null)
aliasesBuilder.AddRange(aliasesAttr.Aliases.Select(x => groupPrefix + x));
Aliases = aliasesBuilder.ToImmutable();
var nameAttr = source.GetCustomAttribute<NameAttribute>();
if (nameAttr != null)
Name = nameAttr.Text;
var summary = source.GetCustomAttribute<SummaryAttribute>();
if (summary != null)
Summary = summary.Text;
var remarksAttr = source.GetCustomAttribute<RemarksAttribute>();
if (remarksAttr != null)
Remarks = remarksAttr.Text;
var priorityAttr = source.GetCustomAttribute<PriorityAttribute>();
Priority = priorityAttr?.Priority ?? 0;
Parameters = BuildParameters(source);
HasVarArgs = Parameters.Count > 0 ? Parameters[Parameters.Count - 1].IsMultiple : false;
Preconditions = BuildPreconditions(source);
_action = BuildAction(source);
}
catch (Exception ex)
{
throw new Exception($"Failed to build command {source.DeclaringType.FullName}.{source.Name}", ex);
}
}
public async Task<PreconditionResult> CheckPreconditions(CommandContext context, IDependencyMap map = null)
{
foreach (PreconditionAttribute precondition in Module.Preconditions)
{
var result = await precondition.CheckPermissions(context, this, map).ConfigureAwait(false);
if (!result.IsSuccess)
return result;
}
foreach (PreconditionAttribute precondition in Preconditions)
{
var result = await precondition.CheckPermissions(context, this, map).ConfigureAwait(false);
if (!result.IsSuccess)
return result;
}
return PreconditionResult.FromSuccess();
}
public async Task<ParseResult> Parse(CommandContext context, SearchResult searchResult, PreconditionResult? preconditionResult = null)
{
if (!searchResult.IsSuccess)
return ParseResult.FromError(searchResult);
if (preconditionResult != null && !preconditionResult.Value.IsSuccess)
return ParseResult.FromError(preconditionResult.Value);
string input = searchResult.Text;
var matchingAliases = Aliases.Where(alias => input.StartsWith(alias));
string matchingAlias = "";
foreach (string alias in matchingAliases)
{
if (alias.Length > matchingAlias.Length)
matchingAlias = alias;
}
input = input.Substring(matchingAlias.Length);
return await CommandParser.ParseArgs(this, context, input, 0).ConfigureAwait(false);
}
public Task<ExecuteResult> Execute(CommandContext context, ParseResult parseResult)
{
if (!parseResult.IsSuccess)
return Task.FromResult(ExecuteResult.FromError(parseResult));
var argList = new object[parseResult.ArgValues.Count];
for (int i = 0; i < parseResult.ArgValues.Count; i++)
{
if (!parseResult.ArgValues[i].IsSuccess)
return Task.FromResult(ExecuteResult.FromError(parseResult.ArgValues[i]));
argList[i] = parseResult.ArgValues[i].Values.First().Value;
}
var paramList = new object[parseResult.ParamValues.Count];
for (int i = 0; i < parseResult.ParamValues.Count; i++)
{
if (!parseResult.ParamValues[i].IsSuccess)
return Task.FromResult(ExecuteResult.FromError(parseResult.ParamValues[i]));
paramList[i] = parseResult.ParamValues[i].Values.First().Value;
}
return Execute(context, argList, paramList);
}
public async Task<ExecuteResult> Execute(CommandContext context, IEnumerable<object> argList, IEnumerable<object> paramList)
{
try
{
var args = GenerateArgs(argList, paramList);
switch (RunMode)
{
case RunMode.Sync: //Always sync
await _action(context, args).ConfigureAwait(false);
break;
case RunMode.Mixed: //Sync until first await statement
var t1 = _action(context, args);
break;
case RunMode.Async: //Always async
var t2 = Task.Run(() => _action(context, args));
break;
}
return ExecuteResult.FromSuccess();
}
catch (Exception ex)
{
return ExecuteResult.FromError(ex);
}
}
private IReadOnlyList<PreconditionAttribute> BuildPreconditions(MethodInfo methodInfo)
{
return methodInfo.GetCustomAttributes<PreconditionAttribute>().ToImmutableArray();
}
private IReadOnlyList<CommandParameter> BuildParameters(MethodInfo methodInfo)
{
var parameters = methodInfo.GetParameters();
var paramBuilder = ImmutableArray.CreateBuilder<CommandParameter>(parameters.Length);
for (int i = 0; i < parameters.Length; i++)
{
var parameter = parameters[i];
var type = parameter.ParameterType;
//Detect 'params'
bool isMultiple = parameter.GetCustomAttribute<ParamArrayAttribute>() != null;
if (isMultiple)
type = type.GetElementType();
var reader = Module.Service.GetTypeReader(type);
var typeInfo = type.GetTypeInfo();
//Detect enums
if (reader == null && typeInfo.IsEnum)
{
reader = EnumTypeReader.GetReader(type);
Module.Service.AddTypeReader(type, reader);
}
if (reader == null)
throw new InvalidOperationException($"{type.FullName} is not supported as a command parameter, are you missing a TypeReader?");
bool isRemainder = parameter.GetCustomAttribute<RemainderAttribute>() != null;
if (isRemainder && i != parameters.Length - 1)
throw new InvalidOperationException("Remainder parameters must be the last parameter in a command.");
string name = parameter.Name;
string summary = parameter.GetCustomAttribute<SummaryAttribute>()?.Text;
bool isOptional = parameter.IsOptional;
object defaultValue = parameter.HasDefaultValue ? parameter.DefaultValue : null;
paramBuilder.Add(new CommandParameter(parameters[i], name, summary, type, reader, isOptional, isRemainder, isMultiple, defaultValue));
}
return paramBuilder.ToImmutable();
}
private Func<CommandContext, object[], Task> BuildAction(MethodInfo methodInfo)
{
if (methodInfo.ReturnType != typeof(Task))
throw new InvalidOperationException("Commands must return a non-generic Task.");
return (context, args) =>
{
var instance = Module.CreateInstance();
instance.Context = context;
try
{
return methodInfo.Invoke(instance, args) as Task ?? Task.CompletedTask;
}
finally
{
(instance as IDisposable)?.Dispose();
}
};
}
private object[] GenerateArgs(IEnumerable<object> argList, IEnumerable<object> paramsList)
{
int argCount = Parameters.Count;
var array = new object[Parameters.Count];
if (HasVarArgs)
argCount--;
int i = 0;
foreach (var arg in argList)
{
if (i == argCount)
throw new InvalidOperationException("Command was invoked with too many parameters");
array[i++] = arg;
}
if (i < argCount)
throw new InvalidOperationException("Command was invoked with too few parameters");
if (HasVarArgs)
{
var func = _arrayConverters.GetOrAdd(Parameters[Parameters.Count - 1].ElementType, t =>
{
var method = _convertParamsMethod.MakeGenericMethod(t);
return (Func<IEnumerable<object>, object>)method.CreateDelegate(typeof(Func<IEnumerable<object>, object>));
});
array[i] = func(paramsList);
}
return array;
}
private static T[] ConvertParamsList<T>(IEnumerable<object> paramsList)
=> paramsList.Cast<T>().ToArray();
public override string ToString() => Name;
private string DebuggerDisplay => $"{Module.Name}.{Name} ({Text})";
}
}