BastliBridge

command.d (1929B)

---

 module bastlibridge.command;
 import bastlibridge.base;
 import bastlibridge.manager;
 import std.datetime : SysTime;
 import std.exception;
 import std.format;
 import std.meta;
 import std.conv;
 import std.algorithm;
 import std.traits;
 import std.experimental.logger;
 
 class CommandException : Exception{
 	this(string msg, string file= __FILE__, size_t line=__LINE__, Throwable next=null){
 		super(msg,file,line,next);
 	}
 }
 
 struct CommandOptions{
 	bool admin=false;
 }
 
 struct CommandMachine{
 	struct Function{
 		void function(Message m, in char[] args) func;
 		CommandOptions co;
 	}
 	Function[string] commands;
 	
 	bool available(in char[] name){
 		return cast(bool)(name in commands);
 	}
 	
 	void execute(in char[] name, Message m, in char[] args, bool handleErrors=true)
 	in{
 		assert(name);
 		assert(m);
 	}
 	do{
 		try{
 			auto cmd=enforce!CommandException(name in commands, format("Command %s unknown", name));
 			if(cmd.co.admin && !m.auth()){
 				throw new CommandException("Permission denied");
 			}
 			cmd.func(m, args);
 		}
 		catch(Exception e){
 			if(handleErrors){
 				m.respond(e.msg);
 				warning(e.toString);
 			}
 			else{
 				throw e;
 			}
 		}
 	}
 	
 	static void wrapperFunction(alias T)(Message m, in char[] args) if(isCallable!T){
 		auto s=args.splitter(" ");
 		auto pop(){
 			if(s.empty)
 				throw new Exception("Too few arguments given");
 			auto ret=s.front;
 			s.popFront();
 			return ret;
 		}
 		alias fct=staticMap!(to,Parameters!T[1..$]);
 		
 		auto ref evaluate(alias Func)(){
 			return Func(pop());
 		}
 		
 		T(m, staticMap!(evaluate, fct));
 	}
 	
 	void add(alias T)(string name){
 		static if(hasUDA!(T, CommandOptions)){
 			add!T(name, getUDA!(T, CommandOptions));
 		}
 		else{
 			add!T(name, CommandOptions.init);
 		}
 		
 	}
 	void add(alias T)(string name, CommandOptions co) if(isCallable!T && is(Parameters!T[0] == Message)){
 		commands[name]=Function(&wrapperFunction!T, co);
 	}
 }
 CommandMachine globalCommands;