"use strict";

const Dragonfly = global.Dragonfly;
const cl = global.botanLoader;
const fs = require( "fs" );

const conf = cl.load( "config.all" ).sx.mvc;

class Chain
{
	constructor( Render, Utils )
	{
		var _self = this;
		this.renderer = Render;
		this.utils = Utils;
		this.onError = function( err )
		{
			if( err )
			{
				Dragonfly.Error( err );
				_self.renderer( err );
			}
			return err;
		}
	}

	// TemplateChainer
	Template( _class, handler, ext )
	{
		var _self = this;
		Dragonfly.Debug( "Chaining template: " + _class );
		var _file = _class.replace( /\./g, "/" );

		ext = ( ext == undefined ) ? ".html" : ext;

		var defWrapper = function( err, data )
		{
			if( _self.onError( err ) ) return;
			handler( _self.utils, data, _class );
		};

		fs.readFile(
			conf.views + _file + ext
			, "utf8"
			, defWrapper
		);
	}

	// General EventChainer
	General( name, handler )
	{
		var _self = this;

		Dragonfly.Debug( "Chaining (General): " + name );
		var wrapper = function( err, obj )
		{
			if( _self.onError( err ) ) return;

			handler( obj );
		};

		return wrapper;
	}

	// MultiChain
	Multi( name, handler, l, timeout, trigger )
	{
		if( l == 0 || l === undefined )
		{
			Dragonfly.Info( "MultiChain " + name + ": length is zero, directly running handler" );
			handler.apply( undefined, [] );
			return () => {};
		}

		var _self = this;

		// Limit the timeout of callbacks to 3 secs
		if( timeout == undefined ) timeout = 3000;

		return (function()
		{
			var a = 0;
			var args = [];
			var aborted = false;

			Dragonfly.Debug( "Chaining (Multi): " + name );

			var abort = function()
			{
				if( aborted ) return;
				aborted = true;
				var err = new Error( "MutilChain " + name + " exceeds timeout for " + timeout + "ms" );
				_self.onError( err );
			};

			setTimeout( abort, timeout );

			return function() {
				if( aborted ) return;

				trigger && trigger.apply( undefined, arguments );

				args[ args.length ] = arguments;

				Dragonfly.Debug(
					"MultiChain " + name + " " + args.length + "/" + l + " triggered"
				);

				if( args.length == l )
				{
					aborted = true;
					handler.apply( undefined, args );
				}
			};
		})();
	}
}

module.exports = Chain;