/*
 * Copyright (c) 2010-2018 Tim Düsterhus.
 *
 * Use of this software is governed by the Business Source License
 * included in the LICENSE file.
 *
 * Change Date: 2024-11-01
 *
 * On the date above, in accordance with the Business Source
 * License, use of this software will be governed by version 2
 * or later of the General Public License.
 */

define([ './CommandHandler'
       , './Parser'
       ], function (CommandHandler, Parser) {
	"use strict";

	const DEPENDENCIES = [ 'CommandHandler' ]
	class Autocompleter {
		constructor(commandHandler) {
			if (!(commandHandler instanceof CommandHandler)) throw new TypeError('You must pass a CommandHandler to the Autocompleter')

			this.commandHandler = commandHandler
		}

		* autocomplete(text) {
			if (text === '/') {
				yield * this.autocompleteCommandTrigger(text, '')
				return
			}

			const [ trigger, parameterString ] = this.commandHandler.splitCommand(text)

			let command
			if (trigger === null) {
				command = this.commandHandler.getCommandByIdentifier('be.bastelstu.chat', 'plain')
			}
			else {
				const triggerDone = Parser.Slash.thenRight(Parser.AlnumTrigger.or(Parser.SymbolicTrigger).thenLeft(Parser.Whitespace)).parse(Parser.Streams.ofString(text))
				if (!triggerDone.isAccepted()) {
					yield * this.autocompleteCommandTrigger(text, trigger)
					return
				}

				command = this.commandHandler.getCommandByTrigger(trigger)
			}

			if (command === null) {
				return
			}

			const values = command.autocomplete(parameterString)

			if (trigger !== null) {
				for (const item of values) {
					yield `/${trigger} ${item}`
				}
			}
			else {
				yield * values
			}
		}

		* autocompleteCommandTrigger(text, prefix) {
			const triggers = Array.from(this.commandHandler.getTriggers())

			triggers.sort()

			for (const trigger of triggers) {
				if (trigger === '') continue
				if (!trigger.startsWith(prefix)) continue
				if (!this.commandHandler.getCommandByTrigger(trigger).isAvailable) continue

				yield `/${trigger} `
			}
		}
	}
	Autocompleter.DEPENDENCIES = DEPENDENCIES

	return Autocompleter
});