<?php

namespace Automata;

use Automata\Storage\ProgramMemory;
use Automata\Storage\ToolMemory;
use Program\Program;
use Program\Word;
use RuntimeException;
use SplStack;

class Machine
{
	public State $state;
	public ToolMemory $toolMemory;
	public ProgramMemory $subProgramMemory;
	public ProgramMemory $partProgramMemory;
	/** @var SplStack|Program[] */
	private SplStack $programStack;
	private ?Program $activeProgram = null;
	private Definitions $definitions;


	public function __construct()
	{
		$this->state = new State();
		$this->definitions = new Definitions();
		$this->toolMemory = new ToolMemory();
		$this->subProgramMemory = new ProgramMemory();
		$this->partProgramMemory = new ProgramMemory();
		$this->programStack = new SplStack();
	}


	public function loadProgram(int $N): void
	{
		$this->programStack = new SplStack();
		$program = $this->partProgramMemory->read($N);
		$this->programStack->push($program);
	}


	public function start(): void
	{
		$this->activeProgram = $this->programStack->pop();
		if (is_null($this->activeProgram)) {
			throw new RuntimeException('No program loaded');
		}
		foreach ($this->activeProgram as $block) {
			// Do we apply a block or a word?
			// Answer: depends! Some commands need
			// more information from other words.
			// TODO: Interpret commands such as preparation of a work cycle

			$words = array_map(fn(Word $w) => $w->toString(), $block->words);
			$words = implode("\t", $words);
			$words = "N{$block->N}\t$words";

			foreach ($block->words as $word) {
				$this->state->apply($word);
				system('clear');
				print("\n  $words\n\n");
				dump($this->state);
				readline();
			}
		}
	}


	public function reset(): void
	{
		$this->activeProgram = null;
	}
}