<?php declare(strict_types=1);

namespace Kilo;

/**
 * @property-read int size
 * @property-read int rsize
 */
class Row {
	use MagicProperties;

	public string $chars = '';
	public string $render = '';

	public array $hl = [];

	public static function new(string $chars): self
	{
		return new self($chars);
	}

	private function __construct($chars)
	{
		$this->chars = $chars;
	}

	public function __get(string $name)
	{
		switch ($name)
		{
			case 'size':
				return strlen($this->chars);

			case 'rsize':
				return strlen($this->render);

			default:
				return NULL;
		}
	}

	public function __toString(): string
	{
		return $this->chars . "\n";
	}

	public function update(): void
	{
		$idx = 0;

		for ($i = 0; $i < $this->size; $i++)
		{
			if ($this->chars[$i] === "\t")
			{
				$this->render[$idx++] = ' ';
				while ($idx % KILO_TAB_STOP !== 0)
				{
					$this->render[$idx++] = ' ';
				}
			}
			else
			{
				$this->render[$idx++] = $this->chars[$i];
			}
		}

		$this->updateSyntax();
	}

	// ------------------------------------------------------------------------
	// ! Syntax Highlighting
	// ------------------------------------------------------------------------

	protected function updateSyntax(): void
	{
		$this->hl = array_fill(0, $this->rsize, Highlight::NORMAL);

		$prevSep = TRUE;

		$i = 0;

		while ($i < $this->rsize)
		{
			$char = $this->render[$i];
			$prevHl = ($i > 0) ? $this->hl[$i - 1] : Highlight::NORMAL;

			// Numbers, including decimal points
			if (
				($char === '.' && $prevHl === Highlight::NUMBER) ||
				(($prevSep || $prevHl === Highlight::NUMBER) && is_digit($char))
			)
			{
				$this->hl[$i] = Highlight::NUMBER;
				$i++;
				$prevSep = FALSE;
				continue;
			}

			$prevSep = is_separator($char);
			$i++;
		}
	}
}