<?php declare(strict_types=1);

namespace Aviat\Kilo;

use Aviat\Kilo\Enum\KeyCode;
use Aviat\Kilo\Enum\KeyType;
use Aviat\Kilo\Type\TerminalSize;

class Terminal {
	/**
	 * Get the size of the current terminal window
	 *
	 * @codeCoverageIgnore
	 * @return TerminalSize
	 */
	public static function size(): TerminalSize
	{
		return new TerminalSize(...self::getWindowSize());
	}

	/**
	 * Get the size of the current terminal window
	 *
	 * @codeCoverageIgnore
	 * @return array
	 */
	public static function getWindowSize(): array
	{
		$ffiSize = Termios::getWindowSize();
		if ($ffiSize !== NULL)
		{
			return $ffiSize;
		}

		// Try using tput
		if (self::has_tput())
		{
			$rows = (int)trim((string)shell_exec('tput lines'));
			$cols = (int)trim((string)shell_exec('tput cols'));

			if ($rows > 0 && $cols > 0)
			{
				return [$rows, $cols];
			}
		}

		// Worst-case, return an arbitrary 'standard' size
		return [25, 80];
	}

	/**
	 * Clear the screen and reset the cursor position
	 */
	public static function clear(): void
	{
		self::write(ANSI::CLEAR_SCREEN . ANSI::RESET_CURSOR);
	}

	/**
	 * Pull input from the stdin stream.
	 *
	 * @codeCoverageIgnore
	 * @param int $len
	 * @return string
	 */
	public static function read(int $len = 128): string
	{
		$handle = fopen('php://stdin', 'rb');
		if ($handle === false)
		{
			return '';
		}

		$input = fread($handle, $len);
		fclose($handle);

		return (is_string($input)) ? $input : '';
	}

	/**
	 * Get the last key input from the terminal and convert to a
	 * more useful format
	 *
	 * @return string
	 */
	public static function readKey(): string
	{
		$c = Terminal::read();

		return match($c)
		{
			// Unambiguous mappings
			KeyCode::ARROW_DOWN => KeyType::ARROW_DOWN,
			KeyCode::ARROW_LEFT => KeyType::ARROW_LEFT,
			KeyCode::ARROW_RIGHT => KeyType::ARROW_RIGHT,
			KeyCode::ARROW_UP => KeyType::ARROW_UP,
			KeyCode::DEL_KEY => KeyType::DEL_KEY,
			KeyCode::PAGE_DOWN => KeyType::PAGE_DOWN,
			KeyCode::PAGE_UP => KeyType::PAGE_UP,

			// Backspace
			KeyCode::CTRL('h'), KeyCode::BACKSPACE => KeyType::BACKSPACE,

			// Escape
			KeyCode::CTRL('l'), KeyCode::ESCAPE => KeyType::ESCAPE,

			// Home Key
			"\eOH", "\e[7~", "\e[1~", ANSI::RESET_CURSOR => KeyType::HOME_KEY,

			// End Key
			"\eOF", "\e[4~", "\e[8~", "\e[F" => KeyType::END_KEY,

			default => $c,
		};
	}

	/**
	 * Write to the stdout stream
	 *
	 * @codeCoverageIgnore
	 * @param string $str
	 * @param int|NULL $len
	 * @return int|false
	 */
	public static function write(string $str, int $len = NULL): int|false
	{
		$handle = fopen('php://stdout', 'ab');
		if ($handle === false)
		{
			return false;
		}

		$res = (is_int($len))
			? fwrite($handle, $str, $len)
			: fwrite($handle, $str);

		fflush($handle);

		fclose($handle);

		return $res;
	}

	/**
	 * See if tput exists for fallback terminal size detection
	 *
	 * @return bool
	 * @codeCoverageIgnore
	 */
	private static function has_tput(): bool
	{
		$cmd = shell_exec('type tput');
		if ( ! is_string($cmd))
		{
			return FALSE;
		}

		return str_contains($cmd, ' is ');
	}
}