<?php
/// CRIMSON --- A simple PHP framework.
/// Copyright © 2024 Freya Murphy <contact@freyacat.org>
///
/// This file is part of CRIMSON.
///
/// CRIMSON is free software; you can redistribute it and/or modify it
/// under the terms of the GNU General Public License as published by
/// the Free Software Foundation; either version 3 of the License, or (at
/// your option) any later version.
///
/// CRIMSON is distributed in the hope that it will be useful, but
/// WITHOUT ANY WARRANTY; without even the implied warranty of
/// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
/// GNU General Public License for more details.
///
/// You should have received a copy of the GNU General Public License
/// along with CRIMSON. If not, see <http://www.gnu.org/licenses/>.

/**
 * Gives access to imporant
 * needed utility functions for
 * accessing everything else!
 */
abstract class Base {

// ======================================================== LOADABLE OBJECTS ==

	// keep track of what has been loaded
	private static array $loaded = array();

	/**
	 * Loads a $type of object from a $dir with a given $name
	 * @param string $name - the name of the object to load
	 * @param string $dir - the directory theese objects are stored in
	 * @param string $type - the type of the object
	 */
	private function load_type($name, $dir, $type): object|NULL
	{

		$path = $dir . '/' . $name . '.php';

		// dont reload an ohject
		if (array_key_exists($path, self::$loaded))
			return self::$loaded[$path];

		// only load a object if it exists
		if (!file_exists($path))
			return NULL;

		$parts = explode('/', $name);
		$part = end($parts);
		$class = ucfirst($part) . '_' . $type;
		require($path);

		$ref = NULL;
		try {
			$ref = new ReflectionClass($class);
		} catch (Exception $_e) {}

		if ($ref === NULL)
			return NULL;

		$obj = $ref->newInstance();
		self::$loaded[$path] = $obj;

		return $obj;
	}

	/**
	 * Loads a model
	 * @param string $name - the name of the model to load
	 */
	public function load_model($name): Model|NULL
	{
		$dir = WEB_ROOT . '/_model';
		return $this->load_type($name, $dir, 'model');
	}

	/**
	 * Loads a controller
	 * @param string $name - the name of the controller to load
	 */
	public function load_controller($name): Controller|NULL
	{
		$dir = WEB_ROOT . '/_controller';
		return $this->load_type($name, $dir, 'controller');
	}

// ==================================================================== LANG ==

	// current loaded language strings
	private static array $loaded_lang = array();
	private static array $loaded_files = array();

	/**
	 * Loads a php lang file into the lang array
	 */
	private function load_lang_file(string $file): void
	{
		if (isset(self::$loaded[$file]))
			return;
		self::$loaded[$file] = TRUE;

		$lang = self::$loaded_lang;
		require($file);
		self::$loaded_lang = $lang;
	}

	/**
	 * Loads each php file lang strings in a directory
	 */
	private function load_lang_dir(string $dir): void
	{
		if ($handle = opendir($dir)) {
			while (false !== ($entry = readdir($handle))) {
				if ($entry === '.' || $entry === '..')
					continue;
				$this->load_lang_file($entry);
			}
		}
	}

	/**
	 * Loads the given common lang
	 */
	public function load_lang(string ...$langs): array
	{
		$root = WEB_ROOT . '/lang';

		foreach ($langs as $lang) {
			$file = "{$root}/{$lang}.php";
			$dir = "{$root}/{$lang}";

			if (file_exists($file))
				$this->load_lang_file($file);
			else if (is_dir($dir))
				$this->load_lang_dir($dir);

		}

		return self::$loaded_lang;
	}

	/**
	 * Returns the currently loaded lang
	 */
	public function get_lang(): array
	{
		return self::$loaded_lang;
	}

// ================================================================ DATABASE ==

	// current database connection
	private static ?DatabaseHelper $db = NULL;

	/**
	 * Loads the database
	 */
	public function db(): DatabaseHelper
	{
		if (!self::$db)
			self::$db = new DatabaseHelper();
		return self::$db;
	}

// ================================================================ METADATA ==

	/**
	 * Gets the stamp for a asset path
	 * @param string $path
	 */
	public function asset_stamp(string $path): int
	{
		if (ENVIRONMENT == 'devlopment')
			return time();
		if (isset(FILE_TIMES[$path]))
			return FILE_TIMES[$path];
		return 0;
	}

	/**
	 * Gets a full path url from a relative path
	 * @param string $path
	 * @param bool $timestamp
 	 */
	public function get_url(string $path, bool $timestamp = FALSE): string
	{
		$scheme = 'http';
		if (isset($_SERVER['HTTP_X_FORWARDED_PROTO']))
			$scheme = $_SERVER['HTTP_X_FORWARDED_PROTO'];

		$host = $_SERVER['HTTP_HOST'];

		if (ENVIRONMENT == 'production') {
			$default = CONFIG['domain'];
			$allowed = CONFIG['allowed_hosts'];
			if (!is_array($allowed))
				$allowed = [$allowed];
			if (!in_array($host, $allowed))
				$host = $default;
		}

		$base = CONFIG['base_path'];
		$url = "{$scheme}://{$host}{$base}{$path}";
		if ($timestamp) {
			$time = $this->asset_stamp($path);
			$url .= "?timestamp={$time}";
		}
		return $url;
	}

	/**
	 * Loads a js html link
	 * @param string $path - the path to the js file
	 */
	public function link_js(string $path): string
	{
		$stamp = $this->asset_stamp("public/$path");
		$href = $this->get_url("public/{$path}?timestamp={$stamp}");
		return '<script src="'. $href .'"></script>';
	}

	/**
	 * Loads a css html link
	 * @param string $path - the path to the css file
	 */
	public function link_css(string $path): string
	{
		$stamp = $this->asset_stamp("public/$path");
		$href = $this->get_url("public/{$path}?timestamp={$stamp}");
		return '<link rel="stylesheet" href="'. $href .'">';
	}

	/**
	 * Loads a css html link
	 * @param string $path - the path to the css file
	 */
	public function embed_css(string $path): string
	{
		$file = PUBLIC_ROOT . '/' . $path;
		if (file_exists($file)) {
			$text = file_get_contents($file);
			return "<style>{$text}</style>";
		} else {
			return "";
		}
	}

// =============================================================== HTTP POST ==

	/**
	 * Gets http POST data from $_POST if x-url-encoded, or parsed from
	 * php://input if AJAX. Returns FALSE if input is not a post request,
	 * or NULL if unable to parse request body.
	 */
	private function get_post_data()
	{
		static $data = NULL;

		if (isset($data))
			return $data;

		// not a POST request
		if ($_SERVER['REQUEST_METHOD'] != 'POST')
			return NULL;

		// ajax
		if (isset($_SERVER['HTTP_X_REQUESTED_WITH']) &&
			$_SERVER['HTTP_X_REQUESTED_WITH'] == 'XMLHttpRequest') {
			$data = json_decode(file_get_contents("php://input"),
				true);
			// on failure, make sure $data is FALSE and not NULL
			if (!$data)
				$data = FALSE;
			return $data;
		}

		// x-url-encoded or form-data
		$data = $_POST;
		return $data;
	}

	/**
	 * Returns HTTP POST information if POST request.
	 * @returns $_POST if $key is not set and request is POST.
	 * @returns value at $key if $key is set and request is POST.
	 * @returns FALSE if value at $key is not set and request is POST.
	 * @returns FALSE if request is POST but has invalid body.
	 * @returns NULL if request is not POST.
	 */
	public function post_data(?string $key = NULL)
	{
		$data = $this->get_post_data();

		if (!$data)
			return $data;

		if (!$key)
			return $data;

		if (!isset($data[$key]))
			return FALSE;

		return $data[$key];
	}

}