<?php
/*
	Copyright (c) TPsoft.org 2000-2025
	Author: Ing. Igor Mino <mino@tpsoft.org>
	License: GNU GPL-3.0 or later

	Description: A set of tools to simplify the work of creating backend APIs for your frontend projects.
	Version: 1.0.0

	Milestones:
	2025-05-28 07:42  Igor - Created

*/

namespace TPsoft\APIlite;

class APIlite
{

	private string $apiName = '';
	private string $endpoint = '';
	private $methods = array();

	public function __construct(?string $format = null, ?string $endpoint = null)
	{
		register_shutdown_function(array($this, '_shutdownHandler'));
		$this->endpoint = $endpoint ?? $this->getCurrentUrl();
		$this->analyzeClass();
		if (isset($_REQUEST['action'])) {
			$this->doAction($_REQUEST['action']);
		} else {
			global $argv;
			if (isset($_REQUEST['format'])) {
				$format = $_REQUEST['format'];
			}
			if (isset($argv)) {
				$switches = array_map('strtolower', is_array($argv) ? $argv : []);
				if (in_array('--html', $switches)) {
					$format = 'html';
				}
				if (in_array('--typescript', $switches)) {
					$format = 'typescript';
				}
			}
			switch ($format) {
				case 'html':
					$this->printHelpHTML();
					break;
				case 'typescript':
					$this->printHelpTypescript();
					break;
				default:
					$this->printHelpJSON();
					break;
			}
		}
	}

	private function _shutdownHandler()
	{
		$error = error_get_last();
		if ($error !== null && in_array($error['type'], [E_ERROR, E_CORE_ERROR, E_COMPILE_ERROR, E_PARSE])) {
			$this->responseERROR($error['message']);
		}
	}

	private function analyzeClass(): bool
	{
		$refClass = new \ReflectionClass($this);
		$this->apiName = $refClass->getShortName();
		$this->methods = array();
		foreach ($refClass->getMethods(\ReflectionMethod::IS_PUBLIC) as $ref_method) {
			$method_name = $ref_method->getName();
			if (substr($method_name, 0, 1) == '_') continue;
			$method = array(
				'name' => $method_name,
				'doc' => null,
				'description' => null,
				'params' => array(),
				'return' => null
			);
			$docComment = $ref_method->getDocComment();
			if ($docComment) {
				$method['doc'] = trim($docComment);
				$method['description'] = $this->parseDescription($method['doc']);
			}
			foreach ($ref_method->getParameters() as $ref_param) {
				$param = array(
					'name' => $ref_param->getName(),
					'type' => null,
					'optional' => $ref_param->isOptional(),
					'default' => null,
					'doc' => null,
				);
				if ($ref_param->hasType()) {
					$param['type'] = $ref_param->getType()->getName();
				}
				if ($ref_param->isOptional()) {
					$param['default'] = $ref_param->getDefaultValue();
				}
				if (!is_null($method['doc'])) {
					$param['doc'] = $this->parseParamDoc($method['doc'], $param['name']);
				}
				$method['params'][] = $param;
			}
			if ($ref_method->hasReturnType()) {
				$ref_type = $ref_method->getReturnType();
				if ($ref_type instanceof \ReflectionNamedType) {
					$method['return'] = $ref_type->getName();
				}
				if ($ref_type instanceof \ReflectionUnionType
					|| $ref_type instanceof \ReflectionIntersectionType )
				{
					$types = $ref_type->getTypes();
					$method['return'] = [];
					foreach ($types as $type) {
						if ($type instanceof \ReflectionNamedType) {
							$method['return'][] = $type->getName();
						}
					}

				}
			}
			$this->methods[] = $method;
		}
		return true;
	}

	private function parseDescription(string $doc): string
	{
		$lines = explode("\n", $doc);
		$desc = array();
		foreach ($lines as $line) {
			$line = trim($line);
			$line = trim(trim($line, '/*'));
			if (substr($line, 0, 1) == '@') {
				break;
			}
			if (strlen($line) <= 0) {
				continue;
			}
			$desc[] = $line;
		}
		return implode("\n", $desc);
	}

	private function parseParamDoc(string $doc, string $param_name): string|null
	{
		$lines = explode("\n", $doc);
		if (substr($param_name, 0, 1) != '$') {
			$param_name = '$' . $param_name;
		}
		foreach ($lines as $line) {
			if (strpos($line, $param_name) !== false) {
				return trim(substr($line, strpos($line, $param_name) + strlen($param_name)));
			}
		}
		return null;
	}

	private function response(array $arr): void
	{
		ob_clean();
		header('Content-Type: application/json');
		$origin = isset($_SERVER['HTTP_ORIGIN']) ? $_SERVER['HTTP_ORIGIN'] : '*';
		header('Access-Control-Allow-Origin: ' . $origin);
		header('Access-Control-Allow-Credentials: true');
		header('Access-Control-Allow-Methods: GET, POST, OPTIONS');
		header('Access-Control-Allow-Headers: Origin, Content-Type, Accept');
		echo json_encode($arr);
		exit;
	}

	private function responseOK(array $data): void
	{
		$this->response(array('status' => 'OK', 'data' => $data));
	}

	private function responseERROR(string $error): void
	{
		$this->response(array('status' => 'ERROR', 'msg' => $error));
	}

	private function printHelpJSON(): void
	{
		$this->response(array(
			'name' => $this->apiName,
			'html_version' => $this->getCurrentUrl().'?format=html',
			'typescript_version' => $this->getCurrentUrl().'?format=typescript',
			'actions' => $this->methods
		));
	}

	private function printHelpHTML(): void
	{
		include __DIR__ . '/help.tpl.php';
	}

	private function printHelpTypescript(): void
	{
		ob_clean();
		header('Content-Type: application/javascript');
		header('Content-Disposition: attachment; filename="' . $this->apiName . '.js"');
		include __DIR__ . '/typescript.tpl.php';
	}

	private function getCurrentUrl(): string {
		$protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' ||
					 $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
		$host = $_SERVER['HTTP_HOST'];
		$uri = $_SERVER['REQUEST_URI'];
		$path = parse_url($uri, PHP_URL_PATH);
		return $protocol . $host . $path;
	}

	private function getMethod(string $action): ?array
	{
		foreach ($this->methods as $method) {
			if ($method['name'] == $action) {
				return $method;
			}
		}
		return null;
	}

	private function doAction(string $action): void
	{
		if ($action == '__HELP__') {
			$this->printHelpJSON();
			return;
		}
		$method = $this->getMethod($action);
		if (is_null($method)) {
			$this->responseERROR('Action "' . $action . '" not found');
			return;
		}
		$params = array();
		foreach ($method['params'] as $param) {
			if (isset($_REQUEST[$param['name']])) {
				$param_value = $_REQUEST[$param['name']];
				switch ($param['type']) {
					case 'int':
						$param_value = (int) $param_value;
						break;
					case 'float':
						$param_value = (float) $this->fixDecimalPoint($param_value);
						break;
					case 'string':
						$param_value = (string) $param_value;
						break;
					case 'bool':
						$param_value = (bool) $param_value;
						break;
					case 'array':
						$param_value = json_decode($param_value, true);
						break;
					case 'object':
						$param_value = json_decode($param_value);
						break;
					default:
						// do nothing
						break;
				}
				$params[$param['name']] = $param_value;
			} else {
				if (!$param['optional']) {
					$this->responseERROR('Parameter "' . $param['name'] . '" is required');
					return;
				}
			}
		}
		try {
			$result = call_user_func_array(array($this, $method['name']), $params);
		} catch (\Exception $e) {
			$this->responseERROR($e->getMessage());
			return;
		}
		$this->responseOK(array('status' => 'OK', 'data' => $result));
	}

	private function fixDecimalPoint(mixed $number): float|array
	{
		if (is_array($number)) {
			foreach ($number as $index => $val) {
				$number[$index] = $this->fixDecimalPoint($val);
			}
			return $number;
		}
		$position_comma = strpos($number, ',');
		$position_dot = strpos($number, '.');
		if (
			$position_comma !== false
			&& $position_dot !== false
		) {
			if ($position_comma < $position_dot) { // e.g.  2,845,478.55
				$_number = str_replace(',', '', $number);
			} else { // e.g. 2.845.478,55
				$_number = str_replace('.', '', $number);
			}
			$number = $_number;
		}
		$number = str_replace(' ', '', $number);
		$number = str_replace(',', '.', $number);
		$pos = strpos($number, '.');
		if ($pos !== false) $number = rtrim($number, '0');
		if (substr($number, -1) == '.') $number .= '0';
		return $number;
	}
}