<?php
// RouteInfo.php
// Created: 2022-01-20
// Updated: 2023-09-11

namespace Index\Routing;

use InvalidArgumentException;
use UnexpectedValueException;

/**
 * Represents a node in the router structure.
 *
 * @internal
 */
class RouteInfo {
    private array $children = [];
    private array $methods = [];
    private array $middlewares = [];
    private ?RouteInfo $dynamicChild = null;

    private function getChild(string $path, ?string &$next = null): RouteInfo {
        $parts = explode('/', $path, 2);
        $name = '_' . $parts[0];

        if(str_starts_with($parts[0], ':'))
            $child = $this->dynamicChild ?? ($this->dynamicChild = new RouteInfo);
        else
            $child = $this->children[$name] ?? ($this->children[$name] = new RouteInfo);

        $next = $parts[1] ?? '';

        return $child;
    }

    /**
     * @internal
     */
    public function addMiddleware(string $path, callable $handler): void {
        if($path === '') {
            $this->middlewares[] = $handler;
            return;
        }

        $this->getChild($path, $next)->addMiddleware($next, $handler);
    }

    /**
     * @internal
     */
    public function addMethod(string $method, string $path, callable $handler): void {
        if($path === '') {
            $this->methods[strtolower($method)] = $handler;
            return;
        }

        $this->getChild($path, $next)->addMethod($method, $next, $handler);
    }

    /**
     * @internal
     */
    public function resolve(string $method, string $path, array $args = [], array $callables = []): RouteCallable {
        if($path === '') {
            $method = strtolower($method);
            $handlers = [];

            if(isset($this->methods[$method])) {
                $handlers[] = $this->methods[$method];
            } else {
                if($method !== 'options') {
                    if(empty($this->methods))
                        throw new RoutePathNotFoundException;
                    throw new RouteMethodNotSupportedException;
                }
            }

            return new RouteCallable(
                array_merge($callables, $this->middlewares, $handlers),
                $args
            );
        }

        $parts = explode('/', $path, 2);
        $name = $parts[0];
        $mName = '_' . $name;

        foreach($this->children as $cName => $cObj)
            if($cName === $mName) {
                $child = $cObj;
                break;
            }

        if(!isset($child)) {
            $args[] = $name;
            $child = $this->dynamicChild;
        }

        if($child === null)
            throw new RoutePathNotFoundException;

        return $child->resolve(
            $method,
            $parts[1] ?? '',
            $args,
            array_merge($callables, $this->middlewares)
        );
    }
}