<?php

namespace CrocWork\Zappy\Routing;

class Route
{
    /**
     * @var string Name for the route. Multple routes can have the same name, linking them.
     */
    private string $name;

    /**
     * @var string Pattern for this route.
     */
    private string $pattern;

    /**
     * @var string|array|callable The callback to run when executing the route.
     */
    private $callback;

    /**
     * @var array<string> The HTTP verbs applicable to this route.
     */
    private array $methods = [];

    /**
     * @var array<string> A list of middlewares that should be run before executing this route.
     */
    private array $middlewares = [];

    /**
     * @var array<string> List of variables taken from the pattern. These are used to pass parameters to the callback function.
     */
    private array $vars = [];

    /**
     * Route constructor.
     *
     * The constructor will initialize a Route object with a pattern, list of applicable HTTP methods and the callback
     * to run for this route. Optionally a list of middlewares to run can also be passed (but can also be set later).
     */
    public function __construct(string $pattern, string|array $methods, string|array|callable $callback, array $middlewares = [])
    {
        if ($methods === []) {
            throw new \InvalidArgumentException('HTTP methods argument was empty; must contain at least one method');
        }

        if(is_string($methods)) $methods = [$methods];
        foreach($methods as $key => $method) {
            $methods[$key] = strtoupper($method);
            if (!in_array($methods[$key], ['GET', 'POST', 'PUT', 'DELETE', 'OPTIONS', 'PATCH', 'HEAD'])) {
                throw new \InvalidArgumentException("Invalid method '{$method}' specified.");
            }
        }

        $this->pattern = $pattern;
        $this->callback = $callback;
        $this->methods = $methods;
        $this->middlewares = $middlewares;
    }

    /**
     * Get the name for the route.
     *
     * @return string
     */
    public function getName(): string
    {
        return $this->name;
    }

    /**
     * Set the name for the route.
     *
     * @param string $name
     * @return $this
     */
    public function setName(string $name): static
    {
        $this->name = $name;
        return $this;
    }

    /**
     * Get the url pattern for the route.
     *
     * @return string
     */
    public function getPattern(): string
    {
        return $this->pattern;
    }

    public function setPattern(string $pattern): static
    {
        $this->pattern = $pattern;
        return $this;
    }

    /**
     * Get the callback function for this route.
     *
     * @return string|array|callable
     */
    public function getCallback(): string|array|callable
    {
        return $this->callback;
    }

    /**
     * Set the callback function for this route.
     *
     * @param string|array|callable $callback
     * @return $this
     */
    public function setCallback(string|array|callable $callback): static
    {
        $this->callback = $callback;
        return $this;
    }

    /**
     * Get the HTTP methods applicable to this route.
     *
     * @return string[]
     */
    public function getMethods(): array
    {
        return $this->methods;
    }

    /**
     * Set the HTTP methods applicable to this route.
     *
     * @param string|string[] $methods
     * @return $this
     */
    public function setMethods(string|array $methods): static
    {
        if(is_string($methods)) {
            $methods = [$methods];
        }

        $this->methods = $methods;
        return $this;
    }

    /**
     * Get the list of middlewares to be run for this route.
     *
     * @return string[]
     */
    public function getMiddlewares(): array
    {
        return $this->middlewares;
    }

    public function setMiddlewares(array $middlewares): static
    {
        $this->middlewares = $middlewares;
        return $this;
    }

    public function addMiddleware(string|array $middleware): static
    {
        if(is_string($middleware)) {
            $middleware = [$middleware];
        }

        foreach($middleware as $value) {
            if(!in_array($value, $this->middlewares)) {
                $this->middlewares[] = $value;
            }
        }

        return $this;
    }

    /**
     * @return array
     */
    public function getVarsNames(): array
    {
        preg_match_all('/{[^}]*}/', $this->pattern, $matches);
        return reset($matches) ?? [];
    }

    /**
     * @return bool
     */
    public function hasVars(): bool
    {
        return $this->getVarsNames() !== [];
    }

    /**
     * @return string[]
     */
    public function getVars(): array
    {
        return $this->vars;
    }

    /**
     * @param string $path
     * @param string $method
     * @return bool
     */
    public function match(string $path, string $method): bool
    {
        $regex = $this->getPattern();
        foreach ($this->getVarsNames() as $variable) {
            $varName = trim($variable, '{\}');
            $regex = str_replace($variable, '(?P<' . $varName . '>[^/]++)', $regex);
        }

        if (in_array($method, $this->getMethods()) && preg_match('#^' . $regex . '$#sD', self::trimPath($path), $matches)) {
            $values = array_filter($matches, static function ($key) {
                return is_string($key);
            }, ARRAY_FILTER_USE_KEY);
            foreach ($values as $key => $value) {
                $this->vars[$key] = $value;
            }
            return true;
        }
        return false;
    }

    /**
     * @return mixed
     */
    public function run()
    {
        //TODO: middlewares
        //TODO: allow for automatically injecting dependencies for function arguments

        if(is_callable($this->callback)) {
            return call_user_func_array($this->callback, $this->vars);
        } elseif (is_array($this->callback) && [0,1] == array_keys($this->callback)) {
            $class = $this->callback[0];
            $method = $this->callback[1];
            if(class_exists($class) && method_exists($class, $method)) {
                $controller = new $class();
                return $controller->$method(...$this->vars);
            }
        }

        throw new \RuntimeException("Could not resolve callable function for route.");
    }

    /**
     * @param string $path
     * @return string
     */
    protected static function trimPath(string $path): string
    {
        return '/' . rtrim(ltrim(trim($path), '/'), '/');
    }
}