<?php
namespace Uiharu;

use InvalidArgumentException;

final class Url {
    private string $scheme = '';
    private string $host = '';
    private int $port = 0;
    private string $user = '';
    private string $pass = '';
    private string $path = '';
    private string $query = '';
    private string $fragment = '';

    private ?string $formatted = null;

    public function __construct(array $parts) {
        if(isset($parts['scheme']))
            $this->scheme = strtolower($parts['scheme']);
        if(isset($parts['host']))
            $this->host = $parts['host'];
        if(isset($parts['port']))
            $this->port = $parts['port'];
        if(isset($parts['user']))
            $this->user = $parts['user'];
        if(isset($parts['pass']))
            $this->pass = $parts['pass'];
        if(isset($parts['path']))
            $this->path = $parts['path'];
        if(isset($parts['query']))
            $this->query = $parts['query'];
        if(isset($parts['fragment']))
            $this->fragment = $parts['fragment'];
    }

    public static function parse(string $urlString): Url {
        $parts = parse_url($urlString);
        if($parts === false)
            throw new InvalidArgumentException('Invalid URL provided.');
        return new Url($parts);
    }

    public function resetString(): void {
        $this->formatted = null;
    }
    public function setScheme(string $scheme): void {
        $this->scheme = $scheme;
        $this->resetString();
    }
    public function discardFragment(): void {
        $this->fragment = '';
        $this->resetString();
    }

    public function hasScheme(): bool {
        return $this->scheme !== '';
    }
    public function hasHost(): bool {
        return $this->host !== '';
    }
    public function hasPort(): bool {
        return $this->port !== 0;
    }
    public function hasUser(): bool {
        return $this->user !== '';
    }
    public function hasPassword(): bool {
        return $this->pass !== '';
    }
    public function hasPath(): bool {
        return $this->path !== '';
    }
    public function hasQuery(): bool {
        return $this->query !== '';
    }
    public function hasFragment(): bool {
        return $this->fragment !== '';
    }

    public function getScheme(): string {
        return $this->scheme;
    }
    public function getHost(): string {
        return $this->host;
    }
    public function getPort(): int {
        return $this->port;
    }
    public function getUser(): string {
        return $this->user;
    }
    public function getPassword(): string {
        return $this->pass;
    }
    public function getPath(): string {
        return $this->path;
    }
    public function getQuery(): string {
        return $this->query;
    }
    public function getFragment(): string {
        return $this->fragment;
    }

    public function hasUserInfo(): bool {
        return $this->hasUser()
            || $this->hasPassword();
    }
    public function hasAuthority(): bool {
        return $this->hasUserInfo()
            || $this->hasHost();
    }

    public function getUserInfo(): string {
        $userInfo = $this->user;
        if($this->pass !== '')
            $userInfo .= ':' . $this->pass;
        return $userInfo;
    }
    public function getAuthority(): string {
        $authority = '//';

        if($this->hasUserInfo())
            $authority .= $this->getUserInfo() . '@';

        $authority .= $this->host;

        if($this->port !== 0)
            $authority .= ':' . $this->port;

        return $authority;
    }

    public function calculateHash(bool $raw = true): string {
        return hash('sha256', (string)$this, $raw);
    }

    public function isHTTP(): bool {
        return $this->scheme === 'http';
    }
    public function isHTTPS(): bool {
        return $this->scheme === 'https';
    }
    public function isWeb(): bool {
        return $this->scheme === 'https'
            || $this->scheme === 'http';
    }

    public function __toString(): string {
        if($this->formatted === null) {
            $string = '';

            if($this->hasScheme())
                $string .= $this->getScheme() . ':';

            $hasAuthority = $this->hasAuthority();
            if($hasAuthority)
                $string .= $this->getAuthority();

            $hasPath = $this->hasPath();
            $path = $this->getPath();

            if($hasAuthority && (!$hasPath || $path[0] !== '/'))
                $string .= '/';
            elseif(!$hasAuthority && $path[1] === '/')
                $path = '/' . trim($path, '/');

            $string .= $path;

            // is all this necessary...?
            if($this->hasQuery()) {
                $string .= '?';
                $parts = explode('&', $this->getQuery());

                foreach($parts as $part) {
                    $param = explode('=', $part, 2);
                    $string .= rawurlencode($param[0]);
                    if(isset($param[1]))
                        $string .= '=' . rawurlencode($param[1]);
                    $string .= '&';
                }

                $string = substr($string, 0, -1);
            }

            if($this->hasFragment())
                $string .= '#' . rawurlencode($this->getFragment());

            $this->formatted = $string;
        }

        return $this->formatted;
    }

    public function toV1(): array {
        $parts = ['uri' => (string)$this];

        if($this->hasScheme())
            $parts['scheme'] = $this->getScheme();
        if($this->hasHost())
            $parts['host'] = $this->getHost();
        if($this->hasPort())
            $parts['port'] = $this->getPort();
        if($this->hasUser())
            $parts['user'] = $this->getUser();
        if($this->hasPassword())
            $parts['pass'] = $parts['password'] = $this->getPassword();
        if($this->hasPath())
            $parts['path'] = $this->getPath();
        if($this->hasQuery())
            $parts['query'] = $this->getQuery();
        if($this->hasFragment())
            $parts['fragment'] = $this->getFragment();

        return $parts;
    }
}