<?php
/*************************************************************
# 076 License

Copyright (c) テクニカル諏訪子

Permission is hereby granted to any person obtaining a copy of the software
Little Beast (the "Software") to use, modify, merge, copy, publish, distribute,
sublicense, and/or sell copies of the Software, subject to the following conditions:

    1. **Origin Attribution**:
       - You must not misrepresent the origin of the Software; you must not claim
         you created the original Software.
       - If the Software is used in a product, you must either:
         a. Provide clear attribution in the product's documentation, user interface,
            or other visible areas, **OR**
         b. Pay the original developers a fee they specify in writing.
    2. **Usage Restriction**:
       - The Software, or any derivative works, dependencies, or libraries
         incorporating it, must not be used for censorship or to suppress freedom of
         speech, expression, or creativity. Prohibited uses include, but are not
         limited to:
         - Censorship of so-called "hate speech", visuals, non-mainstream opinions,
           ideas, or objective reality.
         - Tools or systems designed to restrict access to information or
           artistic works.
    3. **Notice Preservation**:
       - This license and the above copyright notice must remain intact in all copies
         of the source code.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
namespace Std\Lib\Tls;

/**
 * TLSの接続をPHPのストリームにする（fread・fgets・fwrite・feof・fclose・stream_set_timeout・stream_selectが使える）
 *
 * Std\Lib\Tls::connect()等が作るので、直接使わない。
 * 読み込み中のエラーは例外にせず、終わり（feof）として扱う（Std\Lib\Tls::error()で確認出来る）。
 */
class Stream {
  public const SCHEME = 'lbtls';

  /** @var resource|null */
  public $context;
  private ?Connection $conn = null;
  private static array $pending = [];

  /**
   * 接続をストリームにする
   *
   * @param Connection $conn  ハンドシェイク済みの接続
   * @return resource
   */
  public static function wrap(Connection $conn) {
    if (!in_array(self::SCHEME, stream_get_wrappers(), true)) stream_wrapper_register(self::SCHEME, self::class);
    $id = spl_object_id($conn);
    self::$pending[$id] = $conn;
    $s = fopen(self::SCHEME.'://'.$id, 'r+');
    unset(self::$pending[$id]);
    // PHPのバッファで書き込みが遅れない様に
    stream_set_write_buffer($s, 0);
    // シーク出来ないストリームにする（stream_seekが無いので失敗し、PHPが印を付ける）。
    // シーク出来るストリームにfwriteすると、PHPは読み込みのバッファ（まだ読んでいない受信データ）を捨てる
    @fseek($s, 0, SEEK_CUR);
    return $s;
  }

  /** ストリームの接続（Tls::info()等） */
  public static function connection($stream): ?Connection {
    if (!is_resource($stream)) return null;
    $w = stream_get_meta_data($stream)['wrapper_data'] ?? null;
    return $w instanceof self ? $w->conn : null;
  }

  public function stream_open(string $path, string $mode, int $options, ?string &$opened): bool {
    $id = (int)substr($path, strlen(self::SCHEME) + 3);
    $this->conn = self::$pending[$id] ?? null;
    return $this->conn !== null;
  }

  public function stream_read(int $count): string|false {
    return $this->conn->read($count);
  }

  public function stream_write(string $data): int {
    try {
      return $this->conn->write($data);
    } catch (TlsException $e) {
      return 0;
    }
  }

  public function stream_eof(): bool {
    return $this->conn->eof();
  }

  public function stream_close(): void {
    $this->conn?->close();
  }

  public function stream_flush(): bool {
    return true;
  }

  public function stream_set_option(int $option, int $arg1, ?int $arg2): bool {
    if ($option === STREAM_OPTION_READ_TIMEOUT) return stream_set_timeout($this->conn->socket(), $arg1, (int)$arg2);
    if ($option === STREAM_OPTION_BLOCKING) return $arg1 === 1; // ブロッキングのみ
    return false;
  }

  /** stream_select()用に下のソケットを返す */
  public function stream_cast(int $castAs) {
    return $this->conn->socket();
  }

  public function stream_stat(): array {
    return [];
  }
}