<?php

namespace think\process\pipes;

use think\Process;

class Unix extends Pipes
{

    /** @var bool */
    private $ttyMode;
    /** @var bool */
    private $ptyMode;
    /** @var bool */
    private $disableOutput;

    public function __construct($ttyMode, $ptyMode, $input, $disableOutput)
    {
        $this->ttyMode       = (bool) $ttyMode;
        $this->ptyMode       = (bool) $ptyMode;
        $this->disableOutput = (bool) $disableOutput;

        if (is_resource($input)) {
            $this->input = $input;
        } else {
            $this->inputBuffer = (string) $input;
        }
    }

    public function __destruct()
    {
        $this->close();
    }

    /**
     * {@inheritdoc}
     */
    public function getDescriptors()
    {
        if ($this->disableOutput) {
            $nullstream = fopen('/dev/null', 'c');

            return [
                ['pipe', 'r'],
                $nullstream,
                $nullstream,
            ];
        }

        if ($this->ttyMode) {
            return [
                ['file', '/dev/tty', 'r'],
                ['file', '/dev/tty', 'w'],
                ['file', '/dev/tty', 'w'],
            ];
        }

        if ($this->ptyMode && Process::isPtySupported()) {
            return [
                ['pty'],
                ['pty'],
                ['pty'],
            ];
        }

        return [
            ['pipe', 'r'],
            ['pipe', 'w'], // stdout
            ['pipe', 'w'], // stderr
        ];
    }

    /**
     * {@inheritdoc}
     */
    public function getFiles()
    {
        return [];
    }

    /**
     * {@inheritdoc}
     */
    public function readAndWrite($blocking, $close = false)
    {

        if (1 === count($this->pipes) && [0] === array_keys($this->pipes)) {
            fclose($this->pipes[0]);
            unset($this->pipes[0]);
        }

        if (empty($this->pipes)) {
            return [];
        }

        $this->unblock();

        $read = [];

        if (null !== $this->input) {
            $r = array_merge($this->pipes, ['input' => $this->input]);
        } else {
            $r = $this->pipes;
        }

        unset($r[0]);

        $w = isset($this->pipes[0]) ? [$this->pipes[0]] : null;
        $e = null;

        if (false === $n = @stream_select($r, $w, $e, 0, $blocking ? Process::TIMEOUT_PRECISION * 1E6 : 0)) {

            if (!$this->hasSystemCallBeenInterrupted()) {
                $this->pipes = [];
            }

            return $read;
        }

        if (0 === $n) {
            return $read;
        }

        foreach ($r as $pipe) {

            $type = (false !== $found = array_search($pipe, $this->pipes)) ? $found : 'input';
            $data = '';
            while ('' !== $dataread = (string) fread($pipe, self::CHUNK_SIZE)) {
                $data .= $dataread;
            }

            if ('' !== $data) {
                if ('input' === $type) {
                    $this->inputBuffer .= $data;
                } else {
                    $read[$type] = $data;
                }
            }

            if (false === $data || (true === $close && feof($pipe) && '' === $data)) {
                if ('input' === $type) {
                    $this->input = null;
                } else {
                    fclose($this->pipes[$type]);
                    unset($this->pipes[$type]);
                }
            }
        }

        if (null !== $w && 0 < count($w)) {
            while (strlen($this->inputBuffer)) {
                $written = fwrite($w[0], $this->inputBuffer, 2 << 18); // write 512k
                if ($written > 0) {
                    $this->inputBuffer = (string) substr($this->inputBuffer, $written);
                } else {
                    break;
                }
            }
        }

        if ('' === $this->inputBuffer && null === $this->input && isset($this->pipes[0])) {
            fclose($this->pipes[0]);
            unset($this->pipes[0]);
        }

        return $read;
    }

    /**
     * {@inheritdoc}
     */
    public function areOpen()
    {
        return (bool) $this->pipes;
    }

    /**
     * 创建一个新的 UnixPipes 实例
     * @param Process         $process
     * @param string|resource $input
     * @return self
     */
    public static function create(Process $process, $input)
    {
        return new static($process->isTty(), $process->isPty(), $input, $process->isOutputDisabled());
    }
}
