#!/usr/bin/env php
<?php
/**
 * Hash Tool
 * =========
 *
 * Small helper script to PHP's hash functions.
 *
 * @author Fabio Ros
 *
 * Examples:
 *
 * ./phash --adler32 somefile.txt
 * ./phash --sha256 mystring
 * ./phash --list
 *
 */

/**
 * Class Hash
 */
class Hash
{
    public $arg;
    public $file;

    private $checkFileSize = 0;
    private $stringIfNotFile = 1;

    /**
     * Hash constructor.
     * @param $argv
     */
    public function __construct($argv)
    {
        if (!isset($argv[1])) {
            $this->outputHelp();
        } else {
            $this->parseOptions($argv);
        }

        if (isset($this->help) || $this->arg === 'help') {
            $this->outputHelp();
            exit();
        }

        if (isset($this->list)) {
            foreach (hash_algos() as $algo) {
                echo '* ' . $algo . "\n";
            }
        }

        if (isset($this->arg)) {
            $this->processFile();
        } else {
//            echo 'Specify some input for the algorithm';
            exit();
        }

        foreach (hash_algos() as $algo) {
            if (isset($this->$algo)) {
                $hash = hash($algo, $this->file);
                echo $hash;

            }
        }

        exit();
    }

    /**
     * Output help
     */
    public function outputHelp()
    {
        echo "PHP Hash tool\n";
        echo "================\n";
        echo "Usage:\n";
        echo "./phash --[options] [file/string]\n\n";
        echo "--list\tshow available algo's\n";
        echo "--algo\tRun file against a hash algorithm\n";
    }

    /**
     * Process the file with some validation
     */
    public function processFile()
    {
        if (substr($this->arg, 0, 2) === './') {
            $this->arg = str_replace('./', __DIR__ . DIRECTORY_SEPARATOR, $this->arg);
        }
        if (is_readable($this->arg)) {
            if (ini_get('memory_limit') !== '-1' && $this->checkFileSize) {
                $this->checkFileSizeWithMemory($this->arg);
            } else {
                $this->file = file_get_contents($this->arg);
            }
        } else {
            if ($this->stringIfNotFile) {
                $this->file = $this->arg;
            } else {
                echo 'File ' . $this->arg . 'is not readable.';
                exit();
            }
        }
    }

    /**
     * Check filesize with memory
     * @todo wip
     * @param $file
     * @return bool
     */
    public function checkFileSizeWithMemory($file)
    {
        $size = filesize($file) + memory_get_usage();
        if ($size <= intval(str_replace('M', '000', ini_get('memory_limit')))) {
            return true;
        } else {
            echo "File $file too big!\n";
            echo "Filesize:" . filesize($file) . "\n";
            echo "Memory Usage:" . memory_get_usage() . "\n";
            echo "Memory limit:" . ini_get('memory_limit') . "\n";
        }
    }

    /**
     * Parse arguments and options
     * @param $options
     */
    public function parseOptions($options)
    {
        array_shift($options);
        foreach ($options as $arg) {
            if (substr($arg, 0, 2) === '--') {
                if (strpos($arg, '=')) {
                    $parsed = explode('=', str_replace('--', '', $arg))[0];
                    $this->$parsed[0] = $parsed[1];
                } else {
                    $parsed = str_replace('--', '', $arg);
                    $this->$parsed = true;
                }
            } else {
                $this->arg = $arg;
            }
        }
    }

}

new Hash($argv);