ImageMagick identify -verbose JSON transformer

parse_identify.php

#!/usr/bin/env php
<?php namespace kamermans\ImageMagick;

/**
 * Parser for the ImageMagick "identify" utility that takes "identify -verbose <file>"
 * output on STDIN and outputs JSON on STDOUT.
 *
 * Example:
 *   identify -verbose foo.jpg | ./parse_identify.php
 */

class IdentifyParser {

    private $data = [];
    private $line_number = 0;

    public function parse($content)
    {
        if (is_array($content)) {
            $lines = $content;
        } else if (is_resource($content)) {
            $lines = explode("\n", stream_get_contents($content));
        } else {
            $lines = explode("\n", $content);
        }

        $raw_data = $this->doParse($lines);
        $this->data = $raw_data['Image'];
        $this->line_number = 0;
    }

    public function toJson($flags=null)
    {
        return json_encode($this->data, $flags);
    }

    public function __toString()
    {
        return $this->toJson(JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES);
    }

    public function toArray()
    {
        return $this->data;
    }

    public function __get($key)
    {
        return array_key_exists($key, $this->data)? $this->data[$key]: false;
    }

    private function doParse($lines, $my_depth=0)
    {

        $data = [];

        while(true) {

            if ($this->line_number >= count($lines)) {
                break;
            }

            $line = rtrim($lines[$this->line_number++]);

            if (strlen($line) === 0) {
                continue;
            }

            if (!preg_match('/^( *)\b(.+?): *(.*)$/', $line, $matches)) {
                die("Unable to parse line:\n'$line'\n");
            }

            list($match, $indent, $key, $value) = $matches;
            $key = trim($key);
            $value = trim($value);

            $current_depth = strlen($indent) / 2;
            if ($current_depth > 0 && $current_depth <= $my_depth) {
                $this->line_number--;
                return $data;
            }

            if (strlen($value) === 0 || $key == "Image") {
                $subdata = $this->doParse($lines, $current_depth);
                $data[$key] = $subdata;

                if ($key == "Image") {
                    $data[$key] = ['Image' => $value] + $data[$key];
                }

            } else {
                $data[$key] = $value;
            }
        }

        return $data;
    }
}

$parser = new IdentifyParser();
$parser->parse(STDIN);

echo "$parser\n";