<?php

/**
 * Simple file upload layer. Handles file metadata and storage
 * FileUtils: part that handles image metadata and thumbnails
 *
 * Version 2019-05-05
 * (c) Vitaliy Filippov 2018+
 */

class FileUtils
{
    const ONLY_BINARY = 1;
    const ONLY_IMAGES = 2;
    const ONLY_SWF = 4;
    const ONLY_VIDEO = 8;
    const IMAGES_VIDEO = 10;
    const ANY_MEDIA = 14;
    const ANYTHING = 15;

    const CROP_XY = 1;
    const CROP_Y = 2;
    const CROP_X = 3;

    public static $quality = 90;
    public static $exifProps = [
        'Model',
        'Orientation',
        'DateTime',
        'DateTimeOriginal',
        'ExposureTime',
        'FNumber',
        'ISOSpeedRatings',
        'FocalLength',
        'FocalLengthIn35mmFilm',
        'GPSLongitude',
        'GPSLongitudeRef',
        'GPSLatitude',
        'GPSLatitudeRef',
    ];

    public static function magick()
    {
        static $class;
        if (!$class)
        {
            // Use GraphicsMagick if possible
            $class = class_exists('Gmagick') ? 'Gmagick' : 'Imagick';
        }
        return new $class();
    }

    /**
     * Get image or file properties (content SHA1, width, height, selected EXIF properties)
     */
    public static function getProps($allowed_types, $mime_blacklist, $fs_path, $orig_name)
    {
        if (!file_exists($fs_path))
        {
            throw new UserException('no-file-uploaded');
        }
        $mime = self::checkMime($fs_path);
        if (!$mime)
        {
            throw new UserException('file-mime-type-unknown');
        }
        elseif (preg_match($mime_blacklist, $mime))
        {
            // Prevent uploads with dangerous MIME types
            throw new UserException('file-mime-type-blacklisted');
        }
        $stdProps = [
            'mimetype' => $mime,
            'sha1' => sha1_file($fs_path),
            'size' => filesize($fs_path),
            'format' => '',
            'width' => 0,
            'height' => 0,
        ];
        $flag = FileUtils::ONLY_BINARY;
        $props = NULL;
        if ($mime == 'application/x-shockwave-flash')
        {
            $props = self::getSWFProps($fs_path);
            if ($props)
                $flag = FileUtils::ONLY_SWF;
        }
        elseif (substr($mime, 0, 6) == 'image/')
        {
            $props = self::getImageProps($fs_path);
            if ($props)
                $flag = FileUtils::ONLY_IMAGES;
        }
        elseif (substr($mime, 0, 6) == 'video/')
        {
            $props = VideoUtils::getVideoProps($fs_path);
            if ($props)
                $flag = FileUtils::ONLY_VIDEO;
        }
        if (!($allowed_types & $flag))
        {
            throw new UserException('file-type-denied', [ 'allowed' => $allowed_types, 'type' => $flag ]);
        }
        $props = ($props ?: []) + $stdProps;
        if (!$props['format'])
        {
            if (!empty($props['filename']))
                $orig_name = preg_replace('#^.*/#is', '', $props['filename']);
            $p = strrpos($orig_name, '.');
            if ($p)
                $props['format'] = strtolower(substr($orig_name, $p+1));
        }
        unset($props['filename']);
        return $props;
    }

    /**
     * Get image properties + compress uploaded BMP images to JPEG
     */
    protected static function getImageProps($fn)
    {
        $format = NULL;
        $props = [];
        try
        {
            $exif = @exif_read_data($fn);
            if ($exif)
            {
                foreach (self::$exifProps as $p)
                {
                    if (isset($exif[$p]))
                    {
                        $props[$p] = $exif[$p];
                    }
                }
            }
            // FIXME Сначала проверять ширину/высоту, не читая саму картинку в память
            $im = static::magick();
            $im->readImage($fn);
            $format = strtolower($im->getImageFormat());
            if ($format == 'jpeg')
            {
                $format = 'jpg';
            }
            if ($format != 'png' &&
                $format != 'gif' &&
                $format != 'jpeg' &&
                $format != 'jpg' &&
                $format != 'pdf' &&
                $format != 'djvu' &&
                $format != 'djv' &&
                ($format != 'ico' || $im->getImageWidth() > 48 || $im->getImageHeight() > 48)) // bmp, tiff, psd...
            {
                $im->mergeImageLayers(Imagick::LAYERMETHOD_FLATTEN);
                if (!empty($props['Orientation']))
                {
                    self::fixOrientation($im, $props['Orientation']);
                    unset($props['Orientation']);
                }
                $im->setCompressionQuality(static::$quality);
                $im->setImageFormat('jpeg');
                $format = 'jpg';
                $fn = tempnam(sys_get_temp_dir(), 'imguniq');
                $im->writeImage($fn);
            }
            $width = $im->getImageWidth();
            $height = $im->getImageHeight();
            if (!empty($props['Orientation']) && $props['Orientation'] >= 5)
            {
                $t = $width;
                $width = $height;
                $height = $t;
            }
        }
        catch (Exception $e)
        {
            // Not an image
            return NULL;
        }
        return [
            'filename' => $fn,
            'width' => $width,
            'height' => $height,
            'format' => $format,
            'props' => $props,
        ];
    }

    /**
     * Get MIME type of a file
     */
    protected static function checkMime($filename)
    {
        $mime = false;
        if (class_exists('finfo'))
        {
            static $finfo;
            if (!$finfo)
            {
                $finfo = new finfo(FILEINFO_MIME_TYPE);
            }
            if ($finfo)
            {
                $mime = $finfo->file($filename);
            }
        }
        elseif (function_exists('mime_content_type'))
        {
            $mime = mime_content_type($filename);
        }
        else
        {
            $mime = shell_exec("file ".escapeshellarg($filename));
        }
        return $mime;
    }

    protected static function getSWFProps($fn)
    {
        $size = shell_exec("swfdump -X -Y ".escapeshellarg($fn));
        if (preg_match('/-X (\d+) -Y (\d+)/', $size, $m))
        {
            return [
                'format' => 'swf',
                'width' => $m[1],
                'height' => $m[2],
            ];
        }
        return NULL;
    }

    /**
     * Fix ImageMagick image $im orientation based on EXIF orientation $orient
     */
    public static function fixOrientation($im, $orient)
    {
        $orient = intval($orient);
        if ($orient > 1 && $orient <= 8)
        {
            if ($orient == 2)
            {
                $im->flopImage();
            }
            elseif ($orient == 3)
            {
                $im->rotateImage($im instanceof Imagick ? new ImagickPixel() : new GmagickPixel(), 180);
            }
            elseif ($orient == 4)
            {
                $im->flipImage();
            }
            elseif ($orient == 5)
            {
                if (method_exists($im, 'transposeImage'))
                {
                    $im->transposeImage();
                }
                else
                {
                    // GraphicsMagick doesn't have Transpose
                    $im->rotateImage($im instanceof Imagick ? new ImagickPixel() : new GmagickPixel(), 90);
                    $im->flopImage();
                }
            }
            elseif ($orient == 6)
            {
                $im->rotateImage($im instanceof Imagick ? new ImagickPixel() : new GmagickPixel(), 90);
            }
            elseif ($orient == 7)
            {
                if (method_exists($im, 'transverseImage'))
                {
                    $im->transverseImage();
                }
                else
                {
                    // GraphicsMagick doesn't have Transverse
                    $im->rotateImage($im instanceof Imagick ? new ImagickPixel() : new GmagickPixel(), 270);
                    $im->flopImage();
                }
            }
            elseif ($orient == 8)
            {
                $im->rotateImage($im instanceof Imagick ? new ImagickPixel() : new GmagickPixel(), 270);
            }
        }
    }

    public static function getGPS($file)
    {
        $props = $file['props'];
        if (empty($props['GPSLatitude']) && empty($props['GPSLongitude']))
        {
            return NULL;
        }
        $latitude = FileUtils::exifGPS($props['GPSLatitude'], $props['GPSLatitudeRef']);
        $longitude = FileUtils::exifGPS($props['GPSLongitude'], $props['GPSLongitudeRef']);
        return [ $latitude, $longitude ];
    }

    public static function exifGPS($coordinate, $hemisphere)
    {
        for ($i = 0; $i < 3; $i++)
        {
            $part = explode('/', $coordinate[$i]);
            if (count($part) == 1)
            {
                $coordinate[$i] = $part[0];
            }
            elseif (count($part) == 2)
            {
                $coordinate[$i] = floatval($part[0])/floatval($part[1]);
            }
            else
            {
                $coordinate[$i] = 0;
            }
        }
        list($degrees, $minutes, $seconds) = $coordinate;
        $sign = ($hemisphere == 'W' || $hemisphere == 'S') ? -1 : 1;
        return $sign * ($degrees + $minutes/60 + $seconds/3600);
    }

    /**
     * Calculate thumbnail image width and height
     */
    public static function thumbnailSize($cw, $ch, $maxw, $maxh)
    {
        if ($maxw <= 0 && $maxh <= 0 || $cw <= 0 || $ch <= 0)
        {
            return [ $cw, $ch ];
        }
        if ($maxw > 0 && ($maxh <= 0 || $maxh/$ch >= $maxw/$cw))
        {
            $nw = $maxw;
            $nh = $ch * $maxw / $cw;
        }
        elseif ($maxh > 0 && ($maxw <= 0 || $maxh/$ch < $maxw/$cw))
        {
            $nw = $cw * $maxh / $ch;
            $nh = $maxh;
        }
        return [ intval($nw), intval($nh) ];
    }

    /**
     * Return file size description
     */
    static $sizeSuffix = [
        'Кб' => [
            'bytes' => 'bytes',
            'Kb' => 'Кб',
            'Mb' => 'Мб',
            'Gb' => 'Гб',
        ],
    ];
    public static function sizeString($bytes, $lang = 'ru')
    {
        $r = $bytes;
        if (is_numeric($r))
        {
            if ($r >= 0 && $r < 1024)
                $r = $r . ' ' . (isset(self::$sizeString[$lang]['bytes']) ? self::$sizeString[$lang]['bytes'] : 'bytes');
            elseif ($r >= 1024 && $r < 1024*1024)
                $r = sprintf('%.2f ', $r/1024) . (isset(self::$sizeString[$lang]['Kb']) ? self::$sizeString[$lang]['Kb'] : 'Kb');
            elseif ($r >= 1024*1024 && $r < 1024*1024*1024)
                $r = sprintf('%.2f ', $r/1024/1024) . (isset(self::$sizeString[$lang]['Mb']) ? self::$sizeString[$lang]['Mb'] : 'Mb');
            elseif ($r >= 1024*1024*1024)
                $r = sprintf('%.2f ', $r/1024/1024/1024) . (isset(self::$sizeString[$lang]['Gb']) ? self::$sizeString[$lang]['Gb'] : 'Gb');
            elseif ($r < 0)
                $r = sprintf('%.2f ', 2-($r/1024/1024/1024)) . (isset(self::$sizeString[$lang]['Gb']) ? self::$sizeString[$lang]['Gb'] : 'Gb');
        }
        return $r;
    }

    /**
     * Recursively create a directory
     */
    public static function mkpath($path, $throw_error = true)
    {
        if (is_dir($path) || @mkdir($path, 0777, true))
        {
            return true;
        }
        if ($throw_error)
        {
            $error = error_get_last();
            throw new Exception("Failed to create path $path: ".$error['message']);
        }
        return false;
    }

    /**
     * Get thumbnail size for $file
     */
    public static function getThumbSize($file, $width, $height, $crop = false)
    {
        if ($width < 0)
            $width = 0;
        if ($height < 0)
            $height = 0;
        if (!$width || !$height)
            $crop = false;
        if (!$file['width'] || !$width && !$height ||
            (!$width || $file['width'] <= $width) &&
            (!$height || $file['height'] < $height) && !$crop ||
            ($file['format'] == 'swf' || $file['format'] == 'video'))
            return NULL;
        if (!$crop)
            return self::thumbnailSize($file['width'], $file['height'], $width, $height);
        return [ $width, $height ];
    }

    /**
     * Convert ImageMagick image $im to a thumbnail
     */
    public static function makeThumb($im, $width, $height, $crop, $orientation, $alignY)
    {
        $cl = get_class($im);
        if ($crop)
        {
            $iw = $im->getImageWidth();
            $ih = $im->getImageHeight();
            if ($crop == FileUtils::CROP_Y && $ih*$width/$iw < $height)
            {
                $height = $ih*$width/$iw;
            }
            elseif ($crop == FileUtils::CROP_X && $iw*$height/$ih < $width)
            {
                $width = $iw*$height/$ih;
            }
            if ($width/$height < $iw/$ih)
            {
                $cw = intval($width*$ih/$height);
                $im->cropImage($cw, $ih, intval(($iw-$cw)/2), 0);
            }
            elseif ($width/$height > $iw/$ih)
            {
                $ch = intval($height*$iw/$width);
                $im->cropImage($iw, $ch, 0, intval(($ih-$ch)*$alignY));
            }
            $im->resizeImage($width, $height, $cl::FILTER_LANCZOS, 1);
            $im->setImagePage($width, $height, 0, 0); /* for gif cropping */
            $iw = $im->getImageWidth();
            $ih = $im->getImageHeight();
        }
        else
        {
            $im->resizeImage($width, $height, $cl::FILTER_LANCZOS, 1);
        }
        $im->stripImage();
        if ($orientation !== NULL)
        {
            self::fixOrientation($im, $orientation);
        }
    }

    /**
     * Get thumbnail type
     */
    public static function getThumbType($file, $width, $height, $crop = false, $alignY = 0.5)
    {
        $size = FileUtils::getThumbSize($file, $width, $height, $crop);
        if (!$size)
        {
            return NULL;
        }
        list($width, $height) = $size;
        if (!$crop)
        {
            $type = intval($width);
        }
        else
        {
            $p = $crop == FileUtils::CROP_Y ? 'cy' : ($crop == FileUtils::CROP_X ? 'cx' : 'c');
            $type = intval($width).'x'.intval($height).'_'.$p.$alignY;
        }
        return [ 'width' => $width, 'height' => $height, 'type' => $type ];
    }

    public static function generateThumbnail($sourcefn, $thumbfn, $file, $width, $height, $crop = false, $alignY = 0.5)
    {
        try
        {
            $im = FileUtils::magick();
            $im->readImage($sourcefn);
            $props = $file['props'];
            if (!empty($props['Orientation']) && $props['Orientation'] > 5)
            {
                /* swap width & height */
                $t = $width;
                $width = $height;
                $height = $t;
                if ($crop == FileUtils::CROP_X || $crop == FileUtils::CROP_Y)
                    $crop = 5-$crop;
            }
            FileUtils::makeThumb($im, $width, $height, $crop, isset($props['Orientation']) ? $props['Orientation'] : NULL, $alignY);
            $im->setCompressionQuality(FileUtils::$quality);
            FileUtils::mkpath(dirname($thumbfn));
            $im->writeImage($thumbfn);
        }
        catch (Exception $e)
        {
            trigger_error("$e");
            return false;
        }
        return true;
    }
}