<?php

namespace App\Services;

use App\Album;
use App\AlbumSources\IAlbumSource;
use App\AlbumSources\IAnalysisQueueSource;
use App\Helpers\AnalysisQueueHelper;
use App\Helpers\ImageHelper;
use App\Helpers\MiscHelper;
use App\Helpers\ThemeHelper;
use App\Photo;

class PhotoService
{
    const METADATA_VERSION = 2;

    /**
     * @var Album
     */
    private $album;

    /**
     * @var IAlbumSource
     */
    private $albumSource;

    /**
     * @var ImageHelper
     */
    private $imageHelper;

    /**
     * @var Photo
     */
    private $photo;

    /**
     * @var ThemeHelper
     */
    private $themeHelper;

    public function __construct(Photo $photo)
    {
        $this->photo = $photo;
        $this->album = $photo->album;
        $this->albumSource = $this->album->getAlbumSource();

        $this->imageHelper = new ImageHelper();
        $this->themeHelper = new ThemeHelper();
    }

    public function analyse($queueToken, $isReanalyse = false)
    {
        /** @var IAnalysisQueueSource $analysisQueueStorage */
        $analysisQueueStorage = AnalysisQueueHelper::getStorageQueueSource();

        $photoFile = $analysisQueueStorage->fetchItemFromAnalysisQueue($queueToken, $this->photo->storage_file_name);

        try
        {
            $imageInfo = null;
            $originalPhotoResource = $this->imageHelper->openImage($photoFile, $imageInfo);
            if ($originalPhotoResource === false)
            {
                throw new \Exception(sprintf('The image "%s" does not appear to be a valid image, or cannot be read', pathinfo($photoFile, PATHINFO_FILENAME)));
            }

            $this->photo->width = $imageInfo[0];
            $this->photo->height = $imageInfo[1];
            $this->photo->mime_type = $imageInfo['mime'];

            // Read the Exif data
            if (empty($this->photo->raw_exif_data))
            {
                $exifData = @exif_read_data($photoFile);
                $isExifDataFound = ($exifData !== false && is_array($exifData));
                $this->photo->raw_exif_data = $isExifDataFound ? base64_encode(serialize($exifData)) : '';
            }
            else
            {
                $exifData = unserialize(base64_decode($this->photo->raw_exif_data));
                $isExifDataFound = ($exifData !== false && is_array($exifData));
            }

            $angleToRotate = 0;

            // If Exif data contains an Orientation, ensure we rotate the original image as such (providing we don't
            // currently have a metadata version - i.e. it hasn't been read and rotated already before)
            if ($isExifDataFound && isset($exifData['Orientation']) && !$isReanalyse)
            {
                switch ($exifData['Orientation'])
                {
                    case 3:
                        $angleToRotate = 180;
                        break;

                    case 6:
                        $angleToRotate = 270;
                        break;

                    case 8:
                        $angleToRotate = 90;
                        break;
                }

                if ($angleToRotate > 0)
                {
                    $originalPhotoResource = $this->imageHelper->rotateImage($originalPhotoResource, $angleToRotate);

                    if ($angleToRotate == 90 || $angleToRotate == 270)
                    {
                        $this->photo->width = $imageInfo[1];
                        $this->photo->height = $imageInfo[0];
                    }

                    $this->imageHelper->saveImage($originalPhotoResource, $photoFile, $imageInfo);
                }
            }

            if ($isExifDataFound)
            {
                $this->photo->metadata_version = self::METADATA_VERSION;
                $this->photo->taken_at = $this->metadataDateTime($exifData, $this->photo->taken_at);
                $this->photo->camera_make = $this->metadataCameraMake($exifData, $this->photo->camera_make);
                $this->photo->camera_model = $this->metadataCameraModel($exifData, $this->photo->camera_model);
                $this->photo->camera_software = $this->metadataCameraSoftware($exifData, $this->photo->camera_software);
                $this->photo->aperture_fnumber = $this->metadataApertureFNumber($exifData, $this->photo->aperture_fnumber);
                $this->photo->iso_number = $this->metadataIsoNumber($exifData, $this->photo->iso_number);
                $this->photo->focal_length = $this->metadataFocalLength($exifData, $this->photo->focal_length);
                $this->photo->shutter_speed = $this->metadataExposureTime($exifData, $this->photo->shutter_speed);
            }

            $this->photo->is_analysed = true;
            $this->photo->save();

            // Save the original
            $this->albumSource->saveThumbnail($this->photo, $photoFile);

            $this->regenerateThumbnails($originalPhotoResource);
        }
        catch (\Exception $ex)
        {
            throw $ex;
        }
        finally
        {
            // Remove the temporary file
            @unlink($photoFile);

            // Remove from the storage
            $analysisQueueStorage->deleteItemFromAnalysisQueue($queueToken, $this->photo->storage_file_name);
        }
    }

    public function changeAlbum(Album $newAlbum)
    {
        /** @var IAlbumSource $currentSource */
        $currentSource = $this->photo->album->getAlbumSource();
        $newSource = $newAlbum->getAlbumSource();

        // First export the original photo from the storage provider
        $photoPath = $this->downloadToTemporaryFolder();

        // Save to the new album
        $newSource->saveThumbnail($this->photo, $photoPath);

        // Delete the original
        $this->delete();

        // Update the ID and new file name
        $this->photo->album_id = $newAlbum->id;
        $this->photo->save();

        // Switch to the new album source
        $this->albumSource = $newSource;

        // Regenerate the thumbnails in the new album
        $this->regenerateThumbnails();
    }

    public function delete()
    {
        // Remove all thumbnails first - so if any fail, we don't delete the original
        $themeInfo = $this->themeHelper->info();
        $thumbnailsRequired = $themeInfo['thumbnails'];

        /** @var mixed $thumbnail */
        foreach ($thumbnailsRequired as $thumbnail)
        {
            $this->albumSource->deleteThumbnail($this->photo, $thumbnail['name']);
        }

        // Next remove the original photo
        $this->albumSource->deleteThumbnail($this->photo);

        // Finally remove the database record
        $this->photo->delete();
    }

    public function downloadOriginalToFolder($folderPath)
    {
        $photoPath = join(DIRECTORY_SEPARATOR, [$folderPath, $this->photo->storage_file_name]);
        $photoHandle = fopen($photoPath, 'w');

        $stream = $this->albumSource->fetchPhotoContent($this->photo);
        $stream->rewind();
        while (!$stream->eof())
        {
            fwrite($photoHandle, $stream->read(4096));
        }
        fflush($photoHandle);
        fclose($photoHandle);
        $stream->close();

        return $photoPath;
    }

    public function flip($horizontal, $vertical)
    {
        // First export the original photo from the storage provider
        $photoPath = $this->downloadToTemporaryFolder();

        $imageInfo = array();
        $originalPhotoImage = $this->imageHelper->openImage($photoPath, $imageInfo);
        if ($this->imageHelper->flipImage($originalPhotoImage, boolval($horizontal), boolval($vertical)))
        {
            $this->imageHelper->saveImage($originalPhotoImage, $photoPath, $imageInfo);

            // Update and save the original image back to the storage provider
            $this->albumSource->saveThumbnail($this->photo, $photoPath);

            // Re-create the thumbnails
            $this->regenerateThumbnails($originalPhotoImage);

            $this->photo->save();
        }

        // Remove the temp file
        @unlink($photoPath);
    }

    public function regenerateThumbnails($originalPhotoResource = null)
    {
        $photoPath = null;

        if (is_null($originalPhotoResource))
        {
            // First export the original photo from the storage provider
            $photoPath = $this->downloadToTemporaryFolder();

            $imageInfo = null;
            $originalPhotoResource = $this->imageHelper->openImage($photoPath, $imageInfo);
        }

        // Generate and save thumbnails
        $themeInfo = $this->themeHelper->info();
        $thumbnailsRequired = $themeInfo['thumbnails'];

        /** @var mixed $thumbnail */
        foreach ($thumbnailsRequired as $thumbnail)
        {
            $generatedThumbnailPath = $this->imageHelper->generateThumbnail($originalPhotoResource, $this->photo, $thumbnail);
            $this->albumSource->saveThumbnail($this->photo, $generatedThumbnailPath, $thumbnail['name']);
            @unlink($generatedThumbnailPath);
        }

        if (is_null($originalPhotoResource) && !is_null($photoPath))
        {
            // Remove the temp file
            @unlink($photoPath);
        }
    }

    public function rotate($angle)
    {
        $imageInfo = array();

        // First export the photo from the storage provider
        $photoPath = $this->downloadToTemporaryFolder();

        $originalPhotoImage = $this->imageHelper->openImage($photoPath, $imageInfo);
        $originalPhotoImage = $this->imageHelper->rotateImage($originalPhotoImage, intval($angle));
        $this->imageHelper->saveImage($originalPhotoImage, $photoPath, $imageInfo);

        // Update and save the original image back to the storage provider
        $this->albumSource->saveThumbnail($this->photo, $photoPath);

        if ($angle == 90 || $angle == 270)
        {
            $width = $this->photo->width;
            $this->photo->width = $this->photo->height;
            $this->photo->height = $width;
        }

        $this->regenerateThumbnails($originalPhotoImage);

        $this->photo->save();

        // Remove the temp file
        @unlink($photoPath);
    }

    private function calculateValueFromFraction($input)
    {
        $split = explode('/', $input);
        if (count($split) != 2)
        {
            return $split;
        }

        $numerator = intval($split[0]);
        $denominator = intval($split[1]);

        return $denominator == 0
            ? 0
            : ($numerator / $denominator);
    }

    private function downloadToTemporaryFolder()
    {
        $photoPath = tempnam(sys_get_temp_dir(), 'BlueTwilight_');
        $photoHandle = fopen($photoPath, 'w');

        $stream = $this->albumSource->fetchPhotoContent($this->photo);
        $stream->rewind();
        while (!$stream->eof())
        {
            fwrite($photoHandle, $stream->read(4096));
        }
        fflush($photoHandle);
        fclose($photoHandle);
        $stream->close();

        return $photoPath;
    }

    private function metadataApertureFNumber(array $exifData, $originalValue = null)
    {
        if (isset($exifData['FNumber']))
        {
            $value = $this->calculateValueFromFraction($exifData['FNumber']);

            if (intval($value) === $value)
            {
                return sprintf('f/%d', $value);
            }

            return sprintf('f/%0.1f', $value);
        }

        return $originalValue;
    }

    private function metadataCameraMake(array $exifData, $originalValue = null)
    {
        if (isset($exifData['Make']))
        {
            return $exifData['Make'];
        }

        return $originalValue;
    }

    private function metadataCameraModel(array $exifData, $originalValue = null)
    {
        if (isset($exifData['Model']))
        {
            return $exifData['Model'];
        }

        return $originalValue;
    }

    private function metadataCameraSoftware(array $exifData, $originalValue = null)
    {
        if (isset($exifData['Software']))
        {
            return $exifData['Software'];
        }

        return $originalValue;
    }

    private function metadataDateTime(array $exifData, $originalValue = null)
    {
        $dateTime = null;
        if (isset($exifData['DateTimeOriginal']))
        {
            $dateTime = $exifData['DateTimeOriginal'];
        }
        else if (isset($exifData['DateTime']))
        {
            $dateTime = $exifData['DateTime'];
        }

        if (is_null($dateTime))
        {
            return $originalValue;
        }

        return preg_replace('/^([\d]{4}):([\d]{2}):([\d]{2})/', '$1-$2-$3', $dateTime);
    }

    private function metadataExposureTime(array $exifData, $originalValue = null)
    {
        if (isset($exifData['ExposureTime']))
        {
            $decimal = $this->calculateValueFromFraction($exifData['ExposureTime']);
            $fraction = MiscHelper::decimalToFraction($decimal);
            return sprintf('%d/%d', $fraction[0], $fraction[1]);
        }

        return $originalValue;
    }

    private function metadataFocalLength(array $exifData, $originalValue = null)
    {
        if (isset($exifData['FocalLength']))
        {
            return $this->calculateValueFromFraction($exifData['FocalLength']);
        }

        return $originalValue;
    }

    private function metadataIsoNumber(array $exifData, $originalValue = null)
    {
        if (isset($exifData['ISOSpeedRatings']))
        {
            return $exifData['ISOSpeedRatings'];
        }

        return $originalValue;
    }
}