index.php

<?php

    error_reporting(E_ALL);
    ini_set('display_errors', 1);

    function createImage($filename){

        $pathinfo = pathinfo($filename);
        $info = getimagesize($filename);

        $extension_arr = explode('?', $pathinfo['extension']);
        $extension = $extension_arr[0];

        $mime = $info['mime'];

        switch ($mime) {
            case 'image/jpeg':
                $image_create_func = 'imagecreatefromjpeg';
                $image_save_func = 'imagejpeg';
                $new_image_ext = 'jpg';
            break;

            case 'image/png':
                $image_create_func = 'imagecreatefrompng';
                $image_save_func = 'imagepng';
                $new_image_ext = 'png';
            break;

            case 'image/gif':
                $image_create_func = 'imagecreatefromgif';
                $image_save_func = 'imagegif';
                $new_image_ext = 'gif';
                break;

            default:
                throw new Exception("Formato não aceito ${mime}");
            break;
        }

        $image_save_func($image_create_func($filename), "store/".sha1($filename).".${extension}");

        return $info;
    }

    function connectDatabase(){

        try{

            $link = new \PDO( 'mysql:host=127.0.0.1;dbname=imagem;',
                              'imagem_user',
                              '<PASSWORD>',
                              array(
                                    \PDO::ATTR_ERRMODE => \PDO::ERRMODE_EXCEPTION,
                                    \PDO::ATTR_PERSISTENT => false
                                )
                            );

            return $link;
        }
        catch(\PDOException $ex){
            print($ex->getMessage());
        }
    }

    function responseAPI($code, $message){
        http_response_code($code);
        echo json_encode(array('status'=> $code, 'message'=> $message));
        die();
    }

    if (!isset($_GET['url'])){
        responseAPI(500, 'Parâmetro url não informado');
    }

    if (!isset($_GET['width'])){
        responseAPI(500, 'Parâmetro width não informado');
    }

    // GET parameters
    $url = $_GET['url'];
    $width_fetch = $_GET['width'];

    // Key unique
    $chave = sha1($url.$width_fetch);

    $link = connectDatabase();
    $handle = $link->prepare('SELECT arq.* FROM arquivos arq WHERE chave = ?');
    $handle->bindValue(1, $chave);
    $handle->execute();

    $result = $handle->fetchAll(\PDO::FETCH_OBJ);

    if ($result) {

        $loaded = $result[0];
        $cachefile = 'cache/'.$chave.'.'.$loaded->extensao;
        $info = getimagesize($cachefile);
    }
    else {

        $info = createImage($_GET['url']);

        $chave_file   = sha1($url);
        $arr_pesquisa = glob("store/${chave_file}.*");

        if (count($arr_pesquisa) > 0){
            $filename = $arr_pesquisa[0];
        }else{
            responseAPI(500, "Arquivo (${chave_file}) não encontrado em STORE.");
        }

        // Original sizes (width, height)
        $width_orig  = $info[0];
        $height_orig = $info[1];

        // Proportional height
        $width = $width_fetch;
        $height = round((($height_orig/$width_orig) * $width));

        $extensao_arr = explode('/', $info['mime']);
        $extensao = $extensao_arr[1];

        $filename = 'store/'.$chave_file.'.'.$extensao;
        $cachefile = 'cache/'.$chave.'.'.$extensao;

        if ($extensao == "jpg" || $extensao == "jpeg"){

            $image_p = imagecreatetruecolor($width, $height);
            $image = imagecreatefromjpeg($filename);
            imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);
            imagejpeg($image_p, $cachefile, 75);
        }
        else if ($extensao == "png"){

            $image_p = imagecreatetruecolor($width, $height);
            $background = imagecolorallocate($image_p, 0, 0, 0);
            imagecolortransparent($image_p, $background);
            imagealphablending($image_p, false);
            imagesavealpha($image_p, true);
            $image = imagecreatefrompng($filename);
            imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);
            imagepng($image_p, $cachefile, 5);
        }

        $handle = $link->prepare('INSERT INTO arquivos(id, width, height, url, extensao, chave) VALUES(NULL, ?, ?, ?, ?, ?);');

        $handle->bindValue(1, $width_fetch, PDO::PARAM_INT);
        $handle->bindValue(2, $height, PDO::PARAM_INT);
        $handle->bindValue(3, urlencode($url));
        $handle->bindValue(4, $extensao);
        $handle->bindValue(5, $chave);

        $handle->execute();
    }

    // Close connection
    $link = null;

    // Send header
    header('Content-Type: '.$info['mime']);

    // Show file
    readfile($cachefile);
?>