From f2ecdfcf97773f8016049abd7daa88a4fa174491 Mon Sep 17 00:00:00 2001
From: Leonid Nikitin <i@kor-elf.net>
Date: Wed, 28 Jun 2023 17:22:19 +0600
Subject: [PATCH] This commit adds an Image interface and implementation that
 will be used in the Captcha generation process. The Image object includes
 methods for manipulating an image, such as adding text, inserting a
 background, and adding a line. These methods will provide the necessary
 functionalities for generating a Captcha.

---
 app/Captcha/Contracts/Image.php |  17 ++++
 app/Captcha/Images/Image.php    | 138 ++++++++++++++++++++++++++++++++
 2 files changed, 155 insertions(+)
 create mode 100644 app/Captcha/Contracts/Image.php
 create mode 100644 app/Captcha/Images/Image.php

diff --git a/app/Captcha/Contracts/Image.php b/app/Captcha/Contracts/Image.php
new file mode 100644
index 0000000..15cb650
--- /dev/null
+++ b/app/Captcha/Contracts/Image.php
@@ -0,0 +1,17 @@
+<?php declare(strict_types=1);
+
+namespace App\Captcha\Contracts;
+
+use App\Captcha\Dto\Coordinators;
+
+interface Image
+{
+    public function __construct(int $width, int $height);
+    public function getWidth(): int;
+    public function getHeight(): int;
+    public function insertBackground(string $pathToFile): self;
+    public function addText(string $text, int $x, int $y, float $size, float $angle, string $hexColor, string $fontName): Coordinators;
+    public function addLine(int $x1, int $y1, int $x2, int $y2, string $hexColor): self;
+    public function encode(): string;
+    public function __destruct();
+}
diff --git a/app/Captcha/Images/Image.php b/app/Captcha/Images/Image.php
new file mode 100644
index 0000000..a9f29f3
--- /dev/null
+++ b/app/Captcha/Images/Image.php
@@ -0,0 +1,138 @@
+<?php declare(strict_types=1);
+
+namespace App\Captcha\Images;
+
+use App\Captcha\Contracts\Image as ImageContract;
+use App\Captcha\Dto\Coordinators;
+use App\Captcha\Exceptions\CaptchaException;
+
+final class Image implements ImageContract
+{
+    private readonly \GdImage $image;
+
+    public function __construct(int $width, int $height) {
+        $this->image = imagecreatetruecolor($width, $height);
+    }
+
+    public function getWidth(): int
+    {
+        return imagesx($this->image);
+    }
+
+    public function getHeight(): int
+    {
+        return imagesy($this->image);
+    }
+
+    public function insertBackground(string $pathToFile): ImageContract
+    {
+        list($backgroundWidth, $backgroundHeight) = getimagesize($pathToFile);
+        $background = $this->createImageFromPathToFile($pathToFile);
+        imagecopyresampled(
+            dst_image: $this->image,
+            src_image: $background,
+            dst_x: 0,
+            dst_y: 0,
+            src_x: 0,
+            src_y: 0,
+            dst_width: $this->getWidth(),
+            dst_height: $this->getHeight(),
+            src_width: $backgroundWidth,
+            src_height: $backgroundHeight
+        );
+        imagedestroy($background);
+
+        return $this;
+    }
+
+    public function addText(string $text, int $x, int $y, float $size, float $angle, string $hexColor, string $fontName): Coordinators
+    {
+        $y += intval($size);
+        $result = imagefttext(
+            image: $this->image,
+            size: $size,
+            angle: $angle,
+            x: $x,
+            y: $y,
+            color: $this->colorConvertHexToColorIndex($hexColor),
+            font_filename: $fontName,
+            text: $text
+        );
+
+        return new Coordinators(
+            x1: $result[0],
+            y1: $result[1],
+            x2: $result[2],
+            y2: $result[3],
+            x3: $result[4],
+            y3: $result[5],
+            x4: $result[6],
+            y4: $result[7]
+        );
+    }
+
+    public function addLine(int $x1, int $y1, int $x2, int $y2, string $hexColor): self
+    {
+        imageline(
+            image: $this->image,
+            x1: $x1,
+            y1: $y1,
+            x2: $x2,
+            y2: $y2,
+            color: $this->colorConvertHexToColorIndex($hexColor)
+        );
+
+        return $this;
+    }
+
+    public function encode(): string
+    {
+        ob_start();
+        imagealphablending($this->image, false);
+        imagesavealpha($this->image, true);
+        imagepng($this->image, null, -1);
+        $mime = image_type_to_mime_type(IMAGETYPE_PNG);
+        $buffer = ob_get_contents();
+        ob_end_clean();
+
+        return sprintf('data:%s;base64,%s',
+            $mime,
+            base64_encode($buffer)
+        );
+    }
+
+    public function __destruct() {
+        imagedestroy($this->image);
+    }
+
+    private function createImageFromPathToFile(string $pathToFile): \GdImage
+    {
+        return match (mime_content_type($pathToFile)) {
+            'image/jpeg' => imagecreatefromjpeg($pathToFile),
+            'image/png'  => imagecreatefrompng($pathToFile),
+            default => throw new CaptchaException('Couldn\'t open the file. Not a valid type. File ' . $pathToFile . '.')
+        };
+    }
+
+    private function colorConvertHexToColorIndex(string $hexColor): int
+    {
+        $hexColor = str_replace('#', '', $hexColor);
+
+        if (strlen($hexColor) === 3) {
+            return imagecolorexact(
+                image: $this->image,
+                red: hexdec(str_repeat(substr($hexColor, 0, 1), 2)),
+                blue: hexdec(str_repeat(substr($hexColor, 1, 1), 2)),
+                green: hexdec(str_repeat(substr($hexColor, 2, 1), 2))
+            );
+        }
+
+        $colorVal = hexdec($hexColor);
+        return imagecolorexact(
+            image: $this->image,
+            red: 0xFF & ($colorVal >> 0x10),
+            blue: 0xFF & ($colorVal >> 0x8),
+            green: 0xFF & $colorVal
+        );
+    }
+}