Add XmlGenerator service and interface

Signed-off-by: Anton Fedurtsya <[email protected]>

services.yaml

@@ -1,5 +1,6 @@
 imports:
   - { resource: src/Repository/services.yaml }
+  - { resource: src/Service/services.yaml }
 
 services:
     _defaults:

src/Service/XmlGenerator.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace FreshAdvance\Sitemap\Service;
+
+use FreshAdvance\Sitemap\DataStructure\UrlInterface;
+
+class XmlGenerator implements XmlGeneratorInterface
+{
+    public function generateUrlItem(UrlInterface $url): string
+    {
+        $attributes = [
+            $this->wrap($url->getLocation(), "loc"),
+            $this->wrap($url->getLastModified(), "lastmod"),
+            $this->wrap($url->getChangeFrequency(), "changefreq"),
+            $this->wrap((string)$url->getPriority(), "priority"),
+        ];
+
+        return $this->wrap(implode("", $attributes), "url");
+    }
+
+    protected function wrap(string $data, string $tag, array $tagAttributes = []): string
+    {
+        $attributes = '';
+        foreach ($tagAttributes as $key => $attributeValue) {
+            $attributes .= " {$key}=\"{$attributeValue}\"";
+        }
+
+        return "<{$tag}{$attributes}>" . $data . "</{$tag}>";
+    }
+
+    public function generateSitemapDocument(iterable $items): string
+    {
+        $document = '<?xml version="1.0" encoding="UTF-8"?>';
+
+        $urlBlocks = [];
+        foreach ($items as $oneItem) {
+            $urlBlocks[] = $this->generateUrlItem($oneItem);
+        }
+
+        return $document
+            . $this->wrap(
+                implode("", $urlBlocks),
+                "urlset",
+                [
+                    "xmlns" => "http://www.sitemaps.org/schemas/sitemap/0.9"
+                ]
+            );
+    }
+}

src/Service/XmlGeneratorInterface.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace FreshAdvance\Sitemap\Service;
+
+interface XmlGeneratorInterface
+{
+    public function generateSitemapDocument(iterable $items): string;
+}

src/Service/services.yaml

@@ -0,0 +1,8 @@
+services:
+
+  _defaults:
+    public: false
+    autowire: true
+
+  FreshAdvance\Sitemap\Service\XmlGeneratorInterface:
+    class: FreshAdvance\Sitemap\Service\XmlGenerator

tests/Unit/Service/XmlGeneratorTest.php

@@ -0,0 +1,54 @@
+<?php
+
+namespace FreshAdvance\Sitemap\Tests\Unit\Service;
+
+use FreshAdvance\Sitemap\DataStructure\UrlInterface;
+use FreshAdvance\Sitemap\Service\XmlGenerator;
+
+class XmlGeneratorTest extends \PHPUnit\Framework\TestCase
+{
+    public function testGenerateUrlItem(): void
+    {
+        $urlStub = $this->createConfiguredMock(UrlInterface::class, [
+            'getLocation' => 'someLocation',
+            'getLastModified' => 'lastModifiedDate',
+            'getChangeFrequency' => 'someFrequency',
+            'getPriority' => 0.6,
+        ]);
+
+        $expectation = implode("", [
+            "<url>",
+            "<loc>someLocation</loc>",
+            "<lastmod>lastModifiedDate</lastmod>",
+            "<changefreq>someFrequency</changefreq>",
+            "<priority>0.6</priority>",
+            "</url>",
+        ]);
+
+        $sut = $this->createPartialMock(XmlGenerator::class, []);
+        $this->assertSame($expectation, $sut->generateUrlItem($urlStub));
+    }
+
+    public function testGenerateSitemapContent(): void
+    {
+        $sut = $this->createPartialMock(XmlGenerator::class, ['generateUrlItem']);
+        $sut->expects($this->exactly(3))->method('generateUrlItem')->willReturn("ItemContent");
+
+        $expectation = implode("", [
+            '<?xml version="1.0" encoding="UTF-8"?>',
+            '<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">',
+            'ItemContent',
+            'ItemContent',
+            'ItemContent',
+            '</urlset>'
+        ]);
+
+        $items = [
+            $this->createStub(UrlInterface::class),
+            $this->createStub(UrlInterface::class),
+            $this->createStub(UrlInterface::class),
+        ];
+
+        $this->assertSame($expectation, $sut->generateSitemapDocument($items));
+    }
+}