Export checkin to CSV

app/Services/CheckinCsvExporter.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace App\Services;
+
+use App\User;
+use Illuminate\Support\Facades\DB;
+use League\Csv\Writer;
+
+class CheckinCsvExporter
+{
+    /** @var User Target user */
+    private $user;
+    /** @var string Output filename */
+    private $filename;
+    /** @var string Output charset */
+    private $charset;
+
+    public function __construct(User $user, string $filename, string $charset)
+    {
+        $this->user = $user;
+        $this->filename = $filename;
+        $this->charset = $charset;
+    }
+
+    public function execute()
+    {
+        $csv = Writer::createFromPath($this->filename, 'wb');
+        $csv->setNewline("\r\n");
+        if ($this->charset === 'SJIS-win') {
+            $csv->addStreamFilter('convert.mbstring.encoding.UTF-8:SJIS-win');
+        }
+
+        $header = ['日時', 'ノート', 'オカズリンク'];
+        for ($i = 1; $i <= 32; $i++) {
+            $header[] = "タグ{$i}";
+        }
+        $csv->insertOne($header);
+
+        DB::transaction(function () use ($csv) {
+            // TODO: そんなに読み取り整合性を保つ努力はしていないのと、chunkの件数これでいいか分からない
+            $this->user->ejaculations()->with('tags')->orderBy('ejaculated_date')
+                ->chunk(1000, function ($ejaculations) use ($csv) {
+                    foreach ($ejaculations as $ejaculation) {
+                        $record = [
+                            $ejaculation->ejaculated_date->format('Y-m-d H:i'),
+                            $ejaculation->note,
+                            $ejaculation->link,
+                        ];
+                        foreach ($ejaculation->tags as $tag) {
+                            $record[] = $tag->name;
+                        }
+                        $csv->insertOne($record);
+                    }
+                });
+        });
+    }
+}