From c4a0b1772a47ab4f169389add6c36f3e6f4f70ea Mon Sep 17 00:00:00 2001
From: DrMaxNix <git@drmaxnix.de>
Date: Sun, 4 Feb 2024 20:40:40 +0100
Subject: [PATCH] :sparkles: newsletter signup api (#45)

---
 .dat/.gitignore              |  2 +
 api/newsletter/subscribe.php | 56 ++++++++++++++++++++++++++
 meta.php                     |  5 ++-
 page/start/newsletter.js     | 36 +++++++++++++++--
 src/newsletter.php           | 78 ++++++++++++++++++++++++++++++++++++
 5 files changed, 172 insertions(+), 5 deletions(-)
 create mode 100644 .dat/.gitignore
 create mode 100644 api/newsletter/subscribe.php
 create mode 100644 src/newsletter.php

diff --git a/.dat/.gitignore b/.dat/.gitignore
new file mode 100644
index 0000000..d6b7ef3
--- /dev/null
+++ b/.dat/.gitignore
@@ -0,0 +1,2 @@
+*
+!.gitignore
diff --git a/api/newsletter/subscribe.php b/api/newsletter/subscribe.php
new file mode 100644
index 0000000..dc444cd
--- /dev/null
+++ b/api/newsletter/subscribe.php
@@ -0,0 +1,56 @@
+<?php
+	declare(strict_types = 1);
+	namespace Kimendisch\Sbgg_Jetzt;
+	use Flake\Error;
+	
+	// DECODE REQUEST //
+	// get json string
+	$json_body = file_get_contents("php://input");
+	if(strlen($json_body) <= 0){
+		http_response_code(400);
+		echo("malformed request body");
+		die();
+	}
+	
+	// try decoding json
+	$request = json_decode($json_body, true);
+	if(json_last_error() != JSON_ERROR_NONE){
+		http_response_code(400);
+		echo("malformed request body");
+		die();
+	}
+	
+	
+	// VALIDATE VALUES //
+	// mail address
+	$mail_address = $request["mail_address"] ?? "";
+	if(!is_string($mail_address)){
+		http_response_code(400);
+		echo("invalid mail address");
+		die();
+	}
+	if(!preg_match("/^[a-zA-Z0-9\.\-\_\+]+@([a-z0-9\-]+\.)+[a-z0-9\-]{2,}$/", $mail_address)){
+		http_response_code(400);
+		echo("invalid mail address");
+		die();
+	}
+	
+	// language
+	$language = $request["language"] ?? "";
+	if(!in_array($language, ["de", "en"])){
+		http_response_code(400);
+		echo("invalid language");
+		die();
+	}
+	
+	
+	// ADD TO MAILING LIST //
+	Newsletter::subscribe(mail_address: $mail_address, language: $language);
+	
+	
+	// POSITIVE RESPONSE //
+	http_response_code(200);
+	echo(json_encode([
+		"success" => true
+	]));
+?>
diff --git a/meta.php b/meta.php
index 850c6b1..0b2f2fb 100644
--- a/meta.php
+++ b/meta.php
@@ -5,6 +5,7 @@
 	
 	// DEPENDENCIES //
 	// used extensions
+	static::$ext[] = "dat";
 	static::$ext[] = "request";
 	static::$ext[] = "lang";
 	static::$ext[] = "page";
@@ -25,6 +26,8 @@
 	// pages
 	static::$route["sbgg.jetzt"] = [
 		["path" => "",			"target" => "page/start"],
-		["path" => ":lang",		"target" => "page/start"]
+		["path" => ":lang",		"target" => "page/start"],
+		
+		["path" => "api/newsletter/subscribe",			"target" => "api/newsletter/subscribe.php"]
 	];
 ?>
diff --git a/page/start/newsletter.js b/page/start/newsletter.js
index e6a8bfb..0ac3150 100644
--- a/page/start/newsletter.js
+++ b/page/start/newsletter.js
@@ -187,13 +187,41 @@ async function newsletter_submit(){
 	
 	
 	// SEND API REQUEST //
-	/**/setTimeout(function(){
+	var xhr = new XMLHttpRequest();
+	xhr.open("POST", "/api/newsletter/subscribe", true);
+	xhr.setRequestHeader("Content-Type", "application/json");
+	xhr.send(JSON.stringify({
+		mail_address: mail_address,
+		language: language
+	}));
+	
+	xhr.onload = function(){
+		let success = true;
+		
+		// validate http status code
+		if(xhr.status !== 200) success = false;
+		
+		// check response
+		if(success){
+			let response = null;
+			try {
+				response = JSON.parse(xhr.response);
+			} catch(e){}
+			
+			if(typeof response !== "object") success = false;
+			if(success && response === null) success = false;
+			if(success && response.success !== true) success = false;
+		}
+		
 		// positive feedback
-		newsletter_feedback_wait.classList.add("gone");
-		newsletter_feedback_success.classList.remove("hidden", "gone");
+		if(success){
+			newsletter_feedback_wait.classList.add("gone");
+			newsletter_feedback_success.classList.remove("hidden", "gone");
+			return;
+		}
 		
 		// negative feedback
 		newsletter_feedback_wait.classList.add("gone");
 		newsletter_feedback_failure.classList.remove("hidden", "gone");
-	/**/}, 700);
+	}
 }
diff --git a/src/newsletter.php b/src/newsletter.php
new file mode 100644
index 0000000..93a68e4
--- /dev/null
+++ b/src/newsletter.php
@@ -0,0 +1,78 @@
+<?php
+	declare(strict_types = 1);
+	namespace Kimendisch\Sbgg_Jetzt;
+	use Flake\Dat;
+	use Flake\Id64;
+	
+	class Newsletter {
+		/**
+		* Add a new mail address to the mailing list.
+		* 
+		* @param string $mail_address		Recipient mail address.
+		* @param string $language			Desired newsletter language.
+		*/
+		public static function subscribe(string $mail_address, string $language): void {
+			// OPEN DATABASE //
+			// acquire runlock
+			$old_ignore_user_abort = (bool)ignore_user_abort(true);
+			
+			// obtain handle
+			$newsletter_db = new Dat("./.dat/newsletter", Dat::MODE_READ_WRITE);
+			
+			
+			// MAYBE INITIALIZE DATABASE //
+			if(!is_array($newsletter_db->get("list"))){
+				// initialize as empty array
+				$newsletter_db->set("list", []);
+			}
+			
+			
+			// UPDATE DATABASE //
+			$entry_key = ["list", $mail_address];
+			
+			// generate unsubscribe key
+			$unsubscribe_key = Id64::new(length: 16);
+			
+			// only allow new entries
+			$is_new = ($newsletter_db->get($entry_key) === null);
+			
+			// maybe add to database
+			if($is_new){
+				$newsletter_db->set($entry_key, [
+					"unsubscribe_key" => $unsubscribe_key,
+					"language" => $language
+				]);
+			}
+			
+			
+			
+			// FINALIZE //
+			// close database
+			$newsletter_db->write_close();
+			
+			if($is_new){
+				// send welcome mail
+				self::send_welcome_mail(mail_address: $mail_address);
+				
+			} else {
+				// fake delay
+				//*/ TODO
+			}
+			
+			// release runlock
+			ignore_user_abort($old_ignore_user_abort);
+		}
+		
+		
+		
+		/**
+		* HELPER: Send welcome mail to new recipient.
+		* 
+		* @param string $mail_address		Recipient mail address.
+		*/
+		private static function send_welcome_mail(string $mail_address): void {
+			/**/print_r(["send_welcome_mail" => $mail_address]);
+			//*/ TODO
+		}
+	}
+?>