add notifications! welcome notifications are sent to new accounts or when a user is mentioned in a post

config.maple

···
 	bio_max_len = 200
 	bio_pattern = '(.|\s)*'
 }
+
+welcome = {
+	summary = 'welcome!'
+	body = 'hello %s and welcome to beep! i hope you enjoy your stay here :D'
+}

doc/todo.md

···
 
 ## in-progress
 
-- [ ] post:mentioning ('tagging') other users in posts
-
 ## planing
 
 - [ ] post:replies
···
 - [x] user:nicknames
 - [x] user:bio/about me
 - [x] user:listed pronouns
+- [x] user:notifications
 - [x] post:likes/dislikes
+- [x] post:mentioning ('tagging') other users in posts
+	- [x] post:mentioning:who mentioned you (send notifications when a user mentions you)
 - [ ] ~~site:stylesheet (and a toggle for html-only mode)~~
 	- replaced with per-user optional stylesheets
 - [x] site:message of the day (admins can add a welcome message displayed on index.html)

src/api.v

···
 
 import veb
 import auth
-import entity { Like, LikeCache, Post, Site, User }
+import entity { Like, LikeCache, Post, Site, User, Notification }
 
-////// Users //////
+////// user //////
 
 @['/api/user/register'; post]
 fn (mut app App) api_user_register(mut ctx Context, username string, password string) veb.Result {
···
 	println('reg: ${username}')
 
 	if x := app.get_user_by_name(username) {
+		app.send_notification_to(
+			x.id,
+			app.config.welcome.summary.replace('%s', x.get_name()),
+			app.config.welcome.body.replace('%s', x.get_name())
+		)
 		token := app.auth.add_token(x.id, ctx.ip()) or {
 			eprintln(err)
-			ctx.error('could not create token for user with id ${user.id}')
+			ctx.error('could not create token for user with id ${x.id}')
 			return ctx.redirect('/')
 		}
 		ctx.set_cookie(
···
 	return ctx.text(user.get_name())
 }
 
-////// Posts //////
+/// user/notification ///
+
+@['/api/user/notification/clear']
+fn (mut app App) api_user_notification_clear(mut ctx Context, id int) veb.Result {
+	if !ctx.is_logged_in() {
+		ctx.error('you are not logged in!')
+		return ctx.redirect('/login')
+	}
+	sql app.db {
+		delete from Notification where id == id
+	} or {
+		ctx.error('failed to delete notification')
+		return ctx.redirect('/inbox')
+	}
+	return ctx.redirect('/inbox')
+}
+
+@['/api/user/notification/clear_all']
+fn (mut app App) api_user_notification_clear_all(mut ctx Context) veb.Result {
+	user := app.whoami(mut ctx) or {
+		ctx.error('you are not logged in!')
+		return ctx.redirect('/login')
+	}
+	sql app.db {
+		delete from Notification where user_id == user.id
+	} or {
+		ctx.error('failed to delete notifications')
+		return ctx.redirect('/inbox')
+	}
+	return ctx.redirect('/inbox')
+}
+
+////// post //////
 
 @['/api/post/new_post'; post]
 fn (mut app App) api_post_new_post(mut ctx Context, title string, body string) veb.Result {
···
 		ctx.error('failed to post!')
 		println('failed to post: ${post} from user ${user.id}')
 		return ctx.redirect('/me')
+	}
+
+	// find the post's id to process mentions with
+	if x := app.get_post_by_author_and_timestamp(user.id, post.posted_at) {
+		app.process_post_mentions(x)
+	} else {
+		ctx.error('failed to get_post_by_timestamp_and_author for ${post}')
 	}
 
 	return ctx.redirect('/me')
···
 	}
 }
 
-////// Site //////
+@['/api/post/get_title']
+fn (mut app App) api_post_get_title(mut ctx Context, id int) veb.Result {
+	post := app.get_post_by_id(id) or { return ctx.server_error('no such post') }
+	return ctx.text(post.title)
+}
+
+////// site //////
 
 @['/api/site/set_motd'; post]
 fn (mut app App) api_site_set_motd(mut ctx Context, motd string) veb.Result {

src/app.v

···
 
 import veb
 import db.pg
+import regex
+import time
 import auth
-import entity { LikeCache, Like, Post, Site, User }
+import entity { LikeCache, Like, Post, Site, User, Notification }
 
 pub struct App {
 	veb.StaticHandler
···
 		select from Post where id == id limit 1
 	} or { [] }
 	if posts.len != 1 {
+		return none
+	}
+	return posts[0]
+}
+
+pub fn (app &App) get_post_by_author_and_timestamp(author_id int, timestamp time.Time) ?Post {
+	posts := sql app.db {
+		select from Post where author_id == author_id && posted_at == timestamp order by posted_at desc limit 1
+	} or { [] }
+	if posts.len == 0 {
 		return none
 	}
 	return posts[0]
···
 	return configs[0]
 }
 
+@[inline]
 pub fn (app &App) get_motd() string {
 	site := app.get_or_create_site_config()
 	return site.motd
 }
+
+pub fn (app &App) get_notifications_for(user_id int) []Notification {
+	notifications := sql app.db {
+		select from Notification where user_id == user_id
+	} or { [] }
+	return notifications
+}
+
+pub fn (app &App) get_notification_count(user_id int, limit int) int {
+	notifications := sql app.db {
+		select from Notification where user_id == user_id limit limit
+	} or { [] }
+	return notifications.len
+}
+
+pub fn (app &App) get_notification_count_for_frontend(user_id int, limit int) string {
+	count := app.get_notification_count(user_id, limit)
+	if count == 0 {
+		return ''
+	} else if count > limit {
+		return ' (${count}+)'
+	} else {
+		return ' (${count})'
+	}
+}
+
+pub fn (app &App) send_notification_to(user_id int, summary string, body string) {
+	notification := Notification{
+		user_id: user_id
+		summary: summary
+		body: body
+	}
+	sql app.db {
+		insert notification into Notification
+	} or {
+		eprintln('failed to send notification ${notification}')
+	}
+}
+
+// sends notifications to each user mentioned in a post
+pub fn (app &App) process_post_mentions(post &Post) {
+	author := app.get_user_by_id(post.author_id) or {
+		eprintln('process_post_mentioned called on a post with a non-existent author: ${post}')
+		return
+	}
+	author_name := author.get_name()
+
+	mut re := regex.regex_opt('@\\(${app.config.user.username_pattern}\\)') or {
+		eprintln('failed to compile regex for process_post_mentions (err: ${err})')
+		return
+	}
+	matches := re.find_all_str(post.body)
+	mut mentioned_users := []int{}
+	for mat in matches {
+		println('found mentioned user: ${mat}')
+		username := mat#[2..-1]
+		user := app.get_user_by_name(username) or {
+			continue
+		}
+
+		if user.id in mentioned_users || user.id == author.id {
+			continue
+		}
+		mentioned_users << user.id
+
+		app.send_notification_to(
+			user.id,
+			'${author_name} mentioned you!',
+			'you have been mentioned in this post: *(${post.id})'
+		)
+	}
+}

src/config.v

···
 		bio_max_len      int
 		bio_pattern      string
 	}
+	welcome struct {
+	pub mut:
+		summary string
+		body    string
+	}
 }
 
 pub fn load_config_from(file_path string) Config {
···
 	config.user.bio_min_len = loaded_user.get('bio_min_len').to_int()
 	config.user.bio_max_len = loaded_user.get('bio_max_len').to_int()
 	config.user.bio_pattern = loaded_user.get('bio_pattern').to_str()
+
+	loaded_welcome := loaded.get('welcome')
+	config.welcome.summary = loaded_welcome.get('summary').to_str()
+	config.welcome.body = loaded_welcome.get('body').to_str()
 
 	return config
 }

src/entity/notification.v

···
+module entity
+
+pub struct Notification {
+pub mut:
+	id      int @[primary; sql: serial]
+	user_id int
+	summary string
+	body    string
+}

src/main.v

···
 		create table entity.Post
 		create table entity.Like
 		create table entity.LikeCache
+		create table entity.Notification
 	}!
 }
 
 fn main() {
 	config := load_config_from(os.args[1])
 
+	println('-> connecting to db...')
 	mut db := pg.connect(pg.Config{
 		host:     config.postgres.host
 		dbname:   config.postgres.db
···
 		password: config.postgres.password
 		port:     config.postgres.port
 	})!
+	println('<- connected')
 
 	defer {
 		db.close()
···
 	// vfmt on
 
 	app.mount_static_folder_at(app.config.static_path, '/static')!
+
+	println('-> initializing database...')
 	init_db(db)!
+	println('<- done')
 
 	// make the website config, if it does not exist
 	app.get_or_create_site_config()

src/pages.v

···
 	return $veb.html()
 }
 
+fn (mut app App) inbox(mut ctx Context) veb.Result {
+	user := app.whoami(mut ctx) or {
+		ctx.error('not logged in')
+		return ctx.redirect('/login')
+	}
+	ctx.title = '${app.config.instance.name} inbox'
+	notifications := app.get_notifications_for(user.id)
+	return $veb.html()
+}
+
 @['/user/:username']
 fn (mut app App) user(mut ctx Context, username string) veb.Result {
 	user := app.whoami(mut ctx) or { User{} }

src/static/js/post.js

···
 	})
 	window.location.reload()
 }
-
-const render_post_body = async (id, mention_pattern) => {
-	const element = document.getElementById(`post-${id}`)
-	var body = element.innerText
-	const matches = body.matchAll(new RegExp(mention_pattern, 'g'))
-	for (const match of matches) {
-		(await fetch('/api/user/get_name?username=' + match[0].substring(2, match[0].length - 1))).text().then(s => {
-			element.innerHTML = element.innerHTML.replace(match[0], '<a href="/user/' + match[0].substring(2, match[0].length - 1) + '">' + s + '</a>')
-		})
-	}
-}

src/static/js/render_body.js

···
+// TODO: move this to the backend?
+const render_body = async id => {
+	const element = document.getElementById(id)
+	var body = element.innerText
+
+	const matches = body.matchAll(/[@#*]\([a-zA-Z0-9_.-]*\)/g)
+	const cache = {}
+	for (const match of matches) {
+		// mention
+		if (match[0][0] == '@') {
+			if (cache.hasOwnProperty(match[0])) {
+				element.innerHTML = element.innerHTML.replace(match[0], cache[match[0]])
+				continue
+			}
+			(await fetch('/api/user/get_name?username=' + match[0].substring(2, match[0].length - 1))).text().then(s => {
+				if (s == 'no such user') {
+					return
+				}
+				const link = document.createElement('a')
+				link.href = `/user/${match[0].substring(2, match[0].length - 1)}`
+				link.innerText = s
+				cache[match[0]] = link.outerHTML
+				element.innerHTML = element.innerHTML.replace(match[0], link.outerHTML)
+			})
+		}
+		// hashtag
+		else if (match[0][0] == '#') {
+		}
+		// post reference
+		else if (match[0][0] == '*') {
+			if (cache.hasOwnProperty(match[0])) {
+				element.innerHTML = element.innerHTML.replace(match[0], cache[match[0]])
+				continue
+			}
+			(await fetch('/api/post/get_title?id=' + match[0].substring(2, match[0].length - 1))).text().then(s => {
+				if (s == 'no such post') {
+					return
+				}
+				const link = document.createElement('a')
+				link.href = `/post/${match[0].substring(2, match[0].length - 1)}`
+				link.innerText = s
+				cache[match[0]] = link.outerHTML
+				element.innerHTML = element.innerHTML.replace(match[0], link.outerHTML)
+			})
+		}
+	}
+}

src/static/style.css

···
-.post {
+.post,
+.notification {
 	border: 2px solid;
 	padding: 8px;
 }
 
-.post p {
+.post p,
+.notification p {
 	margin: 0;
 }
 
-.post + .post {
+.post + .post,
+.notification + .notification {
 	margin-top: 6px;
 }
 

src/templates/inbox.html

···
+@include 'partial/header.html'
+
+@if ctx.is_logged_in()
+<script src="/static/js/render_body.js"></script>
+
+<h1>inbox</h1>
+
+<div>
+	@if notifications.len == 0
+	<p>your inbox is empty!</p>
+	@else
+	<a href="/api/user/notification/clear_all">clear all</a>
+	<hr>
+	@for notification in notifications.reverse()
+	<div class="notification">
+		<p><strong>@notification.summary</strong></p>
+		<pre id="notif-@{notification.id}">@notification.body</pre>
+		<a href="/api/user/notification/clear?id=@{notification.id}">clear</a>
+		<script>
+			render_body('notif-@{notification.id}')
+		</script>
+	</div>
+	@end
+	@end
+</div>
+@else
+<p>uh oh, you need to be logged in to view this page</p>
+@end
+
+@include 'partial/footer.html'

src/templates/partial/header.html

···
 		@if ctx.is_logged_in()
 		<a href="/me">profile</a>
 		-
+		<a href="/inbox">inbox@{app.get_notification_count_for_frontend(user.id, 99)}</a>
+		-
 		<a href="/api/user/logout">log out</a>
 		@else
 		<a href="/login">log in</a>

src/templates/post.html

···
 @include 'partial/header.html'
 
 <script src="/static/js/post.js"></script>
+<script src="/static/js/render_body.js"></script>
 
 <div class="post post-full">
 	<h2><a href="/user/@{(app.get_user_by_id(post.author_id) or { app.get_unknown_user() }).username}"><strong>@{(app.get_user_by_id(post.author_id) or { app.get_unknown_user() }).get_name()}</strong></a> - @post.title</h2>
···
 </div>
 
 <script type="module">
-	await render_post_body(@{post.id}, '@@\\(@{app.config.user.username_pattern}\\)')
+	await render_body('post-@{post.id}')
 </script>
 
 @include 'partial/footer.html'