big update

Cargo.toml

@@ -9,7 +9,7 @@ edition = "2021"
 rss = "2.0"
 reqwest = {version = "0.11", default-features = false, features = ["rustls"]}
 tokio = {version = "1.28", features = ["rt-multi-thread", "signal"]}
-lazy-regex = "2.5.0"
+lazy-regex = "3.0.2"
 #time = {version = "0.3", features = ["local-offset" ,"macros", "parsing"]}
 chrono = "0.4.25"
 chrono-tz = "0.8.2"
@@ -17,6 +17,8 @@ anyhow = "1.0.71"
 log = "0.4.18"
 env_logger = "0.10.0"
 dotenvy = "0.15.7"
+sled = { version = "0.34.7", features = ["compression"] }
+bincode = "1.3.3"
 
 [dependencies.serenity]
 version = "0.11"

src/main.rs

@@ -1,37 +1,76 @@
 use anyhow::{anyhow, Context};
-use chrono::{DateTime, NaiveDateTime, TimeZone};
+use chrono::{DateTime, NaiveDateTime, TimeZone, Utc};
 use lazy_regex::regex;
-use log::{debug, error, info};
+use log::{debug, info};
 use reqwest::IntoUrl;
-use rss::{Channel, Item};
 use serenity::http::Http;
 use serenity::json::Value;
 use serenity::model::channel::Embed;
-use serenity::model::prelude::Webhook;
-use std::collections::HashSet;
+use serenity::model::webhook::Webhook;
+use std::borrow::Cow;
 use std::env;
-use std::fs::{File, OpenOptions};
-use std::io::{BufRead, BufReader, Write};
-use std::time::Duration;
 
-const REFRESH_INTERVAL: Duration = Duration::from_secs(10 * 60);
+struct RefreshDb(sled::Db);
 
-async fn get_rss_channel<T: IntoUrl>(url: T) -> anyhow::Result<Channel> {
-    let content = reqwest::get(url).await?.bytes().await?;
-    let channel = Channel::read_from(&content[..])?;
-    Ok(channel)
+impl RefreshDb {
+    fn get(&self, guid: &str) -> anyhow::Result<Option<DateTime<Utc>>> {
+        self.0
+            .get(guid)
+            .with_context(|| "db error: unable to get value")?
+            .map(|b| {
+                bincode::deserialize::<i64>(&b)
+                    .with_context(|| "db error: unable to deserialize i64")
+            })
+            .transpose()?
+            .map(|i| {
+                Utc.timestamp_opt(i, 0)
+                    .single()
+                    .with_context(|| "db error: unable to parse timestamp from i64")
+            })
+            .transpose()
+    }
+
+    fn insert(&self, guid: String, datetime: DateTime<Utc>) -> anyhow::Result<()> {
+        let timestamp = datetime.timestamp();
+        let bytes = bincode::serialize(&timestamp).with_context(|| "db error")?;
+        self.0.insert(guid, bytes).with_context(|| "db error")?;
+        Ok(())
+    }
 }
 
-fn validity_time_to_timestamp(input: &str) -> anyhow::Result<i64> {
+struct DisbahnClient {
+    webhook: Webhook,
+    http: Http,
+    rss_url: String,
+    known_guids: RefreshDb,
+}
+
+impl DisbahnClient {
+    fn new(webhook: Webhook, http: Http, rss_url: String, known_guids: RefreshDb) -> Self {
+        Self {
+            webhook,
+            http,
+            rss_url,
+            known_guids,
+        }
+    }
+
+    async fn get_rss_channel<T: IntoUrl>(url: T) -> anyhow::Result<rss::Channel> {
+        let content = reqwest::get(url).await?.bytes().await?;
+        let channel = rss::Channel::read_from(&content[..])?;
+        Ok(channel)
+    }
+
+    fn validity_time_to_timestamp(input: &str) -> anyhow::Result<i64> {
         let naive = NaiveDateTime::parse_from_str(input, "%Y-%m-%d %H:%M:%S")?;
         let timestamp = chrono_tz::Europe::Berlin
             .from_local_datetime(&naive)
             .unwrap()
             .timestamp();
         Ok(timestamp)
-}
+    }
 
-fn html_to_discord_markdown(input: &str) -> String {
+    fn html_to_discord_markdown(input: &str) -> String {
         let re_times = regex!(r#"^.*<br\s*/>\s*<br\s*/>"#i);
         let re_bold = regex!(r#"<b\s*>((.|\n)*?)</b\s*>"#i);
         let re_italic = regex!(r#"<i\s*>((.|\n)*?)</i\s*>"#i);
@@ -44,17 +83,17 @@ fn html_to_discord_markdown(input: &str) -> String {
         let input = re_strikethrough.replace_all(&input, "~~$1~~");
         let input = re_newline.replace_all(&input, "\n");
         input.to_string()
-}
+    }
 
-fn icon_name_to_url(name: &str) -> &str {
+    fn icon_name_to_url(name: &str) -> &str {
         match name {
             "HIM1" => "https://upload.wikimedia.org/wikipedia/commons/thumb/a/a9/Zeichen_123_-_Arbeitsstelle%2C_StVO_2013.svg/273px-Zeichen_123_-_Arbeitsstelle%2C_StVO_2013.svg.png",
             "HIM2" => "https://upload.wikimedia.org/wikipedia/commons/thumb/0/02/Zeichen_101_-_Gefahrstelle%2C_StVO_1970.svg/273px-Zeichen_101_-_Gefahrstelle%2C_StVO_1970.svg.png",
-        _ => "https://upload.wikimedia.org/wikipedia/commons/thumb/8/8a/RWB-RWBA_Information.svg/240px-RWB-RWBA_Information.svg.png",
+            _ => "https://upload.wikimedia.org/wikipedia/commons/thumb/5/56/Zeichen_365-61_-_Informationsstelle%2C_StVO_2013.svg/240px-Zeichen_365-61_-_Informationsstelle%2C_StVO_2013.svg.png",
+        }
     }
-}
 
-fn item_to_embed(item: &Item) -> anyhow::Result<Value> {
+    fn item_to_embed(item: &rss::Item, is_update: bool) -> anyhow::Result<Value> {
         const COLOUR: u32 = 0x008d4f;
         const FOOTER_ICON_URL: &str = "https://www.zuginfo.nrw/img/customer/apple-touch-icon.png";
 
@@ -68,34 +107,40 @@ fn item_to_embed(item: &Item) -> anyhow::Result<Value> {
             .find(|c| c.domain() == Some("validityBegin"))
             .ok_or(anyhow!("Missing validityBegin category"))?
             .name;
-    let validity_begin = validity_time_to_timestamp(validity_begin)?;
+        let validity_begin = Self::validity_time_to_timestamp(validity_begin)?;
 
         let validity_end = &categories
             .iter()
             .find(|c| c.domain() == Some("validityEnd"))
             .ok_or(anyhow!("Missing validityEnd category"))?
             .name;
-    let validity_end = validity_time_to_timestamp(validity_end)?;
+        let validity_end = Self::validity_time_to_timestamp(validity_end)?;
 
         let icon = categories
             .iter()
             .find(|c| c.domain() == Some("icon"))
             .map(|c| c.name())
             .unwrap_or("");
-    let icon_url = icon_name_to_url(icon);
+        let icon_url = Self::icon_name_to_url(icon);
 
-    let description =
-        html_to_discord_markdown(item.description().ok_or(anyhow!("Missing description"))?);
+        let description = Self::html_to_discord_markdown(
+            item.description().ok_or(anyhow!("Missing description"))?,
+        );
 
-    let pub_date = item.pub_date().ok_or(anyhow!("Missing publication date"))?;
-    let pub_timestamp = DateTime::parse_from_rfc2822(pub_date)
-        .with_context(|| format!("Unable to parse publication date string {pub_date:?}"))?
+        let pub_date_str = item.pub_date().ok_or(anyhow!("Missing publication date"))?;
+        let pub_datetime = DateTime::parse_from_rfc2822(pub_date_str)
+            .with_context(|| format!("Unable to parse publication date string {pub_date_str:?}"))?
             .naive_utc()
-        .and_utc()
-        .to_rfc3339_opts(chrono::SecondsFormat::Secs, true);
+            .and_utc();
+
+        let pub_timestamp = pub_datetime.to_rfc3339_opts(chrono::SecondsFormat::Secs, true);
 
         let embed = Embed::fake(|e| {
-        e.title(title)
+            e.title(if is_update {
+                Cow::Owned(format!("UPDATE: {title}"))
+            } else {
+                Cow::Borrowed(title)
+            })
             .url(link)
             .thumbnail(icon_url)
             .colour(COLOUR)
@@ -111,35 +156,53 @@ fn item_to_embed(item: &Item) -> anyhow::Result<Value> {
         });
 
         Ok(embed)
-}
+    }
 
-async fn refresh_and_process_rss(
-    feed_url: &str,
-    http: &Http,
-    webhook: &Webhook,
-    known_guids: &mut HashSet<String>,
-    known_guids_file: &mut File,
-) -> anyhow::Result<()> {
+    async fn refresh(&mut self) -> anyhow::Result<()> {
         debug!("Refreshing RSS feed ...");
-    let channel = get_rss_channel(feed_url)
+        let channel = Self::get_rss_channel(&self.rss_url)
             .await
             .map_err(|e| anyhow!(e.to_string()))
             .with_context(|| "Failed to get RSS channel")?;
-    for item in channel.items() {
+
+        let items = channel.items();
+
+        for item in items {
             let guid = item.guid().ok_or(anyhow!("Missing GUID"))?.value();
-        if !known_guids.contains(guid) {
-            info!("New item: {}", guid);
-            known_guids.insert(guid.to_owned());
-            writeln!(known_guids_file, "{}", guid).with_context(|| "Failed to write known GUID")?;
-            let embed = item_to_embed(item)?;
-            webhook
-                .execute(&http, false, |w| w.embeds(vec![embed]))
+            let pub_date_str = item.pub_date().ok_or(anyhow!("Missing publication date"))?;
+            let pub_datetime = DateTime::parse_from_rfc2822(pub_date_str)
+                .with_context(|| {
+                    format!("Unable to parse publication date string {pub_date_str:?}")
+                })?
+                .naive_utc()
+                .and_utc();
+
+            let is_update;
+            if let Some(last_pub_datetime) = self.known_guids.get(guid)? {
+                if last_pub_datetime < pub_datetime {
+                    is_update = true;
+                    info!("Updated item: {guid}");
+                } else {
+                    continue;
+                }
+            } else {
+                is_update = false;
+                info!("New item: {guid}");
+            }
+
+            let embed = Self::item_to_embed(item, is_update)?;
+            self.webhook
+                .execute(&self.http, false, |w| w.embeds(vec![embed]))
                 .await
                 .with_context(|| "Failed to execute webhook")?;
+            self.known_guids
+                .insert(guid.to_string(), pub_datetime)
+                .with_context(|| "Failed to write to database")?;
         }
-    }
+
         debug!("Done.");
         Ok(())
+    }
 }
 
 #[tokio::main]
@@ -152,36 +215,15 @@ async fn main() -> anyhow::Result<()> {
 
     let webhook_url = env::var("WEBHOOK_URL")?;
     let feed_url = env::var("FEED_URL")?;
-    let known_guids_file = env::var("KNOWN_GUIDS_FILE")?;
+    let known_guids_db = env::var("KNOWN_GUIDS_DB")?;
 
-    let mut known_guids_file = OpenOptions::new()
-        .read(true)
-        .write(true)
-        .create(true)
-        .open(known_guids_file)?;
+    let known_guids_db =
+        RefreshDb(sled::open(known_guids_db).with_context(|| "unable to open database")?);
 
     let http = Http::new("");
     let webhook = http.get_webhook_from_url(&webhook_url).await.unwrap();
 
-    let mut known_guids: HashSet<String> = HashSet::new();
-    for line in BufReader::new(&known_guids_file).lines() {
-        let line = line?;
-        known_guids.insert(line);
-    }
+    let mut disbahn_client = DisbahnClient::new(webhook, http, feed_url, known_guids_db);
 
-    loop {
-        if let Err(err) = refresh_and_process_rss(
-            &feed_url,
-            &http,
-            &webhook,
-            &mut known_guids,
-            &mut known_guids_file,
-        )
-        .await
-        {
-            error!("Error: {}", err);
-        }
-
-        tokio::time::sleep(REFRESH_INTERVAL).await;
-    }
+    disbahn_client.refresh().await
 }