refactor(handler): use a single Handler type

src/handler.rs

@@ -0,0 +1,86 @@
+use crate::{
+    download::{DownloadResult, process_download_result},
+    error::Result,
+};
+use regex::{Error as RegexError, Regex};
+use std::{pin::Pin, sync::Arc};
+use teloxide::{Bot, types::ChatId};
+use tracing::info;
+
+#[derive(Debug, Clone)]
+pub struct Handler {
+    name: &'static str,
+    regex: Regex,
+    handler_fn: fn(&str) -> Pin<Box<dyn Future<Output = Result<DownloadResult>> + Send>>,
+}
+
+impl Handler {
+    #[must_use]
+    pub fn new(
+        name: &'static str,
+        regex_pattern: &'static str,
+        handler_fn: fn(&str) -> Pin<Box<dyn Future<Output = Result<DownloadResult>> + Send>>,
+    ) -> std::result::Result<Self, RegexError> {
+        let regex = Regex::new(regex_pattern)?;
+        Ok(Self {
+            name,
+            regex,
+            handler_fn,
+        })
+    }
+
+    #[inline]
+    #[must_use]
+    pub const fn name(&self) -> &'static str {
+        self.name
+    }
+
+    #[must_use]
+    pub fn try_extract(&self, text: &str) -> Option<String> {
+        self.regex
+            .captures(text)
+            .and_then(|c| c.get(0).map(|m| m.as_str().to_owned()))
+    }
+
+    pub async fn handle(&self, bot: &Bot, chat_id: ChatId, url: String) -> Result<()> {
+        info!(handler = %self.name(), url = %url, "handling url");
+        let dr = (self.handler_fn)(&url).await?;
+        process_download_result(bot, chat_id, dr).await
+    }
+}
+
+macro_rules! handler {
+    ($feature:expr, $regex:expr, $download_fn:path) => {
+        #[cfg(feature = $feature)]
+        Handler::new($feature, $regex, |url| {
+            Box::pin($download_fn(url.to_string()))
+        })
+        .expect(concat!("failed to create ", $feature, " handler"))
+    };
+}
+
+pub fn create_handlers() -> Arc<[Handler]> {
+    [
+        handler!(
+            "instagram",
+            r"https?://(?:www\.)?(?:instagram\.com|instagr\.am)/(?:p|reel|tv)/([A-Za-z0-9_-]+)",
+            crate::download::download_instagram
+        ),
+        handler!(
+            "youtube",
+            r"https?:\/\/(?:www\.)?youtube\.com\/shorts\/[A-Za-z0-9_-]+(?:\?[^\s]*)?",
+            crate::download::download_youtube
+        ),
+        handler!(
+            "twitter",
+            r"https?://(?:www\.)?twitter\.com/([A-Za-z0-9_]+(?:/[A-Za-z0-9_]+)?)/status/(\d{1,20})",
+            crate::download::download_twitter
+        ),
+        handler!(
+            "tiktok",
+            r"https?://(?:www\.)?(?:vm|vt|tt|tik)\.tiktok\.com/([A-Za-z0-9_-]+)[/?#]?",
+            crate::download::download_tiktok
+        ),
+    ]
+    .into()
+}