fix(unfurl): key the cache on available provider credentials (#1688)

fluxer_unfurl/src/router_impl.rs

@@ -19,6 +19,14 @@ impl UnfurlRouter {
                 .build(),
         }
     }
+
+    fn invalidate_all_variants(&self, url: &str) {
+        for mode in [NsfwMode::Block, NsfwMode::Flag, NsfwMode::Allow] {
+            for capability in PROVIDER_CAPABILITIES {
+                self.l1.invalidate(&unfurl_cache_key(url, mode, capability));
+            }
+        }
+    }
 }
 
 impl RouterService for UnfurlRouter {
@@ -43,7 +51,8 @@ impl RouterService for UnfurlRouter {
                 nsfw_mode,
                 bypass_cache,
                 cache_only,
-                ..
+                youtube_api_key,
+                klipy_api_key,
             } => {
                 if *bypass_cache {
                     return None;
@@ -51,7 +60,11 @@ impl RouterService for UnfurlRouter {
                 let mode = if *cache_only { "cache-only" } else { "full" };
                 Some(format!(
                     "{mode}:{}",
-                    unfurl_cache_key(url, nsfw_mode.unwrap_or_default())
+                    unfurl_cache_key(
+                        url,
+                        nsfw_mode.unwrap_or_default(),
+                        provider_capability(youtube_api_key, klipy_api_key)
+                    )
                 ))
             }
             UnfurlRequest::Invalidate { .. } => None,
@@ -64,12 +77,18 @@ impl RouterService for UnfurlRouter {
                 url,
                 nsfw_mode,
                 bypass_cache,
+                youtube_api_key,
+                klipy_api_key,
                 ..
             } => {
                 if *bypass_cache {
                     None
                 } else {
-                    let key = unfurl_cache_key(url, nsfw_mode.unwrap_or_default());
+                    let key = unfurl_cache_key(
+                        url,
+                        nsfw_mode.unwrap_or_default(),
+                        provider_capability(youtube_api_key, klipy_api_key),
+                    );
                     self.l1.get(&key)
                 }
             }
@@ -79,38 +98,58 @@ impl RouterService for UnfurlRouter {
 
     fn l1_insert(&self, req: &UnfurlRequest, resp: &UnfurlResponse) {
         match req {
-            UnfurlRequest::Unfurl { url, nsfw_mode, .. } => {
+            UnfurlRequest::Unfurl {
+                url,
+                nsfw_mode,
+                youtube_api_key,
+                klipy_api_key,
+                ..
+            } => {
                 if let UnfurlResponse::Resolved(result) = resp
                     && !result.embeds.is_empty()
                 {
                     self.l1.insert(
-                        unfurl_cache_key(url, nsfw_mode.unwrap_or_default()),
+                        unfurl_cache_key(
+                            url,
+                            nsfw_mode.unwrap_or_default(),
+                            provider_capability(youtube_api_key, klipy_api_key),
+                        ),
                         resp.clone(),
                     );
                 }
             }
             UnfurlRequest::Invalidate { url } => {
-                self.l1.invalidate(&unfurl_cache_key(url, NsfwMode::Block));
-                self.l1.invalidate(&unfurl_cache_key(url, NsfwMode::Flag));
-                self.l1.invalidate(&unfurl_cache_key(url, NsfwMode::Allow));
+                self.invalidate_all_variants(url);
             }
         }
     }
 
     fn l1_invalidate(&self, key: &str) {
-        self.l1.invalidate(&unfurl_cache_key(key, NsfwMode::Block));
-        self.l1.invalidate(&unfurl_cache_key(key, NsfwMode::Flag));
-        self.l1.invalidate(&unfurl_cache_key(key, NsfwMode::Allow));
+        self.invalidate_all_variants(key);
     }
 }
 
-fn unfurl_cache_key(url: &str, nsfw_mode: NsfwMode) -> String {
+const PROVIDER_CAPABILITIES: &[&str] = &["none", "youtube", "klipy", "youtube+klipy"];
+
+fn provider_capability(
+    youtube_api_key: &Option<String>,
+    klipy_api_key: &Option<String>,
+) -> &'static str {
+    match (youtube_api_key.is_some(), klipy_api_key.is_some()) {
+        (true, true) => "youtube+klipy",
+        (true, false) => "youtube",
+        (false, true) => "klipy",
+        (false, false) => "none",
+    }
+}
+
+fn unfurl_cache_key(url: &str, nsfw_mode: NsfwMode, capability: &str) -> String {
     let mode = match nsfw_mode {
         NsfwMode::Block => "block",
         NsfwMode::Flag => "flag",
         NsfwMode::Allow => "allow",
     };
-    format!("{mode}:{url}")
+    format!("{mode}:{capability}:{url}")
 }
 
 #[cfg(test)]
@@ -128,6 +167,55 @@ mod tests {
         }
     }
 
+    fn resolved_response() -> UnfurlResponse {
+        UnfurlResponse::Resolved(std::sync::Arc::new(crate::types::UnfurlResult {
+            embeds: vec![crate::types::MessageEmbed::new("link")],
+            cache_ttl_seconds: None,
+        }))
+    }
+
+    fn unfurl(url: &str, youtube_api_key: Option<&str>) -> UnfurlRequest {
+        UnfurlRequest::Unfurl {
+            url: url.to_owned(),
+            nsfw_mode: Some(NsfwMode::Block),
+            bypass_cache: false,
+            cache_only: false,
+            youtube_api_key: youtube_api_key.map(str::to_owned),
+            klipy_api_key: None,
+        }
+    }
+
+    #[test]
+    fn configuring_a_youtube_key_does_not_reuse_the_keyless_cache_entry() {
+        let router = UnfurlRouter::new(16);
+        let url = "https://www.youtube.com/watch?v=dQw4w9WgXcQ";
+        router.l1_insert(&unfurl(url, None), &resolved_response());
+        assert!(
+            router.l1_lookup(&unfurl(url, Some("configured"))).is_none(),
+            "a result resolved without a YouTube key must not be served once a key is configured"
+        );
+        assert!(
+            router.l1_lookup(&unfurl(url, None)).is_some(),
+            "the keyless entry must still serve keyless requests"
+        );
+    }
+
+    #[test]
+    fn invalidate_clears_every_provider_capability_variant() {
+        let router = UnfurlRouter::new(16);
+        let url = "https://www.youtube.com/watch?v=dQw4w9WgXcQ";
+        router.l1_insert(&unfurl(url, None), &resolved_response());
+        router.l1_insert(&unfurl(url, Some("configured")), &resolved_response());
+        router.l1_insert(
+            &UnfurlRequest::Invalidate {
+                url: url.to_owned(),
+            },
+            &resolved_response(),
+        );
+        assert!(router.l1_lookup(&unfurl(url, None)).is_none());
+        assert!(router.l1_lookup(&unfurl(url, Some("configured"))).is_none());
+    }
+
     #[test]
     fn coalesce_key_separates_cache_only_from_full_unfurls() {
         assert_ne!(