feat(ug-parser): implement UgTabFetcher for file and URL sources

crates/infrastructure/ug-parser/src/fetcher.rs

@@ -1 +1,53 @@
-pub struct UgTabFetcher;
+use async_trait::async_trait;
+use domain::{FetchError, TabFetcherPort, TabSource};
+
+pub struct UgTabFetcher {
+    client: reqwest::Client,
+}
+
+impl UgTabFetcher {
+    pub fn new() -> Self {
+        Self { client: reqwest::Client::new() }
+    }
+}
+
+#[async_trait]
+impl TabFetcherPort for UgTabFetcher {
+    async fn fetch(&self, source: TabSource) -> Result<String, FetchError> {
+        match source {
+            TabSource::File(path) => {
+                Ok(tokio::fs::read_to_string(&path).await?)
+            }
+            TabSource::Url(url) => {
+                let resp = self.client.get(&url).send().await
+                    .map_err(|e| FetchError::Network(e.to_string()))?;
+                let content_type = resp.headers()
+                    .get(reqwest::header::CONTENT_TYPE)
+                    .and_then(|v| v.to_str().ok())
+                    .unwrap_or("");
+                if !content_type.contains("text/html") {
+                    return Err(FetchError::InvalidContentType);
+                }
+                resp.text().await.map_err(|e| FetchError::Network(e.to_string()))
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use domain::TabSource;
+    use std::path::PathBuf;
+
+    #[tokio::test]
+    async fn fetch_local_file() {
+        let fetcher = UgTabFetcher::new();
+        let path = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+            .parent().unwrap().parent().unwrap().parent().unwrap()
+            .join("samples/A DROP IN THE OCEAN.html");
+        let html = fetcher.fetch(TabSource::File(path)).await.unwrap();
+        assert!(html.contains("[Chorus]"));
+        assert!(html.contains("data-name=\"Em\""));
+    }
+}