feat: default project id (#191)

* feat: default project id

* fix: clippy

* fix: use match

src/db/mod.rs

@@ -114,6 +114,18 @@ impl FirestoreDb {
         .await
     }
 
+    pub async fn for_default_project_id() -> FirestoreResult<Self> {
+        match FirestoreDbOptions::for_default_project_id().await {
+            Some(options) => Self::with_options(options).await,
+            _ => Err(FirestoreError::InvalidParametersError(
+                FirestoreInvalidParametersError::new(FirestoreInvalidParametersPublicDetails::new(
+                    "google_project_id".to_string(),
+                    "Unable to retrieve google_project_id".to_string(),
+                )),
+            )),
+        }
+    }
+
     pub async fn with_options_service_account_key_file(
         options: FirestoreDbOptions,
         service_account_key_path: std::path::PathBuf,

src/db/options.rs

@@ -1,3 +1,4 @@
+use gcloud_sdk::GoogleEnvironment;
 use rsb_derive::Builder;
 
 #[derive(Debug, Eq, PartialEq, Clone, Builder)]
@@ -13,4 +14,12 @@ pub struct FirestoreDbOptions {
     pub firebase_api_url: Option<String>,
 }
 
+impl FirestoreDbOptions {
+    pub async fn for_default_project_id() -> Option<FirestoreDbOptions> {
+        let google_project_id = GoogleEnvironment::detect_google_project_id().await;
+
+        google_project_id.map(FirestoreDbOptions::new)
+    }
+}
+
 pub const FIREBASE_DEFAULT_DATABASE_ID: &str = "(default)";