refactoring: continuing to break stuff out

src/retrieval/graph.rs

@@ -0,0 +1,65 @@
+use surrealdb::{engine::remote::ws::Client, Surreal};
+
+use crate::error::ProcessingError;
+
+/// Retrieves database entries that match a specific source identifier.
+///
+/// This function queries the database for all records in a specified table that have
+/// a matching `source_id` field. It's commonly used to find related entities or
+/// track the origin of database entries.
+///
+/// # Arguments
+///
+/// * `source_id` - The identifier to search for in the database
+/// * `table_name` - The name of the table to search in
+/// * `db_client` - The SurrealDB client instance for database operations
+///
+/// # Type Parameters
+///
+/// * `T` - The type to deserialize the query results into. Must implement `serde::Deserialize`
+///
+/// # Returns
+///
+/// Returns a `Result` containing either:
+/// * `Ok(Vec<T>)` - A vector of matching records deserialized into type `T`
+/// * `Err(ProcessingError)` - An error if the database query fails
+///
+/// # Errors
+///
+/// This function will return a `ProcessingError` if:
+/// * The database query fails to execute
+/// * The results cannot be deserialized into type `T`
+///
+/// # Example
+///
+/// ```rust
+/// #[derive(serde::Deserialize)]
+/// struct KnowledgeEntity {
+///     id: String,
+///     source_id: String,
+///     // ... other fields
+/// }
+///
+/// let results = find_entities_by_source_id::<KnowledgeEntity>(
+///     "source123".to_string(),
+///     "knowledge_entity".to_string(),
+///     &db_client
+/// ).await?;
+/// ```
+pub async fn find_entities_by_source_id<T>(
+    source_id: String,
+    table_name: String,
+    db_client: &Surreal<Client>,
+) -> Result<Vec<T>, ProcessingError>
+where
+    T: for<'de> serde::Deserialize<'de>,
+{
+    let query = format!(
+        "SELECT * FROM {} WHERE source_id = '{}'",
+        table_name, source_id
+    );
+
+    let matching_entities: Vec<T> = db_client.query(query).await?.take(0)?;
+
+    Ok(matching_entities)
+}