feat: updated similarity search function

supabase/migrations/20241008165113_function_issue.sql

@@ -0,0 +1,38 @@
+DROP FUNCTION IF EXISTS find_similar_issues;
+
+CREATE OR REPLACE FUNCTION find_similar_issues(current_id VARCHAR, query_embedding vector(1024), threshold float8, top_k INT)
+RETURNS TABLE(issue_id VARCHAR, issue_plaintext TEXT, similarity float8) AS $$
+DECLARE
+    current_quantized vector(1024);
+    current_repo TEXT;
+    current_org TEXT;
+BEGIN
+    -- Ensure the query_embedding is in the correct format
+    current_quantized := query_embedding;
+
+    -- Extract the current issue's repo and org from the payload
+    SELECT
+        payload->'repository'->>'name'::text,
+        payload->'repository'->'owner'->>'login'::text
+    INTO current_repo, current_org
+    FROM issues
+    WHERE id = current_id;
+
+    -- Check if the current issue has valid repo and org
+    IF current_repo IS NULL OR current_org IS NULL THEN
+        RETURN;  -- Exit if current issue's repo or org is null
+    END IF;
+
+    RETURN QUERY
+    SELECT id AS issue_id,
+           plaintext AS issue_plaintext,
+           (l2_distance(current_quantized, embedding)) AS similarity
+    FROM issues
+    WHERE id <> current_id
+        AND current_repo = payload->'repository'->>'name'::text
+        AND current_org =  payload->'repository'->'owner'->>'login'::text
+        AND l2_distance(current_quantized, embedding) > threshold  -- Ensure similarity exceeds threshold
+    ORDER BY similarity DESC
+    LIMIT top_k;
+END;
+$$ LANGUAGE plpgsql;