BEGIN;
  -- Create pg_net extension
  CREATE EXTENSION IF NOT EXISTS pg_net SCHEMA extensions;
  
  -- Create supabase_functions schema
  CREATE SCHEMA IF NOT EXISTS supabase_functions AUTHORIZATION postgres;
  
  -- Grant basic permissions
  GRANT USAGE ON SCHEMA supabase_functions TO postgres, anon, authenticated, service_role;
  ALTER DEFAULT PRIVILEGES IN SCHEMA supabase_functions GRANT ALL ON TABLES TO postgres, anon, authenticated, service_role;
  ALTER DEFAULT PRIVILEGES IN SCHEMA supabase_functions GRANT ALL ON FUNCTIONS TO postgres, anon, authenticated, service_role;
  ALTER DEFAULT PRIVILEGES IN SCHEMA supabase_functions GRANT ALL ON SEQUENCES TO postgres, anon, authenticated, service_role;
  
  -- supabase_functions.migrations definition
  CREATE TABLE IF NOT EXISTS supabase_functions.migrations (
    version text PRIMARY KEY,
    inserted_at timestamptz NOT NULL DEFAULT NOW()
  );
  
  -- Initial supabase_functions migration
  INSERT INTO supabase_functions.migrations (version) VALUES ('initial') ON CONFLICT DO NOTHING;
  
  -- supabase_functions.hooks definition
  CREATE TABLE IF NOT EXISTS supabase_functions.hooks (
    id bigserial PRIMARY KEY,
    hook_table_id integer NOT NULL,
    hook_name text NOT NULL,
    created_at timestamptz NOT NULL DEFAULT NOW(),
    request_id bigint
  );
  
  -- Create indexes if they don't exist
  CREATE INDEX IF NOT EXISTS supabase_functions_hooks_request_id_idx ON supabase_functions.hooks USING btree (request_id);
  CREATE INDEX IF NOT EXISTS supabase_functions_hooks_h_table_id_h_name_idx ON supabase_functions.hooks USING btree (hook_table_id, hook_name);
  
  COMMENT ON TABLE supabase_functions.hooks IS 'Supabase Functions Hooks: Audit trail for triggered hooks.';
  
  -- Create the http_request function
  CREATE OR REPLACE FUNCTION supabase_functions.http_request()
    RETURNS trigger
    LANGUAGE plpgsql
    AS $function$
    DECLARE
      request_id bigint;
      payload jsonb;
      url text := TG_ARGV[0]::text;
      method text := TG_ARGV[1]::text;
      headers jsonb DEFAULT '{}'::jsonb;
      params jsonb DEFAULT '{}'::jsonb;
      timeout_ms integer DEFAULT 1000;
    BEGIN
      IF url IS NULL OR url = 'null' THEN
        RAISE EXCEPTION 'url argument is missing';
      END IF;

      IF method IS NULL OR method = 'null' THEN
        RAISE EXCEPTION 'method argument is missing';
      END IF;

      IF TG_ARGV[2] IS NULL OR TG_ARGV[2] = 'null' THEN
        headers = '{"Content-Type": "application/json"}'::jsonb;
      ELSE
        headers = TG_ARGV[2]::jsonb;
      END IF;

      IF TG_ARGV[3] IS NULL OR TG_ARGV[3] = 'null' THEN
        params = '{}'::jsonb;
      ELSE
        params = TG_ARGV[3]::jsonb;
      END IF;

      IF TG_ARGV[4] IS NULL OR TG_ARGV[4] = 'null' THEN
        timeout_ms = 1000;
      ELSE
        timeout_ms = TG_ARGV[4]::integer;
      END IF;

      CASE
        WHEN method = 'GET' THEN
          SELECT http_get INTO request_id FROM net.http_get(
            url,
            params,
            headers,
            timeout_ms
          );
        WHEN method = 'POST' THEN
          payload = jsonb_build_object(
            'old_record', OLD,
            'record', NEW,
            'type', TG_OP,
            'table', TG_TABLE_NAME,
            'schema', TG_TABLE_SCHEMA
          );

          SELECT http_post INTO request_id FROM net.http_post(
            url,
            payload,
            params,
            headers,
            timeout_ms
          );
        ELSE
          RAISE EXCEPTION 'method argument % is invalid', method;
      END CASE;

      INSERT INTO supabase_functions.hooks
        (hook_table_id, hook_name, request_id)
      VALUES
        (TG_RELID, TG_NAME, request_id);

      RETURN NEW;
    END
  $function$;
  
  -- Set function properties
  ALTER FUNCTION supabase_functions.http_request() SECURITY DEFINER;
  ALTER FUNCTION supabase_functions.http_request() SET search_path = supabase_functions;
  
  -- Grant execute permissions
  REVOKE ALL ON FUNCTION supabase_functions.http_request() FROM PUBLIC;
  GRANT EXECUTE ON FUNCTION supabase_functions.http_request() TO postgres, anon, authenticated, service_role;
  
  -- Grant pg_net permissions
  GRANT USAGE ON SCHEMA net TO postgres, anon, authenticated, service_role;
  GRANT EXECUTE ON FUNCTION net.http_get(url text, params jsonb, headers jsonb, timeout_milliseconds integer) TO postgres, anon, authenticated, service_role;
  GRANT EXECUTE ON FUNCTION net.http_post(url text, body jsonb, params jsonb, headers jsonb, timeout_milliseconds integer) TO postgres, anon, authenticated, service_role;
  
  -- Add migration record
  INSERT INTO supabase_functions.migrations (version) VALUES ('20210809183423_update_grants') ON CONFLICT DO NOTHING;
  
COMMIT;