CREATE TYPE cdb_dataservices_client.ds_fdw_metadata as (schemaname text, tabname text, servername text);
CREATE TYPE cdb_dataservices_client.ds_return_metadata as (colnames text[], coltypes text[]);

CREATE OR REPLACE FUNCTION cdb_dataservices_client._DST_PrepareTableOBS_GetMeasure(table_name text, output_table_name text, function_name text, params json)
RETURNS boolean AS $$
DECLARE
  username text;
  user_db_role text;
  orgname text;
  user_schema text;
  result boolean;
BEGIN
  IF session_user = 'publicuser' OR session_user ~ 'cartodb_publicuser_*' THEN
    RAISE EXCEPTION 'The api_key must be provided';
  END IF;

  SELECT session_user INTO user_db_role;

  SELECT u, o INTO username, orgname FROM cdb_dataservices_client._cdb_entity_config() AS (u text, o text);
  -- JSON value stored "" is taken as literal
  IF username IS NULL OR username = '' OR username = '""' THEN
    RAISE EXCEPTION 'Username is a mandatory argument';
  END IF;

  IF orgname IS NULL OR orgname = '' OR orgname = '""' THEN
    user_schema := 'public';
  ELSE
    user_schema := username;
  END IF;

  SELECT cdb_dataservices_client.__DST_PrepareTableOBS_GetMeasure(username, orgname, user_db_role, user_schema, output_table_name, function_name, params) INTO result;

  RETURN result;
END;
$$ LANGUAGE 'plpgsql' SECURITY DEFINER;

CREATE OR REPLACE FUNCTION cdb_dataservices_client._DST_PopulateTableOBS_GetMeasure(table_name text, output_table_name text, function_name text, params json)
RETURNS boolean AS $$
DECLARE
  username text;
  user_db_role text;
  orgname text;
  dbname text;
  user_schema text;
  result boolean;
BEGIN
  IF session_user = 'publicuser' OR session_user ~ 'cartodb_publicuser_*' THEN
    RAISE EXCEPTION 'The api_key must be provided';
  END IF;

  SELECT session_user INTO user_db_role;

  SELECT u, o INTO username, orgname FROM cdb_dataservices_client._cdb_entity_config() AS (u text, o text);
  -- JSON value stored "" is taken as literal
  IF username IS NULL OR username = '' OR username = '""' THEN
    RAISE EXCEPTION 'Username is a mandatory argument';
  END IF;

  IF orgname IS NULL OR orgname = '' OR orgname = '""' THEN
    user_schema := 'public';
  ELSE
    user_schema := username;
  END IF;

  SELECT current_database() INTO dbname;

  SELECT cdb_dataservices_client.__DST_PopulateTableOBS_GetMeasure(username, orgname, user_db_role, user_schema, dbname, table_name, output_table_name, function_name, params) INTO result;

  RETURN result;
END;
$$ LANGUAGE 'plpgsql' SECURITY DEFINER;


CREATE OR REPLACE FUNCTION cdb_dataservices_client.__DST_PrepareTableOBS_GetMeasure(username text, orgname text, user_db_role text, user_schema text, output_table_name text, function_name text, params json)
RETURNS boolean AS $$
    # Obtain return types for augmentation procedure
    ds_return_metadata = plpy.execute("SELECT colnames, coltypes "
        "FROM cdb_dataservices_client._DST_GetReturnMetadata({username}::text, {orgname}::text, {function_name}::text, {params}::json);"
        .format(
            username=plpy.quote_nullable(username),
            orgname=plpy.quote_nullable(orgname),
            function_name=plpy.quote_literal(function_name),
            params=plpy.quote_literal(params)
            )
        )

    colnames_arr = ds_return_metadata[0]["colnames"]
    coltypes_arr = ds_return_metadata[0]["coltypes"]

    # Prepare column and type strings required in the SQL queries
    columns_with_types_arr = [colnames_arr[i] + ' ' + coltypes_arr[i] for i in range(0,len(colnames_arr))]
    columns_with_types = ','.join(columns_with_types_arr)

    # Create a new table with the required columns
    plpy.execute('CREATE TABLE "{schema}".{table_name} ( '
        'cartodb_id int, the_geom geometry, {columns_with_types} '
        ');'
        .format(schema=user_schema, table_name=output_table_name, columns_with_types=columns_with_types)
        )

    plpy.execute('ALTER TABLE "{schema}".{table_name} OWNER TO "{user}";'
        .format(schema=user_schema, table_name=output_table_name, user=user_db_role)
        )

    return True
$$ LANGUAGE plpythonu;


CREATE OR REPLACE FUNCTION cdb_dataservices_client._DST_ConnectUserTable(username text, orgname text, user_db_role text, user_schema text, dbname text, table_name text)
RETURNS cdb_dataservices_client.ds_fdw_metadata AS $$
    CONNECT _server_conn_str();
    TARGET cdb_dataservices_server._DST_ConnectUserTable;
$$ LANGUAGE plproxy;

CREATE OR REPLACE FUNCTION cdb_dataservices_client._DST_GetReturnMetadata(username text, orgname text, function_name text, params json)
RETURNS cdb_dataservices_client.ds_return_metadata AS $$
    CONNECT _server_conn_str();
    TARGET cdb_dataservices_server._DST_GetReturnMetadata;
$$ LANGUAGE plproxy;

CREATE OR REPLACE FUNCTION cdb_dataservices_client._DST_FetchJoinFdwTableData(username text, orgname text, table_schema text, table_name text, function_name text, params json)
RETURNS SETOF record AS $$
    CONNECT _server_conn_str();
    TARGET cdb_dataservices_server._DST_FetchJoinFdwTableData;
$$ LANGUAGE plproxy;

CREATE OR REPLACE FUNCTION cdb_dataservices_client._DST_DisconnectUserTable(username text, orgname text, table_schema text, table_name text, server_name text)
RETURNS boolean AS $$
    CONNECT _server_conn_str();
    TARGET cdb_dataservices_server._DST_DisconnectUserTable;
$$ LANGUAGE plproxy;