-module(ts_timeline).
-export([create_table/1, new/1, update/1, list/3]).

-include("ts_db_records.hrl").
-include_lib("stdlib/include/qlc.hrl").

create_table(TableOpts) ->
    mnesia:create_table(ts_timeline,
        TableOpts ++ [{attributes, record_info(fields, ts_timeline)},
                      {type, ordered_set}]).

new(TR = #ts_timeline{}) ->
    case mnesia:dirty_read(ts_timeline, TR#ts_timeline.ref) of
        [ExistingRecord] -> {error, {record_exists, ExistingRecord}};
        [] -> mnesia:dirty_write(TR)
    end.

update(TR = #ts_timeline{}) ->
    
    % look for the existing record
    case mnesia:dirty_read(ts_timeline, TR#ts_timeline.ref) of
        % record does not exist
        [] -> no_record;
        % record exists, update
        [Record] -> mnesia:dirty_write(TR)
    end.

list(Username, Start, Length) -> 
    ts_common:list(
        qlc:q([T || T <- mnesia:table(ts_timeline),
                    T#ts_timeline.ref = {Username, _}]),
        Start, Length).