-module(dotenv_config_parser).
-include("dotenv_config.hrl").
-callback get_parser() -> parser().
-ifdef(EUNIT).
-compile(export_all).
-endif.
-export([parse_file/1, parse_config/2]).
-export_type([parser/0, parsed_config/0, parsed_config_raw/0]).
-spec parse_file(file:name_all()) -> {ok, parsed_config_raw()} | {error, any()}.
parse_file(FileName) ->
case file:read_file(FileName) of
{ok, FileContent} ->
parse_file_content(FileContent);
{error, Reason} ->
{error, Reason}
end.
-spec parse_file_content(binary()) -> {ok, parsed_config_raw()} | {error, any()}.
parse_file_content(FileContent) ->
Lines = binary:split(FileContent, <<"\n">>, [global, trim_all]),
{_, ParsedConfigFileRaw} = lists:foldl(
fun
(Line, {{multi_line, {ConfigItemName, ParsedHead}}, ParsedLines}) ->
case parse_multi_line(Line, ParsedHead) of
{ok, end_multi_line} ->
{single_line, maps:put(ConfigItemName, ParsedHead, ParsedLines)};
{ok, ParsedHead1} ->
{{multi_line, {ConfigItemName, ParsedHead1}}, ParsedLines}
end;
(Line, {single_line, ParsedLines}) ->
case parse_single_line(Line) of
{ok, {ConfigItemName, multi_line_start}} ->
{{multi_line, {ConfigItemName, <<>>}}, ParsedLines};
{ok, {ConfigItemName, ConfigItemRawValue}} ->
{single_line, maps:put(ConfigItemName, ConfigItemRawValue, ParsedLines)};
error ->
exit(<<"Can't parse this line from doteenv config: ", Line/binary>>)
end
end,
{single_line, #{}},
Lines
),
{ok, ParsedConfigFileRaw}.
-spec parse_multi_line(binary(), config_item_raw_value()) ->
{ok, config_item_raw_value()} | {ok, end_multi_line}.
parse_multi_line(Line, ParsedHead) ->
case {ParsedHead, string:trim(Line)} of
{_, <<"\"\"\"">>} ->
{ok, end_multi_line};
{<<>>, _} ->
{ok, <<Line/binary>>};
{ParsedHead, _} ->
{ok, <<ParsedHead/binary, "\n", Line/binary>>}
end.
-spec parse_single_line(binary()) ->
{ok, {config_item_name(), config_item_raw_value()}}
| {ok, {config_item_name(), multi_line_start}}
| error.
parse_single_line(Line) ->
case binary:split(Line, <<"=">>, [trim_all]) of
[Key, <<"\"\"\"">>] ->
{ok, {string:trim(Key), multi_line_start}};
[Key, Value] ->
{ok, {string:trim(Key), string:trim(Value)}};
_ ->
error
end.
-spec parse_config(parsed_config_raw(), module()) -> {ok, parsed_config()}.
parse_config(Config, Module) ->
ConfigItemsParsers = Module:get_parser(),
ParsedConfig = lists:foldl(
fun({ConfigItemName, Parser}, ParsedConfigAcc) ->
DefaultValue = get_default_value(Config, ConfigItemName),
case get_environment_variable(ConfigItemName, DefaultValue) of
not_found ->
exit(<<"Can't find config item: ", ConfigItemName/binary>>);
already_stored ->
ParsedConfigAcc;
ConfigItemRawValue ->
ConfigItemRawValue1 = maybe_trim_quotes(ConfigItemRawValue),
case parse_config_item(ConfigItemRawValue1, Config, Parser) of
{ok, ConfigItemValue} ->
[{ConfigItemName, ConfigItemValue} | ParsedConfigAcc];
error ->
BinParser = dotenv_config_error:to_binary(Parser),
exit(
<<"Can't parse config item: ", ConfigItemName/binary, " of value: ",
ConfigItemRawValue1/binary, " to type: ", BinParser/binary>>
)
end
end
end,
[],
ConfigItemsParsers
),
{ok, ParsedConfig}.
-spec maybe_trim_quotes(config_item_raw_value()) -> config_item_raw_value().
maybe_trim_quotes(ConfigItemRawValue) ->
LastByte = byte_size(ConfigItemRawValue) - 1,
case {binary:at(ConfigItemRawValue, 0), binary:at(ConfigItemRawValue, LastByte)} of
% double quotes
{34, 34} ->
string:trim(ConfigItemRawValue, both, "\"");
% single quotes
{39, 39} ->
string:trim(ConfigItemRawValue, both, "\'");
_ ->
ConfigItemRawValue
end.
-spec get_default_value(parsed_config_raw(), config_item_name()) ->
config_item_raw_value() | not_found | already_stored.
get_default_value(Config, ConfigItemName) ->
MaybeValueFromConfig = maps:get(ConfigItemName, Config, not_found),
IsAlreadyStored = is_value_already_stored(ConfigItemName),
case {MaybeValueFromConfig, IsAlreadyStored} of
{not_found, false} ->
not_found;
{not_found, true} ->
already_stored;
{ValueFromConfig, _} ->
ValueFromConfig
end.
-spec get_environment_variable(
config_item_name(), config_item_raw_value() | not_found | already_stored
) -> config_item_raw_value() | not_found | already_stored.
get_environment_variable(ConfigItemName, Default) ->
case os:getenv(binary_to_list(ConfigItemName)) of
false ->
Default;
EnvironmentValue ->
list_to_binary(EnvironmentValue)
end.
-spec is_value_already_stored(config_item_name()) -> boolean().
is_value_already_stored(ConfigItemName) ->
case dotenv_config_storage:get(ConfigItemName) of
{error, not_found} ->
false;
{ok, _StoredValue} ->
true
end.
-spec parse_config_item(config_item_raw_value(), parsed_config_raw(), config_item_type()) ->
{ok, config_item_value()} | error.
parse_config_item(ConfigItemRawValue, _ConfigRaw, str) ->
{ok, ConfigItemRawValue};
parse_config_item(ConfigItemRawValue, _ConfigRaw, int) ->
case string:to_integer(ConfigItemRawValue) of
{Value, _Rest} when is_integer(Value) ->
{ok, Value};
_ ->
error
end;
parse_config_item(ConfigItemRawValue, _ConfigRaw, bool) ->
try binary_to_existing_atom(ConfigItemRawValue) of
true -> {ok, true};
false -> {ok, false}
catch
_:_ ->
error
end;
parse_config_item(ConfigItemRawValue, _ConfigRaw, json) ->
try jiffy:decode(ConfigItemRawValue, [return_maps]) of
JsonValue ->
{ok, JsonValue}
catch
_:_ ->
error
end;
parse_config_item(ConfigItemRawValue, _ConfigRaw, atom) ->
try binary_to_atom(ConfigItemRawValue) of
AtomValue ->
{ok, AtomValue}
catch
_:_ ->
error
end;
parse_config_item(ConfigItemRawValue, _ConfigRaw, module) ->
try binary_to_existing_atom(ConfigItemRawValue) of
ModuleValue ->
case code:ensure_loaded(ModuleValue) of
{module, ModuleValue} ->
{ok, ModuleValue};
_ ->
error
end
catch
_:_ ->
error
end;
parse_config_item(ConfigItemRawValue, _ConfigRaw, charlist) ->
{ok, binary_to_list(ConfigItemRawValue)};
parse_config_item(ConfigItemRawValue, ConfigRaw, [Type | Rest]) ->
case Type of
{exact, ExactValue} when ExactValue =:= ConfigItemRawValue ->
{ok, ExactValue};
SingleType when is_atom(SingleType) ->
parse_config_item(ConfigItemRawValue, ConfigRaw, SingleType);
{exact, _} ->
parse_config_item(ConfigItemRawValue, ConfigRaw, Rest)
end;
parse_config_item(ConfigItemRawValue, ConfigRaw, ConvertFunction) when
is_function(ConvertFunction)
->
FunctionToRun =
case proplists:get_value(arity, erlang:fun_info(ConvertFunction)) of
1 ->
fun() -> ConvertFunction(ConfigItemRawValue) end;
2 ->
fun() -> ConvertFunction(ConfigItemRawValue, ConfigRaw) end
end,
try FunctionToRun() of
ConfigItemValue ->
{ok, ConfigItemValue}
catch
_:_ ->
error
end;
parse_config_item(_, _, _) ->
error.