-module(rebar_prv_lock).

-behaviour(provider).

-export([init/1,
         do/1,
         format_error/1]).

-include("rebar.hrl").

-define(PROVIDER, lock).
-define(DEPS, [install_deps]).

%% ===================================================================
%% Public API
%% ===================================================================

-spec init(rebar_state:t()) -> {ok, rebar_state:t()}.
init(State) ->
    State1 = rebar_state:add_provider(State, providers:create([{name, ?PROVIDER},
                                                               {module, ?MODULE},
                                                               {bare, true},
                                                               {deps, ?DEPS},
                                                               {example, ""},
                                                               {short_desc, "Locks dependencies."},
                                                               {desc, info("Locks dependencies")},
                                                               {opts, []}])),
    {ok, State1}.

-spec do(rebar_state:t()) -> {ok, rebar_state:t()} | {error, string()}.
do(State) ->
    case rebar_state:get(State, locks, []) of
        [] ->
            AllDeps = rebar_state:get(State, {all_deps, default}, []),
            Locks = lists:map(fun(Dep) ->
                                      Dir = rebar_app_info:dir(Dep),
                                      Source = rebar_app_info:source(Dep),

                                      %% If source is tuple it is a source dep
                                      %% e.g. {git, "git://github.com/ninenines/cowboy.git", "master"}
                                      case Source of
                                          Source when is_tuple(Source) ->
                                              {rebar_app_info:name(Dep)
                                              ,rebar_app_info:original_vsn(Dep)
                                              ,rebar_fetch:lock_source(Dir, Source)
                                              ,rebar_app_info:dep_level(Dep)};
                                          _Source ->
                                              {rebar_app_info:name(Dep)
                                              ,rebar_app_info:original_vsn(Dep)}
                                      end
                              end, AllDeps),
            Dir = rebar_state:dir(State),
            file:write_file(filename:join(Dir, "rebar.lock"), io_lib:format("~p.~n", [Locks])),
            {ok, rebar_state:set(State, locks, Locks)};
        _Locks ->
            {ok, State}
    end.

-spec format_error(any()) -> iolist().
format_error(Reason) ->
    io_lib:format("~p", [Reason]).

info(_) ->
    "".