%% -*- tab-width: 4;erlang-indent-level: 4;indent-tabs-mode: nil -*-
%% ex: ts=4 sw=4 et
%% -------------------------------------------------------------------
%%
%% rebar: Erlang Build Tools
%%
%% Copyright (c) 2009 Dave Smith (dizzyd@dizzyd.com)
%%
%% Permission is hereby granted, free of charge, to any person obtaining a copy
%% of this software and associated documentation files (the "Software"), to deal
%% in the Software without restriction, including without limitation the rights
%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
%% copies of the Software, and to permit persons to whom the Software is
%% furnished to do so, subject to the following conditions:
%%
%% The above copyright notice and this permission notice shall be included in
%% all copies or substantial portions of the Software.
%%
%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
%% THE SOFTWARE.
%% -------------------------------------------------------------------
-module(rebar_deps).

-include("rebar.hrl").

-export([preprocess/2,
         compile/2,
         'check-deps'/2,
         'get-deps'/2,
         'delete-deps'/2]).

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

preprocess(Config, _) ->
    DepsDir = get_deps_dir(Config),
    Config2 = rebar_config:set(Config, deps_dir, DepsDir),

    %% Check for available deps, using the list of deps specified in our config.
    %% We use the directory from the list of tuples for deps with source information to
    %% update our list of directories to process.
    case catch(check_deps(rebar_config:get_local(Config, deps, []), [], DepsDir)) of
        Deps when is_list(Deps) ->
            %% Walk all the deps and make sure they are available on the code path,
            %% if the application we're interested in actually exists there.
            ok = update_deps_code_path(Deps),
            {ok, Config2, [Dir || {Dir, _, _, _} <- Deps]};
        {'EXIT', Reason} ->
            ?ABORT("Error while processing dependencies: ~p\n", [Reason])
    end.

compile(Config, AppFile) ->
    'check-deps'(Config, AppFile).

'check-deps'(Config, _) ->
    %% Get a list of deps that need to be downloaded and display them only
    DepsDir = get_deps_dir(Config),
    case catch(check_deps(rebar_config:get_local(Config, deps, []), [], DepsDir)) of
        [] ->
            ok;
        Deps when is_list(Deps) ->
            [?CONSOLE("Dependency not available: ~p-~p (~p)\n", [App, VsnRegex, Source]) ||
                {_Dir, App, VsnRegex, Source} <- Deps],
            ?FAIL;
        {'EXIT', Reason} ->
            ?ABORT("Error while processing dependencies: ~p\n", [Reason])
    end.

'get-deps'(Config, _) ->
    DepsDir = get_deps_dir(Config),

    %% Get a list of deps that need to be downloaded
    case catch(check_deps(rebar_config:get_local(Config, deps, []), [], DepsDir)) of
        Deps when is_list(Deps) ->
            %% Now for each dependency tuple, pull it
            [use_source(Dir, App, VsnRegex, Source) || {Dir, App, VsnRegex, Source} <- Deps],
            ok;
        {'EXIT', Reason} ->
            ?ABORT("Error while processing dependencies: ~p\n", [Reason])
    end.

'delete-deps'(Config, _) ->
    %% Delete all the deps which we downloaded (or would have caused to be
    %% downloaded).
    DepsDir = rebar_config:get(Config, deps_dir, rebar_utils:get_cwd()),
    ?DEBUG("Delete deps: ~p\n", [rebar_config:get(Config, deps, [])]),
    delete_deps(rebar_config:get_local(Config, deps, []), DepsDir).

%% ===================================================================
%% Internal functions
%% ===================================================================

get_deps_dir(Config) ->
    %% Get the directory where we will place downloaded deps. Take steps
    %% to ensure that if we're doing a multi-level build, all the deps will
    %% wind up in a single directory; avoiding potential pain from having
    %% multiple copies of the same dep scattered throughout the source tree.
    %%
    %% The first definition of deps_dir is the one we use; we also fully
    %% qualify it to ensure everyone sees it properly.
    case rebar_config:get_all(Config, deps_dir) of
        [] ->
            DepsDir = filename:absname("deps");
        AllDirs ->
            DepsDir = filename:absname(hd(lists:reverse(AllDirs)))
    end,
    ?DEBUG("~s: Using deps dir: ~s\n", [rebar_utils:get_cwd(), DepsDir]),
    DepsDir.

update_deps_code_path([]) ->
    ok;
update_deps_code_path([{AppDir, App, VsnRegex, _Source} | Rest]) ->
    case is_app_available(App, VsnRegex, AppDir) of
        true ->
            code:add_patha(filename:join(AppDir, ebin));
        false ->
            ok
    end,
    update_deps_code_path(Rest).

check_deps([], Acc, _Dir) ->
    Acc;
check_deps([App | Rest], Acc, Dir) when is_atom(App) ->
    require_app(App, ".*"),
    check_deps(Rest, Acc, Dir);
check_deps([{App, VsnRegex} | Rest], Acc, Dir) when is_atom(App) ->
    require_app(App, VsnRegex),
    check_deps(Rest, Acc, Dir);
check_deps([{App, VsnRegex, Source} | Rest], Acc, Dir) ->
    case is_app_available(App, VsnRegex) of
        true ->
            check_deps(Rest, Acc, Dir);
        false ->
            %% App is not on our code path OR the version that is available
            %% doesn't match our regex. Return a tuple containing the target dir
            %% and source information.
            AppDir = filename:join(Dir, App),
            check_deps(Rest, [{AppDir, App, VsnRegex, Source} | Acc], Dir)
    end;
check_deps([Other | _Rest], _Acc, _Dir) ->
    ?ABORT("Invalid dependency specification ~p in ~s\n",
           [Other, rebar_utils:get_cwd()]).


delete_deps([], _DepsDir) ->
    ok;
delete_deps([{App, _VsnRegex, _Source} | Rest], DepsDir) ->
    AppDir = filename:join(DepsDir, App),
    case filelib:is_dir(AppDir) of
        true ->
            ?INFO("Delete dependency dir ~s\n", [AppDir]),
            rebar_file_utils:rm_rf(AppDir);
        false ->
            ok
    end,
    delete_deps(Rest, DepsDir);
delete_deps([_Other | Rest], DepsDir) ->
    delete_deps(Rest, DepsDir).



require_app(App, VsnRegex) ->
    case is_app_available(App, VsnRegex) of
        true ->
            ok;
        false ->
            %% The requested app is not available on the code path
            ?ABORT("~s: Dependency ~s-~s not available.\n",
                   [rebar_utils:get_cwd(), App, VsnRegex])
    end.

require_source_engine(Source) ->
    case source_engine_avail(Source) of
        true ->
            ok;
        false ->
            ?ABORT("No command line interface available to process ~p\n", [Source])
    end.


is_app_available(App, VsnRegex) ->
    case code:lib_dir(App) of
        {error, bad_name} ->
            false;
        Path ->
            is_app_available(App, VsnRegex, Path)
    end.

is_app_available(App, VsnRegex, Path) ->
    case rebar_app_utils:is_app_dir(Path) of
        {true, AppFile} ->
            case rebar_app_utils:load_app_file(AppFile) of
                {ok, App, AppData} ->
                    {vsn, Vsn} = lists:keyfind(vsn, 1, AppData),
                    ?INFO("Looking for ~s-~s ; found ~s-~s at ~s\n",
                          [App, VsnRegex, App, Vsn, Path]),
                    case re:run(Vsn, VsnRegex, [{capture, none}]) of
                        match ->
                            true;
                        nomatch ->
                            ?WARN("~s has version ~p; requested regex was ~s\n",
                                  [AppFile, Vsn, VsnRegex]),
                            false
                    end;
                {ok, OtherApp, _} ->
                    ?WARN("~s has application id ~p; expected ~p\n", [AppFile, OtherApp, App]),
                    false;
                {error, Reason} ->
                    ?ABORT("Failed to parse ~s: ~p\n", [AppFile, Reason])
            end;
        false ->
            ?WARN("Expected ~s to be an app dir (containing ebin/*.app), but no .app found.\n",
                  [Path]),
            false
    end.

use_source(AppDir, App, VsnRegex, Source) ->
    ?CONSOLE("Pulling ~p from ~p\n", [App, Source]),
    use_source(AppDir, App, VsnRegex, Source, 3).

use_source(_AppDir, _App, _VsnRegex, Source, 0) ->
    ?ABORT("Failed to acquire source from ~p after 3 tries.\n", [Source]);
use_source(AppDir, App, VsnRegex, Source, Count) ->
    case filelib:is_dir(AppDir) of
        true ->
            %% Already downloaded -- verify the versioning matches up with our regex
            case is_app_available(App, VsnRegex, AppDir) of
                true ->
                    %% Available version matches up -- we're good to go; add the
                    %% app dir to our code path
                    code:add_patha(filename:join(AppDir, ebin)),
                    ok;
                false ->
                    %% The app that was downloaded doesn't match up (or had
                    %% errors or something). For the time being, abort.
                    ?ABORT("Dependency dir ~s does not satisfy version regex ~s.\n",
                           [AppDir, VsnRegex])
            end;
        false ->
            require_source_engine(Source),
            download_source(AppDir, Source),
            use_source(AppDir, App, VsnRegex, Source, Count-1)
    end.

download_source(AppDir, {hg, Url, Rev}) ->
    ok = filelib:ensure_dir(AppDir),
    Cmd = ?FMT("hg clone -u ~s ~s", [Rev, Url]),
    rebar_utils:sh(Cmd, [], filename:dirname(AppDir));
download_source(AppDir, {git, Url, Rev}) ->
    ok = filelib:ensure_dir(AppDir),
    rebar_utils:sh(?FMT("git clone -n ~s", [Url]), [], filename:dirname(AppDir)),
    rebar_utils:sh(?FMT("git checkout ~s", [Rev]), [], AppDir);
download_source(AppDir, {bzr, Url, Rev}) ->
    ok = filelib:ensure_dir(AppDir),
    rebar_utils:sh(?FMT("bzr branch -r ~s ~s ~s",
                        [Rev, Url, filename:basename(AppDir)]), [],
                   filename:dirname(AppDir));
download_source(AppDir, {svn, Url, Rev}) ->
    ok = filelib:ensure_dir(AppDir),
    rebar_utils:sh(?FMT("svn checkout -r ~s ~s ~s",
                        [Rev, Url, filename:basename(AppDir)]), [],
                   filename:dirname(AppDir)).


%% ===================================================================
%% Source helper functions
%% ===================================================================

source_engine_avail({Name, _, _})
  when Name == hg; Name == git; Name == svn; Name == bzr ->
    case scm_client_vsn(Name) >= required_scm_client_vsn(Name) of
        true ->
            true;
        false ->
            ?ABORT("Rebar requires version ~p or higher of ~s\n",
                   [required_scm_client_vsn(Name), Name])
    end.

scm_client_vsn(false, _VsnArg, _VsnRegex) ->
    false;
scm_client_vsn(Path, VsnArg, VsnRegex) ->
    Info = os:cmd(Path ++ VsnArg),
    case re:run(Info, VsnRegex, [{capture, all_but_first, list}]) of
        {match, Match} ->
            list_to_tuple([list_to_integer(S) || S <- Match]);
        _ ->
            false
    end.

required_scm_client_vsn(hg)  -> {1, 4};
required_scm_client_vsn(git) -> {1, 6};
required_scm_client_vsn(bzr) -> {2, 0};
required_scm_client_vsn(svn) -> {1, 6}.

scm_client_vsn(hg) ->
    scm_client_vsn(os:find_executable(hg), " --version", "version (\\d+).(\\d+)");
scm_client_vsn(git) ->
    scm_client_vsn(os:find_executable(git), " --version", "git version (\\d+).(\\d+)");
scm_client_vsn(bzr) ->
    scm_client_vsn(os:find_executable(bzr), " --version", "Bazaar \\(bzr\\) (\\d+).(\\d+)");
scm_client_vsn(svn) ->
    scm_client_vsn(os:find_executable(svn), " --version", "svn, version (\\d+).(\\d+)");
scm_client_vsn(_) ->
    undefined.