%%%-------------------------------------------------------------------
%%% @author anlicheng
%%% @copyright (C) 2025, <COMPANY>
%%% @doc
%%%
%%% @end
%%% Created : 07. 5月 2025 15:47
%%%-------------------------------------------------------------------
-module(efka_inetd_task).
-author("anlicheng").
-include("efka_tables.hrl").

-behaviour(gen_server).

%% API
-export([start_link/3]).
-export([deploy/1]).
-export([maybe_create_env_file/2]).
-export([test/0]).

%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).

-define(SERVER, ?MODULE).

-record(state, {
    root_dir :: string(),
    task_id :: integer(),
    config = #{}
}).

test() ->
    M = #{
        <<"image">> => <<"docker.1ms.run/library/nginx:latest">>,
        <<"container_name">> => <<"my_nginx">>,
        <<"command">> => [<<"nginx">>,<<"-g">>,<<"daemon off;">>],
        <<"entrypoint">> => [<<"/docker-entrypoint.sh">>],
        <<"envs">> => [<<"ENV1=val1">>, <<"ENV2=val2">>],
        <<"env_file">> => [<<"./env.list">>],
        <<"ports">> => [<<"8080:80">>, <<"443:443">>],
        <<"expose">> => [<<"80">>, <<"443">>],
        <<"volumes">> => [<<"/host/data:/data">>, <<"/host/log:/var/log">>],
        <<"networks">> => [<<"mynet">>],
        <<"labels">> => #{ <<"role">> => <<"web">>, <<"env">> => <<"prod">> },
        <<"restart">> => <<"always">>,
        <<"user">> => <<"www-data">>,
        <<"working_dir">> => <<"/app">>,
        <<"hostname">> => <<"myhost">>,
        <<"privileged">> => true,
        <<"cap_add">> => [<<"NET_ADMIN">>],
        <<"cap_drop">> => [<<"MKNOD">>],
        <<"devices">> => [<<"/dev/snd:/dev/snd">>],
        <<"mem_limit">> => <<"512m">>,
        <<"mem_reservation">> => <<"256m">>,
        <<"cpu_shares">> => 512,
        <<"cpus">> => 1.5,
        <<"ulimits">> => #{ <<"nofile">> => <<"1024:2048">> },
        <<"sysctls">> => #{ <<"net.ipv4.ip_forward">> => <<"1">> },
        <<"tmpfs">> => [<<"/tmp">>],
        <<"extra_hosts">> => [<<"host1:192.168.0.1">>],
        <<"healthcheck">> => #{
            %<<"test">> => [<<"CMD-SHELL">>, <<"curl -f http://localhost || exit 1">>],
            <<"test">> => [<<"CMD">>, <<"ls">>, <<"-l">>],
            <<"interval">> => <<"30s">>,
            <<"timeout">> => <<"10s">>,
            <<"retries">> => 3
        }
    },

    TaskId = 1,
    RootDir = "/tmp/",

    Res = do_deploy(TaskId, RootDir, M),
    lager:debug("res is: ~p", [Res]).

%%%===================================================================
%%% API
%%%===================================================================

-spec deploy(Pid :: pid()) -> no_return().
deploy(Pid) when is_pid(Pid) ->
    gen_server:cast(Pid, deploy).

%% @doc Spawns the server and registers the local name (unique)
-spec(start_link(TaskId :: integer(), RootDir :: string(), Config :: map()) ->
    {ok, Pid :: pid()} | ignore | {error, Reason :: term()}).
start_link(TaskId, RootDir, Config) when is_integer(TaskId), is_list(RootDir), is_map(Config) ->
    gen_server:start_link(?MODULE, [TaskId, RootDir, Config], []).

%%%===================================================================
%%% gen_server callbacks
%%%===================================================================

%% @private
%% @doc Initializes the server
-spec(init(Args :: term()) ->
    {ok, State :: #state{}} | {ok, State :: #state{}, timeout() | hibernate} |
    {stop, Reason :: term()} | ignore).
init([TaskId, RootDir, Config]) ->
    {ok, #state{task_id = TaskId, root_dir = RootDir, config = Config}}.

%% @private
%% @doc Handling call messages
-spec(handle_call(Request :: term(), From :: {pid(), Tag :: term()},
    State :: #state{}) ->
    {reply, Reply :: term(), NewState :: #state{}} |
    {reply, Reply :: term(), NewState :: #state{}, timeout() | hibernate} |
    {noreply, NewState :: #state{}} |
    {noreply, NewState :: #state{}, timeout() | hibernate} |
    {stop, Reason :: term(), Reply :: term(), NewState :: #state{}} |
    {stop, Reason :: term(), NewState :: #state{}}).
handle_call(_Request, _From, State = #state{}) ->
    {reply, ok, State}.

%% @private
%% @doc Handling cast messages
-spec(handle_cast(Request :: term(), State :: #state{}) ->
    {noreply, NewState :: #state{}} |
    {noreply, NewState :: #state{}, timeout() | hibernate} |
    {stop, Reason :: term(), NewState :: #state{}}).
handle_cast(deploy, State = #state{task_id = TaskId, root_dir = RootDir, config = Config}) ->
    do_deploy(TaskId, RootDir, Config),
    {stop, normal, State};
handle_cast(_Request, State) ->
    {stop, normal, State}.

%% @private
%% @doc Handling all non call/cast messages
-spec(handle_info(Info :: timeout() | term(), State :: #state{}) ->
    {noreply, NewState :: #state{}} |
    {noreply, NewState :: #state{}, timeout() | hibernate} |
    {stop, Reason :: term(), NewState :: #state{}}).
handle_info(_Info, State = #state{}) ->
    {noreply, State}.

%% @private
%% @doc This function is called by a gen_server when it is about to
%% terminate. It should be the opposite of Module:init/1 and do any
%% necessary cleaning up. When it returns, the gen_server terminates
%% with Reason. The return value is ignored.
-spec(terminate(Reason :: (normal | shutdown | {shutdown, term()} | term()),
    State :: #state{}) -> term()).
terminate(_Reason, _State = #state{}) ->
    ok.

%% @private
%% @doc Convert process state when code is changed
-spec(code_change(OldVsn :: term() | {down, term()}, State :: #state{},
    Extra :: term()) ->
    {ok, NewState :: #state{}} | {error, Reason :: term()}).
code_change(_OldVsn, State = #state{}, _Extra) ->
    {ok, State}.

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

%{
%   "image": "nginx:latest",
%   "container_name": "my_nginx",
%   "ports": ["8080:80", "443:443"],
%   "volumes": ["/host/data:/data", "/host/log:/var/log"],
%   "envs": ["ENV1=val1", "ENV2=val2"],
%   "entrypoint": ["/docker-entrypoint.sh"],
%   "command": ["nginx", "-g", "daemon off;"],
%   "restart": "always"
%}
-spec do_deploy(TaskId :: integer(), RootDir :: string(), Config :: map()) -> ok | {error, Reason :: any()}.
do_deploy(TaskId, RootDir, Config) when is_integer(TaskId), is_list(RootDir), is_map(Config) ->
    %% 尝试拉取镜像
    ContainerName = maps:get(<<"container_name">>, Config),
    Image0 = maps:get(<<"image">>, Config),
    Image = normalize_image(Image0),

    {ok, ContainerDir} = ensure_dirs(RootDir, ContainerName),
    case try_pull_image(Image) of
        ok ->
            %% 创建container
            %% 如果存在envs参数，则生成环境变量参数文件
            %maybe_create_env_file(ContainerDir, maps:get(<<"envs">>, Config, [])),
            %% 创建镜像, 并预留配置文件的绑定位置: "/etc/容器名称/"
            case efka_docker_command:check_container_exist(ContainerName) of
                true ->
                    {error, <<"container exist">>};
                false ->
                    case efka_docker_command:create_container(ContainerName, ContainerDir, Config) of
                        {ok, ContainerId} ->
                            {ok, ContainerId};
                        {error, Reason} ->
                            {error, Reason}
                    end
            end;
        {error, Reason} ->
            {error, Reason}
    end.

-spec try_pull_image(Image :: binary()) -> ok | {error, Reason :: any()}.
try_pull_image(Image) when is_binary(Image) ->
    case efka_docker_command:check_image_exist(Image) of
        true ->
            ok;
        false ->
            efka_docker_command:pull_image(Image)
    end.

maybe_create_env_file(_ContainerDir, []) ->
    ok;
maybe_create_env_file(ContainerDir, Envs) when is_list(Envs)->
    lager:debug("envs: ~p", [Envs]),
    TargetFile = ContainerDir ++ "env",
    {ok, IoDevice} = file:open(TargetFile, [write, binary]),
    lists:foreach(fun(Env) -> file:write(IoDevice, <<Env/binary, $\n>>) end, Envs),
    ok = file:close(IoDevice),
    {ok, TargetFile}.

-spec ensure_dirs(RootDir :: string(), ContainerName :: binary()) -> {ok, ServerRootDir :: string()}.
ensure_dirs(RootDir, ContainerName) when is_list(RootDir), is_binary(ContainerName) ->
    %% 根目录
    ServiceRootDir = RootDir ++ "/" ++ binary_to_list(ContainerName) ++ "/",
    ok = filelib:ensure_dir(ServiceRootDir),
    {ok, ServiceRootDir}.

-spec normalize_image(binary()) -> binary().
normalize_image(Image) when is_binary(Image) ->
    Parts = binary:split(Image, <<"/">>, [global]),
    {PrefixParts, [Last]} = lists:split(length(Parts) - 1, Parts),
    NormalizedLast = case binary:split(Last, <<":">>, [global]) of
                         [_Name] -> <<Last/binary, ":latest">>;
                         [_Name, _Tag] -> Last
                     end,
    iolist_to_binary(lists:join(<<"/">>, PrefixParts ++ [NormalizedLast])).