-module(refrakt@migrate).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/refrakt/migrate.gleam").
-export([run_from_directory/3]).
-export_type([migration/0]).

-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.

-type migration() :: {migration, integer(), binary(), binary(), binary()}.

-file("src/refrakt/migrate.gleam", 79).
-spec parse_migration(binary(), binary()) -> {ok, migration()} | {error, nil}.
parse_migration(Dir, Filename) ->
    Parts = gleam@string:split(Filename, <<"_"/utf8>>),
    case Parts of
        [Num_str | Rest] ->
            case gleam_stdlib:parse_int(Num_str) of
                {ok, Num} ->
                    Name = begin
                        _pipe = Rest,
                        _pipe@1 = gleam@string:join(_pipe, <<"_"/utf8>>),
                        gleam@string:replace(
                            _pipe@1,
                            <<".sql"/utf8>>,
                            <<""/utf8>>
                        )
                    end,
                    case simplifile:read(
                        <<<<Dir/binary, "/"/utf8>>/binary, Filename/binary>>
                    ) of
                        {ok, Sql} ->
                            {ok, {migration, Num, Name, Filename, Sql}};

                        {error, _} ->
                            {error, nil}
                    end;

                {error, _} ->
                    {error, nil}
            end;

        _ ->
            {error, nil}
    end.

-file("src/refrakt/migrate.gleam", 107).
-spec apply_migrations(
    list(migration()),
    fun((binary()) -> {ok, nil} | {error, binary()})
) -> {ok, nil} | {error, binary()}.
apply_migrations(Migrations, Db_execute) ->
    case Migrations of
        [] ->
            {ok, nil};

        [Migration | Rest] ->
            gleam_stdlib:println(
                <<<<"  "/utf8, (erlang:element(4, Migration))/binary>>/binary,
                    " ..."/utf8>>
            ),
            gleam@result:'try'(
                begin
                    _pipe = Db_execute(erlang:element(5, Migration)),
                    gleam@result:map_error(
                        _pipe,
                        fun(E) ->
                            <<<<<<"Migration "/utf8,
                                        (erlang:element(4, Migration))/binary>>/binary,
                                    " failed: "/utf8>>/binary,
                                E/binary>>
                        end
                    )
                end,
                fun(_) ->
                    gleam@result:'try'(
                        Db_execute(
                            <<<<"INSERT INTO _migrations (name) VALUES ('"/utf8,
                                    (erlang:element(4, Migration))/binary>>/binary,
                                "')"/utf8>>
                        ),
                        fun(_) ->
                            gleam_stdlib:println(
                                <<<<"  "/utf8,
                                        (erlang:element(4, Migration))/binary>>/binary,
                                    " ✓"/utf8>>
                            ),
                            apply_migrations(Rest, Db_execute)
                        end
                    )
                end
            )
    end.

-file("src/refrakt/migrate.gleam", 33).
?DOC(
    " Run all pending migrations in a directory.\n"
    " Returns the number of migrations applied.\n"
).
-spec run_from_directory(
    fun((binary()) -> {ok, nil} | {error, binary()}),
    fun((binary()) -> {ok, list(binary())} | {error, binary()}),
    binary()
) -> {ok, integer()} | {error, binary()}.
run_from_directory(Db_execute, Db_query_strings, Migrations_dir) ->
    gleam@result:'try'(
        Db_execute(
            <<"CREATE TABLE IF NOT EXISTS _migrations (
      name TEXT PRIMARY KEY,
      applied_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
    )"/utf8>>
        ),
        fun(_) ->
            gleam@result:'try'(
                Db_query_strings(
                    <<"SELECT name FROM _migrations ORDER BY name"/utf8>>
                ),
                fun(Applied) ->
                    gleam@result:'try'(
                        begin
                            _pipe = simplifile_erl:read_directory(
                                Migrations_dir
                            ),
                            gleam@result:replace_error(
                                _pipe,
                                <<"Could not read migrations directory: "/utf8,
                                    Migrations_dir/binary>>
                            )
                        end,
                        fun(Files) ->
                            Migrations = begin
                                _pipe@1 = Files,
                                _pipe@2 = gleam@list:filter(
                                    _pipe@1,
                                    fun(F) ->
                                        gleam_stdlib:string_ends_with(
                                            F,
                                            <<".sql"/utf8>>
                                        )
                                    end
                                ),
                                _pipe@3 = gleam@list:filter_map(
                                    _pipe@2,
                                    fun(Filename) ->
                                        parse_migration(
                                            Migrations_dir,
                                            Filename
                                        )
                                    end
                                ),
                                gleam@list:sort(
                                    _pipe@3,
                                    fun(A, B) ->
                                        gleam@int:compare(
                                            erlang:element(2, A),
                                            erlang:element(2, B)
                                        )
                                    end
                                )
                            end,
                            Pending = begin
                                _pipe@4 = Migrations,
                                gleam@list:filter(
                                    _pipe@4,
                                    fun(M) ->
                                        not gleam@list:contains(
                                            Applied,
                                            erlang:element(4, M)
                                        )
                                    end
                                )
                            end,
                            gleam@result:'try'(
                                apply_migrations(Pending, Db_execute),
                                fun(_) -> {ok, erlang:length(Pending)} end
                            )
                        end
                    )
                end
            )
        end
    ).