%% Copyright (c) 2017-2024 Guilherme Andrade
%%
%% 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.
%%
%% locus is an independent project and has not been authorized, sponsored,
%% or otherwise approved by MaxMind.

%% @doc The main API
-module(locus).

%% ------------------------------------------------------------------
%% API Function Exports
%% ------------------------------------------------------------------

-export([start_loader/2]).                -ignore_xref(start_loader/2).
-export([start_loader/3]).                -ignore_xref(start_loader/3).
-export([stop_loader/1]).                 -ignore_xref(stop_loader/1).
-export([loader_child_spec/2]).           -ignore_xref(loader_child_spec/2).
-export([loader_child_spec/3]).           -ignore_xref(loader_child_spec/3).
-export([loader_child_spec/4]).           -ignore_xref(loader_child_spec/4).
-export([await_loader/1]).                -ignore_xref(await_loader/1).
-export([await_loader/2]).                -ignore_xref(await_loader/2).
-export([await_loaders/2]).               -ignore_xref(await_loaders/2).
-export([lookup/2]).                      -ignore_xref(lookup/2).
-export([get_info/1]).                    -ignore_xref(get_info/1).
-export([get_info/2]).                    -ignore_xref(get_info/2).
-export([check/1]).                       -ignore_xref(check/1).

-ifdef(TEST).
-export([parse_database_edition/1]).
-endif.

%% ------------------------------------------------------------------
%% CLI-only Function Exports
%% ------------------------------------------------------------------

-ifdef(ESCRIPTIZING).
-export([main/1]).                        -ignore_xref(main/1).
-endif.

%% ------------------------------------------------------------------
%% Macro Definitions
%% ------------------------------------------------------------------

-define(might_be_chardata(V), (is_binary((V)) orelse ?is_proper_list((V)))).
-define(is_proper_list(V), (length((V)) >= 0)).

%% ------------------------------------------------------------------
%% Type Definitions
%% ------------------------------------------------------------------

-type database_edition() :: maxmind_database_edition().
-export_type([database_edition/0]).

-type maxmind_database_edition() ::
    {maxmind, atom() | unicode:chardata()} |
    legacy_maxmind_database_edition().
-export_type([maxmind_database_edition/0]).

-type legacy_maxmind_database_edition() :: atom().
-export_type([legacy_maxmind_database_edition/0]).

-type database_url() :: unicode:chardata().
-export_type([database_url/0]).

-type custom_fetcher() :: {custom_fetcher, module(), Args :: term()}.
-export_type([custom_fetcher/0]).

-type database_error() :: database_unknown | database_not_loaded.
-export_type([database_error/0]).

-type database_entry() :: locus_mmdb_data:value().
-export_type([database_entry/0]).

-type ip_address_prefix() :: locus_mmdb_tree:ip_address_prefix().
-export_type([ip_address_prefix/0]).

-type database_info() ::
    #{ metadata := database_metadata(),
       source := database_source(),
       version := database_version()
     }.
-export_type([database_info/0]).

-type database_metadata() :: locus_mmdb_metadata:t().
-export_type([database_metadata/0]).

-type database_source() :: locus_loader:source().
-export_type([database_source/0]).

-type database_version() :: calendar:datetime().
-export_type([database_version/0]).

%% ------------------------------------------------------------------
%% API Function Definitions
%% ------------------------------------------------------------------

%% @doc Like `:start_loader/3' but with default options
%%
%% <ul>
%% <li>`DatabaseId' must be an atom.</li>
%% <li>`LoadFrom' must be either:
%%  <ul>
%%      <li>a `database_edition()' tuple, or</li>
%%      <li>a `DatabaseURL' containing either a string or binary representation
%%      of a HTTP(s) URL or local path, or</li>
%%      <li>a `{custom_fetcher, Module, Args}' tuple, with `Module' implementing
%%      the `locus_custom_fetcher' behaviour</li>
%%  </ul>
%% </li>
%% </ul>
%%
%% Returns:
%% <ul>
%% <li>`ok' in case of success.</li>
%% <li>`{error, invalid_url}' if the source is invalid.</li>
%% <li>`{error, already_started}' if the loader under `DatabaseId' has already been started.</li>
%% </ul>
%% @see await_loader/1
%% @see await_loader/2
%% @see start_loader/3
-spec start_loader(DatabaseId, LoadFrom) -> ok | {error, Error}
            when DatabaseId :: atom(),
                 LoadFrom :: DatabaseEdition | DatabaseURL | CustomFetcher,
                 DatabaseEdition :: database_edition(),
                 DatabaseURL :: database_url(),
                 CustomFetcher :: custom_fetcher(),
                 Error :: invalid_url | already_started | application_not_running.
start_loader(DatabaseId, LoadFrom) ->
    start_loader(DatabaseId, LoadFrom, []).

%% @doc Starts a database loader under id `DatabaseId' with options `Opts'.
%%
%% <ul>
%% <li>`DatabaseId' must be an atom.</li>
%% <li>`LoadFrom' must be either:
%%  <ul>
%%      <li>a `database_edition()' tuple, or</li>
%%      <li>a `DatabaseURL' containing either a string or binary representation
%%      of a HTTP(s) URL or local path, or</li>
%%      <li>a `{custom_fetcher, Module, Args}' tuple, with `Module' implementing
%%      the `locus_custom_fetcher' behaviour</li>
%%  </ul>
%% </li>
%% <li>`Opts' must be a list of `locus_database:opt()' values</li>
%% </ul>
%%
%% Returns:
%% <ul>
%% <li>`ok' in case of success.</li>
%% <li>`{error, invalid_url}' if the source is invalid.</li>
%% <li>`{error, already_started}' if the loader under `DatabaseId' has already been started.</li>
%% </ul>
%% @see await_loader/1
%% @see await_loader/2
%% @see start_loader/2
-spec start_loader(DatabaseId, LoadFrom, Opts) -> ok | {error, Error}
            when DatabaseId :: atom(),
                 LoadFrom :: DatabaseEdition | DatabaseURL | CustomFetcher,
                 DatabaseEdition :: database_edition(),
                 DatabaseURL :: database_url(),
                 CustomFetcher :: custom_fetcher(),
                 Opts :: [locus_database:opt()],
                 Error :: (invalid_url | already_started |
                           {invalid_opt, term()} | application_not_running).
start_loader(DatabaseId, {maxmind, _} = DatabaseEdition, Opts) ->
    Origin = parse_database_edition(DatabaseEdition),
    OptsWithDefaults = opts_with_defaults(Opts),
    locus_database:start(DatabaseId, Origin, OptsWithDefaults);
start_loader(DatabaseId, DatabaseEdition, Opts)
  when is_atom(DatabaseEdition) ->
    % Deprecated edition format
    Origin = parse_database_edition(DatabaseEdition),
    OptsWithDefaults = opts_with_defaults(Opts),
    locus_database:start(DatabaseId, Origin, OptsWithDefaults);
start_loader(DatabaseId, DatabaseURL, Opts)
  when ?might_be_chardata(DatabaseURL) ->
    case parse_url(DatabaseURL) of
        false ->
            {error, invalid_url};
        Origin ->
            OptsWithDefaults = opts_with_defaults(Opts),
            locus_database:start(DatabaseId, Origin, OptsWithDefaults)
    end;
start_loader(DatabaseId, {custom_fetcher, Module, _Args} = CustomFetcher, Opts)
  when is_atom(Module) ->
    Origin = CustomFetcher,
    OptsWithDefaults = opts_with_defaults(Opts),
    locus_database:start(DatabaseId, Origin, OptsWithDefaults).

%% @doc Stops the database loader under id `DatabaseId'.
%%
%% <ul>
%% <li>`DatabaseId' must be an atom and refer to a database loader.</li>
%% </ul>
%%
%% Returns `ok' in case of success, `{error, not_found}' otherwise.
-spec stop_loader(DatabaseId) -> ok | {error, Error}
            when DatabaseId :: atom(),
                 Error :: not_found.
stop_loader(DatabaseId) ->
    locus_database:stop(DatabaseId, _Reason = normal).

%% @doc Like `:loader_child_spec/2' but with default options
%%
%% <ul>
%% <li>`DatabaseId' must be an atom.</li>
%% <li>`LoadFrom' must be either:
%%  <ul>
%%      <li>a `database_edition()' tuple, or</li>
%%      <li>a `DatabaseURL' containing either a string or binary representation
%%      of a HTTP(s) URL or local path, or</li>
%%      <li>a `{custom_fetcher, Module, Args}' tuple, with `Module' implementing
%%      the `locus_custom_fetcher' behaviour</li>
%%  </ul>
%% </li>
%% </ul>
%%
%% Returns:
%% <ul>
%% <li>A `supervisor:child_spec()'.</li>
%% </ul>
%% @see loader_child_spec/3
%% @see await_loader/1
%% @see await_loader/2
%% @see start_loader/2
-spec loader_child_spec(DatabaseId, LoadFrom) -> ChildSpec | no_return()
            when DatabaseId :: atom(),
                 LoadFrom :: DatabaseEdition | DatabaseURL | CustomFetcher,
                 DatabaseEdition :: database_edition(),
                 DatabaseURL :: database_url(),
                 CustomFetcher :: custom_fetcher(),
                 ChildSpec :: locus_database:static_child_spec().
loader_child_spec(DatabaseId, LoadFrom) ->
    loader_child_spec(DatabaseId, LoadFrom, []).

%% @doc Like `:loader_child_spec/3' but with default child id
%%
%% <ul>
%% <li>`DatabaseId' must be an atom.</li>
%% <li>`LoadFrom' must be either:
%%  <ul>
%%      <li>a `database_edition()' tuple, or</li>
%%      <li>a `DatabaseURL' containing either a string or binary representation
%%      of a HTTP(s) URL or local path, or</li>
%%      <li>a `{custom_fetcher, Module, Args}' tuple, with `Module' implementing
%%      the `locus_custom_fetcher' behaviour</li>
%%  </ul>
%% </li>
%% <li>`Opts' must be a list of `locus_database:opt()' values</li>
%% </ul>
%%
%% Returns:
%% <ul>
%% <li>A `supervisor:child_spec()'.</li>
%% </ul>
%% @see loader_child_spec/2
%% @see loader_child_spec/4
%% @see await_loader/1
%% @see await_loader/2
%% @see start_loader/3
-spec loader_child_spec(DatabaseId, LoadFrom, Opts) -> ChildSpec | no_return()
            when DatabaseId :: atom(),
                 LoadFrom :: DatabaseEdition | DatabaseURL | CustomFetcher,
                 DatabaseEdition :: database_edition(),
                 DatabaseURL :: database_url(),
                 CustomFetcher :: custom_fetcher(),
                 Opts :: [locus_database:opt()],
                 ChildSpec :: locus_database:static_child_spec().
loader_child_spec(DatabaseId, LoadFrom, Opts) ->
    loader_child_spec({locus_database, DatabaseId}, DatabaseId, LoadFrom, Opts).

%% @doc Returns a supervisor child spec for a database loader
%% under id `DatabaseId' with options `Opts'.
%%
%% <ul>
%% <li>`DatabaseId' must be an atom.</li>
%% <li>`LoadFrom' must be either:
%%  <ul>
%%      <li>a `database_edition()' tuple, or</li>
%%      <li>a `DatabaseURL' containing either a string or binary representation
%%      of a HTTP(s) URL or local path, or</li>
%%      <li>a `{custom_fetcher, Module, Args}' tuple, with `Module' implementing
%%      the `locus_custom_fetcher' behaviour</li>
%%  </ul>
%% </li>
%% <li>`Opts' must be a list of `locus_database:opt()' values</li>
%% </ul>
%%
%% Returns:
%% <ul>
%% <li>A `supervisor:child_spec()'.</li>
%% </ul>
%% @see loader_child_spec/3
%% @see await_loader/1
%% @see await_loader/2
%% @see start_loader/3
-spec loader_child_spec(ChildId, DatabaseId, LoadFrom, Opts)
        -> ChildSpec | no_return()
            when ChildId :: term(),
                 DatabaseId :: atom(),
                 LoadFrom :: DatabaseEdition | DatabaseURL | CustomFetcher,
                 DatabaseEdition :: database_edition(),
                 DatabaseURL :: database_url(),
                 CustomFetcher :: custom_fetcher(),
                 Opts :: [locus_database:opt()],
                 ChildSpec :: locus_database:static_child_spec().
loader_child_spec(ChildId, DatabaseId, {maxmind, _} = DatabaseEdition, Opts) ->
    Origin = parse_database_edition(DatabaseEdition),
    OptsWithDefaults = opts_with_defaults(Opts),
    locus_database:static_child_spec(ChildId, DatabaseId, Origin, OptsWithDefaults);
loader_child_spec(ChildId, DatabaseId, DatabaseEdition, Opts)
  when is_atom(DatabaseEdition) ->
    % Deprecated edition format
    Origin = parse_database_edition(DatabaseEdition),
    OptsWithDefaults = opts_with_defaults(Opts),
    locus_database:static_child_spec(ChildId, DatabaseId, Origin, OptsWithDefaults);
loader_child_spec(ChildId, DatabaseId, DatabaseURL, Opts)
  when ?might_be_chardata(DatabaseURL) ->
    case parse_url(DatabaseURL) of
        false ->
            error(invalid_url);
        Origin ->
            OptsWithDefaults = opts_with_defaults(Opts),
            locus_database:static_child_spec(ChildId, DatabaseId, Origin, OptsWithDefaults)
    end;
loader_child_spec(ChildId, DatabaseId, {custom_fetcher, Module, _Args} = CustomFetcher, Opts)
  when is_atom(Module) ->
    Origin = CustomFetcher,
    OptsWithDefaults = opts_with_defaults(Opts),
    locus_database:static_child_spec(ChildId, DatabaseId, Origin, OptsWithDefaults).

%% @doc Like `await_loader/1' but with a default timeout of 30 seconds.
%%
%% <ul>
%% <li>`DatabaseId' must be an atom and refer to a database loader.</li>
%% </ul>
%%
%% Returns:
%% <ul>
%% <li>`{ok, LoadedVersion}' when the database is ready to use.</li>
%% <li>`{error, database_unknown}' if the database loader for `DatabaseId' hasn't been started.</li>
%% <li>`{error, {database_stopped, _}}'
%%      if the database loader for `DatabaseId' stopped while we waited.</li>
%% <li>`{error, {timeout, [_]}}'
%%      if all the load attempts performed before timing out have failed.</li>
%% </ul>
%% @see await_loader/2
-spec await_loader(DatabaseId) -> {ok, LoadedVersion} | {error, Reason}
            when DatabaseId :: atom(),
                 LoadedVersion :: database_version(),
                 Reason :: (database_unknown |
                            {database_stopped, term()} |
                            {timeout, LoadAttemptFailures}),
                 LoadAttemptFailures :: [term()].
await_loader(DatabaseId) ->
    await_loader(DatabaseId, 30000).

%% @doc Blocks caller execution until either readiness is achieved
%% or the default timeout is triggered.
%%
%% <ul>
%% <li>`DatabaseId' must be an atom and refer to a database loader.</li>
%% <li>`Timeout' must be either a non-negative integer (milliseconds) or `infinity'.</li>
%% </ul>
%%
%% Returns:
%% <ul>
%% <li>`{ok, LoadedVersion}' when the database is ready to use.</li>
%% <li>`{error, database_unknown}' if the database loader for `DatabaseId' hasn't been started.</li>
%% <li>`{error, {database_stopped, _}}'
%%      if the database loader for `DatabaseId' stopped while we waited.</li>
%% <li>`{error, {timeout, [_]}}'
%%      if all the load attempts performed before timing out have failed.</li>
%% </ul>
%% @see await_loader/1
%% @see await_loaders/2
-spec await_loader(DatabaseId, Timeout) -> {ok, LoadedVersion} | {error, Reason}
            when DatabaseId :: atom(),
                 Timeout :: timeout(),
                 LoadedVersion :: database_version(),
                 Reason :: (database_unknown |
                            {database_stopped, term()} |
                            {timeout, LoadAttemptFailures}),
                 LoadAttemptFailures :: [term()].
await_loader(DatabaseId, Timeout) ->
    case await_loaders([DatabaseId], Timeout) of
        {ok, #{DatabaseId := LoadedVersion}} ->
            {ok, LoadedVersion};
        {error, {#{DatabaseId := Reason}, _}} ->
            {error, Reason}
    end.

%% <ul>
%% <li>`DatabaseIds' must be a list of atoms that refer to database loaders.</li>
%% <li>`Timeout' must be either a non-negative integer (milliseconds) or `infinity'.</li>
%% </ul>
%%
%% Returns:
%% <ul>
%% <li>`{ok, #{DatabaseId => LoadedVersion}}' when all the databases are ready to use.</li>
%% <li>`{error, {DatabaseId, database_unknown}}'
%%      if the database loader for `DatabaseId' hasn't been started.</li>
%% <li>`{error, {DatabaseId, {loading, term()}}}'
%%      if loading `DatabaseId' failed for some reason.</li>
%% <li>`{error, timeout}' if we've given up on waiting.</li>
%% </ul>

%% @doc Like `await_loader/2' but it can concurrently await status from more than one database.
%%
%% <ul>
%% <li>`DatabaseIds' must be list of atom referring to database loaders.</li>
%% <li>`Timeout' must be either a non-negative integer (milliseconds) or `infinity'.</li>
%% </ul>
%%
%% Returns:
%% <ul>
%% <li>`{ok, #{DatabaseId => LoadedVersion}}' when all the database are ready to use.</li>
%% <li>`{error, {#{DatabaseId => ErrorReason}, _}}' in case of errors.</li>
%% </ul>
%% @see await_loader/2
-spec await_loaders(DatabaseIds, Timeout) -> ({ok, Successes} |
                                              {error, {ErrorPerDatabase, PartialSuccesses}})
            when DatabaseIds :: [DatabaseId],
                 Timeout :: timeout(),
                 Successes :: LoadedVersionPerDatabase,
                 PartialSuccesses :: LoadedVersionPerDatabase,
                 LoadedVersionPerDatabase :: #{DatabaseId => LoadedVersion},
                 LoadedVersion :: database_version(),
                 ErrorPerDatabase :: #{DatabaseId := Reason},
                 Reason :: (database_unknown |
                            {database_stopped, term()} |
                            {timeout, LoadAttemptFailures}),
                 LoadAttemptFailures :: [term()].
await_loaders(DatabaseIds, Timeout) ->
    ReplyRef = make_ref(),
    UniqueDatabaseIds = lists:usort(DatabaseIds),
    Waiters = launch_waiters(ReplyRef, Timeout, UniqueDatabaseIds),
    perform_wait(ReplyRef, Waiters, #{}, #{}).

%% @doc Looks-up info on IPv4 and IPv6 addresses.
%%
%% <ul>
%% <li>`DatabaseId' must be an atom and refer to a database loader.</li>
%% <li>`Address' must be either an `inet:ip_address()' tuple, or a string/binary
%%    containing a valid representation of the address.</li>
%% </ul>
%%
%% Returns:
%% <ul>
%% <li>`{ok, Entry}' in case of success</li>
%% <li>`not_found' if no data was found for this `Address'.</li>
%% <li>`{error, invalid_address}' if `Address' is not either a `inet:ip_address()'
%%    tuple or a valid textual representation of an IP address.</li>
%% <li>`{error, database_unknown}' if the database loader for `DatabaseId' hasn't been started.</li>
%% <li>`{error, database_not_loaded}' if the database hasn't yet been loaded.</li>
%% <li>`{error, ipv4_database}' if `Address' represents an IPv6 address and the database
%%      only supports IPv4 addresses.</li>
%% </ul>
-spec lookup(DatabaseId, Address) -> {ok, Entry} | not_found | {error, Error}
            when DatabaseId :: atom(),
                 Address :: inet:ip_address() | string() | binary(),
                 Entry :: database_entry(),
                 Error :: (database_unknown | database_not_loaded |
                           {invalid_address, Address} |
                           ipv4_database).
lookup(DatabaseId, Address) ->
    case locus_database:find(DatabaseId) of
        {ok, Database, _Source, _Version} ->
            locus_mmdb:lookup_address(Address, Database);
        Error ->
            Error
    end.

%% @doc Returns the properties of a currently loaded database.
%%
%% <ul>
%% <li>`DatabaseId' must be an atom and refer to a database loader.</li>
%% </ul>
%%
%% Returns:
%% <ul>
%% <li>`{ok, database_info()}' in case of success</li>
%% <li>`{error, database_unknown}' if the database loader for `DatabaseId' hasn't been started.</li>
%% <li>`{error, database_not_loaded}' if the database hasn't yet been loaded.</li>
%% </ul>
%% @see get_info/2
-spec get_info(DatabaseId) -> {ok, Info} | {error, Error}
            when DatabaseId :: atom(),
                 Info :: database_info(),
                 Error :: database_unknown | database_not_loaded.
get_info(DatabaseId) ->
    case locus_database:find(DatabaseId) of
        {ok, Database, Source, Version} ->
            Info = database_info(Database, Source, Version),
            {ok, Info};
        Error ->
            Error
    end.

%% @doc Returns a specific property of a currently loaded database.
%%
%% <ul>
%% <li>`DatabaseId' must be an atom and refer to a database loader.</li>
%% <li>`Property' must be either `metadata', `source' or `version'.</li>
%% </ul>
%%
%% Returns:
%% <ul>
%% <li>`{ok, Value}' in case of success</li>
%% <li>`{error, database_unknown}' if the database loader for `DatabaseId' hasn't been started.</li>
%% <li>`{error, database_not_loaded}' if the database hasn't yet been loaded.</li>
%% </ul>
%% @see get_info/1
-spec get_info(DatabaseId, Property) -> {ok, Value} | {error, Error}
            when DatabaseId :: atom(),
                 Property :: metadata | source | version,
                 Value :: database_metadata() | database_source() | database_version(),
                 Error :: database_unknown | database_not_loaded.
get_info(DatabaseId, Property) ->
    case get_info(DatabaseId) of
        {ok, Info} ->
            Value = maps:get(Property, Info),
            {ok, Value};
        {error, Error} ->
            {error, Error}
    end.

%% @doc Analyzes a loaded database for corruption or incompatibility.
%%
%% <ul>
%% <li>`DatabaseId' must be an atom and refer to a database loader.</li>
%% </ul>
%%
%% Returns:
%% <ul>
%% <li>`ok' if the database is wholesome.</li>
%% <li>`{error, database_unknown}' if the database loader for `DatabaseId' hasn't been started.</li>
%% <li>`{error, database_not_loaded}' if the database hasn't yet been loaded.</li>
%% <li>`{validation_warnings, [CheckWarning, ...]}' in case something smells within the database
%%    (check the definitions in {@link locus_mmdb_check})
%% </li>
%% <li>`{validation_errors, [CheckError], [...]}' in case of corruption or incompatibility
%%    (check the definitions in {@link locus_mmdb_check})
%% </li>
%% </ul>
-spec check(DatabaseId) -> ok
                           | {error, Error}
                           | {validation_warnings, [ValidationWarning, ...]}
                           | {validation_errors, [ValidationError, ...], [ValidationWarning]}
            when DatabaseId :: atom(),
                 Error :: database_unknown | database_not_loaded,
                 ValidationWarning :: locus_mmdb_check:warning(),
                 ValidationError :: locus_mmdb_check:error().
check(DatabaseId) ->
    case locus_database:find(DatabaseId) of
        {ok, Database, _Source, _Version} ->
            check_(Database);
        {error, _} = Error ->
            Error
    end.

%% ------------------------------------------------------------------
%% CLI-only Function Definitions
%% ------------------------------------------------------------------

-ifdef(ESCRIPTIZING).
-spec main([string()]) -> no_return().
%% @private
main(Args) ->
    locus_cli:main(Args).
-endif.

%% ------------------------------------------------------------------
%% Internal Function Definitions
%% ------------------------------------------------------------------

-spec parse_database_edition(database_edition()) -> {maxmind, atom()}.
parse_database_edition({maxmind, Atom})
  when is_atom(Atom) ->
    {maxmind, Atom};
parse_database_edition({maxmind, Chardata})
  when ?might_be_chardata(Chardata) ->
    Charlist = unicode:characters_to_list(Chardata),
    Atom = list_to_atom(Charlist),
    {maxmind, Atom};
parse_database_edition(LegacyMaxMindDatabaseEdition)
  when is_atom(LegacyMaxMindDatabaseEdition) ->
    {maxmind, LegacyMaxMindDatabaseEdition}.

-spec parse_url(database_url()) -> locus_database:origin() | false.
parse_url(DatabaseURL) ->
    case parse_http_url(DatabaseURL) of
        Origin when is_tuple(Origin) ->
            Origin;
        false ->
            parse_filesystem_url(DatabaseURL)
    end.

parse_http_url(DatabaseURL) when is_list(DatabaseURL) ->
    try unicode:characters_to_binary(DatabaseURL) of
        <<BinaryChardata/bytes>> ->
            parse_http_url(BinaryChardata);
        _ ->
            false
    catch
        _:_ -> false
    end;
parse_http_url(DatabaseURL) ->
    ByteList = binary_to_list(DatabaseURL),
    try io_lib:printable_latin1_list(ByteList) andalso
        locus_util:parse_absolute_http_url(ByteList)
    of
        false ->
            false;
        {ok, _Result} ->
            {http, ByteList};
        {error, _Reason} ->
            false
    catch
        error:badarg -> false
    end.

parse_filesystem_url(DatabaseURL) ->
    try unicode:characters_to_list(DatabaseURL) of
        Path when is_list(Path) ->
            {filesystem, filename:absname(Path)};
        {error, _Parsed, _RestData} ->
            false;
        {incomplete, _Parsed, _RestData} ->
            false
    catch
        error:badarg -> false
    end.

-spec database_info(locus_mmdb:database(), locus_loader:source(), calendar:datetime())
        -> database_info().
database_info(Database, Source, Version) ->
    #{metadata := Metadata} = Database,
    #{metadata => Metadata, source => Source, version => Version}.

opts_with_defaults(Opts) ->
    [{event_subscriber, locus_logger} | Opts].

launch_waiters(ReplyRef, Timeout, UniqueDatabaseIds) ->
    [{DatabaseId, locus_waiter:start(ReplyRef, DatabaseId, Timeout)}
     || DatabaseId <- UniqueDatabaseIds].

perform_wait(_ReplyRef, [], Successes, Failures) ->
    case map_size(Failures) =:= 0 of
        true ->
            {ok, Successes};
        false ->
            {error, {Failures, Successes}}
    end;
perform_wait(ReplyRef, WaitersLeft, Successes, Failures) ->
    case receive_waiter_reply(ReplyRef) of
        {DatabaseId, {ok, Version}} ->
            {value, _, RemainingWaitersLeft} = lists:keytake(DatabaseId, 1, WaitersLeft),
            UpdatedSuccesses = Successes#{ DatabaseId => Version },
            perform_wait(ReplyRef, RemainingWaitersLeft, UpdatedSuccesses, Failures);
        {DatabaseId, {error, Reason}} ->
            {value, _, RemainingWaitersLeft} = lists:keytake(DatabaseId, 1, WaitersLeft),
            UpdatedFailures = Failures#{ DatabaseId => Reason },
            perform_wait(ReplyRef, RemainingWaitersLeft, Successes, UpdatedFailures)
    end.

receive_waiter_reply(ReplyRef) ->
    receive
        {ReplyRef, DatabaseId, Reply} ->
            {DatabaseId, Reply}
    end.

check_(Database) ->
    case locus_mmdb_check:run(Database) of
        ok ->
            ok;
        {warnings, Warnings} ->
            {validation_warnings, Warnings};
        {errors, Errors, Warnings} ->
            {validation_errors, Errors, Warnings}
    end.