-module(ephp_lib_math).

-author('manuel@altenwald.com').

-behaviour(ephp_lib).

-export([init_func/0, init_config/0, init_const/0, php_round/3, php_ceil/3, php_floor/3,
         php_sqrt/3, php_abs/3, php_asin/3, php_asinh/3, php_atan/3, php_atan2/4, php_atanh/3,
         php_acos/3, php_acosh/3, bindec/3, php_sin/3, php_sinh/3, php_tan/3, php_tanh/3,
         php_cos/3, php_cosh/3, php_pow/4, base_convert/5, pi/2, php_max/4, php_min/4, php_exp/3,
         php_log/4]).

-include("ephp.hrl").
-include("ephp_array.hrl").

-define(M_PI, 3.14159265358979323846).
-define(M_E, 2.7182818284590452354).
-define(M_LOG2E, 1.4426950408889634074).
-define(M_LOG10E, 0.43429448190325182765).
-define(M_LN2, 0.69314718055994530942).
-define(M_LN10, 2.30258509299404568402).
-define(M_PI_2, 1.57079632679489661923).
-define(M_PI_4, 0.78539816339744830962).
-define(M_1_PI, 0.31830988618379067154).
-define(M_2_PI, 0.63661977236758134308).
-define(M_QSRTPI, 1.77245385090551602729).
-define(M_2_SQRTPI, 1.12837916709551257390).
-define(M_SQRT2, 1.41421356237309504880).
-define(M_SQRT3, 1.73205080756887729352).
-define(M_SQRT1_2, 0.70710678118654752440).
-define(M_LNPI, 1.14472988584940017414).
-define(M_EULER, 0.57721566490153286061).

-spec init_func() -> ephp_lib:php_function_results().
init_func() ->
    [{php_ceil, [{alias, <<"ceil">>}]}, {php_floor, [{alias, <<"floor">>}]},
     {php_round, [{alias, <<"round">>}]}, {php_sqrt, [{args, [double]}, {alias, <<"sqrt">>}]},
     {php_abs, [{alias, <<"abs">>}]}, {php_acos, [{args, [double]}, {alias, <<"acos">>}]},
     {php_acosh, [{args, [double]}, {alias, <<"acosh">>}]},
     {php_asin, [{args, [double]}, {alias, <<"asin">>}]},
     {php_asinh, [{args, [double]}, {alias, <<"asinh">>}]},
     {php_atan, [{args, [double]}, {alias, <<"atan">>}]},
     {php_atan2, [{args, [double, double]}, {alias, <<"atan2">>}]},
     {php_atanh, [{args, [double]}, {alias, <<"atanh">>}]}, {php_exp, [{alias, <<"exp">>}]},
     {php_max, [{alias, <<"max">>}]}, {php_min, [{alias, <<"min">>}]}, bindec,
     {php_cos, [{args, [double]}, {alias, <<"cos">>}]},
     {php_cosh, [{args, [double]}, {alias, <<"cosh">>}]},
     {php_sin, [{args, [double]}, {alias, <<"sin">>}]},
     {php_sinh, [{args, [double]}, {alias, <<"sinh">>}]},
     {php_tan, [{args, [double]}, {alias, <<"tan">>}]},
     {php_tanh, [{args, [double]}, {alias, <<"tanh">>}]}, {php_pow, [{alias, <<"pow">>}]},
     {php_log, [{args, [double, {double, ?M_E}]}, {alias, <<"log">>}]}, base_convert, pi].

-spec init_config() -> ephp_lib:php_config_results().
init_config() ->
    [{<<"precision">>, 14}].

-spec init_const() -> ephp_lib:php_const_results().
init_const() ->
    [{<<"M_PI">>, ?M_PI},
     {<<"M_E">>, ?M_E},
     {<<"M_LOG2E">>, ?M_LOG2E},
     {<<"M_LOG10E">>, ?M_LOG10E},
     {<<"M_LN2">>, ?M_LN2},
     {<<"M_LN10">>, ?M_LN10},
     {<<"M_PI_2">>, ?M_PI_2},
     {<<"M_PI_4">>, ?M_PI_4},
     {<<"M_1_PI">>, ?M_1_PI},
     {<<"M_2_PI">>, ?M_2_PI},
     {<<"M_QSRTPI">>, ?M_QSRTPI},
     {<<"M_2_SQRTPI">>, ?M_2_SQRTPI},
     {<<"M_SQRT2">>, ?M_SQRT2},
     {<<"M_SQRT3">>, ?M_SQRT3},
     {<<"M_SQRT1_2">>, ?M_SQRT1_2},
     {<<"M_LNPI">>, ?M_LNPI},
     {<<"M_EULER">>, ?M_EULER},
     {<<"PHP_ROUND_HALF_UP">>, 1},
     {<<"PHP_ROUND_HALF_DOWN">>, 2},
     {<<"PHP_ROUND_HALF_EVEN">>, 3},
     {<<"PHP_ROUND_HALF_ODD">>, 4},
     {<<"NAN">>, nan},
     {<<"INF">>, infinity},
     {<<"PHP_INT_SIZE">>, ?PHP_INT_SIZE},
     {<<"PHP_INT_MAX">>, ?PHP_INT_MAX}].

-spec php_ceil(ephp:context_id(), line(), var_value()) -> integer().
php_ceil(_Context, _Line, {_, Value}) when is_number(Value) ->
    ephp_data:ceiling(Value);
php_ceil(_Context, _Line, {_, Value}) ->
    ephp_data:ceiling(
        ephp_data:bin_to_number(Value)).

-spec php_floor(ephp:context_id(), line(), var_value()) -> integer().
php_floor(_Context, _Line, {_, Value}) when is_number(Value) ->
    ephp_data:flooring(Value);
php_floor(_Context, _Line, {_, Value}) ->
    ephp_data:flooring(
        ephp_data:bin_to_number(Value)).

-spec php_round(ephp:context_id(), line(), var_value()) -> integer().
php_round(_Context, _Line, {_, Value}) when is_number(Value) ->
    round(Value);
php_round(_Context, _Line, {_, Value}) ->
    round(ephp_data:bin_to_number(Value)).

-spec php_sqrt(ephp:context_id(), line(), var_value()) -> float().
php_sqrt(_Context, _Line, {_, Value}) ->
    math:sqrt(float(Value)).

-spec php_abs(ephp:context_id(), line(), number()) -> number().
php_abs(_Context, _Line, {_, Number}) when is_number(Number) ->
    abs(Number);
php_abs(_Context, _Line, {_, String}) when is_binary(String) ->
    abs(ephp_data:bin_to_number(String));
php_abs(_Context, _Line, _NotANumber) ->
    false.

-spec php_acos(ephp:context_id(), line(), {any(), number()}) -> php_float().
php_acos(_Context, _Line, {_, Number}) ->
    try
        math:acos(Number)
    catch
        error:badarith ->
            nan
    end.

-spec php_acosh(ephp:context_id(), line(), {any(), number()}) -> float().
php_acosh(_Context, _Line, {_Var, Number}) ->
    math:acosh(Number).

-spec php_asin(ephp:context_id(), line(), {any(), number()}) -> float().
php_asin(_Context, _Line, {_, Number}) ->
    math:asin(Number).

-spec php_asinh(ephp:context_id(), line(), {any(), number()}) -> float().
php_asinh(_Context, _Line, {_, Number}) ->
    math:asinh(Number).

-spec php_atan(ephp:context_id(), line(), {any(), number()}) -> float().
php_atan(_Context, _Line, {_, Number}) ->
    math:atan(Number).

-spec php_atanh(ephp:context_id(), line(), {any(), number()}) -> float().
php_atanh(_Context, _Line, {_, Number}) ->
    1 / 2 * math:log((1 + Number) / (1 - Number)).

-spec php_atan2(ephp:context_id(), line(), {any(), number()}, {any(), number()}) ->
                   float().
php_atan2(_Context, _Line, {_, Number1}, {_, Number2}) ->
    math:atan2(Number1, Number2).

-spec filter_bin(binary(), binary()) -> binary().
%@hidden
filter_bin(<<>>, B) ->
    B;
filter_bin(<<A:8, Rest/binary>>, B) when A =:= $0 orelse A =:= $1 ->
    filter_bin(Rest, <<B/binary, A:8>>);
filter_bin(<<_/utf8, Rest/binary>>, B) ->
    filter_bin(Rest, B).

-spec bindec(ephp:context_id(), line(), var_value()) -> integer().
bindec(_Context, _Line, {_, String}) when is_binary(String) ->
    Filtered = filter_bin(String, <<"0">>),
    binary_to_integer(Filtered, 2);
bindec(Context, Line, {Var, A}) when ?IS_ARRAY(A) ->
    Level = ?E_NOTICE,
    File = ephp_context:get_active_file(Context),
    Type = <<"string">>,
    Error = {error, earrayconv, Line, File, Level, {Type}},
    ephp_error:handle_error(Context, Error),
    bindec(Context, Line, {Var, <<>>});
bindec(_Context, Line, {_, #obj_ref{pid = Objects, ref = ObjectId}}) ->
    ClassName = ephp_object:get_class_name(Objects, ObjectId),
    ephp_error:error({error, enotostring, Line, ?E_RECOVERABLE_ERROR, {ClassName}});
bindec(Context, Line, {Var, Other}) ->
    bindec(Context, Line, {Var, ephp_data:to_bin(Other)}).

-spec php_cos(ephp:context_id(), line(), {any(), number()}) -> float().
php_cos(_Context, _Line, {_, Number}) ->
    math:cos(Number).

-spec php_cosh(ephp:context_id(), line(), {any(), number()}) -> float().
php_cosh(_Context, _Line, {_Var, Number}) ->
    math:cosh(Number).

-spec php_sin(ephp:context_id(), line(), {any(), number()}) -> float().
php_sin(_Context, _Line, {_, Number}) ->
    math:sin(Number).

-spec php_sinh(ephp:context_id(), line(), {any(), number()}) -> float().
php_sinh(_Context, _Line, {_, Number}) ->
    math:sinh(Number).

-spec php_tan(ephp:context_id(), line(), {any(), number()}) -> float().
php_tan(_Context, _Line, {_, Number}) ->
    math:tan(Number).

-spec php_tanh(ephp:context_id(), line(), {any(), number()}) -> float().
php_tanh(_Context, _Line, {_, Number}) ->
    math:tanh(Number).

-spec get_pow_value(ephp:context_id(), line(), mixed()) -> number().
get_pow_value(Context, Line, #obj_ref{pid = Objects, ref = ObjectId}) ->
    ClassName = ephp_object:get_class_name(Objects, ObjectId),
    File = ephp_context:get_active_file(Context),
    Level = ?E_NOTICE,
    Data = {ClassName, <<"int">>},
    Error = {error, enocast, Line, File, Level, Data},
    ephp_error:handle_error(Context, Error),
    1;
get_pow_value(_Context, _Line, N) ->
    ephp_data:bin_to_number(
        ephp_data:to_bin(N)).

-spec php_pow(ephp:context_id(), line(), var_value(), var_value()) -> float() | integer().
php_pow(Context, Line, {_, Base}, {_, Power}) ->
    B = get_pow_value(Context, Line, Base),
    P = get_pow_value(Context, Line, Power),
    math:pow(B, P).

-spec php_log(ephp:context_id(), line(), var_value(), var_value()) -> float().
php_log(_Context, _Line, {_, X}, {_, X}) ->
    1.0;
php_log(_Context, _Line, {_, X}, {_, B}) when B > 0 ->
    math:log(X) / math:log(B).

base_convert_error(Context, Line, ArgNum, ArgData) ->
    Level = ?E_WARNING,
    Function = <<"base_convert">>,
    WrongType = ephp_data:gettype(ArgData),
    File = ephp_context:get_active_file(Context),
    Data = {Function, ArgNum, <<"long">>, WrongType},
    Error = {error, ewrongarg, Line, File, Level, Data},
    ephp_error:handle_error(Context, Error),
    <<>>.

base_convert_invalid(Context, Line, Spec, Val) ->
    Level = ?E_WARNING,
    Function = <<"base_convert">>,
    File = ephp_context:get_active_file(Context),
    Data = {Function, Spec, Val},
    Error = {error, einvalid, Line, File, Level, Data},
    ephp_error:handle_error(Context, Error),
    <<>>.

base(N) ->
    lists:sublist([$0, $1, $2, $3, $4, $5, $6, $7, $8, $9, $a, $b, $c, $d, $e, $f, $g, $h, $i,
                   $j, $k, $l, $m, $n, $o, $p, $q, $r, $s, $t, $u, $v, $w, $x, $y, $z],
                  N).

filter_base(Text, Base) ->
    filter_base(Text, base(Base), <<"0">>).

filter_base(<<>>, _Base, Filtered) ->
    Filtered;
filter_base(<<A:8, Rest/binary>>, Base, Filtered) when A >= $A andalso A =< $Z ->
    Char = A + ($a - $A),
    filter_base(<<Char:8, Rest/binary>>, Base, Filtered);
filter_base(<<A:8, Rest/binary>>, Base, Filtered) ->
    case lists:member(A, Base) of
        true ->
            filter_base(Rest, Base, <<Filtered/binary, A:8>>);
        false ->
            filter_base(Rest, Base, Filtered)
    end.

-spec base_convert(ephp:context_id(), line(), var_value(), var_value(), var_value()) ->
                      binary().
base_convert(Context, Line, _, {_, From}, _) when not is_integer(From) ->
    base_convert_error(Context, Line, 2, From);
base_convert(Context, Line, _, _, {_, To}) when not is_integer(To) ->
    base_convert_error(Context, Line, 3, To);
base_convert(Context, Line, _, {_, From}, _) when From < 2 orelse From > 36 ->
    base_convert_invalid(Context, Line, <<"from base">>, From);
base_convert(Context, Line, _, _, {_, To}) when To < 2 orelse To > 36 ->
    base_convert_invalid(Context, Line, <<"to base">>, To);
base_convert(_Context, _Line, {_, String}, {_, From}, {_, To}) when is_binary(String) ->
    Filtered = filter_base(String, From),
    To10 = binary_to_integer(Filtered, From),
    integer_to_binary(To10, To);
base_convert(Context, Line, {Var, A}, From, To) when ?IS_ARRAY(A) ->
    Level = ?E_NOTICE,
    File = ephp_context:get_active_file(Context),
    Type = <<"string">>,
    Error = {error, earrayconv, Line, File, Level, {Type}},
    ephp_error:handle_error(Context, Error),
    base_convert(Context, Line, {Var, <<>>}, From, To);
base_convert(_Context, Line, {_, #obj_ref{pid = Objects, ref = ObjectId}}, _From, _To) ->
    ClassName = ephp_object:get_class_name(Objects, ObjectId),
    ephp_error:error({error, enotostring, Line, ?E_RECOVERABLE_ERROR, {ClassName}});
base_convert(Context, Line, {Var, Other}, From, To) ->
    base_convert(Context, Line, {Var, ephp_data:to_bin(Other)}, From, To).

-spec pi(ephp:context_id(), line()) -> float().
pi(Context, Line) ->
    ephp_context:get_const(Context, <<"M_PI">>, Line).

-spec php_min(ephp:context_id(), line(), Num1 :: var_value(), Num2 :: var_value()) ->
                 integer().
php_min(_Context, _Line, {_, Num1}, {_, Num2}) ->
    if Num1 < Num2 ->
           Num1;
       true ->
           Num2
    end.

-spec php_max(ephp:context_id(), line(), Num1 :: var_value(), Num2 :: var_value()) ->
                 integer().
php_max(_Context, _Line, {_, Num1}, {_, Num2}) ->
    if Num1 > Num2 ->
           Num1;
       true ->
           Num2
    end.

-spec php_exp(ephp:context_id(), line(), Arg :: var_value()) -> float().
php_exp(_Context, _Line, {_, Arg}) ->
    math:exp(Arg).