ranged_int

-module(ranged_int@interface).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).
-define(FILEPATH, "src/ranged_int/interface.gleam").
-export([overflowable_limits/2, max_limit/1, min_limit/1, from_bigint/2, compare/3, math_op/4, math_op_unary/3, fallible_op/4, eject/2, overflow/2]).
-export_type([overflowable/0, non_overflowable/0, limits/1, overflowable_limits/0, interface/2]).

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

?MODULEDOC(
    " The ranged integer \"interface\".\n"
    "\n"
    " This module contains types and functions to be implemented and used to\n"
    " create custom ranged integer types.\n"
    "\n"
    " See the README for instructions on how to create your own type with this\n"
    " module.\n"
).

-type overflowable() :: overflowable.

-type non_overflowable() :: non_overflowable.

-opaque limits(DYE) :: {limits,
        ranged_int@internal@limit:limit(),
        ranged_int@internal@limit:limit()} |
    {gleam_phantom, DYE}.

-type overflowable_limits() :: {overflowable_limits,
        bigi:big_int(),
        bigi:big_int()}.

-type interface(DYF, DYG) :: {interface,
        fun((DYF) -> bigi:big_int()),
        fun((bigi:big_int()) -> DYF),
        fun(() -> limits(DYG))}.

-file("src/ranged_int/interface.gleam", 64).
?DOC(
    " Construct limits for an overflowable ranged integer. The given limits are\n"
    " inclusive.\n"
).
-spec overflowable_limits(bigi:big_int(), bigi:big_int()) -> limits(overflowable()).
overflowable_limits(Min, Max) ->
    {limits, {bounded, Min}, {bounded, Max}}.

-file("src/ranged_int/interface.gleam", 70).
?DOC(
    " Construct limits for a non-overflowable ranged integer that only has a\n"
    " maximum limit. The given limit is inclusive.\n"
).
-spec max_limit(bigi:big_int()) -> limits(non_overflowable()).
max_limit(Max) ->
    {limits, unbounded, {bounded, Max}}.

-file("src/ranged_int/interface.gleam", 76).
?DOC(
    " Construct limits for a non-overflowable ranged integer that only has a\n"
    " minimum limit. The given limit is inclusive.\n"
).
-spec min_limit(bigi:big_int()) -> limits(non_overflowable()).
min_limit(Min) ->
    {limits, {bounded, Min}, unbounded}.

-file("src/ranged_int/interface.gleam", 81).
?DOC(" Create a ranged integer from a big integer.\n").
-spec from_bigint(bigi:big_int(), interface(DYN, any())) -> {ok, DYN} |
    {error, ranged_int@utils:overflow()}.
from_bigint(Value, Interface) ->
    Limits = (erlang:element(4, Interface))(),
    case ranged_int@internal@limit:check_limits(
        Value,
        erlang:element(2, Limits),
        erlang:element(3, Limits)
    ) of
        no_overflow ->
            {ok, (erlang:element(3, Interface))(Value)};

        {overflow, Amount} ->
            {error, {would_overflow, Amount}};

        {underflow, Amount@1} ->
            {error, {would_underflow, Amount@1}}
    end.

-file("src/ranged_int/interface.gleam", 95).
?DOC(
    " Compare two ranged integers, returning an order that denotes if `int1` is\n"
    " lower, bigger than, or equal to `int2`.\n"
).
-spec compare(DYS, DYS, interface(DYS, any())) -> gleam@order:order().
compare(Int1, Int2, Interface) ->
    bigi_ffi:compare(
        (erlang:element(2, Interface))(Int1),
        (erlang:element(2, Interface))(Int2)
    ).

-file("src/ranged_int/interface.gleam", 104).
?DOC(" Run a math operation on a ranged integer and an unranged big integer.\n").
-spec math_op(
    DYW,
    bigi:big_int(),
    interface(DYW, any()),
    fun((bigi:big_int(), bigi:big_int()) -> bigi:big_int())
) -> {ok, DYW} | {error, ranged_int@utils:overflow()}.
math_op(Int1, Int2, Interface, Op) ->
    Limits = (erlang:element(4, Interface))(),
    Int1@1 = (erlang:element(2, Interface))(Int1),
    Result = Op(Int1@1, Int2),
    case ranged_int@internal@limit:check_limits(
        Result,
        erlang:element(2, Limits),
        erlang:element(3, Limits)
    ) of
        no_overflow ->
            {ok, (erlang:element(3, Interface))(Result)};

        {overflow, Amount} ->
            {error, {would_overflow, Amount}};

        {underflow, Amount@1} ->
            {error, {would_underflow, Amount@1}}
    end.

-file("src/ranged_int/interface.gleam", 121).
?DOC(" Run a unary math operation on a ranged integer.\n").
-spec math_op_unary(
    DZB,
    interface(DZB, any()),
    fun((bigi:big_int()) -> bigi:big_int())
) -> {ok, DZB} | {error, ranged_int@utils:overflow()}.
math_op_unary(Int, Interface, Op) ->
    Limits = (erlang:element(4, Interface))(),
    Int@1 = (erlang:element(2, Interface))(Int),
    Result = Op(Int@1),
    case ranged_int@internal@limit:check_limits(
        Result,
        erlang:element(2, Limits),
        erlang:element(3, Limits)
    ) of
        no_overflow ->
            {ok, (erlang:element(3, Interface))(Result)};

        {overflow, Amount} ->
            {error, {would_overflow, Amount}};

        {underflow, Amount@1} ->
            {error, {would_underflow, Amount@1}}
    end.

-file("src/ranged_int/interface.gleam", 141).
?DOC(
    " Run a math operation that may fail on a ranged integer and an unranged big\n"
    " integer.\n"
    "\n"
    " Some functions such as `bigi.divide_no_zero` will return an error if the\n"
    " arguments are invalid. This error is passed upwards by this function.\n"
).
-spec fallible_op(
    DZG,
    bigi:big_int(),
    interface(DZG, any()),
    fun((bigi:big_int(), bigi:big_int()) -> {ok, bigi:big_int()} | {error, DZK})
) -> {ok, {ok, DZG} | {error, ranged_int@utils:overflow()}} | {error, DZK}.
fallible_op(Int1, Int2, Interface, Op) ->
    Limits = (erlang:element(4, Interface))(),
    Int1@1 = (erlang:element(2, Interface))(Int1),
    gleam@result:'try'(
        Op(Int1@1, Int2),
        fun(Result) ->
            {ok,
                case ranged_int@internal@limit:check_limits(
                    Result,
                    erlang:element(2, Limits),
                    erlang:element(3, Limits)
                ) of
                    no_overflow ->
                        {ok, (erlang:element(3, Interface))(Result)};

                    {overflow, Amount} ->
                        {error, {would_overflow, Amount}};

                    {underflow, Amount@1} ->
                        {error, {would_underflow, Amount@1}}
                end}
        end
    ).

-file("src/ranged_int/interface.gleam", 177).
?DOC(
    " Eject the result of an operation to big integer. The big integer may be\n"
    " outside the range of the original ranged integers.\n"
).
-spec eject(
    {ok, DZV} | {error, ranged_int@utils:overflow()},
    interface(DZV, any())
) -> bigi:big_int().
eject(Value, Interface) ->
    case Value of
        {ok, New_value} ->
            (erlang:element(2, Interface))(New_value);

        {error, Overflow} ->
            case {Overflow, (erlang:element(4, Interface))()} of
                {{would_overflow, Amount}, {limits, _, {bounded, Max}}} ->
                    bigi_ffi:add(Max, Amount);

                {{would_underflow, Amount@1}, {limits, {bounded, Min}, _}} ->
                    bigi_ffi:subtract(Min, Amount@1);

                {_, _} ->
                    erlang:error(#{gleam_error => panic,
                            message => <<"Overflowed but there was no corresponding limit (o_O)"/utf8>>,
                            file => <<?FILEPATH/utf8>>,
                            module => <<"ranged_int/interface"/utf8>>,
                            function => <<"eject"/utf8>>,
                            line => 186})
            end
    end.

-file("src/ranged_int/interface.gleam", 192).
-spec destructure_limits(limits(overflowable())) -> overflowable_limits().
destructure_limits(Limits) ->
    Min@1 = case erlang:element(2, Limits) of
        {bounded, Min} -> Min;
        _assert_fail ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Pattern match failed, no pattern matched the value."/utf8>>,
                        file => <<?FILEPATH/utf8>>,
                        module => <<"ranged_int/interface"/utf8>>,
                        function => <<"destructure_limits"/utf8>>,
                        line => 194,
                        value => _assert_fail,
                        start => 6907,
                        'end' => 6949,
                        pattern_start => 6918,
                        pattern_end => 6936})
    end,
    Max@1 = case erlang:element(3, Limits) of
        {bounded, Max} -> Max;
        _assert_fail@1 ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Pattern match failed, no pattern matched the value."/utf8>>,
                        file => <<?FILEPATH/utf8>>,
                        module => <<"ranged_int/interface"/utf8>>,
                        function => <<"destructure_limits"/utf8>>,
                        line => 195,
                        value => _assert_fail@1,
                        start => 6952,
                        'end' => 6994,
                        pattern_start => 6963,
                        pattern_end => 6981})
    end,
    {overflowable_limits, Min@1, Max@1}.

-file("src/ranged_int/interface.gleam", 164).
?DOC(
    " Map the overflow result of an operation to the integer's allowed range.\n"
    "\n"
    " The overflow is calculated using a modulo against the amount of integers in\n"
    " the allowed range. This matches the unsigned integer overflow logic of C/C++\n"
    " but is also defined for signed (negative) values.\n"
    "\n"
    " This can only be called for overflowable integers.\n"
).
-spec overflow(
    {ok, DZQ} | {error, ranged_int@utils:overflow()},
    interface(DZQ, overflowable())
) -> DZQ.
overflow(Value, Interface) ->
    case Value of
        {ok, New_value} ->
            New_value;

        {error, Overflow} ->
            {overflowable_limits, Min, Max} = destructure_limits(
                (erlang:element(4, Interface))()
            ),
            _pipe = ranged_int@utils:overflow(Overflow, Min, Max),
            (erlang:element(3, Interface))(_pipe)
    end.