-module(eval).
-compile(no_auto_import).

-export([run/2, step/2, succeed/1, succeed2/1, succeed3/1, succeed4/1, succeed5/1, succeed6/1, throw/1, from/1, from_option/2, from_result/1, map/2, map2/3, map_error/2, replace/2, replace_error/2, apply/2, then/2, all/1, attempt/2]).
-export_type([eval/3]).

-opaque eval(EHB, EHC, EHD) :: {eval,
                                fun((EHD) -> {EHD, {ok, EHB} | {error, EHC}})}.

-spec run(eval(EHG, EHH, EHI), EHI) -> {ok, EHG} | {error, EHH}.
run(Eval, Context) ->
    _pipe = step(Eval, Context),
    gleam@pair:second(_pipe).

-spec step(eval(EHO, EHP, EHQ), EHQ) -> {EHQ, {ok, EHO} | {error, EHP}}.
step(Eval, Ctx) ->
    {eval, Eval@1} = Eval,
    Eval@1(Ctx).

-spec succeed(EHW) -> eval(EHW, any(), any()).
succeed(Value) ->
    {eval, fun(Ctx) -> {Ctx, {ok, Value}} end}.

-spec succeed2(fun((EIC, EID) -> EIE)) -> eval(fun((EIC) -> fun((EID) -> EIE)), any(), any()).
succeed2(F) ->
    _pipe = gleam@function:curry2(F),
    succeed(_pipe).

-spec succeed3(fun((EIK, EIL, EIM) -> EIN)) -> eval(fun((EIK) -> fun((EIL) -> fun((EIM) -> EIN))), any(), any()).
succeed3(F) ->
    _pipe = gleam@function:curry3(F),
    succeed(_pipe).

-spec succeed4(fun((EIT, EIU, EIV, EIW) -> EIX)) -> eval(fun((EIT) -> fun((EIU) -> fun((EIV) -> fun((EIW) -> EIX)))), EIX, any()).
succeed4(F) ->
    _pipe = gleam@function:curry4(F),
    succeed(_pipe).

-spec succeed5(fun((EJC, EJD, EJE, EJF, EJG) -> EJH)) -> eval(fun((EJC) -> fun((EJD) -> fun((EJE) -> fun((EJF) -> fun((EJG) -> EJH))))), EJG, any()).
succeed5(F) ->
    _pipe = gleam@function:curry5(F),
    succeed(_pipe).

-spec succeed6(fun((EJM, EJN, EJO, EJP, EJQ, EJR) -> EJS)) -> eval(fun((EJM) -> fun((EJN) -> fun((EJO) -> fun((EJP) -> fun((EJQ) -> fun((EJR) -> EJS)))))), EJQ, any()).
succeed6(F) ->
    _pipe = gleam@function:curry6(F),
    succeed(_pipe).

-spec throw(EJX) -> eval(any(), EJX, any()).
throw(Error) ->
    {eval, fun(Ctx) -> {Ctx, {error, Error}} end}.

-spec from(fun((EKD) -> {EKD, {ok, EKE} | {error, EKF}})) -> eval(EKE, EKF, EKD).
from(Eval) ->
    {eval, Eval}.

-spec from_option(gleam@option:option(EKL), EKN) -> eval(EKL, EKN, any()).
from_option(Value, Error) ->
    case Value of
        {some, A} ->
            succeed(A);

        none ->
            throw(Error)
    end.

-spec from_result({ok, EKS} | {error, EKT}) -> eval(EKS, EKT, any()).
from_result(Value) ->
    case Value of
        {ok, A} ->
            succeed(A);

        {error, E} ->
            throw(E)
    end.

-spec map(eval(ELA, ELB, ELC), fun((ELA) -> ELG)) -> eval(ELG, ELB, ELC).
map(Eval, F) ->
    {eval,
     fun(Ctx) ->
         {Ctx@1, Result} = step(Eval, Ctx),
         case Result of
             {ok, A} ->
                 {Ctx@1, {ok, F(A)}};

             {error, E} ->
                 {Ctx@1, {error, E}}
         end
     end}.

-spec map2(eval(ELK, ELL, ELM), eval(ELQ, ELL, ELM), fun((ELK, ELQ) -> ELU)) -> eval(ELU, ELL, ELM).
map2(Eval_a, Eval_b, F) ->
    {eval,
     fun(Ctx) ->
         {Ctx@1, Result1} = step(Eval_a, Ctx),
         case Result1 of
             {ok, A} ->
                 {Ctx@2, Result2} = step(Eval_b, Ctx@1),
                 case Result2 of
                     {ok, B} ->
                         {Ctx@2, {ok, F(A, B)}};

                     {error, E} ->
                         {Ctx@2, {error, E}}
                 end;

             {error, E@1} ->
                 {Ctx@1, {error, E@1}}
         end
     end}.

-spec map_error(eval(ELY, ELZ, EMA), fun((ELZ) -> EME)) -> eval(ELY, EME, EMA).
map_error(Eval, F) ->
    {eval,
     fun(Ctx) ->
         {Ctx@1, Result} = step(Eval, Ctx),
         case Result of
             {ok, A} ->
                 {Ctx@1, {ok, A}};

             {error, E} ->
                 {Ctx@1, {error, F(E)}}
         end
     end}.

-spec replace(eval(any(), EMJ, EMK), EMO) -> eval(EMO, EMJ, EMK).
replace(Eval, Replacement) ->
    {eval,
     fun(Ctx) ->
         {Ctx@1, Result} = step(Eval, Ctx),
         case Result of
             {ok, _@1} ->
                 {Ctx@1, {ok, Replacement}};

             {error, E} ->
                 {Ctx@1, {error, E}}
         end
     end}.

-spec replace_error(eval(EMS, any(), EMU), EMY) -> eval(EMS, EMY, EMU).
replace_error(Eval, Replacement) ->
    {eval,
     fun(Ctx) ->
         {Ctx@1, Result} = step(Eval, Ctx),
         case Result of
             {ok, A} ->
                 {Ctx@1, {ok, A}};

             {error, _@1} ->
                 {Ctx@1, {error, Replacement}}
         end
     end}.

-spec apply(eval(fun((ENC) -> END), ENE, ENF), eval(ENC, ENE, ENF)) -> eval(END, ENE, ENF).
apply(Eval_f, Eval_a) ->
    map2(Eval_f, Eval_a, fun(F, A) -> F(A) end).

-spec then(eval(ENP, ENQ, ENR), fun((ENP) -> eval(ENV, ENQ, ENR))) -> eval(ENV, ENQ, ENR).
then(Eval, F) ->
    {eval,
     fun(Ctx) ->
         {Ctx@1, Result} = step(Eval, Ctx),
         case Result of
             {ok, A} ->
                 step(F(A), Ctx@1);

             {error, E} ->
                 {Ctx@1, {error, E}}
         end
     end}.

-spec all(list(eval(EOC, EOD, EOE))) -> eval(list(EOC), EOD, EOE).
all(Evals) ->
    Prepend = fun(List, A) -> [A | List] end,
    Callback = fun(A@1, List@1) -> map2(A@1, List@1, Prepend) end,
    _pipe = gleam@list:fold(Evals, succeed([]), Callback),
    map(_pipe, fun gleam@list:reverse/1).

-spec attempt(eval(EON, EOO, EOP), fun((EOP, EOO) -> eval(EON, EOO, EOP))) -> eval(EON, EOO, EOP).
attempt(Eval, F) ->
    {eval,
     fun(Ctx) ->
         {Ctx_, Result} = step(Eval, Ctx),
         case Result of
             {ok, A} ->
                 {Ctx_, {ok, A}};

             {error, E} ->
                 step(F(Ctx_, E), Ctx)
         end
     end}.