package Torello.JSON;

import Torello.Java.UnreachableError;

import java.util.function.ObjIntConsumer;
import java.util.function.IntConsumer;
import java.util.function.Predicate;
import java.util.function.Function;

import javax.json.JsonValue;
import javax.json.JsonString;

import java.math.BigDecimal;


// NOTE: This is not Rocket-Science.  It just looks really complicated.
// 
// Stuff with "Types" becomes so heinous to look at.  I started this package in
// 2022, and it is now 2025.  The Package Torello.JSON has more testing code than
// literally any of the other packages in this Library.
// 
// I'm still not done testing it.  There is still more that I should do.
// 
// The only purpose of making a "String-Handler" is so that the MAIN-PROCESSING-LOOP
// which is in class "ProcessJsonArr" is short, simple & sweet.  It just calls the handlers that
// are saved inside of the "SettingsRec".  The SettingsRec gets a String-Handler from this class!
// 
// 
// *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
// The 'ja' instance declared in class "SettingsRec" **IS NOT** declared final.  It can be reset !
// *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
// 
// IMPORTANT NOTE: The 'ja' that is passed to the Functional-Interface Implementatons which are 
// constructed in this method is "de-referenced" from the SettingsRec -- It **IS NOT** passed as
// a parameter to this method.  If it **WERE NOT** retrieved from the 'SettingsRec', then 'sr'
// instance, then the 'ja' that would be used would be permanently-solidified to the 'ja' 
// referenced that were passed right at the beginning, upon construction of the SettingsRec
// instance.

@Torello.JavaDoc.Annotations.StaticFunctional
public class ChooseStringHandler
{
    private ChooseStringHandler() {}


    static <T> ObjIntConsumer<JsonString> useUserParser(
            final SettingsRec<T, ?>     sr,
            final Class<T>              CLASS,
            final ACCEPTOR<T>           acceptor,
            final Function<String, T>   userParser,
            final IntConsumer           handlerSPEX
        ) 
    {
        return (final JsonString js, final int i) ->
        {
            try
                { acceptor.accept(userParser.apply(js.getString()), i); }

            catch (Exception e)
            {
                // IMPORTANT NOTE: See the comment at the top of this class regarding the 'sr.ja'
                // versus 'ja' (being passed as a parameter to this method).

                if (handlerSPEX != null) handlerSPEX.accept(i);
                else throw new JsonStrParseArrException(e, sr.ja, i, js, CLASS);
            }
        };
    }

    static <T> ObjIntConsumer<JsonString> parseString(
            final SettingsRec<T, ?>     sr,
            final Class<T>              CLASS,
            final ACCEPTOR<T>           acceptor,
            final IntConsumer           handlerSPEX,
            final IntConsumer           handlerZLS,
            final Predicate<String>     validStrTester,
            final Function<String, T>   defaultParser
        )
    {
        return (final JsonString js, final int i) ->
        {
            String s = js.getString();

            if (s.length() == 0)
            {
                if (handlerZLS != null) handlerZLS.accept(i);


                // IMPORTANT NOTE: See the comment at the top of this class regarding the 'sr.ja'
                // versus 'ja' (being passed as a parameter to this method).

                else throw new JsonStrParseArrException(
                    new IllegalArgumentException("Zero Length String"),
                    sr.ja, i, js, CLASS
                );
            }

            // StringParse.isInteger(s), isLong(String) **AND** s -> true (Double)
            else if (validStrTester.test(s))

                // Integer.parseInt(String), Long.parseLong, Double.parseDouble
                acceptor.accept(defaultParser.apply(s), i);

            else if (handlerSPEX != null) handlerSPEX.accept(i);


            // IMPORTANT NOTE: See the comment at the top of this class regarding the 'sr.ja'
            // versus 'ja' (being passed as a parameter to this method).

            else throw new JsonStrParseArrException
                (getSPEX(s, defaultParser), sr.ja, i, js, CLASS);
        };
    }

    // Small Internal, static, helper
    private static Exception getSPEX(final String s, final Function<String, ?> converter)
    {
        try
            { converter.apply(s); }

        catch (Exception e)
            { return e; }

        throw new UnreachableError();
    }

    @SuppressWarnings("unchecked")
    static <T> ObjIntConsumer<JsonString> parseStringNUMBER(
            final SettingsRec<T, ?> sr,
            final Class<T>          CLASS,
            final ACCEPTOR<T>       acceptor,
            final IntConsumer       handlerSPEX,
            final IntConsumer       handlerZLS
        )
    {
        return (final JsonString js, final int i) ->
        {
            String s = js.getString();

            if (s.length() == 0)
            {
                if (handlerZLS != null) handlerZLS.accept(i);


                // IMPORTANT NOTE: See the comment at the top of this class regarding the 'sr.ja'
                // versus 'ja' (being passed as a parameter to this method).

                else throw new JsonStrParseArrException(
                    new IllegalArgumentException("Zero Length String"),
                    sr.ja, i, js, CLASS
                );

                return;
            }

            final BigDecimal bd;

            try
                { bd = new BigDecimal(s); }

            catch (Exception e)
            {
                if (handlerSPEX != null) handlerSPEX.accept(i);

                else throw new JsonStrParseArrException
                    (e, sr.ja, i, js, Number.class);

                return;
            }

            // ((ObjIntConsumer<Number>) ACCEPTOR).accept(ReadNumberJSON.convertToNumber(bd), i);
            ((ACCEPTOR<Number>) acceptor).accept(ReadNumberJSON.convertToNumber(bd), i);
        };
    }
}