package Torello.Java.JSON;

import Torello.JavaDoc.IntoHTMLTable;
import static Torello.JavaDoc.IntoHTMLTable.Background.*;

import javax.json.JsonArray;
import javax.json.JsonObject;
import javax.json.JsonValue;
import javax.json.JsonNumber;
import javax.json.JsonString;

import static javax.json.JsonValue.ValueType.*;

import java.math.BigDecimal;
import java.util.function.Function;
import java.util.function.ObjIntConsumer;

/**
 * This class is the "Central Artery" for all Json-Array Processing done in this package.
 * These four FOR-LOOPS handle 100% of the array processors done by all of the "RJArr"
 * classes offered.
 *  
 * These four methods are extremely similar, but have a few minor subtleties that prevent 
 * them from being unified into a single handler for all types.
 */
public class ProcessJsonArray
{
    private ProcessJsonArray() { }


    // ********************************************************************************************
    // ********************************************************************************************
    // Un-Synchronized Method Variants
    // ********************************************************************************************
    // ********************************************************************************************


    /**
     * Any and all Json-Array Processors that are intended to read an array of {@link JsonNumber}
     * will invoke this method to do their Type-Conversions.
     * 
     * @param <NUMERIC_DATA_TYPE> <EMBED CLASS='external-html' DATA-FILE-ID=PJA_NUM_DATA_TYPE>
     * @param <RETURN_TYPE> <EMBED CLASS='external-html' DATA-FILE-ID=PJA_NUM_RETURN_TYPE>
     * 
     * @param ja This should be any instance of {@link JsonArray}.  It is expected that if this
     * array does not contain explicit {@link JsonNumber} values, that is should at least contain
     * values that are to converted or properly parsed into Java-Numbers.
     * 
     * @param rec <EMBED CLASS='external-html' DATA-FILE-ID=PJA_REC_PARAM>
     * 
     * @return An instance of the type specified by Type-Parameter {@code 'RETURN_TYPE'}
     */
    public static <NUMERIC_DATA_TYPE extends Number, RETURN_TYPE> RETURN_TYPE numericToJava(
            final JsonArray                                     ja,
            final SettingsRec<NUMERIC_DATA_TYPE, RETURN_TYPE>   rec
        )
    {
        rec.ja = ja;

        final int SIZE = ja.size();

        JsonValue jv;


        // If 'RETURN_TYPE' is a Stream, this builds a new Stream, and saves it to the
        // internally-used "EffectivelyFinal" instance.  It's quite simple, actually.
        //
        // If 'RETURN_TYPE' is a Consumer, this is a simple "No-Op"

        rec.constructNewBuilder.run();

        for (int i=0; i < SIZE; i++)

            switch ((jv = ja.get(i)).getValueType())
            {
                // javax.json.JsonValue.ValueType.NULL
                case NULL: rec.handlerNull.accept(i); break;

                // javax.json.JsonValue.ValueType.NUMBER
                case NUMBER: rec.handlerNumber.accept((JsonNumber) jv, i); break;

                // javax.json.JsonValue.ValueType.STRING
                case STRING: rec.handlerJsonString.accept((JsonString) jv, i); break;

                // OBJECT, ARRAY, TRUE, FALSE
                default:

                    if (rec.handlerWrongType != null)
                        rec.handlerWrongType.accept(i);
                    else
                        throw new JsonTypeArrException(ja, i, NUMBER, jv, rec.CLASS);
            }

        // Run Stream.Builder.build()
        return rec.runBuilderDotBuild.get();
    }

    /**
     * Any and all Json-Array Processors that are intended to read an array of Json-Boolean Values
     * will invoke this method to do their Type-Conversions.
     * 
     * @param <RETURN_TYPE> <EMBED CLASS='external-html' DATA-FILE-ID=PJA_BL_RETURN_TYPE>
     * 
     * @param ja This should be any instance of {@link JsonArray}.  It is expected that if this
     * array does not contain explicit Json-Boolean values, that is should at least contain values
     * that are to converted or properly parsed into Java-Booleans.
     * 
     * @param rec <EMBED CLASS='external-html' DATA-FILE-ID=PJA_REC_PARAM>
     * 
     * @return An instance of {@code Stream<Boolean>}.  If the provided instance of 
     * {@code SettingsRec} has been constructed for a {@code Consumer}, then this method will  
     * return null.
     */
    public static <RETURN_TYPE> RETURN_TYPE booleanToJava(
            final JsonArray                         ja,
            final SettingsRec<Boolean, RETURN_TYPE> rec
        )
    {
        final int SIZE = ja.size();

        JsonValue jv = null;

        rec.ja = ja;

        // If 'RETURN_TYPE' is a Consumer, this is a simple "No-Op"
        rec.constructNewBuilder.run();

        for (int i=0; i < SIZE; i++)

            switch ((jv = ja.get(i)).getValueType())
            {
                // javax.json.JsonValue.ValueType.NULL, TRUE, FALSE & STRING
                case NULL:      rec.handlerNull.accept(i); break;
                case TRUE:      rec.ACCEPTOR.accept(true, i); break;
                case FALSE:     rec.ACCEPTOR.accept(false, i); break;
                case STRING:    rec.handlerJsonString.accept((JsonString) jv, i); break;

                // javax.json.JsonValue.ValueType.NUMBER, OBJECT, ARRAY
                default:
                    if (rec.handlerWrongType != null) rec.handlerWrongType.accept(i);
                    else throw new JsonTypeArrException(ja, i, TRUE, jv, Boolean.class);
            }


        // Run Stream.Builder.build() - IF NEEDED
        // 'get()' simply returns null if the SettingsRec<T, U> had a "consumer"
        // for it's 'U' Type, rather than a Stream.

        return rec.runBuilderDotBuild.get();
    }

    /**
     * Used to convert {@code JsonObject}'s into Java-Objects
     * 
     * @param <T> The Class / Type of the Objects to be extracted from the {@link JsonArray}
     * @param <RETURN_TYPE> <EMBED CLASS='external-html' DATA-FILE-ID=PJA_T_RETURN_TYPE>
     * 
     * @param ja This should be any instance of {@link JsonArray}.  It is expected that this array
     * contain explicit {@link JsonObject} values, that can be converted in.to {@code 'T'}
     * 
     * @param rec <EMBED CLASS='external-html' DATA-FILE-ID=PJA_REC_PARAM>
     * 
     * @return An instance of the type specified by Type-Parameter {@code 'RETURN_TYPE'}.
     */
    public static <T, RETURN_TYPE> RETURN_TYPE objToJava(
            final JsonArray                     ja,
            final SettingsRec<T, RETURN_TYPE>   rec
        )
    {
        final int SIZE = ja.size();

        JsonValue jv = null;

        rec.ja = ja;


        // For Stream<T>, this builds a new Stream.Builder
        // for Consumer<T>, this is a "No-Op"

        rec.constructNewBuilder.run();

        for (int i=0; i < SIZE; i++)

            switch ((jv = ja.get(i)).getValueType())
            {
                // javax.json.JsonValue.ValueType.NULL
                case NULL:
                    rec.handlerNull.accept(i);
                    break;

                // javax.json.JsonValue.ValueType.OBJECT
                case OBJECT:
                    T obj = rec.builder1Or2
                        ? rec.objBuilder.apply((JsonObject) jv)
                        : rec.objBuilder2.apply(i, (JsonObject) jv);

                    rec.ACCEPTOR.accept(obj, i);
                    break;

                // javax.json.JsonValue.ValueType.NUMBER, STRING, TRUE, FALSE, ARRAY
                default:
                    if (rec.handlerWrongType != null) rec.handlerWrongType.accept(i);
                    else throw new JsonTypeArrException(ja, i, TRUE, jv, rec.CLASS);
            }


        // For Stream<T>, this runs Stream.Builder.build()
        // For Consumer<T>, this automatically returns null

        return rec.runBuilderDotBuild.get();
    }

    /**
     * Any and all Json-Array Processors that are intended to read an array of {@link JsonString}
     * Values will invoke this method to do their Type-Conversions.
     * 
     * @param <RETURN_TYPE> <EMBED CLASS='external-html' DATA-FILE-ID=PJA_STR_RETURN_TYPE>
     * 
     * @param ja This should be any instance of {@link JsonArray}.
     * 
     * @param rec <EMBED CLASS='external-html' DATA-FILE-ID=PJA_REC_PARAM>
     * 
     * @return An instance of {@code Stream<String>}.  If the provided instance of
     * {@code SettingsRec} has been constructed for a {@code Consumer}, then this method will
     * return null.
     */
    public static <RETURN_TYPE> RETURN_TYPE strToJava(
            final JsonArray                         ja,
            final SettingsRec<String, RETURN_TYPE>  rec
        )
    {
        final int SIZE = ja.size();

        JsonValue jv = null;

        rec.ja = ja;

        if (rec.constructNewBuilder != null) rec.constructNewBuilder.run();

        for (int i=0; i < SIZE; i++)

            switch ((jv = ja.get(i)).getValueType())
            {
                // javax.json.JsonValue.ValueType.NULL
                case NULL:
                    rec.handlerNull.accept(i);
                    break;

                // javax.json.JsonValue.ValueType.STRING
                case STRING:
                    rec.ACCEPTOR.accept(((JsonString) jv).getString(), i);
                    break;

                // OBJECT, ARRAY, TRUE, FALSE, NUMBER
                default:
                    rec.jsonStringWrongTypeHandler.accept(jv, i);
            }


        // Returns the Built-Stream, for Streams.
        // Returns 'null' for Consumer's

        return rec.runBuilderDotBuild.get();
    }


    // ********************************************************************************************
    // ********************************************************************************************
    // Synchronized Method Variants
    // ********************************************************************************************
    // ********************************************************************************************


    /**
     * <BR>Synchronized: Nothing More than a "Synchronized Wrapper" which can be used in a
     *                   Multi-Threaded Programming-Environment.
     * <BR>Wraps: Method {@link #numericToJava(JsonArray, SettingsRec)}
     * <BR>Locking-Object: Input-Parameter {@code 'rec'}, the {@code SettingsRec} instance 
     * <BR>IMPORTANT: Synchronization <B><I>is only needed</I></B> when the {@code SettingsRec}
     *                instance shall be "re-used" in other threads.
     */
    @IntoHTMLTable(background=BlueDither, title="Synchronized Variant of Method 'numericToJava'")
    public static <NUMERIC_DATA_TYPE extends Number, RETURN_TYPE> RETURN_TYPE
        numericToJavaSync(
            final JsonArray                                     ja,
            final SettingsRec<NUMERIC_DATA_TYPE, RETURN_TYPE>   rec
        )
    { synchronized (rec) { return numericToJava(ja, rec); } }

    /**
     * <BR>Synchronized: Nothing More than a "Synchronized Wrapper" which can be used in a
     *                   Multi-Threaded Programming-Environment.
     * <BR>Wraps: Method {@link #booleanToJava(JsonArray, SettingsRec)}
     * <BR>Locking-Object: Input-Parameter {@code 'rec'}, the {@code SettingsRec} instance 
     * <BR>IMPORTANT: Synchronizations <B><I>is only needed</I></B> when the {@code SettingsRec}
     *                instance shall be "re-used" in other threads.
     */
    @IntoHTMLTable(background=GreenDither, title="Synchronized Variant of Method 'booleanToJava'")
    public static <RETURN_TYPE> RETURN_TYPE booleanToJavaSync(
            final JsonArray                         ja,
            final SettingsRec<Boolean, RETURN_TYPE> rec
        )
    { synchronized (rec) { return booleanToJava(ja, rec); } }

    /**
     * <BR>Synchronized: Nothing More than a "Synchronized Wrapper" which can be used in a
     *                     Multi-Threaded Programming-Environment.
     * <BR>Wraps: Method {@link #objToJava(JsonArray, SettingsRec)}
     * <BR>Locking-Object: Input-Parameter {@code 'rec'}, the {@code SettingsRec} instance 
     * <BR>IMPORTANT: Synchronizations <B><I>is only needed</I></B> when the {@code SettingsRec}
     *                instance shall be "re-used" in other threads.
     */
    @IntoHTMLTable(background=BlueDither, title="Synchronized Variant of Method 'objToJava'")
    public static <T, RETURN_TYPE> RETURN_TYPE objToJavaSync(
            final JsonArray                     ja,
            final SettingsRec<T, RETURN_TYPE>   rec
        )
    { synchronized (rec) { return objToJava(ja, rec); } }

    /**
     * <BR>Synchronized: Nothing More than a "Synchronized Wrapper" which can be used in a
     *                     Multi-Threaded Programming-Environment.
     * <BR>Wraps: Method {@link #strToJava(JsonArray, SettingsRec)}
     * <BR>Locking-Object: Input-Parameter {@code 'rec'}, the {@code SettingsRec} instance 
     * <BR>IMPORTANT: Synchronizations <B><I>is only needed</I></B> when the {@code SettingsRec}
     *                instance shall be "re-used" in other threads.
     */
    @IntoHTMLTable(background=GreenDither, title="Synchronized Variant of Method 'strToJava'")
    public static <RETURN_TYPE> RETURN_TYPE strToJavaSync(
        final JsonArray                         ja,
        final SettingsRec<String, RETURN_TYPE>  rec
    )
    { synchronized (rec) { return strToJava(ja, rec); } }

}