package Torello.JSON;

import Torello.JavaDoc.Annotations.IntoHTMLTable;
import static Torello.JavaDoc.Annotations.IntoHTMLTable.Background.GreenDither;
import static Torello.JavaDoc.Annotations.IntoHTMLTable.Background.BlueDither;

import java.util.function.Predicate;
import java.util.function.ToIntFunction;
import java.util.function.ToLongFunction;
import java.util.function.ToDoubleFunction;

import Torello.Java.Function.ToByteFunction;
import Torello.Java.Function.ToShortFunction;
import Torello.Java.Function.ToFloatFunction;

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

import static javax.json.JsonValue.ValueType.STRING;
import static javax.json.JsonValue.ValueType.NULL;

/**
 * Builds on the J2EE Standard Release JSON Parsing Tools by providing additional
 * help with converting JSON Data into <B STYLE='color: red'>Java Primitive-Types</B>
 * 
 * <EMBED CLASS='external-html' DATA-FILE-ID=ALL_CLASSES_NOTE>
 * <EMBED CLASS='external-html' DATA-FILE-ID=PARSE_PRIM_JSON>
 * <EMBED CLASS='external-html' DATA-FILE-ID=PARSE_PRIM_PTABLE>
 * <EMBED CLASS='external-html' DATA-CH=char DATA-FILE-ID=JAVA_LANG_CHAR>
 * 
 * @see JsonObject
 * @see JsonArray
 */
@Torello.JavaDoc.Annotations.StaticFunctional
public class ParsePrimJSON
{
    // This is a static class.  Has no program state.
    private ParsePrimJSON() { }


    // ********************************************************************************************
    // ********************************************************************************************
    // int
    // ********************************************************************************************
    // ********************************************************************************************


    /** <EMBED CLASS='external-html' DATA-JTYPE=int DATA-FILE-ID=PARSE_PRIM_JA> */
    @IntoHTMLTable(
        title="Extract a JsonString from a JsonArray, and Parse into a Java 'int' Primitive",
        background=BlueDither
    )
    public static int parseInt(
            final JsonArray             ja,
            final int                   index,
            final ToIntFunction<String> optionalUserParser
        )
    {
        final JsonString js = GET(ja, index, int.class);

        try
        {
            return (optionalUserParser != null)
                ? optionalUserParser.applyAsInt(js.getString())
                : Integer.parseInt(js.getString().trim());
        }

        catch (Exception e)
            { throw new JsonStrParseArrException(e, ja, index, js, int.class); }
    }

    /** <EMBED CLASS='external-html' DATA-JTYPE=long DATA-FILE-ID=PARSE_PRIM_JA> */
    @IntoHTMLTable(
        title="Extract a JsonString from a JsonArray, and Parse into a Java 'long' Primitive",
        background=GreenDither
    )
    public static long parseLong(
            final JsonArray                 ja,
            final int                       index,
            final ToLongFunction<String>    optionalUserParser
        )
    {
        final JsonString js = GET(ja, index, long.class);

        try
        {
            return (optionalUserParser != null)
                ? optionalUserParser.applyAsLong(js.getString())
                : Long.parseLong(js.getString().trim());
        }

        catch (Exception e)
            { throw new JsonStrParseArrException(e, ja, index, js, long.class); }
    }

    /** <EMBED CLASS='external-html' DATA-JTYPE=short DATA-FILE-ID=PARSE_PRIM_JA> */
    @IntoHTMLTable(
        title="Extract a JsonString from a JsonArray, and Parse into a Java 'short' Primitive",
        background=BlueDither
    )
    public static short parseShort(
            final JsonArray                 ja,
            final int                       index,
            final ToShortFunction<String>   optionalUserParser
        )
    {
        final JsonString js = GET(ja, index, short.class);

        try
        {
            return (optionalUserParser != null)
                ? optionalUserParser.applyAsShort(js.getString())
                : Short.parseShort(js.getString().trim());
        }

        catch (Exception e)
            { throw new JsonStrParseArrException(e, ja, index, js, short.class); }
    }

    /** <EMBED CLASS='external-html' DATA-JTYPE=byte DATA-FILE-ID=PARSE_PRIM_JA> */
    @IntoHTMLTable(
        title="Extract a JsonString from a JsonArray, and Parse into a Java 'byte' Primitive",
        background=GreenDither
    )
    public static byte parseByte(
            final JsonArray                 ja,
            final int                       index,
            final ToByteFunction<String>    optionalUserParser
        )
    {
        final JsonString js = GET(ja, index, byte.class);

        try
        {
            return (optionalUserParser != null)
                ? optionalUserParser.applyAsByte(js.getString())
                : Byte.parseByte(js.getString().trim());
        }

        catch (Exception e)
            { throw new JsonStrParseArrException(e, ja, index, js, byte.class); }
    }

    /** <EMBED CLASS='external-html' DATA-JTYPE=double DATA-FILE-ID=PARSE_PRIM_JA> */
    @IntoHTMLTable(
        title="Extract a JsonString from a JsonArray, and Parse into a Java 'double' Primitive",
        background=BlueDither
    )
    public static double parseDouble(
            final JsonArray                 ja,
            final int                       index,
            final ToDoubleFunction<String>  optionalUserParser
        )
    {
        final JsonString js = GET(ja, index, double.class);

        try
        {
            return (optionalUserParser != null)
                ? optionalUserParser.applyAsDouble(js.getString())
                : Double.parseDouble(js.getString().trim());
        }

        catch (Exception e)
            { throw new JsonStrParseArrException(e, ja, index, js, double.class); }
    }

    /** <EMBED CLASS='external-html' DATA-JTYPE=float DATA-FILE-ID=PARSE_PRIM_JA> */
    @IntoHTMLTable(
        title="Extract a JsonString from a JsonArray, and Parse into a Java 'float' Primitive",
        background=GreenDither
    )
    public static float parseFloat(
            final JsonArray                 ja,
            final int                       index,
            final ToFloatFunction<String>   optionalUserParser
        )
    {
        final JsonString js = GET(ja, index, float.class);

        try
        {
            return (optionalUserParser != null)
                ? optionalUserParser.applyAsFloat(js.getString())
                : Float.parseFloat(js.getString().trim());
        }

        catch (Exception e)
            { throw new JsonStrParseArrException(e, ja, index, js, float.class); }
    }

    /** <EMBED CLASS='external-html' DATA-JTYPE=boolean DATA-FILE-ID=PARSE_PRIM_JA> */
    @IntoHTMLTable(
        title="Extract a JsonString from a JsonArray, and Parse into a Java 'boolean' Primitive",
        background=BlueDither
    )
    public static boolean parseBoolean(
            final JsonArray         ja,
            final int               index,
            final Predicate<String> optionalUserParser
        )
    {
        final JsonString js = GET(ja, index, boolean.class);

        try
        {
            return (optionalUserParser != null)
                ? optionalUserParser.test(js.getString())
                : Boolean.parseBoolean(js.getString().trim());
        }

        catch (Exception e)
            { throw new JsonStrParseArrException(e, ja, index, js, boolean.class); }
    }


    // ********************************************************************************************
    // ********************************************************************************************
    // The Internal Methods
    // ********************************************************************************************
    // ********************************************************************************************


    /**
     * This is an internal helper method for retrieving an element from a {@link JsonArray},
     * and converting it to one of the standard <B STYLE='color: red;'>Java Types</B>.
     * 
     * @param ja                Any instance of {@link JsonArray}
     * @param index             Any index into the array which holds a {@link JsonString}
     * @param primitiveClass    Expected Primitive Class, to be returned by caller method
     *
     * @return The extracted {@link JsonString}.
     * 
     * @throws JsonNullPrimitiveArrException If the array element at {@code 'index'} contains
     *                                       <B STYLE='color: red'>Json-Null</B>
     * @throws JsonTypeArrException         If the array element at {@code 'index'} doesn't contain
     *                                      {@link JsonString}
     * @throws IndexOutOfBoundsException    If {@code 'index'} is out of the bounds of {@code 'ja'}
     * 
     * @see #parseInt(JsonArray, int, ToIntFunction)
     * @see #parseLong(JsonArray, int, ToLongFunction)
     * @see #parseShort(JsonArray, int, ToShortFunction)
     * @see #parseByte(JsonArray, int, ToByteFunction)
     * @see #parseDouble(JsonArray, int, ToDoubleFunction)
     * @see #parseFloat(JsonArray, int, ToFloatFunction)
     */
    protected static <T> JsonString GET(
            final JsonArray ja,
            final int       index,
            final Class<T>  primitiveClass
        )
    {
        // This will throw an IndexOutOfBoundsException if the index is out of bounds.
        final JsonValue jv = ja.get(index);

        switch (jv.getValueType())
        {
            // This particular Array-Location (the one specified by 'index') contained an actual
            // 'null' in its place.  Primitives cannot be assinged null, but fortunately there is
            // a JsonException descendant class that handles this exact situation.

            case NULL: throw new JsonNullPrimitiveArrException
                (ja, index, STRING, primitiveClass);

            case STRING: return (JsonString) jv;

            // The JsonValue at the specified array-index does not contain a JsonString.
            default: throw new JsonTypeArrException
                (ja, index, STRING, jv, primitiveClass);
        }
    }


    // ********************************************************************************************
    // ********************************************************************************************
    // int
    // ********************************************************************************************
    // ********************************************************************************************


    /** <EMBED CLASS='external-html' DATA-JTYPE=int DATA-FILE-ID=PARSE_PRIM_JO> */
    @IntoHTMLTable(
        title="Extract a JsonString from a JsonObject, and Parse into a Java 'int' Primitive",
        background=BlueDither
    )
    public static int parseInt(
            final JsonObject            jo,
            final String                propertyName,
            final ToIntFunction<String> optionalUserParser
        )
    {
        final JsonString js = GET(jo, propertyName, int.class);

        try
        {
            return (optionalUserParser != null)
                ? optionalUserParser.applyAsInt(js.getString())
                : Integer.parseInt(js.getString().trim());
        }

        catch (Exception e)
            { throw new JsonStrParseObjException(e, jo, propertyName, js, int.class); }
    }

    /** <EMBED CLASS='external-html' DATA-JTYPE=long DATA-FILE-ID=PARSE_PRIM_JO> */
    @IntoHTMLTable(
        title="Extract a JsonString from a JsonObject, and Parse into a Java 'long' Primitive",
        background=GreenDither
    )
    public static long parseLong(
            final JsonObject                jo,
            final String                    propertyName,
            final ToLongFunction<String>    optionalUserParser
        )
    {
        final JsonString js = GET(jo, propertyName, long.class);

        try
        {
            return (optionalUserParser != null)
                ? optionalUserParser.applyAsLong(js.getString())
                : Long.parseLong(js.getString().trim());
        }

        catch (Exception e)
            { throw new JsonStrParseObjException(e, jo, propertyName, js, long.class); }
    }

    /** <EMBED CLASS='external-html' DATA-JTYPE=short DATA-FILE-ID=PARSE_PRIM_JO> */
    @IntoHTMLTable(
        title="Extract a JsonString from a JsonObject, and Parse into a Java 'short' Primitive",
        background=BlueDither
    )
    public static short parseShort(
            final JsonObject                jo,
            final String                    propertyName,
            final ToShortFunction<String>   optionalUserParser
        )
    {
        final JsonString js = GET(jo, propertyName, short.class);

        try
        {
            return (optionalUserParser != null)
                ? optionalUserParser.applyAsShort(js.getString())
                : Short.parseShort(js.getString().trim());
        }

        catch (Exception e)
            { throw new JsonStrParseObjException(e, jo, propertyName, js, short.class); }
    }

    /** <EMBED CLASS='external-html' DATA-JTYPE=byte DATA-FILE-ID=PARSE_PRIM_JO> */
    @IntoHTMLTable(
        title="Extract a JsonString from a JsonObject, and Parse into a Java 'byte' Primitive",
        background=GreenDither
    )
    public static byte parseByte(
            final JsonObject                jo,
            final String                    propertyName,
            final ToByteFunction<String>    optionalUserParser
        )
    {
        final JsonString js = GET(jo, propertyName, byte.class);

        try
        {
            return (optionalUserParser != null)
                ? optionalUserParser.applyAsByte(js.getString())
                : Byte.parseByte(js.getString().trim());
        }

        catch (Exception e)
            { throw new JsonStrParseObjException(e, jo, propertyName, js, byte.class); }
    }

    /** <EMBED CLASS='external-html' DATA-JTYPE=double DATA-FILE-ID=PARSE_PRIM_JO> */
    @IntoHTMLTable(
        title="Extract a JsonString from a JsonObject, and Parse into a Java 'double' Primitive",
        background=BlueDither
    )
    public static double parseDouble(
            final JsonObject                jo,
            final String                    propertyName,
            final ToDoubleFunction<String>  optionalUserParser
        )
    {
        final JsonString js = GET(jo, propertyName, double.class);

        try
        {
            return (optionalUserParser != null)
                ? optionalUserParser.applyAsDouble(js.getString())
                : Double.parseDouble(js.getString().trim());
        }

        catch (Exception e)
            { throw new JsonStrParseObjException(e, jo, propertyName, js, double.class); }
    }

    /** <EMBED CLASS='external-html' DATA-JTYPE=float DATA-FILE-ID=PARSE_PRIM_JO> */
    @IntoHTMLTable(
        title="Extract a JsonString from a JsonObject, and Parse into a Java 'float' Primitive",
        background=GreenDither
    )
    public static float parseFloat(
            final JsonObject                jo,
            final String                    propertyName,
            final ToFloatFunction<String>   optionalUserParser
        )
    {
        final JsonString js = GET(jo, propertyName, float.class);

        try
        {
            return (optionalUserParser != null)
                ? optionalUserParser.applyAsFloat(js.getString())
                : Float.parseFloat(js.getString().trim());
        }

        catch (Exception e)
            { throw new JsonStrParseObjException(e, jo, propertyName, js, float.class); }
    }

    /** <EMBED CLASS='external-html' DATA-JTYPE=boolean DATA-FILE-ID=PARSE_PRIM_JO> */
    @IntoHTMLTable(
        title="Extract a JsonString from a JsonObject, and Parse into a Java 'boolean' Primitive",
        background=BlueDither
    )
    public static boolean parseBoolean(
            final JsonObject        jo,
            final String            propertyName,
            final Predicate<String> optionalUserParser
        )
    {
        final JsonString js = GET(jo, propertyName, boolean.class);

        try
        {
            return (optionalUserParser != null)
                ? optionalUserParser.test(js.getString())
                : Boolean.parseBoolean(js.getString().trim());
        }

        catch (Exception e)
            { throw new JsonStrParseObjException(e, jo, propertyName, js, boolean.class); }
    }


    // ********************************************************************************************
    // ********************************************************************************************
    // The Internal Methods
    // ********************************************************************************************
    // ********************************************************************************************


    /**
     * This is an internal helper method for retrieving a property from a {@link JsonObject},
     * and converting it to one of the standard <B STYLE='color: red;'>Java Types</B>.
     * 
     * @param jo Any instance of {@link JsonObject}
     * @param propertyName Any property name contained by {@code 'jo'}, having a {@link JsonString}
     * @param primitiveClass Expected Primitive Class, to be returned by caller method
     * 
     * @return The extracted {@link JsonString}.
     * 
     * @throws JsonNullPrimitiveObjException If the specified property contains
     *                                       <B STYLE='color: red'>Json-Null</B>
     * @throws JsonTypeObjException          If the specified property doesn't contain
     *                                       {@link JsonString}
     * @throws JsonPropMissingException      If the property is missing.
     * 
     * @see #parseInt(JsonObject, String, ToIntFunction)
     * @see #parseLong(JsonObject, String, ToLongFunction)
     * @see #parseShort(JsonObject, String, ToShortFunction)
     * @see #parseByte(JsonObject, String, ToByteFunction)
     * @see #parseDouble(JsonObject, String, ToDoubleFunction)
     * @see #parseFloat(JsonObject, String, ToFloatFunction)
     */
    protected static <T> JsonString GET(
            final JsonObject    jo,
            final String        propertyName,
            final Class<T>      primitiveClass
        )
    {
        // Here, a 'get' request was made for a property that isn't actually listed among the
        // properties in the provided JsonObject.  Since this internal 'GET' is used by methods
        // that are trying to return a Java Primitive (like 'int' or 'float'), then an exception
        // has to be thrown.  The option of returning 'null' isn't possible here!
    
        if (! jo.containsKey(propertyName)) throw new JsonPropMissingException
            (jo, propertyName, STRING, primitiveClass);

        final JsonValue jv = jo.get(propertyName);

        switch (jv.getValueType())
        {
            // A Json-"null" was listed as the "value" assigned to this property
            // Primitive's cannot encode "null."  Fortunately, there is a specialized Java-HTML
            // JsonException sub-class that handles exactly this type of situation.
            // 
            // "someJsonObjectPropert": null,

            case NULL: throw new JsonNullPrimitiveObjException
                (jo, propertyName, STRING, primitiveClass);

            case STRING: return (JsonString) jv;

            // The JsonObject property does not contain a JsonString.
            default: throw new JsonTypeObjException
                (jo, propertyName, STRING, jv, primitiveClass);
        }
    }

}