/*

 * Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package java.lang.reflect;

import org.apidesign.bck2brwsr.core.Exported;

import org.apidesign.bck2brwsr.core.JavaScriptBody;

import org.apidesign.bck2brwsr.core.JavaScriptPrototype;

/**

 * The {@code Array} class provides static methods to dynamically create and

 * access Java arrays.

 *

 * <p>{@code Array} permits widening conversions to occur during a get or set

 * operation, but throws an {@code IllegalArgumentException} if a narrowing

 * conversion would occur.

 *

 * @author Nakul Saraiya

 */

@JavaScriptPrototype(prototype = "new Array", container = "Array.prototype")

public final

class Array {

    /**

     * Constructor.  Class Array is not instantiable.

     */

    private Array() {}

    /**

     * Creates a new array with the specified component type and

     * length.

     * Invoking this method is equivalent to creating an array

     * as follows:

     * <blockquote>

     * <pre>

     * int[] x = {length};

     * Array.newInstance(componentType, x);

     * </pre>

     * </blockquote>

     *

     * @param componentType the {@code Class} object representing the

     * component type of the new array

     * @param length the length of the new array

     * @return the new array

     * @exception NullPointerException if the specified

     * {@code componentType} parameter is null

     * @exception IllegalArgumentException if componentType is {@link Void#TYPE}

     * @exception NegativeArraySizeException if the specified {@code length}

     * is negative

     */

    public static Object newInstance(Class<?> componentType, int length)

    throws NegativeArraySizeException {

        if (length < 0) {

            throw new NegativeArraySizeException();

        }

        String sig = Method.findArraySignature(componentType);

        return newArray(componentType.isPrimitive(), sig, null, length);

    }

    /**

     * Creates a new array

     * with the specified component type and dimensions.

     * If {@code componentType}

     * represents a non-array class or interface, the new array

     * has {@code dimensions.length} dimensions and

     * {@code componentType} as its component type. If

     * {@code componentType} represents an array class, the

     * number of dimensions of the new array is equal to the sum

     * of {@code dimensions.length} and the number of

     * dimensions of {@code componentType}. In this case, the

     * component type of the new array is the component type of

     * {@code componentType}.

     *

     * <p>The number of dimensions of the new array must not

     * exceed the number of array dimensions supported by the

     * implementation (typically 255).

     *

     * @param componentType the {@code Class} object representing the component

     * type of the new array

     * @param dimensions an array of {@code int} representing the dimensions of

     * the new array

     * @return the new array

     * @exception NullPointerException if the specified

     * {@code componentType} argument is null

     * @exception IllegalArgumentException if the specified {@code dimensions}

     * argument is a zero-dimensional array, or if the number of

     * requested dimensions exceeds the limit on the number of array dimensions

     * supported by the implementation (typically 255), or if componentType

     * is {@link Void#TYPE}.

     * @exception NegativeArraySizeException if any of the components in

     * the specified {@code dimensions} argument is negative.

     */

    public static Object newInstance(Class<?> componentType, int... dimensions)

        throws IllegalArgumentException, NegativeArraySizeException {

        StringBuilder sig = new StringBuilder();

        for (int i = 1; i < dimensions.length; i++) {

            sig.append('[');

        }

        sig.append(Method.findArraySignature(componentType));

        return multiNewArray(sig.toString(), dimensions, 0);

    }

    /**

     * Returns the length of the specified array object, as an {@code int}.

     *

     * @param array the array

     * @return the length of the array

     * @exception IllegalArgumentException if the object argument is not

     * an array

     */

    public static int getLength(Object array)

    throws IllegalArgumentException {

        if (!array.getClass().isArray()) {

            throw new IllegalArgumentException("Argument is not an array");

        }

        return length(array);

    }

    @JavaScriptBody(args = { "arr" }, body = "return arr.length;")

    private static native int length(Object arr);

    /**

     * Returns the value of the indexed component in the specified

     * array object.  The value is automatically wrapped in an object

     * if it has a primitive type.

     *

     * @param array the array

     * @param index the index

     * @return the (possibly wrapped) value of the indexed component in

     * the specified array

     * @exception NullPointerException If the specified object is null

     * @exception IllegalArgumentException If the specified object is not

     * an array

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to the

     * length of the specified array

     */

    public static Object get(Object array, int index)

    throws IllegalArgumentException, ArrayIndexOutOfBoundsException {

        final Class<?> t = array.getClass().getComponentType();

        if (t.isPrimitive()) {

            return fromPrimitive(t, array, index);

        } else {

            return ((Object[])array)[index];

        }

    }

    /**

     * Returns the value of the indexed component in the specified

     * array object, as a {@code boolean}.

     *

     * @param array the array

     * @param index the index

     * @return the value of the indexed component in the specified array

     * @exception NullPointerException If the specified object is null

     * @exception IllegalArgumentException If the specified object is not

     * an array, or if the indexed element cannot be converted to the

     * return type by an identity or widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to the

     * length of the specified array

     * @see Array#get

     */

    public static native boolean getBoolean(Object array, int index)

        throws IllegalArgumentException, ArrayIndexOutOfBoundsException;

    /**

     * Returns the value of the indexed component in the specified

     * array object, as a {@code byte}.

     *

     * @param array the array

     * @param index the index

     * @return the value of the indexed component in the specified array

     * @exception NullPointerException If the specified object is null

     * @exception IllegalArgumentException If the specified object is not

     * an array, or if the indexed element cannot be converted to the

     * return type by an identity or widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to the

     * length of the specified array

     * @see Array#get

     */

    public static byte getByte(Object array, int index)

    throws IllegalArgumentException, ArrayIndexOutOfBoundsException {

        if (!Method.samePrimitive(array.getClass().getComponentType(), Byte.TYPE)) {

            throw new IllegalArgumentException();

        }

        byte[] arr = (byte[]) array;

        return arr[index];

    }

    /**

     * Returns the value of the indexed component in the specified

     * array object, as a {@code char}.

     *

     * @param array the array

     * @param index the index

     * @return the value of the indexed component in the specified array

     * @exception NullPointerException If the specified object is null

     * @exception IllegalArgumentException If the specified object is not

     * an array, or if the indexed element cannot be converted to the

     * return type by an identity or widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to the

     * length of the specified array

     * @see Array#get

     */

    public static native char getChar(Object array, int index)

        throws IllegalArgumentException, ArrayIndexOutOfBoundsException;

    /**

     * Returns the value of the indexed component in the specified

     * array object, as a {@code short}.

     *

     * @param array the array

     * @param index the index

     * @return the value of the indexed component in the specified array

     * @exception NullPointerException If the specified object is null

     * @exception IllegalArgumentException If the specified object is not

     * an array, or if the indexed element cannot be converted to the

     * return type by an identity or widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to the

     * length of the specified array

     * @see Array#get

     */

    public static short getShort(Object array, int index)

    throws IllegalArgumentException, ArrayIndexOutOfBoundsException {

        final Class<?> t = array.getClass().getComponentType();

        if (Method.samePrimitive(t, Short.TYPE)) {

            short[] arr = (short[]) array;

            return arr[index];

        }

        return getByte(array, index);

    }

    /**

     * Returns the value of the indexed component in the specified

     * array object, as an {@code int}.

     *

     * @param array the array

     * @param index the index

     * @return the value of the indexed component in the specified array

     * @exception NullPointerException If the specified object is null

     * @exception IllegalArgumentException If the specified object is not

     * an array, or if the indexed element cannot be converted to the

     * return type by an identity or widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to the

     * length of the specified array

     * @see Array#get

     */

    public static int getInt(Object array, int index) 

    throws IllegalArgumentException, ArrayIndexOutOfBoundsException {

        final Class<?> t = array.getClass().getComponentType();

        if (Method.samePrimitive(t, Integer.TYPE)) {

            int[] arr = (int[]) array;

            return arr[index];

        }

        return getShort(array, index);

    }

    /**

     * Returns the value of the indexed component in the specified

     * array object, as a {@code long}.

     *

     * @param array the array

     * @param index the index

     * @return the value of the indexed component in the specified array

     * @exception NullPointerException If the specified object is null

     * @exception IllegalArgumentException If the specified object is not

     * an array, or if the indexed element cannot be converted to the

     * return type by an identity or widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to the

     * length of the specified array

     * @see Array#get

     */

    public static long getLong(Object array, int index)

    throws IllegalArgumentException, ArrayIndexOutOfBoundsException {

        final Class<?> t = array.getClass().getComponentType();

        if (Method.samePrimitive(t, Long.TYPE)) {

            long[] arr = (long[]) array;

            return arr[index];

        }

        return getInt(array, index);

    }

    /**

     * Returns the value of the indexed component in the specified

     * array object, as a {@code float}.

     *

     * @param array the array

     * @param index the index

     * @return the value of the indexed component in the specified array

     * @exception NullPointerException If the specified object is null

     * @exception IllegalArgumentException If the specified object is not

     * an array, or if the indexed element cannot be converted to the

     * return type by an identity or widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to the

     * length of the specified array

     * @see Array#get

     */

    public static float getFloat(Object array, int index)

    throws IllegalArgumentException, ArrayIndexOutOfBoundsException {

        final Class<?> t = array.getClass().getComponentType();

        if (Method.samePrimitive(t, Float.TYPE)) {

            float[] arr = (float[]) array;

            return arr[index];

        }

        return getLong(array, index);

    }

    /**

     * Returns the value of the indexed component in the specified

     * array object, as a {@code double}.

     *

     * @param array the array

     * @param index the index

     * @return the value of the indexed component in the specified array

     * @exception NullPointerException If the specified object is null

     * @exception IllegalArgumentException If the specified object is not

     * an array, or if the indexed element cannot be converted to the

     * return type by an identity or widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to the

     * length of the specified array

     * @see Array#get

     */

    public static double getDouble(Object array, int index)

    throws IllegalArgumentException, ArrayIndexOutOfBoundsException {

        final Class<?> t = array.getClass().getComponentType();

        if (Method.samePrimitive(t, Double.TYPE)) {

            double[] arr = (double[]) array;

            return arr[index];

        }

        return getFloat(array, index);

    }

    /**

     * Sets the value of the indexed component of the specified array

     * object to the specified new value.  The new value is first

     * automatically unwrapped if the array has a primitive component

     * type.

     * @param array the array

     * @param index the index into the array

     * @param value the new value of the indexed component

     * @exception NullPointerException If the specified object argument

     * is null

     * @exception IllegalArgumentException If the specified object argument

     * is not an array, or if the array component type is primitive and

     * an unwrapping conversion fails

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to

     * the length of the specified array

     */

    public static void set(Object array, int index, Object value)

    throws IllegalArgumentException, ArrayIndexOutOfBoundsException {

        if (array.getClass().getComponentType().isPrimitive()) {

            throw new IllegalArgumentException();

        } else {

            Object[] arr = (Object[])array;

            arr[index] = value;

        }

    }

    /**

     * Sets the value of the indexed component of the specified array

     * object to the specified {@code boolean} value.

     * @param array the array

     * @param index the index into the array

     * @param z the new value of the indexed component

     * @exception NullPointerException If the specified object argument

     * is null

     * @exception IllegalArgumentException If the specified object argument

     * is not an array, or if the specified value cannot be converted

     * to the underlying array's component type by an identity or a

     * primitive widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to

     * the length of the specified array

     * @see Array#set

     */

    public static native void setBoolean(Object array, int index, boolean z)

        throws IllegalArgumentException, ArrayIndexOutOfBoundsException;

    /**

     * Sets the value of the indexed component of the specified array

     * object to the specified {@code byte} value.

     * @param array the array

     * @param index the index into the array

     * @param b the new value of the indexed component

     * @exception NullPointerException If the specified object argument

     * is null

     * @exception IllegalArgumentException If the specified object argument

     * is not an array, or if the specified value cannot be converted

     * to the underlying array's component type by an identity or a

     * primitive widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to

     * the length of the specified array

     * @see Array#set

     */

    public static void setByte(Object array, int index, byte b)

    throws IllegalArgumentException, ArrayIndexOutOfBoundsException {

        Class<?> t = array.getClass().getComponentType();

        if (Method.samePrimitive(t, Byte.TYPE)) {

            byte[] arr = (byte[]) array;

            arr[index] = b;

        } else {

            setShort(array, index, b);

        }

    }

    /**

     * Sets the value of the indexed component of the specified array

     * object to the specified {@code char} value.

     * @param array the array

     * @param index the index into the array

     * @param c the new value of the indexed component

     * @exception NullPointerException If the specified object argument

     * is null

     * @exception IllegalArgumentException If the specified object argument

     * is not an array, or if the specified value cannot be converted

     * to the underlying array's component type by an identity or a

     * primitive widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to

     * the length of the specified array

     * @see Array#set

     */

    public static native void setChar(Object array, int index, char c)

        throws IllegalArgumentException, ArrayIndexOutOfBoundsException;

    /**

     * Sets the value of the indexed component of the specified array

     * object to the specified {@code short} value.

     * @param array the array

     * @param index the index into the array

     * @param s the new value of the indexed component

     * @exception NullPointerException If the specified object argument

     * is null

     * @exception IllegalArgumentException If the specified object argument

     * is not an array, or if the specified value cannot be converted

     * to the underlying array's component type by an identity or a

     * primitive widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to

     * the length of the specified array

     * @see Array#set

     */

    public static void setShort(Object array, int index, short s)

    throws IllegalArgumentException, ArrayIndexOutOfBoundsException {

        Class<?> t = array.getClass().getComponentType();

        if (Method.samePrimitive(t, Short.TYPE)) {

            short[] arr = (short[]) array;

            arr[index] = s;

        } else {

            setInt(array, index, s);

        }

    }

    /**

     * Sets the value of the indexed component of the specified array

     * object to the specified {@code int} value.

     * @param array the array

     * @param index the index into the array

     * @param i the new value of the indexed component

     * @exception NullPointerException If the specified object argument

     * is null

     * @exception IllegalArgumentException If the specified object argument

     * is not an array, or if the specified value cannot be converted

     * to the underlying array's component type by an identity or a

     * primitive widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to

     * the length of the specified array

     * @see Array#set

     */

    public static void setInt(Object array, int index, int i)

    throws IllegalArgumentException, ArrayIndexOutOfBoundsException {

        Class<?> t = array.getClass().getComponentType();

        if (Method.samePrimitive(t, Integer.TYPE)) {

            int[] arr = (int[]) array;

            arr[index] = i;

        } else {

            setLong(array, index, i);

        }

    }

    /**

     * Sets the value of the indexed component of the specified array

     * object to the specified {@code long} value.

     * @param array the array

     * @param index the index into the array

     * @param l the new value of the indexed component

     * @exception NullPointerException If the specified object argument

     * is null

     * @exception IllegalArgumentException If the specified object argument

     * is not an array, or if the specified value cannot be converted

     * to the underlying array's component type by an identity or a

     * primitive widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to

     * the length of the specified array

     * @see Array#set

     */

    public static void setLong(Object array, int index, long l)

    throws IllegalArgumentException, ArrayIndexOutOfBoundsException {

        Class<?> t = array.getClass().getComponentType();

        if (Method.samePrimitive(t, Long.TYPE)) {

            long[] arr = (long[]) array;

            arr[index] = l;

        } else {

            setFloat(array, index, l);

        }

    }

    /**

     * Sets the value of the indexed component of the specified array

     * object to the specified {@code float} value.

     * @param array the array

     * @param index the index into the array

     * @param f the new value of the indexed component

     * @exception NullPointerException If the specified object argument

     * is null

     * @exception IllegalArgumentException If the specified object argument

     * is not an array, or if the specified value cannot be converted

     * to the underlying array's component type by an identity or a

     * primitive widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to

     * the length of the specified array

     * @see Array#set

     */

    public static void setFloat(Object array, int index, float f)

    throws IllegalArgumentException, ArrayIndexOutOfBoundsException {

        Class<?> t = array.getClass().getComponentType();

        if (Method.samePrimitive(t, Float.TYPE)) {

            float[] arr = (float[])array;

            arr[index] = f;

        } else {

            setDouble(array, index, f);

        }

    }

    /**

     * Sets the value of the indexed component of the specified array

     * object to the specified {@code double} value.

     * @param array the array

     * @param index the index into the array

     * @param d the new value of the indexed component

     * @exception NullPointerException If the specified object argument

     * is null

     * @exception IllegalArgumentException If the specified object argument

     * is not an array, or if the specified value cannot be converted

     * to the underlying array's component type by an identity or a

     * primitive widening conversion

     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}

     * argument is negative, or if it is greater than or equal to

     * the length of the specified array

     * @see Array#set

     */

    public static void setDouble(Object array, int index, double d)

    throws IllegalArgumentException, ArrayIndexOutOfBoundsException {

        Class<?> t = array.getClass().getComponentType();

        if (Method.samePrimitive(t, Double.TYPE)) {

            double[] arr = (double[])array;

            arr[index] = d;

        } else {

            throw new IllegalArgumentException("argument type mismatch");

        }

    }

    /*

     * Private

     */

    @JavaScriptBody(args = { "primitive", "sig", "fn", "length" }, body =

          "var arr = new Array(length);\n"

        + "var value = primitive ? 0 : null;\n"

        + "for(var i = 0; i < length; i++) arr[i] = value;\n"

        + "arr.jvmName = sig;\n"

        + "arr.fnc = fn;\n"

//        + "java.lang.System.out.println('Assigned ' + arr.jvmName + ' fn: ' + (!!arr.fnc));\n"

        + "return arr;"

    )

    @Exported

    private static native Object newArray(boolean primitive, String sig, Object fn, int length);

    @Exported

    private static boolean isInstance(Object arr, String sig)  {

        if (arr == null) {

            return false;

        }

        return sig.equals(arr.getClass().getName());

    }

    @Exported

    private static boolean isInstance(Object arr, int dimensions, Object fn) throws ClassNotFoundException {

        if (arr == null) {

            return false;

        }

//        log("isInstance for " + arr + " and " + dimensions);

        Class<?> c = arr.getClass();

        while (dimensions-- > 0) {

//            log(" class: " + c);

            c = c.getComponentType();

//            log(" next class: " + c);

            if (c == null) {

                return false;

            }

        }

        Class<?> t = classFromFn(fn);

//        log(" to check: " + t);

        return t.isAssignableFrom(c);

    }

    @JavaScriptBody(args = { "cntstr" }, body = "return cntstr(false).constructor.$class;")

    private static native Class<?> classFromFn(Object cntstr);

//    @JavaScriptBody(args = { "m" }, body = "java.lang.System.out.println(m.toString().toString());")

//    private static native void log(Object m);

    @Exported

    private static Object multiNewArray(String sig, int[] dims, Object fn)

    throws IllegalArgumentException, NegativeArraySizeException {

        return multiNewArray(sig, dims, 0, fn);

    }

    private static Object multiNewArray(String sig, int[] dims, int index, Object fn)

    throws IllegalArgumentException, NegativeArraySizeException {

        if (dims.length == index + 1) {

            return newArray(sig.length() == 2, sig, fn, dims[index]);

        }

        Object arr = newArray(false, sig, null, dims[index]);

        String compsig = sig.substring(1);

        int len = getLength(arr);

        for (int i = 0; i < len; i++) {

            setArray(arr, i, multiNewArray(compsig, dims, index + 1, fn));

        }

        return arr;

    }

    private static Object fromPrimitive(Class<?> t, Object array, int index) {

        return Method.fromPrimitive(t, atArray(array, index));

    }

    @JavaScriptBody(args = { "array", "index" }, body = "return array[index];")

    private static native Object atArray(Object array, int index);

    @JavaScriptBody(args = { "array", "index", "v" }, body = "array[index] = v;")

    private static native Object setArray(Object array, int index, Object v);

}