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 * The Universal Permissive License (UPL), Version 1.0
 *
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 * person obtaining a copy of this software, associated documentation and/or
 * data (collectively the "Software"), free of charge and under any and all
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 * (a) the Software, and
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 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
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package com.oracle.truffle.regex.tregex.nodes.input;

import java.util.Arrays;

import com.oracle.truffle.api.ArrayUtils;
import com.oracle.truffle.api.dsl.Cached;
import com.oracle.truffle.api.dsl.Specialization;
import com.oracle.truffle.api.interop.TruffleObject;
import com.oracle.truffle.api.nodes.Node;

public abstract class InputEqualsNode extends Node {

    public static InputEqualsNode create() {
        return InputEqualsNodeGen.create();
    }

    public abstract boolean execute(Object input, Object string, Object mask);

    @Specialization(guards = "mask == null")
    public boolean doBytes(byte[] input, byte[] string, @SuppressWarnings("unused") Object mask) {
        return Arrays.equals(input, string);
    }

    @Specialization(guards = "mask != null")
    public boolean doBytesMask(byte[] input, byte[] string, byte[] mask) {
        return input.length == string.length && ArrayUtils.regionEqualsWithOrMask(input, 0, string, 0, mask.length, mask);
    }

    @Specialization(guards = "mask == null")
    public boolean doString(String input, String string, @SuppressWarnings("unused") Object mask) {
        return input.equals(string);
    }

    @Specialization(guards = "mask != null")
    public boolean doStringMask(String input, String string, String mask) {
        return input.length() == string.length() && ArrayUtils.regionEqualsWithOrMask(input, 0, string, 0, mask.length(), mask);
    }

    @Specialization(guards = "mask == null")
    public boolean doTruffleObjBytes(TruffleObject input, byte[] string, @SuppressWarnings("unused") Object mask,
                    @Cached InputLengthNode lengthNode,
                    @Cached InputReadNode charAtNode) {
        return equalsTruffleObj(input, string, null, lengthNode, charAtNode);
    }

    @Specialization(guards = "mask != null")
    public boolean doTruffleObjBytesMask(TruffleObject input, byte[] string, byte[] mask,
                    @Cached InputLengthNode lengthNode,
                    @Cached InputReadNode charAtNode) {
        return equalsTruffleObj(input, string, mask, lengthNode, charAtNode);
    }

    @Specialization(guards = "mask == null")
    public boolean doTruffleObjString(TruffleObject input, String string, @SuppressWarnings("unused") Object mask,
                    @Cached InputLengthNode lengthNode,
                    @Cached InputReadNode charAtNode) {
        return equalsTruffleObj(input, string, null, lengthNode, charAtNode);
    }

    @Specialization(guards = "mask != null")
    public boolean doTruffleObjStringMask(TruffleObject input, String string, String mask,
                    @Cached InputLengthNode lengthNode,
                    @Cached InputReadNode charAtNode) {
        return equalsTruffleObj(input, string, mask, lengthNode, charAtNode);
    }

    private static boolean equalsTruffleObj(TruffleObject input, String string, String mask, InputLengthNode lengthNode, InputReadNode charAtNode) {
        if (lengthNode.execute(input) != string.length()) {
            return false;
        }
        for (int i = 0; i < string.length(); i++) {
            if (InputReadNode.readWithMask(input, i, mask, i, charAtNode) != string.charAt(i)) {
                return false;
            }
        }
        return true;
    }

    private static boolean equalsTruffleObj(TruffleObject input, byte[] string, byte[] mask, InputLengthNode lengthNode, InputReadNode charAtNode) {
        if (lengthNode.execute(input) != string.length) {
            return false;
        }
        for (int i = 0; i < string.length; i++) {
            if (InputReadNode.readWithMask(input, i, mask, i, charAtNode) != Byte.toUnsignedInt(string[i])) {
                return false;
            }
        }
        return true;
    }
}