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 * The Universal Permissive License (UPL), Version 1.0
 *
 * Subject to the condition set forth below, permission is hereby granted to any
 * person obtaining a copy of this software, associated documentation and/or
 * data (collectively the "Software"), free of charge and under any and all
 * copyright rights in the Software, and any and all patent rights owned or
 * freely licensable by each licensor hereunder covering either (i) the
 * unmodified Software as contributed to or provided by such licensor, or (ii)
 * the Larger Works (as defined below), to deal in both
 *
 * (a) the Software, and
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 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
 * one is included with the Software each a "Larger Work" to which the Software
 * is contributed by such licensors),
 *
 * without restriction, including without limitation the rights to copy, create
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 * Software and the Larger Work(s), and to sublicense the foregoing rights on
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package com.oracle.truffle.js.nodes.cast;

import com.oracle.truffle.api.dsl.Cached;
import com.oracle.truffle.api.dsl.Specialization;
import com.oracle.truffle.api.profiles.BranchProfile;
import com.oracle.truffle.api.profiles.ConditionProfile;
import com.oracle.truffle.js.nodes.JavaScriptBaseNode;
import com.oracle.truffle.js.runtime.Boundaries;
import com.oracle.truffle.js.runtime.JSRuntime;

public abstract class JSTrimWhitespaceNode extends JavaScriptBaseNode {

    private final ConditionProfile isFastNonWhitespace = ConditionProfile.createBinaryProfile();
    private final ConditionProfile isFastWhitespace = ConditionProfile.createBinaryProfile();

    public static JSTrimWhitespaceNode create() {
        return JSTrimWhitespaceNodeGen.create();
    }

    public abstract String executeString(String operand);

    protected boolean startsOrEndsWithWhitespace(String string) {
        assert string.length() > 0;
        return isWhiteSpace(string, 0) || isWhiteSpace(string, string.length() - 1);
    }

    @Specialization(guards = "string.length() == 0")
    protected String doStringZero(String string) {
        return string;
    }

    @Specialization(guards = {"string.length() > 0", "!startsOrEndsWithWhitespace(string)"})
    protected String doStringNoWhitespace(String string) {
        return string;
    }

    @Specialization(guards = {"string.length() > 0", "startsOrEndsWithWhitespace(string)"})
    protected String doString(String string,
                    @Cached("create()") BranchProfile needFirstBranch,
                    @Cached("create()") BranchProfile needLastBranch,
                    @Cached("createBinaryProfile()") ConditionProfile needSubstring) {
        int len = string.length();
        int firstIdx = 0;
        if (isWhiteSpace(string, 0)) {
            needFirstBranch.enter();
            firstIdx = JSRuntime.firstNonWhitespaceIndex(string, false);
        }
        int lastIdx = len - 1;
        if (isWhiteSpace(string, len - 1)) {
            needLastBranch.enter();
            lastIdx = JSRuntime.lastNonWhitespaceIndex(string, false);
        }
        if (needSubstring.profile(firstIdx > lastIdx)) {
            return "";
        } else {
            return Boundaries.substring(string, firstIdx, lastIdx + 1);
        }
    }

    private boolean isWhiteSpace(String str, int index) {
        char c = str.charAt(index);
        if (isFastNonWhitespace.profile(0x0020 < c && c < 0x00A0)) {
            return false;
        } else if (isFastWhitespace.profile(c == ' ' || c == '\n' || c == '\r' || c == '\t')) {
            return true;
        } else {
            return JSRuntime.isWhiteSpace(str.charAt(index));
        }
    }
}