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// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
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package org.apache.juneau;

/**
 * Converts property names to underscore-lower-case format.
 *
 * <h5 class='section'>Example:</h5>
 * <ul>
 * 	<li><js>"fooBar"</js> -&gt; <js>"foo_bar"</js>
 * 	<li><js>"fooBarURL"</js> -&gt; <js>"foo_bar_url"</js>
 * 	<li><js>"FooBarURL"</js> -&gt; <js>"foo_bar_url"</js>
 * </ul>
 */
public final class PropertyNamerULC implements PropertyNamer {

	@Override /* PropertyNamer */
	public String getPropertyName(String name) {
		if (name == null || name.isEmpty())
			return name;

		int numUCs = 0;
		boolean isPrevUC = Character.isUpperCase(name.charAt(0));
		for (int i = 1; i < name.length(); i++) {
			char c = name.charAt(i);
			if (Character.isUpperCase(c)) {
				if (! isPrevUC)
					numUCs++;
				isPrevUC = true;
			} else {
				isPrevUC = false;
			}
		}

		char[] name2 = new char[name.length() + numUCs];
		isPrevUC = Character.isUpperCase(name.charAt(0));
		name2[0] = Character.toLowerCase(name.charAt(0));
		int ni = 0;
		for (int i = 0; i < name.length(); i++) {
			char c = name.charAt(i);
			if (Character.isUpperCase(c)) {
				if (! isPrevUC)
					name2[ni++] = '_';
				isPrevUC = true;
				name2[ni++] = Character.toLowerCase(c);
			} else {
				isPrevUC = false;
				name2[ni++] = c;
			}
		}

		return new String(name2);
	}
}