/*
 * Copyright 2007 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.zxing;

import java.util.List;

/**
 * Encapsulates a type of hint that a caller may pass to a barcode reader to
 * help it more quickly or accurately decode it. It is up to implementations to
 * decide what, if anything, to do with the information that is supplied.
 * 
 * @author Sean Owen
 * @author dswitkin@google.com (Daniel Switkin)
 * @see Reader#decode(BinaryBitmap,java.util.Map)
 */
public enum DecodeHintType {

	/**
	 * Unspecified, application-specific hint. Maps to an unspecified
	 * {@link Object}.
	 */
	OTHER(Object.class),

	/**
	 * Image is a pure monochrome image of a barcode. Doesn't matter what it
	 * maps to; use {@link Boolean#TRUE}.
	 */
	PURE_BARCODE(Void.class),

	/**
	 * Image is known to be of one of a few possible formats. Maps to a
	 * {@link List} of {@link BarcodeFormat}s.
	 */
	POSSIBLE_FORMATS(List.class),

	/**
	 * Spend more time to try to find a barcode; optimize for accuracy, not
	 * speed. Doesn't matter what it maps to; use {@link Boolean#TRUE}.
	 */
	TRY_HARDER(Void.class),

	/**
	 * Specifies what character encoding to use when decoding, where applicable
	 * (type String)
	 */
	CHARACTER_SET(String.class),

	/**
	 * Allowed lengths of encoded data -- reject anything else. Maps to an
	 * {@code int[]}.
	 */
	ALLOWED_LENGTHS(int[].class),

	/**
	 * Assume Code 39 codes employ a check digit. Doesn't matter what it maps
	 * to; use {@link Boolean#TRUE}.
	 */
	ASSUME_CODE_39_CHECK_DIGIT(Void.class),

	/**
	 * Assume the barcode is being processed as a GS1 barcode, and modify
	 * behavior as needed. For example this affects FNC1 handling for Code 128
	 * (aka GS1-128). Doesn't matter what it maps to; use {@link Boolean#TRUE}.
	 */
	ASSUME_GS1(Void.class),

	/**
	 * If true, return the start and end digits in a Codabar barcode instead of
	 * stripping them. They are alpha, whereas the rest are numeric. By default,
	 * they are stripped, but this causes them to not be. Doesn't matter what it
	 * maps to; use {@link Boolean#TRUE}.
	 */
	RETURN_CODABAR_START_END(Void.class),

	/**
	 * The caller needs to be notified via callback when a possible
	 * {@link ResultPoint} is found. Maps to a {@link ResultPointCallback}.
	 */
	NEED_RESULT_POINT_CALLBACK(ResultPointCallback.class),

	/**
	 * Allowed extension lengths for EAN or UPC barcodes. Other formats will
	 * ignore this. Maps to an {@code int[]} of the allowed extension lengths,
	 * for example [2], [5], or [2, 5]. If it is optional to have an extension,
	 * do not set this hint. If this is set, and a UPC or EAN barcode is found
	 * but an extension is not, then no result will be returned at all.
	 */
	ALLOWED_EAN_EXTENSIONS(int[].class),

	// End of enumeration values.
	;

	/**
	 * Data type the hint is expecting. Among the possible values the
	 * {@link Void} stands out as being used for hints that do not expect a
	 * value to be supplied (flag hints). Such hints will possibly have their
	 * value ignored, or replaced by a {@link Boolean#TRUE}. Hint suppliers
	 * should probably use {@link Boolean#TRUE} as directed by the actual hint
	 * documentation.
	 */
	private final Class<?> valueType;

	DecodeHintType(Class<?> valueType) {
		this.valueType = valueType;
	}

	public Class<?> getValueType() {
		return valueType;
	}

}