src/core/oned/rss/expanded/RSSExpandedReader.ts
import BarcodeFormat from '../../../BarcodeFormat';
// import ResultPoint from '../../../ResultPoint';
import BitArray from '../../../common/BitArray';
import MathUtils from '../../../common/detector/MathUtils';
import DecodeHintType from '../../../DecodeHintType';
// import FormatException from '../../../FormatException';
import NotFoundException from '../../../NotFoundException';
import Result from '../../../Result';
import System from '../../../util/System';
import AbstractRSSReader from '../../rss/AbstractRSSReader';
import DataCharacter from '../../rss/DataCharacter';
import FinderPattern from '../../rss/FinderPattern';
import RSSUtils from '../../rss/RSSUtils';
import AbstractExpandedDecoder from '../expanded/decoders/AbstractExpandedDecoder';
import BitArrayBuilder from './BitArrayBuilder';
import { createDecoder } from './decoders/AbstractExpandedDecoderComplement';
import ExpandedPair from './ExpandedPair';
import ExpandedRow from './ExpandedRow';
// import java.util.ArrayList;
// import java.util.Iterator;
// import java.util.List;
// import java.util.Map;
// import java.util.Collections;
/** @experimental */
export default class RSSExpandedReader extends AbstractRSSReader {
private static readonly SYMBOL_WIDEST = [7, 5, 4, 3, 1];
private static readonly EVEN_TOTAL_SUBSET = [4, 20, 52, 104, 204];
private static readonly GSUM = [0, 348, 1388, 2948, 3988];
private static readonly FINDER_PATTERNS = [
Int32Array.from([1, 8, 4, 1]), // A
Int32Array.from([3, 6, 4, 1]), // B
Int32Array.from([3, 4, 6, 1]), // C
Int32Array.from([3, 2, 8, 1]), // D
Int32Array.from([2, 6, 5, 1]), // E
Int32Array.from([2, 2, 9, 1]), // F
];
private static readonly WEIGHTS = [
[1, 3, 9, 27, 81, 32, 96, 77],
[20, 60, 180, 118, 143, 7, 21, 63],
[189, 145, 13, 39, 117, 140, 209, 205],
[193, 157, 49, 147, 19, 57, 171, 91],
[62, 186, 136, 197, 169, 85, 44, 132],
[185, 133, 188, 142, 4, 12, 36, 108],
[113, 128, 173, 97, 80, 29, 87, 50],
[150, 28, 84, 41, 123, 158, 52, 156],
[46, 138, 203, 187, 139, 206, 196, 166],
[76, 17, 51, 153, 37, 111, 122, 155],
[43, 129, 176, 106, 107, 110, 119, 146],
[16, 48, 144, 10, 30, 90, 59, 177],
[109, 116, 137, 200, 178, 112, 125, 164],
[70, 210, 208, 202, 184, 130, 179, 115],
[134, 191, 151, 31, 93, 68, 204, 190],
[148, 22, 66, 198, 172, 94, 71, 2],
[6, 18, 54, 162, 64, 192, 154, 40],
[120, 149, 25, 75, 14, 42, 126, 167],
[79, 26, 78, 23, 69, 207, 199, 175],
[103, 98, 83, 38, 114, 131, 182, 124],
[161, 61, 183, 127, 170, 88, 53, 159],
[55, 165, 73, 8, 24, 72, 5, 15],
[45, 135, 194, 160, 58, 174, 100, 89],
];
private static readonly FINDER_PAT_A = 0;
private static readonly FINDER_PAT_B = 1;
private static readonly FINDER_PAT_C = 2;
private static readonly FINDER_PAT_D = 3;
private static readonly FINDER_PAT_E = 4;
private static readonly FINDER_PAT_F = 5;
private static readonly FINDER_PATTERN_SEQUENCES = [
[RSSExpandedReader.FINDER_PAT_A, RSSExpandedReader.FINDER_PAT_A],
[
RSSExpandedReader.FINDER_PAT_A,
RSSExpandedReader.FINDER_PAT_B,
RSSExpandedReader.FINDER_PAT_B,
],
[
RSSExpandedReader.FINDER_PAT_A,
RSSExpandedReader.FINDER_PAT_C,
RSSExpandedReader.FINDER_PAT_B,
RSSExpandedReader.FINDER_PAT_D,
],
[
RSSExpandedReader.FINDER_PAT_A,
RSSExpandedReader.FINDER_PAT_E,
RSSExpandedReader.FINDER_PAT_B,
RSSExpandedReader.FINDER_PAT_D,
RSSExpandedReader.FINDER_PAT_C,
],
[
RSSExpandedReader.FINDER_PAT_A,
RSSExpandedReader.FINDER_PAT_E,
RSSExpandedReader.FINDER_PAT_B,
RSSExpandedReader.FINDER_PAT_D,
RSSExpandedReader.FINDER_PAT_D,
RSSExpandedReader.FINDER_PAT_F,
],
[
RSSExpandedReader.FINDER_PAT_A,
RSSExpandedReader.FINDER_PAT_E,
RSSExpandedReader.FINDER_PAT_B,
RSSExpandedReader.FINDER_PAT_D,
RSSExpandedReader.FINDER_PAT_E,
RSSExpandedReader.FINDER_PAT_F,
RSSExpandedReader.FINDER_PAT_F,
],
[
RSSExpandedReader.FINDER_PAT_A,
RSSExpandedReader.FINDER_PAT_A,
RSSExpandedReader.FINDER_PAT_B,
RSSExpandedReader.FINDER_PAT_B,
RSSExpandedReader.FINDER_PAT_C,
RSSExpandedReader.FINDER_PAT_C,
RSSExpandedReader.FINDER_PAT_D,
RSSExpandedReader.FINDER_PAT_D,
],
[
RSSExpandedReader.FINDER_PAT_A,
RSSExpandedReader.FINDER_PAT_A,
RSSExpandedReader.FINDER_PAT_B,
RSSExpandedReader.FINDER_PAT_B,
RSSExpandedReader.FINDER_PAT_C,
RSSExpandedReader.FINDER_PAT_C,
RSSExpandedReader.FINDER_PAT_D,
RSSExpandedReader.FINDER_PAT_E,
RSSExpandedReader.FINDER_PAT_E,
],
[
RSSExpandedReader.FINDER_PAT_A,
RSSExpandedReader.FINDER_PAT_A,
RSSExpandedReader.FINDER_PAT_B,
RSSExpandedReader.FINDER_PAT_B,
RSSExpandedReader.FINDER_PAT_C,
RSSExpandedReader.FINDER_PAT_C,
RSSExpandedReader.FINDER_PAT_D,
RSSExpandedReader.FINDER_PAT_E,
RSSExpandedReader.FINDER_PAT_F,
RSSExpandedReader.FINDER_PAT_F,
],
[
RSSExpandedReader.FINDER_PAT_A,
RSSExpandedReader.FINDER_PAT_A,
RSSExpandedReader.FINDER_PAT_B,
RSSExpandedReader.FINDER_PAT_B,
RSSExpandedReader.FINDER_PAT_C,
RSSExpandedReader.FINDER_PAT_D,
RSSExpandedReader.FINDER_PAT_D,
RSSExpandedReader.FINDER_PAT_E,
RSSExpandedReader.FINDER_PAT_E,
RSSExpandedReader.FINDER_PAT_F,
RSSExpandedReader.FINDER_PAT_F,
],
];
private static readonly MAX_PAIRS = 11;
private pairs: any = new Array<any>(RSSExpandedReader.MAX_PAIRS);
private rows: any = new Array<any>();
private readonly startEnd = [2];
private startFromEven: boolean;
public decodeRow(
rowNumber: number,
row: BitArray,
hints: Map<DecodeHintType, any>
): Result {
// Rows can start with even pattern in case in prev rows there where odd number of patters.
// So lets try twice
// this.pairs.clear();
this.pairs.length = 0;
this.startFromEven = false;
try {
return RSSExpandedReader.constructResult(
this.decodeRow2pairs(rowNumber, row)
);
} catch (e) {
// OK
// console.log(e);
}
this.pairs.length = 0;
this.startFromEven = true;
return RSSExpandedReader.constructResult(
this.decodeRow2pairs(rowNumber, row)
);
}
public reset(): void {
this.pairs.length = 0;
this.rows.length = 0;
}
// Not private for testing
decodeRow2pairs(rowNumber: number, row: BitArray): Array<ExpandedPair> {
let done = false;
while (!done) {
try {
this.pairs.push(this.retrieveNextPair(row, this.pairs, rowNumber));
} catch (error) {
if (error instanceof NotFoundException) {
if (!this.pairs.length) {
throw new NotFoundException();
}
// exit this loop when retrieveNextPair() fails and throws
done = true;
}
}
}
// TODO: verify sequence of finder patterns as in checkPairSequence()
if (this.checkChecksum()) {
return this.pairs;
}
let tryStackedDecode;
if (this.rows.length) {
tryStackedDecode = true;
} else {
tryStackedDecode = false;
}
// let tryStackedDecode = !this.rows.isEmpty();
this.storeRow(rowNumber, false); // TODO: deal with reversed rows
if (tryStackedDecode) {
// When the image is 180-rotated, then rows are sorted in wrong direction.
// Try twice with both the directions.
let ps = this.checkRowsBoolean(false);
if (ps != null) {
return ps;
}
ps = this.checkRowsBoolean(true);
if (ps != null) {
return ps;
}
}
throw new NotFoundException();
}
// Need to Verify
private checkRowsBoolean(reverse: boolean): Array<ExpandedPair> {
// Limit number of rows we are checking
// We use recursive algorithm with pure complexity and don't want it to take forever
// Stacked barcode can have up to 11 rows, so 25 seems reasonable enough
if (this.rows.length > 25) {
this.rows.length = 0; // We will never have a chance to get result, so clear it
return null;
}
this.pairs.length = 0;
if (reverse) {
this.rows = this.rows.reverse();
// Collections.reverse(this.rows);
}
let ps: Array<ExpandedPair> = null;
try {
ps = this.checkRows(new Array<ExpandedRow>(), 0);
} catch (e) {
// OK
console.log(e);
}
if (reverse) {
this.rows = this.rows.reverse();
// Collections.reverse(this.rows);
}
return ps;
}
// Try to construct a valid rows sequence
// Recursion is used to implement backtracking
private checkRows(
collectedRows: any,
currentRow: number
): Array<ExpandedPair> {
for (let i = currentRow; i < this.rows.length; i++) {
let row: any = this.rows[i];
this.pairs.length = 0;
for (let collectedRow of collectedRows) {
this.pairs.push(collectedRow.getPairs());
}
this.pairs.push(row.getPairs());
if (!RSSExpandedReader.isValidSequence(this.pairs)) {
continue;
}
if (this.checkChecksum()) {
return this.pairs;
}
let rs = new Array<any>(collectedRows);
rs.push(row);
try {
// Recursion: try to add more rows
return this.checkRows(rs, i + 1);
} catch (e) {
// We failed, try the next candidate
console.log(e);
}
}
throw new NotFoundException();
}
// Whether the pairs form a valid find pattern sequence,
// either complete or a prefix
private static isValidSequence(pairs: Array<ExpandedPair>): boolean {
for (let sequence of RSSExpandedReader.FINDER_PATTERN_SEQUENCES) {
if (pairs.length > sequence.length) {
continue;
}
let stop = true;
for (let j = 0; j < pairs.length; j++) {
if (pairs[j].getFinderPattern().getValue() !== sequence[j]) {
stop = false;
break;
}
}
if (stop) {
return true;
}
}
return false;
}
private storeRow(rowNumber: number, wasReversed: boolean): void {
// Discard if duplicate above or below; otherwise insert in order by row number.
let insertPos = 0;
let prevIsSame = false;
let nextIsSame = false;
while (insertPos < this.rows.length) {
let erow = this.rows[insertPos];
if (erow.getRowNumber() > rowNumber) {
nextIsSame = erow.isEquivalent(this.pairs);
break;
}
prevIsSame = erow.isEquivalent(this.pairs);
insertPos++;
}
if (nextIsSame || prevIsSame) {
return;
}
// When the row was partially decoded (e.g. 2 pairs found instead of 3),
// it will prevent us from detecting the barcode.
// Try to merge partial rows
// Check whether the row is part of an allready detected row
if (RSSExpandedReader.isPartialRow(this.pairs, this.rows)) {
return;
}
this.rows.push(
insertPos,
new ExpandedRow(this.pairs, rowNumber, wasReversed)
);
this.removePartialRows(this.pairs, this.rows);
}
// Remove all the rows that contains only specified pairs
private removePartialRows(
pairs: Array<ExpandedPair>,
rows: Array<ExpandedRow>
): void {
// for (Iterator<ExpandedRow> iterator = rows.iterator(); iterator.hasNext();) {
// ExpandedRow r = iterator.next();
// if (r.getPairs().size() == pairs.size()) {
// continue;
// }
// boolean allFound = true;
// for (ExpandedPair p : r.getPairs()) {
// boolean found = false;
// for (ExpandedPair pp : pairs) {
// if (p.equals(pp)) {
// found = true;
// break;
// }
// }
// if (!found) {
// allFound = false;
// break;
// }
// }
// if (allFound) {
// // 'pairs' contains all the pairs from the row 'r'
// iterator.remove();
// }
// }
for (let row of rows) {
if (row.getPairs().length === pairs.length) {
continue;
}
let allFound = true;
for (let p of row.getPairs()) {
let found = false;
for (let pp of pairs) {
if (ExpandedPair.equals(p, pp)) {
found = true;
break;
}
}
if (!found) {
allFound = false;
}
}
}
}
// Returns true when one of the rows already contains all the pairs
private static isPartialRow(pairs: any, rows: any): boolean {
for (let r of rows) {
let allFound = true;
for (let p of pairs) {
let found = false;
for (let pp of r.getPairs()) {
if (p.equals(pp)) {
found = true;
break;
}
}
if (!found) {
allFound = false;
break;
}
}
if (allFound) {
// the row 'r' contain all the pairs from 'pairs'
return true;
}
}
return false;
}
// Only used for unit testing
getRows() {
return this.rows;
}
// Not private for unit testing
static constructResult(pairs: Array<ExpandedPair>) {
let binary = BitArrayBuilder.buildBitArray(pairs);
let decoder = createDecoder(binary);
let resultingString = decoder.parseInformation();
let firstPoints = pairs[0].getFinderPattern().getResultPoints();
let lastPoints = pairs[pairs.length - 1]
.getFinderPattern()
.getResultPoints();
let points = [firstPoints[0], firstPoints[1], lastPoints[0], lastPoints[1]];
return new Result(
resultingString,
null,
null,
points,
BarcodeFormat.RSS_EXPANDED,
null
);
}
private checkChecksum(): boolean {
let firstPair = this.pairs.get(0);
let checkCharacter = firstPair.getLeftChar();
let firstCharacter = firstPair.getRightChar();
if (firstCharacter === null) {
return false;
}
let checksum = firstCharacter.getChecksumPortion();
let s = 2;
for (let i = 1; i < this.pairs.size(); ++i) {
let currentPair = this.pairs.get(i);
checksum += currentPair.getLeftChar().getChecksumPortion();
s++;
let currentRightChar = currentPair.getRightChar();
if (currentRightChar != null) {
checksum += currentRightChar.getChecksumPortion();
s++;
}
}
checksum %= 211;
let checkCharacterValue = 211 * (s - 4) + checksum;
return checkCharacterValue === checkCharacter.getValue();
}
private static getNextSecondBar(row: BitArray, initialPos: number): number {
let currentPos;
if (row.get(initialPos)) {
currentPos = row.getNextUnset(initialPos);
currentPos = row.getNextSet(currentPos);
} else {
currentPos = row.getNextSet(initialPos);
currentPos = row.getNextUnset(currentPos);
}
return currentPos;
}
// not private for testing
retrieveNextPair(
row: BitArray,
previousPairs: Array<ExpandedPair>,
rowNumber: number
): ExpandedPair {
let isOddPattern = previousPairs.length % 2 === 0;
if (this.startFromEven) {
isOddPattern = !isOddPattern;
}
let pattern;
let keepFinding = true;
let forcedOffset = -1;
do {
this.findNextPair(row, previousPairs, forcedOffset);
pattern = this.parseFoundFinderPattern(row, rowNumber, isOddPattern);
if (pattern === null) {
forcedOffset = RSSExpandedReader.getNextSecondBar(
row,
this.startEnd[0]
);
} else {
keepFinding = false;
}
} while (keepFinding);
// When stacked symbol is split over multiple rows, there's no way to guess if this pair can be last or not.
// boolean mayBeLast = checkPairSequence(previousPairs, pattern);
let leftChar = this.decodeDataCharacter(row, pattern, isOddPattern, true);
if (
!this.isEmptyPair(previousPairs) &&
previousPairs[previousPairs.length - 1].mustBeLast()
) {
throw new NotFoundException();
}
let rightChar;
try {
rightChar = this.decodeDataCharacter(row, pattern, isOddPattern, false);
} catch (e) {
rightChar = null;
console.log(e);
}
return new ExpandedPair(leftChar, rightChar, pattern, true);
}
isEmptyPair(pairs) {
if (pairs.length === 0) {
return true;
}
return false;
}
private findNextPair(
row: BitArray,
previousPairs: Array<ExpandedPair>,
forcedOffset: number
): void {
let counters = this.getDecodeFinderCounters();
counters[0] = 0;
counters[1] = 0;
counters[2] = 0;
counters[3] = 0;
let width = row.getSize();
let rowOffset;
if (forcedOffset >= 0) {
rowOffset = forcedOffset;
} else if (this.isEmptyPair(previousPairs)) {
rowOffset = 0;
} else {
let lastPair = previousPairs[previousPairs.length - 1];
rowOffset = lastPair.getFinderPattern().getStartEnd()[1];
}
let searchingEvenPair = previousPairs.length % 2 !== 0;
if (this.startFromEven) {
searchingEvenPair = !searchingEvenPair;
}
let isWhite = false;
while (rowOffset < width) {
isWhite = !row.get(rowOffset);
if (!isWhite) {
break;
}
rowOffset++;
}
let counterPosition = 0;
let patternStart = rowOffset;
for (let x = rowOffset; x < width; x++) {
if (row.get(x) !== isWhite) {
counters[counterPosition]++;
} else {
if (counterPosition === 3) {
if (searchingEvenPair) {
RSSExpandedReader.reverseCounters(counters);
}
if (RSSExpandedReader.isFinderPattern(counters)) {
this.startEnd[0] = patternStart;
this.startEnd[1] = x;
return;
}
if (searchingEvenPair) {
RSSExpandedReader.reverseCounters(counters);
}
patternStart += counters[0] + counters[1];
counters[0] = counters[2];
counters[1] = counters[3];
counters[2] = 0;
counters[3] = 0;
counterPosition--;
} else {
counterPosition++;
}
counters[counterPosition] = 1;
isWhite = !isWhite;
}
}
throw new NotFoundException();
}
private static reverseCounters(counters): void {
let length = counters.length;
for (let i = 0; i < length / 2; ++i) {
let tmp = counters[i];
counters[i] = counters[length - i - 1];
counters[length - i - 1] = tmp;
}
}
private parseFoundFinderPattern(
row: BitArray,
rowNumber: number,
oddPattern: boolean
): FinderPattern {
// Actually we found elements 2-5.
let firstCounter;
let start;
let end;
if (oddPattern) {
// If pattern number is odd, we need to locate element 1 *before* the current block.
let firstElementStart = this.startEnd[0] - 1;
// Locate element 1
while (firstElementStart >= 0 && !row.get(firstElementStart)) {
firstElementStart--;
}
firstElementStart++;
firstCounter = this.startEnd[0] - firstElementStart;
start = firstElementStart;
end = this.startEnd[1];
} else {
// If pattern number is even, the pattern is reversed, so we need to locate element 1 *after* the current block.
start = this.startEnd[0];
end = row.getNextUnset(this.startEnd[1] + 1);
firstCounter = end - this.startEnd[1];
}
// Make 'counters' hold 1-4
let counters = this.getDecodeFinderCounters();
System.arraycopy(counters, 0, counters, 1, counters.length - 1);
counters[0] = firstCounter;
let value;
try {
value = this.parseFinderValue(
counters,
RSSExpandedReader.FINDER_PATTERNS
);
} catch (e) {
return null;
}
// return new FinderPattern(value, new int[] { start, end }, start, end, rowNumber});
return new FinderPattern(value, [start, end], start, end, rowNumber);
}
decodeDataCharacter(
row: BitArray,
pattern: FinderPattern,
isOddPattern: boolean,
leftChar: boolean
) {
let counters = this.getDataCharacterCounters();
for (let x = 0; x < counters.length; x++) {
counters[x] = 0;
}
if (leftChar) {
RSSExpandedReader.recordPatternInReverse(
row,
pattern.getStartEnd()[0],
counters
);
} else {
RSSExpandedReader.recordPattern(row, pattern.getStartEnd()[1], counters);
// reverse it
for (let i = 0, j = counters.length - 1; i < j; i++, j--) {
let temp = counters[i];
counters[i] = counters[j];
counters[j] = temp;
}
} // counters[] has the pixels of the module
let numModules = 17; // left and right data characters have all the same length
let elementWidth = MathUtils.sum(new Int32Array(counters)) / numModules;
// Sanity check: element width for pattern and the character should match
let expectedElementWidth =
(pattern.getStartEnd()[1] - pattern.getStartEnd()[0]) / 15.0;
if (
Math.abs(elementWidth - expectedElementWidth) / expectedElementWidth >
0.3
) {
throw new NotFoundException();
}
let oddCounts = this.getOddCounts();
let evenCounts = this.getEvenCounts();
let oddRoundingErrors = this.getOddRoundingErrors();
let evenRoundingErrors = this.getEvenRoundingErrors();
for (let i = 0; i < counters.length; i++) {
let value = (1.0 * counters[i]) / elementWidth;
let count = value + 0.5; // Round
if (count < 1) {
if (value < 0.3) {
throw new NotFoundException();
}
count = 1;
} else if (count > 8) {
if (value > 8.7) {
throw new NotFoundException();
}
count = 8;
}
let offset = i / 2;
if ((i & 0x01) === 0) {
oddCounts[offset] = count;
oddRoundingErrors[offset] = value - count;
} else {
evenCounts[offset] = count;
evenRoundingErrors[offset] = value - count;
}
}
this.adjustOddEvenCounts(numModules);
let weightRowNumber =
4 * pattern.getValue() + (isOddPattern ? 0 : 2) + (leftChar ? 0 : 1) - 1;
let oddSum = 0;
let oddChecksumPortion = 0;
for (let i = oddCounts.length - 1; i >= 0; i--) {
if (RSSExpandedReader.isNotA1left(pattern, isOddPattern, leftChar)) {
let weight = RSSExpandedReader.WEIGHTS[weightRowNumber][2 * i];
oddChecksumPortion += oddCounts[i] * weight;
}
oddSum += oddCounts[i];
}
let evenChecksumPortion = 0;
// int evenSum = 0;
for (let i = evenCounts.length - 1; i >= 0; i--) {
if (RSSExpandedReader.isNotA1left(pattern, isOddPattern, leftChar)) {
let weight = RSSExpandedReader.WEIGHTS[weightRowNumber][2 * i + 1];
evenChecksumPortion += evenCounts[i] * weight;
}
// evenSum += evenCounts[i];
}
let checksumPortion = oddChecksumPortion + evenChecksumPortion;
if ((oddSum & 0x01) !== 0 || oddSum > 13 || oddSum < 4) {
throw new NotFoundException();
}
let group = (13 - oddSum) / 2;
let oddWidest = RSSExpandedReader.SYMBOL_WIDEST[group];
let evenWidest = 9 - oddWidest;
let vOdd = RSSUtils.getRSSvalue(oddCounts, oddWidest, true);
let vEven = RSSUtils.getRSSvalue(evenCounts, evenWidest, false);
let tEven = RSSExpandedReader.EVEN_TOTAL_SUBSET[group];
let gSum = RSSExpandedReader.GSUM[group];
let value = vOdd * tEven + vEven + gSum;
return new DataCharacter(value, checksumPortion);
}
private static isNotA1left(
pattern: FinderPattern,
isOddPattern: boolean,
leftChar: boolean
): boolean {
// A1: pattern.getValue is 0 (A), and it's an oddPattern, and it is a left char
return !(pattern.getValue() === 0 && isOddPattern && leftChar);
}
private adjustOddEvenCounts(numModules) {
let oddSum = MathUtils.sum(new Int32Array(this.getOddCounts()));
let evenSum = MathUtils.sum(new Int32Array(this.getEvenCounts()));
let incrementOdd = false;
let decrementOdd = false;
if (oddSum > 13) {
decrementOdd = true;
} else if (oddSum < 4) {
incrementOdd = true;
}
let incrementEven = false;
let decrementEven = false;
if (evenSum > 13) {
decrementEven = true;
} else if (evenSum < 4) {
incrementEven = true;
}
let mismatch = oddSum + evenSum - numModules;
let oddParityBad = (oddSum & 0x01) === 1;
let evenParityBad = (evenSum & 0x01) === 0;
if (mismatch === 1) {
if (oddParityBad) {
if (evenParityBad) {
throw new NotFoundException();
}
decrementOdd = true;
} else {
if (!evenParityBad) {
throw new NotFoundException();
}
decrementEven = true;
}
} else if (mismatch === -1) {
if (oddParityBad) {
if (evenParityBad) {
throw new NotFoundException();
}
incrementOdd = true;
} else {
if (!evenParityBad) {
throw new NotFoundException();
}
incrementEven = true;
}
} else if (mismatch === 0) {
if (oddParityBad) {
if (!evenParityBad) {
throw new NotFoundException();
}
// Both bad
if (oddSum < evenSum) {
incrementOdd = true;
decrementEven = true;
} else {
decrementOdd = true;
incrementEven = true;
}
} else {
if (evenParityBad) {
throw new NotFoundException();
}
// Nothing to do!
}
} else {
throw new NotFoundException();
}
if (incrementOdd) {
if (decrementOdd) {
throw new NotFoundException();
}
RSSExpandedReader.increment(
this.getOddCounts(),
this.getOddRoundingErrors()
);
}
if (decrementOdd) {
RSSExpandedReader.decrement(
this.getOddCounts(),
this.getOddRoundingErrors()
);
}
if (incrementEven) {
if (decrementEven) {
throw new NotFoundException();
}
RSSExpandedReader.increment(
this.getEvenCounts(),
this.getOddRoundingErrors()
);
}
if (decrementEven) {
RSSExpandedReader.decrement(
this.getEvenCounts(),
this.getEvenRoundingErrors()
);
}
}
}