/*
 * Copyright (C) 2010 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.
 */

/*
 * These authors would like to acknowledge the Spanish Ministry of Industry,
 * Tourism and Trade, for the support in the project TSI020301-2008-2
 * "PIRAmIDE: Personalizable Interactions with Resources on AmI-enabled
 * Mobile Dynamic Environments", led by Treelogic
 * ( http://www.treelogic.com/ ):
 *
 *   http://www.piramidepse.com/
 */

use std::collections::HashMap;

use crate::{
    common::{BitArray, Result},
    oned::{
        record_pattern, record_pattern_in_reverse,
        rss::{
            rss_utils, AbstractRSSReaderTrait, DataCharacter, DataCharacterTrait, FinderPattern,
            Pair,
        },
        OneDReader,
    },
    BarcodeFormat, Binarizer, DecodeHintType, DecodeHintValue, DecodingHintDictionary, Exceptions,
    RXingResult, RXingResultMetadataType, RXingResultMetadataValue, Reader,
};

use once_cell::sync::Lazy;

use super::{bit_array_builder, decoders::abstract_expanded_decoder, ExpandedPair, ExpandedRow};

const FINDER_PAT_A: u32 = 0;
const FINDER_PAT_B: u32 = 1;
const FINDER_PAT_C: u32 = 2;
const FINDER_PAT_D: u32 = 3;
const FINDER_PAT_E: u32 = 4;
const FINDER_PAT_F: u32 = 5;

static FINDER_PATTERN_SEQUENCES: Lazy<Vec<Vec<u32>>> = Lazy::new(|| {
    vec![
        vec![FINDER_PAT_A, FINDER_PAT_A],
        vec![FINDER_PAT_A, FINDER_PAT_B, FINDER_PAT_B],
        vec![FINDER_PAT_A, FINDER_PAT_C, FINDER_PAT_B, FINDER_PAT_D],
        vec![
            FINDER_PAT_A,
            FINDER_PAT_E,
            FINDER_PAT_B,
            FINDER_PAT_D,
            FINDER_PAT_C,
        ],
        vec![
            FINDER_PAT_A,
            FINDER_PAT_E,
            FINDER_PAT_B,
            FINDER_PAT_D,
            FINDER_PAT_D,
            FINDER_PAT_F,
        ],
        vec![
            FINDER_PAT_A,
            FINDER_PAT_E,
            FINDER_PAT_B,
            FINDER_PAT_D,
            FINDER_PAT_E,
            FINDER_PAT_F,
            FINDER_PAT_F,
        ],
        vec![
            FINDER_PAT_A,
            FINDER_PAT_A,
            FINDER_PAT_B,
            FINDER_PAT_B,
            FINDER_PAT_C,
            FINDER_PAT_C,
            FINDER_PAT_D,
            FINDER_PAT_D,
        ],
        vec![
            FINDER_PAT_A,
            FINDER_PAT_A,
            FINDER_PAT_B,
            FINDER_PAT_B,
            FINDER_PAT_C,
            FINDER_PAT_C,
            FINDER_PAT_D,
            FINDER_PAT_E,
            FINDER_PAT_E,
        ],
        vec![
            FINDER_PAT_A,
            FINDER_PAT_A,
            FINDER_PAT_B,
            FINDER_PAT_B,
            FINDER_PAT_C,
            FINDER_PAT_C,
            FINDER_PAT_D,
            FINDER_PAT_E,
            FINDER_PAT_F,
            FINDER_PAT_F,
        ],
        vec![
            FINDER_PAT_A,
            FINDER_PAT_A,
            FINDER_PAT_B,
            FINDER_PAT_B,
            FINDER_PAT_C,
            FINDER_PAT_D,
            FINDER_PAT_D,
            FINDER_PAT_E,
            FINDER_PAT_E,
            FINDER_PAT_F,
            FINDER_PAT_F,
        ],
    ]
});

/**
 * @author Pablo Orduña, University of Deusto (pablo.orduna@deusto.es)
 * @author Eduardo Castillejo, University of Deusto (eduardo.castillejo@deusto.es)
 */
#[derive(Default)]
pub struct RSSExpandedReader {
    _possibleLeftPairs: Vec<Pair>,
    _possibleRightPairs: Vec<Pair>,
    decodeFinderCounters: [u32; 4],
    dataCharacterCounters: [u32; 8],
    oddRoundingErrors: [f32; 4],
    evenRoundingErrors: [f32; 4],
    oddCounts: [u32; 4],
    evenCounts: [u32; 4],

    pub(super) pairs: Vec<ExpandedPair>,
    pub(super) rows: Vec<ExpandedRow>,
    startEnd: [u32; 2],
    startFromEven: bool,
}
impl AbstractRSSReaderTrait for RSSExpandedReader {}
impl OneDReader for RSSExpandedReader {
    fn decode_row(
        &mut self,
        rowNumber: u32,
        row: &crate::common::BitArray,
        _hints: &crate::DecodingHintDictionary,
    ) -> Result<crate::RXingResult> {
        // Rows can start with even pattern in case in prev rows there where odd number of patters.
        // So lets try twice
        self.pairs.clear();
        self.startFromEven = false;
        if let Ok(decoded_two_pairs) = self.decodeRow2pairs(rowNumber, row) {
            if let Ok(possible_result) = Self::constructRXingResult(&decoded_two_pairs) {
                return Ok(possible_result);
            }
        }

        self.pairs.clear();
        self.startFromEven = true;
        Self::constructRXingResult(&self.decodeRow2pairs(rowNumber, row)?)
    }
}
impl Reader for RSSExpandedReader {
    fn decode<B: Binarizer>(&mut self, image: &mut crate::BinaryBitmap<B>) -> Result<RXingResult> {
        self.decode_with_hints(image, &HashMap::new())
    }

    // Note that we don't try rotation without the try harder flag, even if rotation was supported.
    fn decode_with_hints<B: Binarizer>(
        &mut self,
        image: &mut crate::BinaryBitmap<B>,
        hints: &DecodingHintDictionary,
    ) -> Result<crate::RXingResult> {
        if let Ok(res) = self._do_decode(image, hints) {
            Ok(res)
        } else {
            let tryHarder = matches!(
                hints.get(&DecodeHintType::TRY_HARDER),
                Some(DecodeHintValue::TryHarder(true))
            );
            if tryHarder && image.is_rotate_supported() {
                let mut rotatedImage = image.rotate_counter_clockwise();
                let mut result = self._do_decode(&mut rotatedImage, hints)?;
                // Record that we found it rotated 90 degrees CCW / 270 degrees CW
                let metadata = result.getRXingResultMetadata();
                let mut orientation = 270;
                if metadata.contains_key(&RXingResultMetadataType::ORIENTATION) {
                    // But if we found it reversed in doDecode(), add in that result here:
                    orientation = (orientation
                        + if let Some(crate::RXingResultMetadataValue::Orientation(or)) =
                            metadata.get(&RXingResultMetadataType::ORIENTATION)
                        {
                            *or
                        } else {
                            0
                        })
                        % 360;
                }
                result.putMetadata(
                    RXingResultMetadataType::ORIENTATION,
                    RXingResultMetadataValue::Orientation(orientation),
                );
                // Update result points
                let height = rotatedImage.get_height();

                let total_points = result.getPoints().len();
                let points = result.getPointsMut();
                for point in points.iter_mut().take(total_points) {
                    std::mem::swap(&mut point.x, &mut point.y);
                    point.x = height as f32 - point.x - 1.0;
                }

                Ok(result)
            } else {
                Err(Exceptions::NOT_FOUND)
            }
        }
    }

    fn reset(&mut self) {
        self.pairs.clear();
        self.rows.clear();
    }
}

impl RSSExpandedReader {
    pub fn new() -> Self {
        Self::default()
    }
    const SYMBOL_WIDEST: [u32; 5] = [7, 5, 4, 3, 1];
    const EVEN_TOTAL_SUBSET: [u32; 5] = [4, 20, 52, 104, 204];
    const GSUM: [u32; 5] = [0, 348, 1388, 2948, 3988];

    const FINDER_PATTERNS: [[u32; 4]; 6] = [
        [1, 8, 4, 1], // A
        [3, 6, 4, 1], // B
        [3, 4, 6, 1], // C
        [3, 2, 8, 1], // D
        [2, 6, 5, 1], // E
        [2, 2, 9, 1], // F
    ];

    const WEIGHTS: [[u32; 8]; 23] = [
        [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],
    ];

    #[allow(dead_code)]
    const MAX_PAIRS: usize = 11;

    // Not private for testing
    pub(super) fn decodeRow2pairs(
        &mut self,
        rowNumber: u32,
        row: &BitArray,
    ) -> Result<Vec<ExpandedPair>> {
        let mut done = false;
        while !done {
            let previousPairs = self.pairs.clone();
            let to_add_res = self.retrieveNextPair(row, &previousPairs, rowNumber);
            if let Ok(to_add) = to_add_res {
                self.pairs.push(to_add);
            } else if self.pairs.is_empty() {
                return Err(to_add_res.err().unwrap_or(Exceptions::ILLEGAL_STATE));
            } else {
                // exit this loop when retrieveNextPair() fails and throws
                done = true;
            }
        }

        // TODO: verify sequence of finder patterns as in checkPairSequence()
        if self.checkChecksum() {
            return Ok(self.pairs.clone());
        }

        let tryStackedDecode = !self.rows.is_empty();
        self.storeRow(rowNumber); // 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 = self.checkRows(false).or(self.checkRows(true));
            if let Some(ps) = ps {
                return Ok(ps);
            }

            // let ps = self.checkRows(false);
            // if let Some(ps) = ps {
            //     return Ok(ps);
            // }
            // let ps = self.checkRows(true);
            // if let Some(ps) = ps {
            //     return Ok(ps);
            // }
        }

        Err(Exceptions::NOT_FOUND)
    }

    fn checkRows(&mut self, reverse: bool) -> Option<Vec<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 self.rows.len() > 25 {
            self.rows.clear(); // We will never have a chance to get result, so clear it
            return None;
        }

        self.pairs.clear();
        if reverse {
            self.rows.reverse();
        }

        let mut c_rows = Vec::new();
        let ps = self.checkRowsDetails(&mut c_rows, 0).ok();
        // let ps = if let Ok(res) = self.checkRowsDetails(&mut c_rows, 0) {
        //     Some(res)
        // } else {
        //     None
        // };
        // } catch (NotFoundException e) {
        // OK
        // }

        if reverse {
            self.rows.reverse();
        }

        ps
    }

    // Try to construct a valid rows sequence
    // Recursion is used to implement backtracking
    fn checkRowsDetails(
        &mut self,
        collectedRows: &mut Vec<ExpandedRow>,
        currentRow: usize,
    ) -> Result<Vec<ExpandedPair>> {
        for i in currentRow..self.rows.len() {
            // for (int i = currentRow; i < rows.size(); i++) {
            let row = self.rows.get(i).ok_or(Exceptions::INDEX_OUT_OF_BOUNDS)?;
            self.pairs.clear();
            for collectedRow in &collectedRows.clone() {
                // for (ExpandedRow collectedRow : collectedRows) {

                self.pairs.append(&mut collectedRow.getPairs().to_vec());
            }
            self.pairs.append(&mut row.getPairs().to_vec());

            if Self::isValidSequence(&self.pairs) {
                if self.checkChecksum() {
                    return Ok(self.pairs.clone());
                }

                // let rs =  collectedRows;
                collectedRows.push(row.clone());
                // try {
                // Recursion: try to add more rows
                if let Ok(cr) = self.checkRowsDetails(collectedRows, i + 1) {
                    return Ok(cr);
                }
                // return checkRows(rs, i + 1);
                // } catch (NotFoundException e) {
                // We failed, try the next candidate
                // }
            }
        }

        Err(Exceptions::NOT_FOUND)
    }

    /// Whether the pairs form a valid find pattern sequence,
    /// either complete or a prefix
    ///
    /// Could potentially panic in a very out of bounds situation
    fn isValidSequence(pairs: &[ExpandedPair]) -> bool {
        for sequence in FINDER_PATTERN_SEQUENCES.iter() {
            // for i in 0..FINDER_PATTERN_SEQUENCES.len() {
            // for sequence in &FINDER_PATTERN_SEQUENCES.iter() {
            // let sequence = FINDER_PATTERN_SEQUENCES.get(i).unwrap();
            // for (int[] sequence : FINDER_PATTERN_SEQUENCES) {
            if pairs.len() <= sequence.len() {
                let mut stop = true;
                for (j, seq) in sequence.iter().enumerate().take(pairs.len()) {
                    // for (int j = 0; j < pairs.size(); j++) {
                    if pairs
                        .get(j)
                        .unwrap()
                        .getFinderPattern()
                        .as_ref()
                        .unwrap()
                        .getValue()
                        != *seq
                    {
                        stop = false;
                        break;
                    }
                }
                if stop {
                    return true;
                }
            }
        }

        false
    }

    fn storeRow(&mut self, rowNumber: u32) {
        // Discard if duplicate above or below; otherwise insert in order by row number.
        let mut insertPos = 0;
        let mut prevIsSame = false;
        let mut nextIsSame = false;
        while insertPos < self.rows.len() {
            if let Some(erow) = self.rows.get(insertPos) {
                if erow.getRowNumber() > rowNumber {
                    nextIsSame = erow.isEquivalent(&self.pairs);
                    break;
                }
                prevIsSame = erow.isEquivalent(&self.pairs);
                insertPos += 1;
            }
        }
        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 already detected row
        if Self::isPartialRow(&self.pairs, &self.rows) {
            return;
        }

        self.rows
            .insert(insertPos, ExpandedRow::new(self.pairs.clone(), rowNumber));

        Self::removePartialRows(&self.pairs, &mut self.rows);
    }

    // Remove all the rows that contains only specified pairs
    fn removePartialRows(pairs: &[ExpandedPair], rows: &mut Vec<ExpandedRow>) {
        rows.retain(|row| {
            let mut allFound = true;
            if row.getPairs().len() != pairs.len() {
                for p in row.getPairs() {
                    // for (ExpandedPair p : r.getPairs()) {
                    if !pairs.contains(p) {
                        allFound = false;
                        break;
                    }
                }
                !allFound
            } else {
                true
            }
        });
    }

    // Returns true when one of the rows already contains all the pairs
    fn isPartialRow(pairs: &[ExpandedPair], rows: &[ExpandedRow]) -> bool {
        for r in rows {
            let mut allFound = true;
            for p in pairs {
                let mut found = false;
                for pp in r.getPairs() {
                    if p == pp {
                        found = true;
                        break;
                    }
                }
                if !found {
                    allFound = false;
                    break;
                }
            }
            if allFound {
                // the row 'r' contain all the pairs from 'pairs'
                return true;
            }
        }
        false
    }

    // Only used for unit testing
    #[cfg(test)]
    #[allow(dead_code)]
    pub(crate) fn getRowsMut(&mut self) -> &mut [ExpandedRow] {
        &mut self.rows
    }
    #[cfg(test)]
    pub(crate) fn getRows(&self) -> &[ExpandedRow] {
        &self.rows
    }

    // Not private for unit testing
    pub(crate) fn constructRXingResult(pairs: &[ExpandedPair]) -> Result<RXingResult> {
        let binary =
            bit_array_builder::buildBitArray(&pairs.to_vec()).ok_or(Exceptions::ILLEGAL_STATE)?;

        let mut decoder = abstract_expanded_decoder::createDecoder(&binary)?;
        let resultingString = decoder.parseInformation()?;

        let firstPoints = pairs
            .get(0)
            .ok_or(Exceptions::INDEX_OUT_OF_BOUNDS)?
            .getFinderPattern()
            .as_ref()
            .ok_or(Exceptions::ILLEGAL_STATE)?
            .getPoints();
        let lastPoints = pairs
            .last()
            .ok_or(Exceptions::INDEX_OUT_OF_BOUNDS)?
            .getFinderPattern()
            .as_ref()
            .ok_or(Exceptions::ILLEGAL_STATE)?
            .getPoints();

        let mut result = RXingResult::new(
            &resultingString,
            Vec::new(),
            vec![firstPoints[0], firstPoints[1], lastPoints[0], lastPoints[1]],
            BarcodeFormat::RSS_EXPANDED,
        );

        result.putMetadata(
            RXingResultMetadataType::SYMBOLOGY_IDENTIFIER,
            RXingResultMetadataValue::SymbologyIdentifier("]e0".to_owned()),
        );

        Ok(result)
    }

    fn checkChecksum(&self) -> bool {
        let Some(firstPair) = self.pairs.get(0) else {
            return false;
        };
        let checkCharacter = firstPair.getLeftChar();
        let Some(firstCharacter) = firstPair.getRightChar() else {
            return false;
        };

        let mut checksum = firstCharacter.getChecksumPortion();
        let mut s = 2;

        for currentPair in self.pairs.iter().skip(1) {
            let Some(currentPairLeftChar) = currentPair.getLeftChar() else {
                return false;
            };
            checksum += currentPairLeftChar.getChecksumPortion();
            s += 1;
            if let Some(currentRightChar) = currentPair.getRightChar() {
                checksum += currentRightChar.getChecksumPortion();
                s += 1;
            }
        }

        checksum %= 211;

        let checkCharacterValue = (211 * (s as i64 - 4) + checksum as i64) as u32;

        if let Some(checkCharacter) = checkCharacter {
            checkCharacterValue == checkCharacter.getValue()
        } else {
            false
        }
    }

    fn getNextSecondBar(row: &BitArray, initialPos: usize) -> usize {
        let mut currentPos;
        if row.get(initialPos) {
            currentPos = row.getNextUnset(initialPos);
            currentPos = row.getNextSet(currentPos);
        } else {
            currentPos = row.getNextSet(initialPos);
            currentPos = row.getNextUnset(currentPos);
        }
        currentPos
    }

    // not private for testing
    pub(super) fn retrieveNextPair(
        &mut self,
        row: &BitArray,
        previousPairs: &[ExpandedPair],
        rowNumber: u32,
    ) -> Result<ExpandedPair> {
        let mut isOddPattern = previousPairs.len() % 2 == 0;
        if self.startFromEven {
            isOddPattern = !isOddPattern;
        }

        let mut pattern;

        let mut keepFinding = true;
        let mut forcedOffset = -1_i32;
        loop {
            self.findNextPair(row, previousPairs, forcedOffset)?;
            pattern = self.parseFoundFinderPattern(row, rowNumber, isOddPattern);
            if pattern.is_none() {
                forcedOffset = Self::getNextSecondBar(row, self.startEnd[0] as usize) as i32;
            } else {
                keepFinding = false;
            }
            if !keepFinding {
                break;
            }
        }

        // 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 = self.decodeDataCharacter(
            row,
            pattern.as_ref().ok_or(Exceptions::NOT_FOUND)?,
            isOddPattern,
            true,
        )?;

        if !previousPairs.is_empty()
            && previousPairs
                .last()
                .ok_or(Exceptions::NOT_FOUND)?
                .mustBeLast()
        {
            return Err(Exceptions::NOT_FOUND);
        }

        let rightChar = self
            .decodeDataCharacter(
                row,
                pattern.as_ref().ok_or(Exceptions::NOT_FOUND)?,
                isOddPattern,
                false,
            )
            .ok();

        Ok(ExpandedPair::new(Some(leftChar), rightChar, pattern))
    }

    fn findNextPair(
        &mut self,
        row: &BitArray,
        previousPairs: &[ExpandedPair],
        forcedOffset: i32,
    ) -> Result<()> {
        let counters = &mut self.decodeFinderCounters;
        counters.fill(0);
        // counters[0] = 0;
        // counters[1] = 0;
        // counters[2] = 0;
        // counters[3] = 0;

        let width = row.get_size();

        let mut rowOffset;
        if forcedOffset >= 0 {
            rowOffset = forcedOffset;
        } else if previousPairs.is_empty() {
            rowOffset = 0;
        } else {
            let lastPair = previousPairs
                .last()
                .ok_or(Exceptions::INDEX_OUT_OF_BOUNDS)?;
            rowOffset = lastPair
                .getFinderPattern()
                .as_ref()
                .ok_or(Exceptions::ILLEGAL_STATE)?
                .getStartEnd()[1] as i32;
        }
        let mut searchingEvenPair = previousPairs.len() % 2 != 0;
        if self.startFromEven {
            searchingEvenPair = !searchingEvenPair;
        }

        let mut isWhite = false;
        while rowOffset < width as i32 {
            isWhite = !row.get(rowOffset as usize);
            if !isWhite {
                break;
            }
            rowOffset += 1;
        }

        let mut counterPosition = 0;
        let mut patternStart = rowOffset;
        for x in rowOffset..width as i32 {
            // for (int x = rowOffset; x < width; x++) {
            if row.get(x as usize) != isWhite {
                counters[counterPosition] += 1;
            } else {
                if counterPosition == 3 {
                    if searchingEvenPair {
                        Self::reverseCounters(counters);
                    }

                    if Self::isFinderPattern(counters) {
                        self.startEnd[0] = patternStart as u32;
                        self.startEnd[1] = x as u32;
                        return Ok(());
                    }

                    if searchingEvenPair {
                        Self::reverseCounters(counters);
                    }

                    patternStart += (counters[0] + counters[1]) as i32;
                    counters[0] = counters[2];
                    counters[1] = counters[3];
                    counters[2] = 0;
                    counters[3] = 0;
                    counterPosition -= 1;
                } else {
                    counterPosition += 1;
                }
                counters[counterPosition] = 1;
                isWhite = !isWhite;
            }
        }
        Err(Exceptions::NOT_FOUND)
    }

    fn reverseCounters(counters: &mut [u32]) {
        counters.reverse();
        // let length = counters.len();
        // for i in 0..length / 2 {
        //     counters.swap(i, length - i - 1);
        // }
    }

    fn parseFoundFinderPattern(
        &self,
        row: &BitArray,
        rowNumber: u32,
        oddPattern: bool,
    ) -> Option<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 mut firstElementStart = self.startEnd[0] as i32 - 1;
            // Locate element 1
            while firstElementStart >= 0 && !row.get(firstElementStart as usize) {
                firstElementStart -= 1;
            }

            firstElementStart += 1;
            firstCounter = self.startEnd[0] as i32 - firstElementStart;
            start = firstElementStart;
            end = self.startEnd[1];
        } else {
            // If pattern number is even, the pattern is reversed, so we need to locate element 1 *after* the current block.

            start = self.startEnd[0] as i32;

            end = row.getNextUnset(self.startEnd[1] as usize + 1) as u32;
            firstCounter = end as i32 - self.startEnd[1] as i32;
        }

        // Make 'counters' hold 1-4
        let mut counters = self.decodeFinderCounters;
        let counters_len = counters.len();
        counters.copy_within(..counters_len - 1, 1);
        // System.arraycopy(counters, 0, counters, 1, counters.length - 1);

        counters[0] = firstCounter as u32;
        let value = Self::parseFinderValue(&counters, &Self::FINDER_PATTERNS).ok()?;

        Some(FinderPattern::new(
            value,
            [start as usize, end as usize],
            start as usize,
            end as usize,
            rowNumber,
        ))
    }

    pub(super) fn decodeDataCharacter(
        &mut self,
        row: &BitArray,
        pattern: &FinderPattern,
        isOddPattern: bool,
        leftChar: bool,
    ) -> Result<DataCharacter> {
        let counters = &mut self.dataCharacterCounters;
        counters.fill(0);

        if leftChar {
            record_pattern_in_reverse(row, pattern.getStartEnd()[0], counters)?;
        } else {
            record_pattern(row, pattern.getStartEnd()[1], counters)?;
            // reverse it
            counters.reverse();
            // let mut i = 0;
            // let mut j = counters.len() - 1;
            // while i < j {
            //     counters.swap(i, j);

            //     i += 1;
            //     j -= 1;
            // }
        } //counters[] has the pixels of the module

        //left and right data characters have all the same length
        let numModules = 17;

        let elementWidth: f32 = (counters.iter().sum::<u32>() as f32) / numModules as f32;

        // Logic check: element width for pattern and the character should match
        let expectedElementWidth: f32 =
            (pattern.getStartEnd()[1] - pattern.getStartEnd()[0]) as f32 / 15.0;
        if (elementWidth - expectedElementWidth).abs() / expectedElementWidth > 0.3 {
            return Err(Exceptions::NOT_FOUND);
        }

        for (i, counter) in counters.iter().enumerate() {
            // for (int i = 0; i < counters.length; i++) {
            let value: f32 = 1.0 * (*counter as f32) / elementWidth;
            let mut count = (value + 0.5) as i32; // Round
            if count < 1 {
                if value < 0.3 {
                    return Err(Exceptions::NOT_FOUND);
                }
                count = 1;
            } else if count > 8 {
                if value > 8.7 {
                    return Err(Exceptions::NOT_FOUND);
                }
                count = 8;
            }
            let offset = i / 2;
            if (i & 0x01) == 0 {
                self.oddCounts[offset] = count as u32;
                self.oddRoundingErrors[offset] = value - count as f32;
            } else {
                self.evenCounts[offset] = count as u32;
                self.evenRoundingErrors[offset] = value - count as f32;
            }
        }

        self.adjustOddEvenCounts(numModules as u32)?;

        let weightRowNumber = (4 * pattern.getValue() as isize
            + (if isOddPattern { 0 } else { 2 })
            + isize::from(!leftChar)
            - 1) as usize;

        let mut oddSum = 0;
        let mut oddChecksumPortion = 0;
        for i in (0..self.oddCounts.len()).rev() {
            if Self::isNotA1left(pattern, isOddPattern, leftChar) {
                let weight = Self::WEIGHTS[weightRowNumber][2 * i];
                oddChecksumPortion += self.oddCounts[i] * weight;
            }
            oddSum += self.oddCounts[i];
        }
        let mut evenChecksumPortion = 0;
        for i in (0..self.evenCounts.len()).rev() {
            if Self::isNotA1left(pattern, isOddPattern, leftChar) {
                let weight = Self::WEIGHTS[weightRowNumber][2 * i + 1];
                evenChecksumPortion += self.evenCounts[i] * weight;
            }
        }
        let checksumPortion = oddChecksumPortion + evenChecksumPortion;

        if (oddSum & 0x01) != 0 || !(4..=13).contains(&oddSum) {
            return Err(Exceptions::NOT_FOUND);
        }

        let group = ((13 - oddSum) / 2) as usize;
        let oddWidest = Self::SYMBOL_WIDEST[group];
        let evenWidest = 9 - oddWidest;
        let vOdd = rss_utils::getRSSvalue(&self.oddCounts, oddWidest, true);
        let vEven = rss_utils::getRSSvalue(&self.evenCounts, evenWidest, false);
        let tEven = Self::EVEN_TOTAL_SUBSET[group];
        let gSum = Self::GSUM[group];
        let value = vOdd * tEven + vEven + gSum;

        Ok(DataCharacter::new(value, checksumPortion))
    }

    #[inline(always)]
    fn isNotA1left(pattern: &FinderPattern, isOddPattern: bool, leftChar: bool) -> bool {
        // A1: pattern.getValue is 0 (A), and it's an oddPattern, and it is a left char
        !(pattern.getValue() == 0 && isOddPattern && leftChar)
    }

    fn adjustOddEvenCounts(&mut self, numModules: u32) -> Result<()> {
        let oddSum = self.oddCounts.iter().sum::<u32>();
        let evenSum = self.evenCounts.iter().sum::<u32>();

        let mut incrementOdd = false;
        let mut decrementOdd = false;

        if oddSum > 13 {
            decrementOdd = true;
        } else if oddSum < 4 {
            incrementOdd = true;
        }
        let mut incrementEven = false;
        let mut decrementEven = false;
        if evenSum > 13 {
            decrementEven = true;
        } else if evenSum < 4 {
            incrementEven = true;
        }

        let mismatch = oddSum as isize + evenSum as isize - numModules as isize;
        let oddParityBad = (oddSum & 0x01) == 1;
        let evenParityBad = (evenSum & 0x01) == 0;
        match mismatch {
            1 => {
                if oddParityBad {
                    if evenParityBad {
                        return Err(Exceptions::NOT_FOUND);
                    }
                    decrementOdd = true;
                } else {
                    if !evenParityBad {
                        return Err(Exceptions::NOT_FOUND);
                    }
                    decrementEven = true;
                }
            }
            -1 => {
                if oddParityBad {
                    if evenParityBad {
                        return Err(Exceptions::NOT_FOUND);
                    }
                    incrementOdd = true;
                } else {
                    if !evenParityBad {
                        return Err(Exceptions::NOT_FOUND);
                    }
                    incrementEven = true;
                }
            }
            0 => {
                if oddParityBad {
                    if !evenParityBad {
                        return Err(Exceptions::NOT_FOUND);
                    }
                    // Both bad
                    if oddSum < evenSum {
                        incrementOdd = true;
                        decrementEven = true;
                    } else {
                        decrementOdd = true;
                        incrementEven = true;
                    }
                } else if evenParityBad {
                    return Err(Exceptions::NOT_FOUND);
                }
            }

            _ => return Err(Exceptions::NOT_FOUND),
        }

        if incrementOdd {
            if decrementOdd {
                return Err(Exceptions::NOT_FOUND);
            }
            Self::increment(&mut self.oddCounts, &self.oddRoundingErrors);
        }
        if decrementOdd {
            Self::decrement(&mut self.oddCounts, &self.oddRoundingErrors);
        }
        if incrementEven {
            if decrementEven {
                return Err(Exceptions::NOT_FOUND);
            }
            Self::increment(&mut self.evenCounts, &self.oddRoundingErrors);
        }
        if decrementEven {
            Self::decrement(&mut self.evenCounts, &self.evenRoundingErrors);
        }

        Ok(())
    }
}