rxing/src/multi/qrcode/qr_code_multi_reader.rs

/*
 * Copyright 2009 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.
 */

use std::{cmp::Ordering, collections::HashMap};

use crate::{
    common::DetectorRXingResult,
    multi::MultipleBarcodeReader,
    qrcode::{
        decoder::{self, QRCodeDecoderMetaData},
        QRCodeReader,
    },
    BarcodeFormat, Exceptions, RXingResult, RXingResultMetadataType, RXingResultMetadataValue,
};

use super::detector::MultiDetector;

/**
 * This implementation can detect and decode multiple QR Codes in an image.
 *
 * @author Sean Owen
 * @author Hannes Erven
 */
pub struct QRCodeMultiReader(QRCodeReader);
impl MultipleBarcodeReader for QRCodeMultiReader {
    fn decodeMultiple(
        &self,
        image: &crate::BinaryBitmap,
    ) -> Result<Vec<crate::RXingResult>, crate::Exceptions> {
        self.decodeMultipleWithHints(image, &HashMap::new())
    }

    fn decodeMultipleWithHints(
        &self,
        image: &crate::BinaryBitmap,
        hints: &crate::DecodingHintDictionary,
    ) -> Result<Vec<crate::RXingResult>, crate::Exceptions> {
        let mut results = Vec::new();
        let detectorRXingResults =
            MultiDetector::new(image.getBlackMatrix().clone()).detectMulti(hints)?;
        for detectorRXingResult in detectorRXingResults {
            let mut proc = || -> Result<(), Exceptions> {
                let decoderRXingResult = decoder::decoder::decode_bitmatrix_with_hints(
                    detectorRXingResult.getBits(),
                    hints,
                )?;
                let mut points = detectorRXingResult.getPoints().clone();
                // If the code was mirrored: swap the bottom-left and the top-right points.
                let other = decoderRXingResult.getOther();
                if other.is::<QRCodeDecoderMetaData>() {
                    (other
                        .downcast::<QRCodeDecoderMetaData>()
                        .expect("must downcast to QRCodeDecoderMetaData"))
                    .applyMirroredCorrection(&mut points);
                }
                // if (decoderRXingResult.getOther() instanceof QRCodeDecoderMetaData) {
                //   ((QRCodeDecoderMetaData) decoderRXingResult.getOther()).applyMirroredCorrection(points);
                // }
                let mut result = RXingResult::new(
                    decoderRXingResult.getText(),
                    decoderRXingResult.getRawBytes().clone(),
                    points,
                    BarcodeFormat::QR_CODE,
                );
                let byteSegments = decoderRXingResult.getByteSegments();
                // if (byteSegments != null) {
                result.putMetadata(
                    RXingResultMetadataType::BYTE_SEGMENTS,
                    RXingResultMetadataValue::ByteSegments(byteSegments.clone()),
                );
                // }
                let ecLevel = decoderRXingResult.getECLevel();
                // if (ecLevel != null) {
                result.putMetadata(
                    RXingResultMetadataType::ERROR_CORRECTION_LEVEL,
                    RXingResultMetadataValue::ErrorCorrectionLevel(ecLevel.to_owned()),
                );
                // }
                if decoderRXingResult.hasStructuredAppend() {
                    result.putMetadata(
                        RXingResultMetadataType::STRUCTURED_APPEND_SEQUENCE,
                        RXingResultMetadataValue::StructuredAppendSequence(
                            decoderRXingResult.getStructuredAppendSequenceNumber(),
                        ),
                    );
                    result.putMetadata(
                        RXingResultMetadataType::STRUCTURED_APPEND_PARITY,
                        RXingResultMetadataValue::StructuredAppendParity(
                            decoderRXingResult.getStructuredAppendParity(),
                        ),
                    );
                }
                results.push(result);

                Ok(())
            };
            let output = proc();
            if output.is_ok() {
                continue;
            } else if let Err(Exceptions::ReaderException(_)) = output {
                // ignore and continue
                continue;
            } else {
                return Err(output.err().unwrap());
            }
        }

        results = Self::processStructuredAppend(results)?;

        Ok(results)
    }
}

impl QRCodeMultiReader {
    fn processStructuredAppend(results: Vec<RXingResult>) -> Result<Vec<RXingResult>, Exceptions> {
        let mut newRXingResults = Vec::new();
        let mut saRXingResults = Vec::new();
        for result in &results {
            if result
                .getRXingResultMetadata()
                .contains_key(&RXingResultMetadataType::STRUCTURED_APPEND_SEQUENCE)
            {
                saRXingResults.push(result.clone());
            } else {
                newRXingResults.push(result.clone());
            }
        }
        if saRXingResults.is_empty() {
            return Ok(results);
        }

        // sort and concatenate the SA list items
        saRXingResults.sort_by(compareRXingResult);
        let mut newText = String::new();
        let mut newRawBytes = Vec::new(); //new ByteArrayOutputStream();
        let mut newByteSegment = Vec::new(); //new ByteArrayOutputStream();
        for saRXingResult in saRXingResults {
            newText.push_str(saRXingResult.getText());
            let saBytes = saRXingResult.getRawBytes();
            newRawBytes.extend_from_slice(saBytes);
            // newRawBytes.write(saBytes, 0, saBytes.len());

            if let Some(RXingResultMetadataValue::ByteSegments(byteSegments)) = saRXingResult
                .getRXingResultMetadata()
                .get(&RXingResultMetadataType::BYTE_SEGMENTS)
            {
                for segment in byteSegments {
                    // newByteSegment.write(segment, 0, segment.len());
                    newByteSegment.extend_from_slice(segment);
                }
            };
        }

        let mut newRXingResult =
            RXingResult::new(&newText, newRawBytes, Vec::new(), BarcodeFormat::QR_CODE);
        if newByteSegment.len() > 0 {
            newRXingResult.putMetadata(
                RXingResultMetadataType::BYTE_SEGMENTS,
                RXingResultMetadataValue::ByteSegments(vec![newByteSegment]),
            );
        }
        newRXingResults.push(newRXingResult);

        Ok(newRXingResults)
    }
}

fn compareRXingResult(a: &RXingResult, b: &RXingResult) -> Ordering {
    let aNumber = if let Some(RXingResultMetadataValue::StructuredAppendSequence(v)) = a
        .getRXingResultMetadata()
        .get(&RXingResultMetadataType::STRUCTURED_APPEND_SEQUENCE)
    {
        v
    } else {
        &-1
    };
    let bNumber = if let Some(RXingResultMetadataValue::StructuredAppendSequence(v)) = b
        .getRXingResultMetadata()
        .get(&RXingResultMetadataType::STRUCTURED_APPEND_SEQUENCE)
    {
        v
    } else {
        &-1
    };

    aNumber.cmp(bNumber)
}