/*
 * 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.
 */

/*namespace com.google.zxing.qrcode {*/

import BarcodeFormat from './../BarcodeFormat';
import BinaryBitmap from './../BinaryBitmap';
import DecodeHintType from './../DecodeHintType';
import Reader from './../Reader';
import Result from './../Result';
import ResultMetadataType from './../ResultMetadataType';
import ResultPoint from './../ResultPoint';
import BitMatrix from './../common/BitMatrix';
import DecoderResult from './../common/DecoderResult';
import DetectorResult from './../common/DetectorResult';
import Decoder from './decoder/Decoder';
import QRCodeDecoderMetaData from './decoder/QRCodeDecoderMetaData';
import Detector from './detector/Detector';
import Exception from './../Exception';

/*import java.util.List;*/
/*import java.util.Map;*/

/**
 * This implementation can detect and decode QR Codes in an image.
 *
 * @author Sean Owen
 */
export default class QRCodeReader implements Reader {

    private static NO_POINTS = new Array<ResultPoint>();

    private decoder = new Decoder();

    protected getDecoder(): Decoder {
        return this.decoder;
    }

    /**
     * Locates and decodes a QR code in an image.
     *
     * @return a representing: string the content encoded by the QR code
     * @throws NotFoundException if a QR code cannot be found
     * @throws FormatException if a QR code cannot be decoded
     * @throws ChecksumException if error correction fails
     */
    /*@Override*/
    // public decode(image: BinaryBitmap): Result /*throws NotFoundException, ChecksumException, FormatException */ {
    //   return this.decode(image, null)
    // }

    /*@Override*/
    public decode(image: BinaryBitmap, hints?: Map<DecodeHintType, any>): Result {
        let decoderResult: DecoderResult;
        let points: Array<ResultPoint>;
        if (hints !== undefined && hints !== null && undefined !== hints.get(DecodeHintType.PURE_BARCODE)) {
            const bits = QRCodeReader.extractPureBits(image.getBlackMatrix());
            decoderResult = this.decoder.decodeBitMatrix(bits, hints);
            points = QRCodeReader.NO_POINTS;
        } else {
            const detectorResult = new Detector(image.getBlackMatrix()).detect(hints);
            decoderResult = this.decoder.decodeBitMatrix(detectorResult.getBits(), hints);
            points = detectorResult.getPoints();
        }

        // If the code was mirrored: swap the bottom-left and the top-right points.
        if (decoderResult.getOther() instanceof QRCodeDecoderMetaData) {
            (<QRCodeDecoderMetaData>decoderResult.getOther()).applyMirroredCorrection(points);
        }

        const result = new Result(decoderResult.getText(), decoderResult.getRawBytes(), undefined, points, BarcodeFormat.QR_CODE, undefined);
        const byteSegments: Array<Uint8Array> = decoderResult.getByteSegments();
        if (byteSegments !== null) {
            result.putMetadata(ResultMetadataType.BYTE_SEGMENTS, byteSegments);
        }
        const ecLevel: string = decoderResult.getECLevel();
        if (ecLevel !== null) {
            result.putMetadata(ResultMetadataType.ERROR_CORRECTION_LEVEL, ecLevel);
        }
        if (decoderResult.hasStructuredAppend()) {
            result.putMetadata(ResultMetadataType.STRUCTURED_APPEND_SEQUENCE,
                decoderResult.getStructuredAppendSequenceNumber());
            result.putMetadata(ResultMetadataType.STRUCTURED_APPEND_PARITY,
                decoderResult.getStructuredAppendParity());
        }
        return result;
    }

    /*@Override*/
    public reset(): void {
        // do nothing
    }

    /**
     * This method detects a code in a "pure" image -- that is, pure monochrome image
     * which contains only an unrotated, unskewed, image of a code, with some white border
     * around it. This is a specialized method that works exceptionally fast in this special
     * case.
     *
     * @see com.google.zxing.datamatrix.DataMatrixReader#extractPureBits(BitMatrix)
     */
    private static extractPureBits(image: BitMatrix): BitMatrix /*throws NotFoundException */ {

        const leftTopBlack: Int32Array = image.getTopLeftOnBit();
        const rightBottomBlack: Int32Array = image.getBottomRightOnBit();
        if (leftTopBlack === null || rightBottomBlack === null) {
            throw new Exception(Exception.NotFoundException);
        }

        const moduleSize: number /*float*/ = this.moduleSize(leftTopBlack, image);

        let top = leftTopBlack[1];
        let bottom = rightBottomBlack[1];
        let left = leftTopBlack[0];
        let right = rightBottomBlack[0];

        // Sanity check!
        if (left >= right || top >= bottom) {
            throw new Exception(Exception.NotFoundException);
        }

        if (bottom - top !== right - left) {
            // Special case, where bottom-right module wasn't black so we found something else in the last row
            // Assume it's a square, so use height as the width
            right = left + (bottom - top);
            if (right >= image.getWidth()) {
                // Abort if that would not make sense -- off image
                throw new Exception(Exception.NotFoundException);
            }
        }

        const matrixWidth = Math.round((right - left + 1) / moduleSize);
        const matrixHeight = Math.round((bottom - top + 1) / moduleSize);
        if (matrixWidth <= 0 || matrixHeight <= 0) {
            throw new Exception(Exception.NotFoundException);
        }
        if (matrixHeight !== matrixWidth) {
            // Only possibly decode square regions
            throw new Exception(Exception.NotFoundException);
        }

        // Push in the "border" by half the module width so that we start
        // sampling in the middle of the module. Just in case the image is a
        // little off, this will help recover.
        const nudge = /*(int) */Math.floor(moduleSize / 2.0);
        top += nudge;
        left += nudge;

        // But careful that this does not sample off the edge
        // "right" is the farthest-right valid pixel location -- right+1 is not necessarily
        // This is positive by how much the inner x loop below would be too large
        const nudgedTooFarRight = left + /*(int) */Math.floor((matrixWidth - 1) * moduleSize) - right;
        if (nudgedTooFarRight > 0) {
            if (nudgedTooFarRight > nudge) {
                // Neither way fits; abort
                throw new Exception(Exception.NotFoundException);
            }
            left -= nudgedTooFarRight;
        }
        // See logic above
        const nudgedTooFarDown = top + /*(int) */Math.floor((matrixHeight - 1) * moduleSize) - bottom;
        if (nudgedTooFarDown > 0) {
            if (nudgedTooFarDown > nudge) {
                // Neither way fits; abort
                throw new Exception(Exception.NotFoundException);
            }
            top -= nudgedTooFarDown;
        }

        // Now just read off the bits
        const bits = new BitMatrix(matrixWidth, matrixHeight);
        for (let y = 0; y < matrixHeight; y++) {
            const iOffset = top + /*(int) */Math.floor(y * moduleSize);
            for (let x = 0; x < matrixWidth; x++) {
                if (image.get(left + /*(int) */Math.floor(x * moduleSize), iOffset)) {
                    bits.set(x, y);
                }
            }
        }
        return bits;
    }

    private static moduleSize(leftTopBlack: Int32Array, image: BitMatrix): number/*float*/ /*throws NotFoundException */ {
        const height: number /*int*/ = image.getHeight();
        const width: number /*int*/ = image.getWidth();
        let x = leftTopBlack[0];
        let y = leftTopBlack[1];
        let inBlack: boolean = true;
        let transitions = 0;
        while (x < width && y < height) {
            if (inBlack !== image.get(x, y)) {
                if (++transitions === 5) {
                    break;
                }
                inBlack = !inBlack;
            }
            x++;
            y++;
        }
        if (x === width || y === height) {
            throw new Exception(Exception.NotFoundException);
        }
        return (x - leftTopBlack[0]) / 7.0;
    }

}