/*
 * Copyright 2008 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 crate::{
    common::{detector::WhiteRectangleDetector, BitMatrix, DefaultGridSampler, GridSampler},
    Exceptions, RXingResultPoint, ResultPoint,
};

use super::DatamatrixDetectorResult;

/**
 * <p>Encapsulates logic that can detect a Data Matrix Code in an image, even if the Data Matrix Code
 * is rotated or skewed, or partially obscured.</p>
 *
 * @author Sean Owen
 */
pub struct Detector<'a> {
    image: &'a BitMatrix,
    rectangleDetector: WhiteRectangleDetector<'a>,
}
impl<'a> Detector<'_> {
    pub fn new(image: &'a BitMatrix) -> Result<Detector<'a>, Exceptions> {
        Ok(Detector {
            rectangleDetector: WhiteRectangleDetector::new_from_image(image)?,
            image,
        })
    }

    /**
     * <p>Detects a Data Matrix Code in an image.</p>
     *
     * @return {@link DetectorRXingResult} encapsulating results of detecting a Data Matrix Code
     * @throws NotFoundException if no Data Matrix Code can be found
     */
    pub fn detect(&self) -> Result<DatamatrixDetectorResult, Exceptions> {
        let cornerPoints = self.rectangleDetector.detect()?;

        let mut points = self.detectSolid1(cornerPoints);
        points = self.detectSolid2(points);
        if let Some(point) = self.correctTopRight(&points) {
            points[3] = point;
        } else {
            return Err(Exceptions::notFound("point 4 unfound".to_owned()));
        }
        // points[3] = self.correctTopRight(&points);
        // if points[3] == null {
        //   throw NotFoundException.getNotFoundInstance();
        // }
        points = self.shiftToModuleCenter(points);

        let topLeft = points[0];
        let bottomLeft = points[1];
        let bottomRight = points[2];
        let topRight = points[3];

        let mut dimensionTop = self.transitionsBetween(&topLeft, &topRight) + 1;
        let mut dimensionRight = self.transitionsBetween(&bottomRight, &topRight) + 1;
        if (dimensionTop & 0x01) == 1 {
            dimensionTop += 1;
        }
        if (dimensionRight & 0x01) == 1 {
            dimensionRight += 1;
        }

        if 4 * dimensionTop < 6 * dimensionRight && 4 * dimensionRight < 6 * dimensionTop {
            // The matrix is square
            dimensionTop = dimensionTop.max(dimensionRight);
            dimensionRight = dimensionTop.max(dimensionRight);
        }

        let bits = Self::sampleGrid(
            self.image,
            &topLeft,
            &bottomLeft,
            &bottomRight,
            &topRight,
            dimensionTop,
            dimensionRight,
        )?;

        Ok(DatamatrixDetectorResult::new(
            bits,
            vec![topLeft, bottomLeft, bottomRight, topRight],
        ))
    }

    fn shiftPoint(point: RXingResultPoint, to: RXingResultPoint, div: u32) -> RXingResultPoint {
        let x = (to.getX() - point.getX()) / (div as f32 + 1.0);
        let y = (to.getY() - point.getY()) / (div as f32 + 1.0);
        RXingResultPoint::new(point.getX() + x, point.getY() + y)
    }

    fn moveAway(point: RXingResultPoint, fromX: f32, fromY: f32) -> RXingResultPoint {
        let mut x = point.getX();
        let mut y = point.getY();

        if x < fromX {
            x -= 1.0;
        } else {
            x += 1.0;
        }

        if y < fromY {
            y -= 1.0;
        } else {
            y += 1.0;
        }

        RXingResultPoint::new(x, y)
    }

    /**
     * Detect a solid side which has minimum transition.
     */
    fn detectSolid1(&self, cornerPoints: [RXingResultPoint; 4]) -> [RXingResultPoint; 4] {
        // 0  2
        // 1  3
        let pointA = cornerPoints[0];
        let pointB = cornerPoints[1];
        let pointC = cornerPoints[3];
        let pointD = cornerPoints[2];

        let trAB = self.transitionsBetween(&pointA, &pointB);
        let trBC = self.transitionsBetween(&pointB, &pointC);
        let trCD = self.transitionsBetween(&pointC, &pointD);
        let trDA = self.transitionsBetween(&pointD, &pointA);

        // 0..3
        // :  :
        // 1--2
        let mut min = trAB;
        let mut points = [pointD, pointA, pointB, pointC];
        if min > trBC {
            min = trBC;
            points[0] = pointA;
            points[1] = pointB;
            points[2] = pointC;
            points[3] = pointD;
        }
        if min > trCD {
            min = trCD;
            points[0] = pointB;
            points[1] = pointC;
            points[2] = pointD;
            points[3] = pointA;
        }
        if min > trDA {
            points[0] = pointC;
            points[1] = pointD;
            points[2] = pointA;
            points[3] = pointB;
        }

        points
    }

    /**
     * Detect a second solid side next to first solid side.
     */
    fn detectSolid2(&self, points: [RXingResultPoint; 4]) -> [RXingResultPoint; 4] {
        // A..D
        // :  :
        // B--C
        let pointA = points[0];
        let pointB = points[1];
        let pointC = points[2];
        let pointD = points[3];

        // Transition detection on the edge is not stable.
        // To safely detect, shift the points to the module center.
        let tr = self.transitionsBetween(&pointA, &pointD);
        let pointBs = Self::shiftPoint(pointB, pointC, (tr + 1) * 4);
        let pointCs = Self::shiftPoint(pointC, pointB, (tr + 1) * 4);
        let trBA = self.transitionsBetween(&pointBs, &pointA);
        let trCD = self.transitionsBetween(&pointCs, &pointD);

        // 0..3
        // |  :
        // 1--2
        if trBA < trCD {
            // solid sides: A-B-C
            [pointA, pointB, pointC, pointD]
            // points[0] = pointA;
            // points[1] = pointB;
            // points[2] = pointC;
            // points[3] = pointD;
        } else {
            // solid sides: B-C-D
            [pointB, pointC, pointD, pointA]
            // points[0] = pointB;
            // points[1] = pointC;
            // points[2] = pointD;
            // points[3] = pointA;
        }
    }

    /**
     * Calculates the corner position of the white top right module.
     */
    fn correctTopRight(&self, points: &[RXingResultPoint; 4]) -> Option<RXingResultPoint> {
        // A..D
        // |  :
        // B--C
        let pointA = points[0];
        let pointB = points[1];
        let pointC = points[2];
        let pointD = points[3];

        // shift points for safe transition detection.
        let mut trTop = self.transitionsBetween(&pointA, &pointD);
        let mut trRight = self.transitionsBetween(&pointB, &pointD);
        let pointAs = Self::shiftPoint(pointA, pointB, (trRight + 1) * 4);
        let pointCs = Self::shiftPoint(pointC, pointB, (trTop + 1) * 4);

        trTop = self.transitionsBetween(&pointAs, &pointD);
        trRight = self.transitionsBetween(&pointCs, &pointD);

        let candidate1 = RXingResultPoint::new(
            pointD.getX() + (pointC.getX() - pointB.getX()) / (trTop as f32 + 1.0),
            pointD.getY() + (pointC.getY() - pointB.getY()) / (trTop as f32 + 1.0),
        );
        let candidate2 = RXingResultPoint::new(
            pointD.getX() + (pointA.getX() - pointB.getX()) / (trRight as f32 + 1.0),
            pointD.getY() + (pointA.getY() - pointB.getY()) / (trRight as f32 + 1.0),
        );

        if !self.isValid(&candidate1) {
            if self.isValid(&candidate2) {
                return Some(candidate2);
            }
            return None;
        }
        if !self.isValid(&candidate2) {
            return Some(candidate1);
        }

        let sumc1 = self.transitionsBetween(&pointAs, &candidate1)
            + self.transitionsBetween(&pointCs, &candidate1);
        let sumc2 = self.transitionsBetween(&pointAs, &candidate2)
            + self.transitionsBetween(&pointCs, &candidate2);

        if sumc1 > sumc2 {
            Some(candidate1)
        } else {
            Some(candidate2)
        }
    }

    /**
     * Shift the edge points to the module center.
     */
    fn shiftToModuleCenter(&self, points: [RXingResultPoint; 4]) -> [RXingResultPoint; 4] {
        // A..D
        // |  :
        // B--C
        let mut pointA = points[0];
        let mut pointB = points[1];
        let mut pointC = points[2];
        let mut pointD = points[3];

        // calculate pseudo dimensions
        let mut dimH = self.transitionsBetween(&pointA, &pointD) + 1;
        let mut dimV = self.transitionsBetween(&pointC, &pointD) + 1;

        // shift points for safe dimension detection
        let mut pointAs = Self::shiftPoint(pointA, pointB, dimV * 4);
        let mut pointCs = Self::shiftPoint(pointC, pointB, dimH * 4);

        //  calculate more precise dimensions
        dimH = self.transitionsBetween(&pointAs, &pointD) + 1;
        dimV = self.transitionsBetween(&pointCs, &pointD) + 1;
        if (dimH & 0x01) == 1 {
            dimH += 1;
        }
        if (dimV & 0x01) == 1 {
            dimV += 1;
        }

        // WhiteRectangleDetector returns points inside of the rectangle.
        // I want points on the edges.
        let centerX = (pointA.getX() + pointB.getX() + pointC.getX() + pointD.getX()) / 4.0;
        let centerY = (pointA.getY() + pointB.getY() + pointC.getY() + pointD.getY()) / 4.0;
        pointA = Self::moveAway(pointA, centerX, centerY);
        pointB = Self::moveAway(pointB, centerX, centerY);
        pointC = Self::moveAway(pointC, centerX, centerY);
        pointD = Self::moveAway(pointD, centerX, centerY);

        let mut pointBs;
        let mut pointDs;

        // shift points to the center of each modules
        pointAs = Self::shiftPoint(pointA, pointB, dimV * 4);
        pointAs = Self::shiftPoint(pointAs, pointD, dimH * 4);
        pointBs = Self::shiftPoint(pointB, pointA, dimV * 4);
        pointBs = Self::shiftPoint(pointBs, pointC, dimH * 4);
        pointCs = Self::shiftPoint(pointC, pointD, dimV * 4);
        pointCs = Self::shiftPoint(pointCs, pointB, dimH * 4);
        pointDs = Self::shiftPoint(pointD, pointC, dimV * 4);
        pointDs = Self::shiftPoint(pointDs, pointA, dimH * 4);

        [pointAs, pointBs, pointCs, pointDs]
    }

    fn isValid(&self, p: &RXingResultPoint) -> bool {
        p.getX() >= 0.0
            && p.getX() <= self.image.getWidth() as f32 - 1.0
            && p.getY() > 0.0
            && p.getY() <= self.image.getHeight() as f32 - 1.0
    }

    fn sampleGrid(
        image: &BitMatrix,
        topLeft: &RXingResultPoint,
        bottomLeft: &RXingResultPoint,
        bottomRight: &RXingResultPoint,
        topRight: &RXingResultPoint,
        dimensionX: u32,
        dimensionY: u32,
    ) -> Result<BitMatrix, Exceptions> {
        let sampler = DefaultGridSampler::default();

        sampler.sample_grid_detailed(
            image,
            dimensionX,
            dimensionY,
            0.5,
            0.5,
            dimensionX as f32 - 0.5,
            0.5,
            dimensionX as f32 - 0.5,
            dimensionY as f32 - 0.5,
            0.5,
            dimensionY as f32 - 0.5,
            topLeft.getX(),
            topLeft.getY(),
            topRight.getX(),
            topRight.getY(),
            bottomRight.getX(),
            bottomRight.getY(),
            bottomLeft.getX(),
            bottomLeft.getY(),
        )
    }

    /**
     * Counts the number of black/white transitions between two points, using something like Bresenham's algorithm.
     */
    fn transitionsBetween(&self, from: &RXingResultPoint, to: &RXingResultPoint) -> u32 {
        // See QR Code Detector, sizeOfBlackWhiteBlackRun()
        let mut fromX = from.getX().floor() as i32;
        let mut fromY = from.getY().floor() as i32;
        let mut toX = to.getX().floor() as i32;
        let mut toY = (self.image.getHeight() - 1).min(to.getY().floor() as u32) as i32;

        let steep = (toY - fromY).abs() > (toX - fromX).abs();
        if steep {
            std::mem::swap(&mut fromX, &mut fromY);
            std::mem::swap(&mut toX, &mut toY);
        }

        let dx = (toX - fromX).abs();
        let dy = (toY - fromY).abs();
        let mut error = -dx / 2;
        let ystep = if fromY < toY { 1 } else { -1 };
        let xstep = if fromX < toX { 1 } else { -1 };
        let mut transitions = 0;
        let mut inBlack = self.image.get(
            if steep { fromY as u32 } else { fromX as u32 },
            if steep { fromX as u32 } else { fromY as u32 },
        );
        let mut x = fromX;
        let mut y = fromY;
        while x != toX {
            // for (int x = fromX, y = fromY; x != toX; x += xstep) {
            let isBlack = self.image.get(
                if steep { y as u32 } else { x as u32 },
                if steep { x as u32 } else { y as u32 },
            );
            if isBlack != inBlack {
                transitions += 1;
                inBlack = isBlack;
            }
            error += dy;
            if error > 0 {
                if y == toY {
                    break;
                }
                y += ystep;
                error -= dx;
            }

            x += xstep;
        }
        transitions
    }
}