/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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.
 *
 *  This code was originally part of the Apache Harmony project.
 *  The Apache Harmony project has been discontinued.
 *  That's why we imported the code into iText.
 */
/**
 * @author Denis M. Kishenko
 */
package com.itextpdf.awt.geom;

import java.io.IOException;
import java.io.Serializable;

import com.itextpdf.awt.geom.misc.HashCode;
import com.itextpdf.awt.geom.misc.Messages;

public class AffineTransform implements Cloneable, Serializable {

    private static final long serialVersionUID = 1330973210523860834L;

    public static final int TYPE_IDENTITY = 0;
    public static final int TYPE_TRANSLATION = 1;
    public static final int TYPE_UNIFORM_SCALE = 2;
    public static final int TYPE_GENERAL_SCALE = 4;
    public static final int TYPE_QUADRANT_ROTATION = 8;
    public static final int TYPE_GENERAL_ROTATION = 16;
    public static final int TYPE_GENERAL_TRANSFORM = 32;
    public static final int TYPE_FLIP = 64;
    public static final int TYPE_MASK_SCALE = TYPE_UNIFORM_SCALE | TYPE_GENERAL_SCALE;
    public static final int TYPE_MASK_ROTATION = TYPE_QUADRANT_ROTATION | TYPE_GENERAL_ROTATION;

    /**
     * The <code>TYPE_UNKNOWN</code> is an initial type value
     */
    static final int TYPE_UNKNOWN = -1;
    
    /**
     * The min value equivalent to zero. If absolute value less then ZERO it considered as zero.  
     */
    static final double ZERO = 1E-10;
   
    /**
     * The values of transformation matrix
     */
    double m00;
    double m10;
    double m01;
    double m11;
    double m02;
    double m12;

    /**
     * The transformation <code>type</code> 
     */
    transient int type;

    public AffineTransform() {
        type = TYPE_IDENTITY;
        m00 = m11 = 1.0;
        m10 = m01 = m02 = m12 = 0.0;
    }

    public AffineTransform(AffineTransform t) {
        this.type = t.type;
        this.m00 = t.m00;
        this.m10 = t.m10;
        this.m01 = t.m01;
        this.m11 = t.m11;
        this.m02 = t.m02;
        this.m12 = t.m12;
    }

    public AffineTransform(float m00, float m10, float m01, float m11, float m02, float m12) {
        this.type = TYPE_UNKNOWN;
        this.m00 = m00;
        this.m10 = m10;
        this.m01 = m01;
        this.m11 = m11;
        this.m02 = m02;
        this.m12 = m12;
    }

    public AffineTransform(double m00, double m10, double m01, double m11, double m02, double m12) {
        this.type = TYPE_UNKNOWN;
        this.m00 = m00;
        this.m10 = m10;
        this.m01 = m01;
        this.m11 = m11;
        this.m02 = m02;
        this.m12 = m12;
    }

    public AffineTransform(float[] matrix) {
        this.type = TYPE_UNKNOWN;
        m00 = matrix[0];
        m10 = matrix[1];
        m01 = matrix[2];
        m11 = matrix[3];
        if (matrix.length > 4) {
            m02 = matrix[4];
            m12 = matrix[5];
        }
    }

    public AffineTransform(double[] matrix) {
        this.type = TYPE_UNKNOWN;
        m00 = matrix[0];
        m10 = matrix[1];
        m01 = matrix[2];
        m11 = matrix[3];
        if (matrix.length > 4) {
            m02 = matrix[4];
            m12 = matrix[5];
        }
    }

    /*
     * Method returns type of affine transformation.
     * 
     * Transform matrix is
     *   m00 m01 m02
     *   m10 m11 m12
     * 
     * According analytic geometry new basis vectors are (m00, m01) and (m10, m11), 
     * translation vector is (m02, m12). Original basis vectors are (1, 0) and (0, 1). 
     * Type transformations classification:  
     *   TYPE_IDENTITY - new basis equals original one and zero translation
     *   TYPE_TRANSLATION - translation vector isn't zero  
     *   TYPE_UNIFORM_SCALE - vectors length of new basis equals
     *   TYPE_GENERAL_SCALE - vectors length of new basis doesn't equal 
     *   TYPE_FLIP - new basis vector orientation differ from original one
     *   TYPE_QUADRANT_ROTATION - new basis is rotated by 90, 180, 270, or 360 degrees     
     *   TYPE_GENERAL_ROTATION - new basis is rotated by arbitrary angle
     *   TYPE_GENERAL_TRANSFORM - transformation can't be inversed
     */
    public int getType() {
        if (type != TYPE_UNKNOWN) {
            return type;
        }

        int type = 0;

        if (m00 * m01 + m10 * m11 != 0.0) {
            type |= TYPE_GENERAL_TRANSFORM;
            return type;
        }

        if (m02 != 0.0 || m12 != 0.0) {
            type |= TYPE_TRANSLATION;
        } else
            if (m00 == 1.0 && m11 == 1.0 && m01 == 0.0 && m10 == 0.0) {
                type = TYPE_IDENTITY;
                return type;
            }

        if (m00 * m11 - m01 * m10 < 0.0) {
            type |= TYPE_FLIP;
        }

        double dx = m00 * m00 + m10 * m10;
        double dy = m01 * m01 + m11 * m11;
        if (dx != dy) {
            type |= TYPE_GENERAL_SCALE;
        } else
            if (dx != 1.0) {
                type |= TYPE_UNIFORM_SCALE;
            }

        if ((m00 == 0.0 && m11 == 0.0) ||
            (m10 == 0.0 && m01 == 0.0 && (m00 < 0.0 || m11 < 0.0)))
        {
            type |= TYPE_QUADRANT_ROTATION;
        } else
            if (m01 != 0.0 || m10 != 0.0) {
                type |= TYPE_GENERAL_ROTATION;
            }

        return type;
    }

    public double getScaleX() {
        return m00;
    }

    public double getScaleY() {
        return m11;
    }

    public double getShearX() {
        return m01;
    }

    public double getShearY() {
        return m10;
    }

    public double getTranslateX() {
        return m02;
    }

    public double getTranslateY() {
        return m12;
    }

    public boolean isIdentity() {
        return getType() == TYPE_IDENTITY;
    }

    public void getMatrix(double[] matrix) {
        matrix[0] = m00;
        matrix[1] = m10;
        matrix[2] = m01;
        matrix[3] = m11;
        if (matrix.length > 4) {
            matrix[4] = m02;
            matrix[5] = m12;
        }
    }

    public double getDeterminant() {
        return m00 * m11 - m01 * m10;
    }

    public void setTransform(double m00, double m10, double m01, double m11, double m02, double m12) {
        this.type = TYPE_UNKNOWN;
        this.m00 = m00;
        this.m10 = m10;
        this.m01 = m01;
        this.m11 = m11;
        this.m02 = m02;
        this.m12 = m12;
    }

    public void setTransform(AffineTransform t) {
        type = t.type;
        setTransform(t.m00, t.m10, t.m01, t.m11, t.m02, t.m12);
    }

    public void setToIdentity() {
        type = TYPE_IDENTITY;
        m00 = m11 = 1.0;
        m10 = m01 = m02 = m12 = 0.0;
    }

    public void setToTranslation(double mx, double my) {
        m00 = m11 = 1.0;
        m01 = m10 = 0.0;
        m02 = mx;
        m12 = my;
        if (mx == 0.0 && my == 0.0) {
            type = TYPE_IDENTITY;
        } else {
            type = TYPE_TRANSLATION;
        }
    }

    public void setToScale(double scx, double scy) {
        m00 = scx;
        m11 = scy;
        m10 = m01 = m02 = m12 = 0.0;
        if (scx != 1.0 || scy != 1.0) {
            type = TYPE_UNKNOWN;
        } else {
            type = TYPE_IDENTITY;
        }
    }

    public void setToShear(double shx, double shy) {
        m00 = m11 = 1.0;
        m02 = m12 = 0.0;
        m01 = shx;
        m10 = shy;
        if (shx != 0.0 || shy != 0.0) {
            type = TYPE_UNKNOWN;
        } else {
            type = TYPE_IDENTITY;
        }
    }

    public void setToRotation(double angle) {
        double sin = Math.sin(angle);
        double cos = Math.cos(angle);
        if (Math.abs(cos) < ZERO) {
            cos = 0.0;
            sin = sin > 0.0 ? 1.0 : -1.0;
        } else
            if (Math.abs(sin) < ZERO) {
                sin = 0.0;
                cos = cos > 0.0 ? 1.0 : -1.0;
            }
        m00 = m11 = cos;
        m01 = -sin;
        m10 = sin;
        m02 = m12 = 0.0;
        type = TYPE_UNKNOWN;
    }

    public void setToRotation(double angle, double px, double py) {
        setToRotation(angle);
        m02 = px * (1.0 - m00) + py * m10;
        m12 = py * (1.0 - m00) - px * m10;
        type = TYPE_UNKNOWN;
    }

    public static AffineTransform getTranslateInstance(double mx, double my) {
        AffineTransform t = new AffineTransform();
        t.setToTranslation(mx, my);
        return t;
    }

    public static AffineTransform getScaleInstance(double scx, double scY) {
        AffineTransform t = new AffineTransform();
        t.setToScale(scx, scY);
        return t;
    }

    public static AffineTransform getShearInstance(double shx, double shy) {
        AffineTransform m = new AffineTransform();
        m.setToShear(shx, shy);
        return m;
    }

    public static AffineTransform getRotateInstance(double angle) {
        AffineTransform t = new AffineTransform();
        t.setToRotation(angle);
        return t;
    }

    public static AffineTransform getRotateInstance(double angle, double x, double y) {
        AffineTransform t = new AffineTransform();
        t.setToRotation(angle, x, y);
        return t;
    }

    public void translate(double mx, double my) {
        concatenate(AffineTransform.getTranslateInstance(mx, my));
    }

    public void scale(double scx, double scy) {
        concatenate(AffineTransform.getScaleInstance(scx, scy));
    }

    public void shear(double shx, double shy) {
        concatenate(AffineTransform.getShearInstance(shx, shy));
    }

    public void rotate(double angle) {
        concatenate(AffineTransform.getRotateInstance(angle));
    }

    public void rotate(double angle, double px, double py) {
        concatenate(AffineTransform.getRotateInstance(angle, px, py));
    }

    /** 
     * Multiply matrix of two AffineTransform objects 
     * @param t1 - the AffineTransform object is a multiplicand
     * @param t2 - the AffineTransform object is a multiplier
     * @return an AffineTransform object that is a result of t1 multiplied by matrix t2. 
     */
    AffineTransform multiply(AffineTransform t1, AffineTransform t2) {
        return new AffineTransform(
                t1.m00 * t2.m00 + t1.m10 * t2.m01,          // m00
                t1.m00 * t2.m10 + t1.m10 * t2.m11,          // m01
                t1.m01 * t2.m00 + t1.m11 * t2.m01,          // m10
                t1.m01 * t2.m10 + t1.m11 * t2.m11,          // m11
                t1.m02 * t2.m00 + t1.m12 * t2.m01 + t2.m02, // m02
                t1.m02 * t2.m10 + t1.m12 * t2.m11 + t2.m12);// m12
    }

    public void concatenate(AffineTransform t) {
        setTransform(multiply(t, this));
    }

    public void preConcatenate(AffineTransform t) {
        setTransform(multiply(this, t));
    }

    public AffineTransform createInverse() throws NoninvertibleTransformException {
        double det = getDeterminant();
        if (Math.abs(det) < ZERO) {
            // awt.204=Determinant is zero
            throw new NoninvertibleTransformException(Messages.getString("awt.204")); //$NON-NLS-1$
        }
        return new AffineTransform(
                 m11 / det, // m00
                -m10 / det, // m10
                -m01 / det, // m01
                 m00 / det, // m11
                (m01 * m12 - m11 * m02) / det, // m02
                (m10 * m02 - m00 * m12) / det  // m12
        );
    }

    public Point2D transform(Point2D src, Point2D dst) {
        if (dst == null) {
            if (src instanceof Point2D.Double) {
                dst = new Point2D.Double();
            } else {
                dst = new Point2D.Float();
            }
        }

        double x = src.getX();
        double y = src.getY();

        dst.setLocation(x * m00 + y * m01 + m02, x * m10 + y * m11 + m12);
        return dst;
    }

    public void transform(Point2D[] src, int srcOff, Point2D[] dst, int dstOff, int length) {
        while (--length >= 0) {
            Point2D srcPoint = src[srcOff++]; 
            double x = srcPoint.getX();
            double y = srcPoint.getY();
            Point2D dstPoint = dst[dstOff]; 
            if (dstPoint == null) {
                if (srcPoint instanceof Point2D.Double) {
                    dstPoint = new Point2D.Double();
                } else {
                    dstPoint = new Point2D.Float();
                }
            }
            dstPoint.setLocation(x * m00 + y * m01 + m02, x * m10 + y * m11 + m12);
            dst[dstOff++] = dstPoint;
        }
    }
    
     public void transform(double[] src, int srcOff, double[] dst, int dstOff, int length) {
        int step = 2;
        if (src == dst && srcOff < dstOff && dstOff < srcOff + length * 2) {
            srcOff = srcOff + length * 2 - 2;
            dstOff = dstOff + length * 2 - 2;
            step = -2;
        }
        while (--length >= 0) {
            double x = src[srcOff + 0];
            double y = src[srcOff + 1];
            dst[dstOff + 0] = x * m00 + y * m01 + m02;
            dst[dstOff + 1] = x * m10 + y * m11 + m12;
            srcOff += step;
            dstOff += step;
        }
    }

    public void transform(float[] src, int srcOff, float[] dst, int dstOff, int length) {
        int step = 2;
        if (src == dst && srcOff < dstOff && dstOff < srcOff + length * 2) {
            srcOff = srcOff + length * 2 - 2;
            dstOff = dstOff + length * 2 - 2;
            step = -2;
        }
        while (--length >= 0) {
            float x = src[srcOff + 0];
            float y = src[srcOff + 1];
            dst[dstOff + 0] = (float)(x * m00 + y * m01 + m02);
            dst[dstOff + 1] = (float)(x * m10 + y * m11 + m12);
            srcOff += step;
            dstOff += step;
        }
    }
    
    public void transform(float[] src, int srcOff, double[] dst, int dstOff, int length) {
        while (--length >= 0) {
            float x = src[srcOff++];
            float y = src[srcOff++];
            dst[dstOff++] = x * m00 + y * m01 + m02;
            dst[dstOff++] = x * m10 + y * m11 + m12;
        }
    }

    public void transform(double[] src, int srcOff, float[] dst, int dstOff, int length) {
        while (--length >= 0) {
            double x = src[srcOff++];
            double y = src[srcOff++];
            dst[dstOff++] = (float)(x * m00 + y * m01 + m02);
            dst[dstOff++] = (float)(x * m10 + y * m11 + m12);
        }
    }

    public Point2D deltaTransform(Point2D src, Point2D dst) {
        if (dst == null) {
            if (src instanceof Point2D.Double) {
                dst = new Point2D.Double();
            } else {
                dst = new Point2D.Float();
            }
        }

        double x = src.getX();
        double y = src.getY();

        dst.setLocation(x * m00 + y * m01, x * m10 + y * m11);
        return dst;
    }

    public void deltaTransform(double[] src, int srcOff, double[] dst, int dstOff, int length) {
        while (--length >= 0) {
            double x = src[srcOff++];
            double y = src[srcOff++];
            dst[dstOff++] = x * m00 + y * m01;
            dst[dstOff++] = x * m10 + y * m11;
        }
    }

    public Point2D inverseTransform(Point2D src, Point2D dst) throws NoninvertibleTransformException {
        double det = getDeterminant();
        if (Math.abs(det) < ZERO) {
            // awt.204=Determinant is zero
            throw new NoninvertibleTransformException(Messages.getString("awt.204")); //$NON-NLS-1$
        }

        if (dst == null) {
            if (src instanceof Point2D.Double) {
                dst = new Point2D.Double();
            } else {
                dst = new Point2D.Float();
            }
        }

        double x = src.getX() - m02;
        double y = src.getY() - m12;

        dst.setLocation((x * m11 - y * m01) / det, (y * m00 - x * m10) / det);
        return dst;
    }

    public void inverseTransform(double[] src, int srcOff, double[] dst, int dstOff, int length)
        throws NoninvertibleTransformException
    {
        double det = getDeterminant();
        if (Math.abs(det) < ZERO) {
            // awt.204=Determinant is zero
            throw new NoninvertibleTransformException(Messages.getString("awt.204")); //$NON-NLS-1$
        }

        while (--length >= 0) {
            double x = src[srcOff++] - m02;
            double y = src[srcOff++] - m12;
            dst[dstOff++] = (x * m11 - y * m01) / det;
            dst[dstOff++] = (y * m00 - x * m10) / det;
        }
    }

    public void inverseTransform(float[] src, int srcOff, float[] dst, int dstOff, int length)
            throws NoninvertibleTransformException
    {
        float det = (float)getDeterminant();
        if (Math.abs(det) < ZERO) {
            // awt.204=Determinant is zero
            throw new NoninvertibleTransformException(Messages.getString("awt.204")); //$NON-NLS-1$
        }

        while (--length >= 0) {
            float x = src[srcOff++] - (float)m02;
            float y = src[srcOff++] - (float)m12;
            dst[dstOff++] = (x * (float)m11 - y * (float)m01) / det;
            dst[dstOff++] = (y * (float)m00 - x * (float)m10) / det;
        }
    }

    public Shape createTransformedShape(Shape src) {
        if (src == null) {
            return null;
        }
        if (src instanceof GeneralPath) {
            return ((GeneralPath)src).createTransformedShape(this);
        }
        PathIterator path = src.getPathIterator(this);
        GeneralPath dst = new GeneralPath(path.getWindingRule());
        dst.append(path, false);
        return dst;
    }

    @Override
    public String toString() {
        return
            getClass().getName() +
            "[[" + m00 + ", " + m01 + ", " + m02 + "], [" //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
                + m10 + ", " + m11 + ", " + m12 + "]]"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
    }

    @Override
    public Object clone() {
        try {
            return super.clone();
        } catch (CloneNotSupportedException e) {
            throw new InternalError();
        }
    }

    @Override
    public int hashCode() {
        HashCode hash = new HashCode();
        hash.append(m00);
        hash.append(m01);
        hash.append(m02);
        hash.append(m10);
        hash.append(m11);
        hash.append(m12);
        return hash.hashCode();
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (obj instanceof AffineTransform) {
            AffineTransform t = (AffineTransform)obj;
            return
                m00 == t.m00 && m01 == t.m01 &&
                m02 == t.m02 && m10 == t.m10 &&
                m11 == t.m11 && m12 == t.m12;
        }
        return false;
    }

    
    /**
     * Write AffineTrasform object to the output steam.
     * @param stream - the output stream
     * @throws IOException - if there are I/O errors while writing to the output strem
     */
    private void writeObject(java.io.ObjectOutputStream stream) throws IOException {
        stream.defaultWriteObject();
    }

    
    /**
     * Read AffineTransform object from the input stream
     * @param stream - the input steam
     * @throws IOException - if there are I/O errors while reading from the input strem
     * @throws ClassNotFoundException - if class could not be found 
     */
    private void readObject(java.io.ObjectInputStream stream) throws IOException, ClassNotFoundException {
        stream.defaultReadObject();
        type = TYPE_UNKNOWN;
    }

}

