package com.netease.nim.uikit.common.ui.imageview;

/*
 * Copyright 2012 Laurence Dawson
 *
 * 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.
 */

/*
 * This class is based upon the file ImageViewTouchBase.java which can be found at:
 * https://dl-ssl.google.com/dl/googlesource/git-repo/repo
 *  
 * Copyright (C) 2009 The Android Open Source Project
 */

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.Configuration;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Rect;
import android.os.Build;
import android.os.SystemClock;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.TranslateAnimation;

import com.netease.nim.uikit.common.util.media.SampleSizeUtil;

public abstract class BaseZoomableImageView extends View {
    // Statics
    static final float sPanRate = 7;
    static final float sScaleRate = 1.25F;
    static final int sPaintDelay = 250;
    static final int sAnimationDelay = 500;
    public static final int MIN_SDK_ENABLE_LAYER_TYPE_HARDWARE = Build.VERSION_CODES.ICE_CREAM_SANDWICH;

    // 横屏时特殊处理,但高大于宽的2倍时，就以宽充满
    private static final float MAX_IMAGE_RATIO_WIDTH_LARGE_LANDSCAPE = 2F;

    private static final float MAX_IMAGE_RATIO_LARGE = 5F;

    // This is the base transformation which is used to show the image
    // initially.  The current computation for this shows the image in
    // it's entirety, letterboxing as needed.  One could chose to
    // show the image as cropped instead.
    //
    // This matrix is recomputed when we go from the thumbnail image to
    // the full size image.
    private Matrix mBaseMatrix = new Matrix();

    // This is the supplementary transformation which reflects what
    // the user has done in terms of zooming and panning.
    //
    // This matrix remains the same when we go from the thumbnail image
    // to the full size image.
    private Matrix mSuppMatrix = new Matrix();

    // This is the final matrix which is computed as the concatentation
    // of the base matrix and the supplementary matrix.
    private Matrix mDisplayMatrix = new Matrix();

    // A replacement ImageView matrix
    private Matrix mMatrix = new Matrix();

    // Used to filter the bitmaps when hardware acceleration is not enabled
    private Paint mPaint;

    // Temporary buffer used for getting the values out of a matrix.
    private float[] mMatrixValues = new float[9];

    // Dimensions for the view
    private int mThisWidth = -1, mThisHeight = -1;

    // The max zoom for the view, determined programatically
    private float mMaxZoom;

    // If not null, calls setImageBitmap when onLayout is triggered
    private Runnable mOnLayoutRunnable = null;

    // Stacked to the internal queue to invalidate the view
    private Runnable mRefresh = null;

    // The time of the last draw operation
    private double mLastDraw = 0;

    // The current bitmap being displayed.
    protected Bitmap mBitmap;

    // Stacked to the internal queue to scroll the view
    private Runnable mFling = null;
    private boolean fling = false;

    // Single tap listener
    protected ImageGestureListener mImageGestureListener;

    protected ViewPager mViewPager;

    private boolean landscape = false;

    // Programatic entry point
    public BaseZoomableImageView(Context context) {
        super(context);
        initBaseZoomableImageView(context);
    }

    // XML entry point
    public BaseZoomableImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        initBaseZoomableImageView(context);
    }

    // Setup the view
    @SuppressLint("NewApi")
    protected void initBaseZoomableImageView(Context context) {
        mPaint = new Paint();
        mPaint.setDither(true);
        mPaint.setFilterBitmap(true);
        mPaint.setAntiAlias(true);
        if (context.getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
            landscape = true;
        } else {
            landscape = false;
        }
        // Setup the refresh runnable
        mRefresh = new Runnable() {
            @Override
            public void run() {
                postInvalidate();
            }
        };
    }

    // Set the single tap listener
    public void setImageGestureListener(ImageGestureListener listener) {
        this.mImageGestureListener = listener;
    }

    public void setViewPager(ViewPager viewPager) {
        this.mViewPager = viewPager;
    }

    // Get the bitmap for the view
    public Bitmap getImageBitmap() {
        return mBitmap;
    }

    // Free the bitmaps and matrices
    public void clear() {
        if (mBitmap != null && !mBitmap.isRecycled()) {
            mBitmap.recycle();
        }
        mBitmap = null;
    }

    // When the layout is calculated, set the
    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        mThisWidth = right - left;
        mThisHeight = bottom - top;
        Runnable r = mOnLayoutRunnable;
        if (r != null) {
            mOnLayoutRunnable = null;
            r.run();
        }
        //		if (mBitmap != null) {
        //			setBaseMatrix(mBitmap, mBaseMatrix);
        //			setImageMatrix(getImageViewMatrix());
        //		}
    }

    // Translate a given point through a given matrix.
    static protected void translatePoint(Matrix matrix, float[] xy) {
        matrix.mapPoints(xy);
    }

    // Identical to the setImageMatrix method in ImageView
    public void setImageMatrix(Matrix m) {
        if (m != null && m.isIdentity()) {
            m = null;
        }

        // don't invalidate unless we're actually changing our matrix
        if (m == null && !this.mMatrix.isIdentity() || m != null && !this.mMatrix.equals(m)) {
            this.mMatrix.set(m);
            invalidate();
        }
    }

    // Sets the bitmap for the image and resets the base
    public void setImageBitmap(final Bitmap bitmap) {
        setImageBitmap(bitmap, true);
    }

    // Sets the bitmap for the image and resets the base
    @SuppressLint("NewApi")
    public void setImageBitmap(final Bitmap bitmap, final boolean fitScreen) {

        //版本过低或者长度大于最大纹理限制，不采用硬件加速
        if (Build.VERSION.SDK_INT >= MIN_SDK_ENABLE_LAYER_TYPE_HARDWARE) {
            if (bitmap != null && (bitmap.getHeight() > SampleSizeUtil.getTextureSize()
                    || bitmap.getWidth() > SampleSizeUtil.getTextureSize())) {
                setLayerType(View.LAYER_TYPE_SOFTWARE, null);
            } else {
                setLayerType(View.LAYER_TYPE_HARDWARE, null);
            }
        }

        final int viewWidth = getWidth();
        if (viewWidth <= 0) {
            mOnLayoutRunnable = new Runnable() {
                public void run() {
                    setImageBitmap(bitmap, fitScreen);
                }
            };
            return;
        }

        Bitmap oldBitmap = this.mBitmap;
        if (bitmap != null) {
            setBaseMatrix(bitmap, mBaseMatrix);
            this.mBitmap = bitmap;
        } else {
            mBaseMatrix.reset();
            this.mBitmap = bitmap;
        }
        if (oldBitmap != null && oldBitmap != mBitmap && !oldBitmap.isRecycled()) {
            oldBitmap.recycle();
        }

        mSuppMatrix.reset();
        setImageMatrix(getImageViewMatrix());
        mMaxZoom = maxZoom();

        // Set the image to fit the screen
        if (fitScreen) {
            zoomToScreen();
        }
    }

    /**
     * Sets the bitmap for the image and resets the base
     *
     * @param bitmap
     * @param selection
     * @date 2014-4-29
     */
    public void setImageBitmap(final Bitmap bitmap, final Rect selection) {
        final int viewWidth = getWidth();


        if (viewWidth <= 0) {
            mOnLayoutRunnable = new Runnable() {
                public void run() {
                    setImageBitmap(bitmap, updateSelection());
                }
            };
            return;
        }

        Bitmap oldBitmap = this.mBitmap;
        if (bitmap != null) {
            setBaseMatrix(bitmap, mBaseMatrix, selection);
            this.mBitmap = bitmap;
        } else {
            mBaseMatrix.reset();
            this.mBitmap = bitmap;
        }
        if (oldBitmap != null && !oldBitmap.isRecycled()) {
            oldBitmap.recycle();
        }

        mSuppMatrix.reset();
        setImageMatrix(getImageViewMatrix());
        mMaxZoom = maxZoom();


    }


    // Unchanged from ImageViewTouchBase
    // Center as much as possible in one or both axis.  Centering is
    // defined as follows:  if the image is scaled down below the
    // view's dimensions then center it (literally).  If the image
    // is scaled larger than the view and is translated out of view
    // then translate it back into view (i.e. eliminate black bars).
    protected void center(boolean vertical, boolean horizontal, boolean animate) {
        if (mBitmap == null)
            return;

        Matrix m = getImageViewMatrix();

        float[] topLeft = new float[]{0, 0};
        float[] botRight = new float[]{mBitmap.getWidth(), mBitmap.getHeight()};

        translatePoint(m, topLeft);
        translatePoint(m, botRight);

        float height = botRight[1] - topLeft[1];
        float width = botRight[0] - topLeft[0];

        float deltaX = 0, deltaY = 0;

        if (vertical) {
            int viewHeight = getHeight();
            if (height < viewHeight) {
                deltaY = (viewHeight - height) / 2 - topLeft[1];
            } else if (topLeft[1] > 0) {
                deltaY = -topLeft[1];
            } else if (botRight[1] < viewHeight) {
                deltaY = getHeight() - botRight[1];
            }
        }

        if (horizontal) {
            int viewWidth = getWidth();
            if (width < viewWidth) {
                deltaX = (viewWidth - width) / 2 - topLeft[0];
            } else if (topLeft[0] > 0) {
                deltaX = -topLeft[0];
            } else if (botRight[0] < viewWidth) {
                deltaX = viewWidth - botRight[0];
            }
        }

        postTranslate(deltaX, deltaY);
        if (animate) {
            Animation a = new TranslateAnimation(-deltaX, 0, -deltaY, 0);
            a.setStartTime(SystemClock.elapsedRealtime());
            a.setDuration(250);
            setAnimation(a);
        }
        setImageMatrix(getImageViewMatrix());
    }

    // Unchanged from ImageViewTouchBase
    protected float getValue(Matrix matrix, int whichValue) {
        matrix.getValues(mMatrixValues);
        return mMatrixValues[whichValue];
    }

    // Get the scale factor out of the matrix.
    protected float getScale(Matrix matrix) {

        // If the bitmap is set return the scale
        if (mBitmap != null)
            return getValue(matrix, Matrix.MSCALE_X);
            // Otherwise return the default value of 1
        else
            return 1f;
    }

    // Returns the current scale of the view
    public float getScale() {
        return getScale(mSuppMatrix);
    }

    // Setup the base matrix so that the image is centered and scaled properly.
    private void setBaseMatrix(Bitmap bitmap, Matrix matrix) {
        float viewWidth = getWidth();
        float viewHeight = getHeight();

        matrix.reset();
        float widthScale = Math.min(viewWidth / (float) bitmap.getWidth(), 1.0f);
        float heightScale = Math.min(viewHeight / (float) bitmap.getHeight(), 1.0f);
        float scale;
        if (widthScale > heightScale) {
            scale = heightScale;
        } else {
            scale = widthScale;
        }
        matrix.setScale(scale, scale);
        matrix.postTranslate(
                (viewWidth - ((float) bitmap.getWidth() * scale)) / 2F,
                (viewHeight - ((float) bitmap.getHeight() * scale)) / 2F);
    }


    /**
     * Setup the base matrix so that the image is centered and scaled properly.
     * 根据Bitmap和Rect，设置初始的显示矩阵Matrix
     *
     * @param bitmap
     * @param matrix
     * @param selection
     * @author Linleja
     * @date 2014-4-29
     */
    private void setBaseMatrix(Bitmap bitmap, Matrix matrix, Rect selection) {
        if (selection == null) {
            return;
        }

        float viewWidth = selection.right - selection.left;
        float viewHeight = selection.bottom - selection.top;

        matrix.reset();


        float widthRatio = viewWidth / (float) bitmap.getWidth();
        float heighRatio = viewHeight / (float) bitmap.getHeight();
        float scale = 1.0f;
        if (widthRatio > heighRatio) {
            scale = widthRatio;


        } else {
            scale = heighRatio;


        }

        matrix.setScale(scale, scale);
        matrix.postTranslate(
                ((getWidth() - (float) bitmap.getWidth() * scale)) / 2F,
                ((getHeight() - (float) bitmap.getHeight() * scale)) / 2F);
    }


    // Combine the base matrix and the supp matrix to make the final matrix.
    protected Matrix getImageViewMatrix() {
        mDisplayMatrix.set(mBaseMatrix);
        mDisplayMatrix.postConcat(mSuppMatrix);
        return mDisplayMatrix;
    }

    // Sets the maximum zoom, which is a scale relative to the base matrix. It is calculated to show
    // the image at 400% zoom regardless of screen or image orientation. If in the future we decode
    // the full 3 megapixel image, rather than the current 1024x768, this should be changed down to
    // 200%.
    protected float maxZoom() {
        if (mBitmap == null)
            return 1F;

        float fw = (float) mBitmap.getWidth() / (float) mThisWidth;
        float fh = (float) mBitmap.getHeight() / (float) mThisHeight;
        float max = Math.max(fw, fh) * 16;


        //设置放大的下限
        if (max < 1F) {
            max = 1F;
        }


        return max;
    }

    // Tries to make best use of the space by zooming the picture
    public float zoomDefault() {
        if (mBitmap == null)
            return 1F;

        float fw = (float) mThisWidth / (float) mBitmap.getWidth();
        float fh = (float) mThisHeight / (float) mBitmap.getHeight();
        return Math.max(Math.min(fw, fh), 1);
    }

    // Unchanged from ImageViewTouchBase
    protected void zoomTo(float scale, float centerX, float centerY) {
        if (scale > mMaxZoom) {
            scale = mMaxZoom;
        }

        float oldScale = getScale();
        float deltaScale = scale / oldScale;

        mSuppMatrix.postScale(deltaScale, deltaScale, centerX, centerY);
        setImageMatrix(getImageViewMatrix());
        center(true, true, false);
    }

    // Unchanged from ImageViewTouchBase
    protected void zoomTo(final float scale, final float centerX, final float centerY, final float durationMs) {
        final float incrementPerMs = (scale - getScale()) / durationMs;
        final float oldScale = getScale();
        final long startTime = System.currentTimeMillis();

        // Setup the zoom runnable
        post(new Runnable() {
            public void run() {
                long now = System.currentTimeMillis();
                float currentMs = Math.min(durationMs, (float) (now - startTime));
                float target = oldScale + (incrementPerMs * currentMs);
                zoomTo(target, centerX, centerY);

                if (currentMs < durationMs) {
                    post(this);
                }
            }
        });
    }

    private boolean adjustLongImageEnable = true;

    public void setAdjustLongImageEnable(boolean enable) {
        this.adjustLongImageEnable = enable;
    }

    public void zoomToScreen() {
        if (mBitmap == null)
            return;

        float scale = 1f;
        float fw = (float) mThisWidth / (float) mBitmap.getWidth();

        boolean needAdjust = false;
        if (adjustLongImageEnable) {
            //长>>>宽 比如长微博 横向撑满屏幕，上下滑动浏览全文
            if ((float) mBitmap.getHeight() / (float) mBitmap.getWidth() > MAX_IMAGE_RATIO_LARGE) {
                needAdjust = true;
                scale = fw;
            } else if (landscape && (float) mBitmap.getHeight() / (float) mBitmap.getWidth() > MAX_IMAGE_RATIO_WIDTH_LARGE_LANDSCAPE) {
                needAdjust = true;
                scale = fw;
            }
        }

        if (needAdjust) {
            float oldScale = getScale();
            float deltaScale = scale / oldScale;

            mBaseMatrix.reset();
            mSuppMatrix.postScale(deltaScale, deltaScale, 0, 0);
            setImageMatrix(getImageViewMatrix());
        } else {
            zoomTo(zoomDefault());
        }
    }

    // Unchanged from ImageViewTouchBase
    public void zoomTo(float scale) {
        float width = getWidth();
        float height = getHeight();

        zoomTo(scale, width / 2F, height / 2F);
    }

    // Unchanged from ImageViewTouchBase
    public void zoomIn() {
        zoomIn(sScaleRate);
    }

    // Unchanged from ImageViewTouchBase
    public void zoomOut() {
        zoomOut(sScaleRate);
    }

    // Unchanged from ImageViewTouchBase
    protected void zoomIn(float rate) {
        if (getScale() >= mMaxZoom) {
            return;     // Don't let the user zoom into the molecular level.
        }
        if (mBitmap == null) {
            return;
        }

        float width = getWidth();
        float height = getHeight();

        mSuppMatrix.postScale(rate, rate, width / 2F, height / 2F);
        setImageMatrix(getImageViewMatrix());

    }

    // Unchanged from ImageViewTouchBase
    protected void zoomOut(float rate) {
        if (mBitmap == null) {
            return;
        }

        float width = getWidth();
        float height = getHeight();

        Matrix tmp = new Matrix(mSuppMatrix);
        tmp.postScale(1F / sScaleRate, 1F / sScaleRate, width / 2F, height / 2F);
        if (getScale(tmp) < 1F) {
            mSuppMatrix.setScale(1F, 1F, width / 2F, height / 2F);
        } else {
            mSuppMatrix.postScale(1F / rate, 1F / rate, width / 2F, height / 2F);
        }
        setImageMatrix(getImageViewMatrix());
        center(true, true, false);

    }

    // Unchanged from ImageViewTouchBase
    protected boolean postTranslate(float dx, float dy) {
        return mSuppMatrix.postTranslate(dx, dy);
    }

    // Fling a view by a distance over time
    protected void scrollBy(float distanceX, float distanceY, final float durationMs) {
        final float dx = distanceX;
        final float dy = distanceY;
        final long startTime = System.currentTimeMillis();

        mFling = new Runnable() {
            float old_x = 0;
            float old_y = 0;

            public void run() {
                long now = System.currentTimeMillis();
                float currentMs = Math.min(durationMs, now - startTime);
                float x = easeOut(currentMs, 0, dx, durationMs);
                float y = easeOut(currentMs, 0, dy, durationMs);
                postTranslate((x - old_x), (y - old_y));
                center(true, true, false);

                old_x = x;
                old_y = y;
                if (currentMs < durationMs) {
                    fling = post(this);
                } else {
                    stopFling();
                }
            }
        };

        fling = post(mFling);
    }

    protected void stopFling() {
        removeCallbacks(mFling);
        if (fling) {
            fling = false;
            onScrollFinish();
        }
    }

    protected boolean fling() {
        return fling;
    }

    // Gradually slows down a fling velocity
    private float easeOut(float time, float start, float end, float duration) {
        return end * ((time = time / duration - 1) * time * time + 1) + start;
    }

    protected void onScrollFinish() {

    }

    // Custom draw operation to draw the bitmap using mMatrix
    @SuppressLint("NewApi")
    @Override
    protected void onDraw(Canvas canvas) {
        // Check if the bitmap was ever set
        if (mBitmap != null && !mBitmap.isRecycled()) {

            // If the current version is above Gingerbread and the layer type is
            // hardware accelerated, the paint is no longer needed
            if (Build.VERSION.SDK_INT >= MIN_SDK_ENABLE_LAYER_TYPE_HARDWARE
                    && getLayerType() == View.LAYER_TYPE_HARDWARE) {
                canvas.drawBitmap(mBitmap, mMatrix, null);
            } else {
                // Check if the time between draws has been met and draw the bitmap
                if ((System.currentTimeMillis() - mLastDraw) > sPaintDelay) {
                    canvas.drawBitmap(mBitmap, mMatrix, mPaint);
                    mLastDraw = System.currentTimeMillis();
                }

                // Otherwise draw the bitmap without the paint and resubmit a new request
                else {
                    canvas.drawBitmap(mBitmap, mMatrix, null);
                    removeCallbacks(mRefresh);
                    postDelayed(mRefresh, sPaintDelay);
                }
            }
        }
    }

    protected boolean isScrollOver(float distanceX) {
        try {
            if (mDisplayMatrix != null) {
                float m_x = getValue(mDisplayMatrix, Matrix.MTRANS_X); //图片的左边离屏宽度
                float width = getWidth() - m_x;
                //width 代表 屏幕宽度+左边离屏宽度
                //mBitmap.getWidth() * getValue(mDisplayMatrix, Matrix.MSCALE_X) 代表 当前图片显示宽度
                //width == mBitmap.getWidth() * getValue(mDisplayMatrix, Matrix.MSCALE_X) 意味着图片右边离屏宽度 == 0，已经滑到最右边
                if ((m_x == 0 && distanceX <= 0) //到达图片的最左边继续往左边滑
                        || (width == mBitmap.getWidth() //到达图片的最右边继续往右边滑
                        * getValue(mDisplayMatrix, Matrix.MSCALE_X) && distanceX >= 0)) {
                    System.out.println("ScrollOver");
                    return true;
                }
            }
        } catch (IllegalArgumentException e) {
            Log.v("Vincent", "isScrollOver");
            e.printStackTrace();
        }

        return false;
    }


    protected Rect updateSelection() {
        return null;
    }

}
