package com.airbnb.lottie.model.layer;

import android.annotation.SuppressLint;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.RectF;
import android.os.Build;
import android.support.annotation.CallSuper;
import android.support.annotation.FloatRange;
import android.support.annotation.Nullable;
import android.util.Log;

import com.airbnb.lottie.L;
import com.airbnb.lottie.LottieComposition;
import com.airbnb.lottie.LottieDrawable;
import com.airbnb.lottie.animation.content.Content;
import com.airbnb.lottie.animation.content.DrawingContent;
import com.airbnb.lottie.animation.keyframe.BaseKeyframeAnimation;
import com.airbnb.lottie.animation.keyframe.FloatKeyframeAnimation;
import com.airbnb.lottie.animation.keyframe.MaskKeyframeAnimation;
import com.airbnb.lottie.animation.keyframe.TransformKeyframeAnimation;
import com.airbnb.lottie.model.KeyPath;
import com.airbnb.lottie.model.KeyPathElement;
import com.airbnb.lottie.model.content.Mask;
import com.airbnb.lottie.value.LottieValueCallback;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public abstract class BaseLayer
    implements DrawingContent, BaseKeyframeAnimation.AnimationListener, KeyPathElement {
  private static final int SAVE_FLAGS = Canvas.CLIP_SAVE_FLAG | Canvas.CLIP_TO_LAYER_SAVE_FLAG |
      Canvas.MATRIX_SAVE_FLAG;

  private static boolean hasLoggedIntersectMasks = false;

  @Nullable
  static BaseLayer forModel(
    Layer layerModel, LottieDrawable drawable, LottieComposition composition) {
    switch (layerModel.getLayerType()) {
      case Shape:
        return new ShapeLayer(drawable, layerModel);
      case PreComp:
        return new CompositionLayer(drawable, layerModel,
            composition.getPrecomps(layerModel.getRefId()), composition);
      case Solid:
        return new SolidLayer(drawable, layerModel);
      case Image:
        return new ImageLayer(drawable, layerModel);
      case Null:
        return new NullLayer(drawable, layerModel);
      case Text:
        return new TextLayer(drawable, layerModel);
      case Unknown:
      default:
        // Do nothing
        L.warn("Unknown layer type " + layerModel.getLayerType());
        return null;
    }
  }

  private final Path path = new Path();
  private final Matrix matrix = new Matrix();
  private final Paint contentPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
  private final Paint addMaskPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
  private final Paint subtractMaskPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
  private final Paint mattePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
  private final Paint clearPaint = new Paint();
  private final RectF rect = new RectF();
  private final RectF maskBoundsRect = new RectF();
  private final RectF matteBoundsRect = new RectF();
  private final RectF tempMaskBoundsRect = new RectF();
  private final String drawTraceName;
  final Matrix boundsMatrix = new Matrix();
  final LottieDrawable lottieDrawable;
  final Layer layerModel;
  @Nullable private MaskKeyframeAnimation mask;
  @Nullable private BaseLayer matteLayer;
  @Nullable private BaseLayer parentLayer;
  private List<BaseLayer> parentLayers;

  private final List<BaseKeyframeAnimation<?, ?>> animations = new ArrayList<>();
  final TransformKeyframeAnimation transform;
  private boolean visible = true;

  BaseLayer(LottieDrawable lottieDrawable, Layer layerModel) {
    this.lottieDrawable = lottieDrawable;
    this.layerModel = layerModel;
    drawTraceName = layerModel.getName() + "#draw";
    clearPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
    addMaskPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
    subtractMaskPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
    if (layerModel.getMatteType() == Layer.MatteType.Invert) {
      mattePaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
    } else {
      mattePaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
    }

    this.transform = layerModel.getTransform().createAnimation();
    transform.addListener(this);

    if (layerModel.getMasks() != null && !layerModel.getMasks().isEmpty()) {
      this.mask = new MaskKeyframeAnimation(layerModel.getMasks());
      for (BaseKeyframeAnimation<?, Path> animation : mask.getMaskAnimations()) {
        addAnimation(animation);
        animation.addUpdateListener(this);
      }
      for (BaseKeyframeAnimation<Integer, Integer> animation : mask.getOpacityAnimations()) {
        addAnimation(animation);
        animation.addUpdateListener(this);
      }
    }
    setupInOutAnimations();
  }

  @Override public void onValueChanged() {
    invalidateSelf();
  }

  Layer getLayerModel() {
    return layerModel;
  }

  void setMatteLayer(@Nullable BaseLayer matteLayer) {
    this.matteLayer = matteLayer;
  }

  boolean hasMatteOnThisLayer() {
    return matteLayer != null;
  }

  void setParentLayer(@Nullable BaseLayer parentLayer) {
    this.parentLayer = parentLayer;
  }

  private void setupInOutAnimations() {
    if (!layerModel.getInOutKeyframes().isEmpty()) {
      final FloatKeyframeAnimation inOutAnimation =
          new FloatKeyframeAnimation(layerModel.getInOutKeyframes());
      inOutAnimation.setIsDiscrete();
      inOutAnimation.addUpdateListener(() -> setVisible(inOutAnimation.getValue() == 1f));
      setVisible(inOutAnimation.getValue() == 1f);
      addAnimation(inOutAnimation);
    } else {
      setVisible(true);
    }
  }

  private void invalidateSelf() {
    lottieDrawable.invalidateSelf();
  }

  @SuppressLint("WrongConstant")
  private void saveLayerCompat(Canvas canvas, RectF rect, Paint paint) { 
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
      // This method was deprecated in API level 26 and not recommented since 22, but its
      // 2-parameter replacement is only available starting at API level 21.
      canvas.saveLayer(rect, paint, SAVE_FLAGS);
    } else {
      canvas.saveLayer(rect, paint);
    }
  }

  public void addAnimation(BaseKeyframeAnimation<?, ?> newAnimation) {
    animations.add(newAnimation);
  }

  @CallSuper @Override public void getBounds(RectF outBounds, Matrix parentMatrix) {
    boundsMatrix.set(parentMatrix);
    boundsMatrix.preConcat(transform.getMatrix());
  }

  @Override
  public void draw(Canvas canvas, Matrix parentMatrix, int parentAlpha) {
    L.beginSection(drawTraceName);
    if (!visible) {
      L.endSection(drawTraceName);
      return;
    }
    buildParentLayerListIfNeeded();
    L.beginSection("Layer#parentMatrix");
    matrix.reset();
    matrix.set(parentMatrix);
    for (int i = parentLayers.size() - 1; i >= 0; i--) {
      matrix.preConcat(parentLayers.get(i).transform.getMatrix());
    }
    L.endSection("Layer#parentMatrix");
    int alpha = (int)
        ((parentAlpha / 255f * (float) transform.getOpacity().getValue() / 100f) * 255);
    if (!hasMatteOnThisLayer() && !hasMasksOnThisLayer()) {
      matrix.preConcat(transform.getMatrix());
      L.beginSection("Layer#drawLayer");
      drawLayer(canvas, matrix, alpha);
      L.endSection("Layer#drawLayer");
      recordRenderTime(L.endSection(drawTraceName));
      return;
    }

    L.beginSection("Layer#computeBounds");
    rect.set(0, 0, 0, 0);
    getBounds(rect, matrix);
    intersectBoundsWithMatte(rect, matrix);

    matrix.preConcat(transform.getMatrix());
    intersectBoundsWithMask(rect, matrix);

    rect.set(0, 0, canvas.getWidth(), canvas.getHeight());
    L.endSection("Layer#computeBounds");

    L.beginSection("Layer#saveLayer");
    saveLayerCompat(canvas, rect, contentPaint);
    L.endSection("Layer#saveLayer");

    // Clear the off screen buffer. This is necessary for some phones.
    clearCanvas(canvas);
    L.beginSection("Layer#drawLayer");
    drawLayer(canvas, matrix, alpha);
    L.endSection("Layer#drawLayer");

    if (hasMasksOnThisLayer()) {
      applyMasks(canvas, matrix);
    }

    if (hasMatteOnThisLayer()) {
      L.beginSection("Layer#drawMatte");
      L.beginSection("Layer#saveLayer");
      saveLayerCompat(canvas, rect, mattePaint);
      L.endSection("Layer#saveLayer");
      clearCanvas(canvas);
      //noinspection ConstantConditions
      matteLayer.draw(canvas, parentMatrix, alpha);
      L.beginSection("Layer#restoreLayer");
      canvas.restore();
      L.endSection("Layer#restoreLayer");
      L.endSection("Layer#drawMatte");
    }

    L.beginSection("Layer#restoreLayer");
    canvas.restore();
    L.endSection("Layer#restoreLayer");
    recordRenderTime(L.endSection(drawTraceName));
  }

  private void recordRenderTime(float ms) {
    lottieDrawable.getComposition()
        .getPerformanceTracker().recordRenderTime(layerModel.getName(), ms);

  }

  private void clearCanvas(Canvas canvas) {
    L.beginSection("Layer#clearLayer");
    // If we don't pad the clear draw, some phones leave a 1px border of the graphics buffer.
    canvas.drawRect(rect.left - 1, rect.top - 1, rect.right + 1, rect.bottom + 1, clearPaint);
    L.endSection("Layer#clearLayer");
  }

  private void intersectBoundsWithMask(RectF rect, Matrix matrix) {
    maskBoundsRect.set(0, 0, 0, 0);
    if (!hasMasksOnThisLayer()) {
      return;
    }
    //noinspection ConstantConditions
    int size = mask.getMasks().size();
    for (int i = 0; i < size; i++) {
      Mask mask = this.mask.getMasks().get(i);
      BaseKeyframeAnimation<?, Path> maskAnimation = this.mask.getMaskAnimations().get(i);
      Path maskPath = maskAnimation.getValue();
      path.set(maskPath);
      path.transform(matrix);

      switch (mask.getMaskMode()) {
        case MaskModeSubtract:
          // If there is a subtract mask, the mask could potentially be the size of the entire
          // canvas so we can't use the mask bounds.
          return;
        case MaskModeIntersect:
          // TODO
          return;
        case MaskModeAdd:
        default:
          path.computeBounds(tempMaskBoundsRect, false);
          // As we iterate through the masks, we want to calculate the union region of the masks.
          // We initialize the rect with the first mask. If we don't call set() on the first call,
          // the rect will always extend to (0,0).
          if (i == 0) {
            maskBoundsRect.set(tempMaskBoundsRect);
          } else {
            maskBoundsRect.set(
              Math.min(maskBoundsRect.left, tempMaskBoundsRect.left),
              Math.min(maskBoundsRect.top, tempMaskBoundsRect.top),
              Math.max(maskBoundsRect.right, tempMaskBoundsRect.right),
              Math.max(maskBoundsRect.bottom, tempMaskBoundsRect.bottom)
            );
          }
      }
    }

    rect.set(
        Math.max(rect.left, maskBoundsRect.left),
        Math.max(rect.top, maskBoundsRect.top),
        Math.min(rect.right, maskBoundsRect.right),
        Math.min(rect.bottom, maskBoundsRect.bottom)
    );
  }

  private void intersectBoundsWithMatte(RectF rect, Matrix matrix) {
    if (!hasMatteOnThisLayer()) {
      return;
    }
    if (layerModel.getMatteType() == Layer.MatteType.Invert) {
      // We can't trim the bounds if the mask is inverted since it extends all the way to the
      // composition bounds.
      return;
    }
    //noinspection ConstantConditions
    matteLayer.getBounds(matteBoundsRect, matrix);
    rect.set(
        Math.max(rect.left, matteBoundsRect.left),
        Math.max(rect.top, matteBoundsRect.top),
        Math.min(rect.right, matteBoundsRect.right),
        Math.min(rect.bottom, matteBoundsRect.bottom)
    );
  }

  abstract void drawLayer(Canvas canvas, Matrix parentMatrix, int parentAlpha);

  private void applyMasks(Canvas canvas, Matrix matrix) {
    applyMasks(canvas, matrix, Mask.MaskMode.MaskModeAdd);
    // Treat intersect masks like add masks. This is not correct but it's closer.
    applyMasks(canvas, matrix, Mask.MaskMode.MaskModeIntersect);
    applyMasks(canvas, matrix, Mask.MaskMode.MaskModeSubtract);
  }

  private void applyMasks(Canvas canvas, Matrix matrix,
      Mask.MaskMode maskMode) {
    Paint paint;
    switch (maskMode) {
      case MaskModeSubtract:
        paint = subtractMaskPaint;
        break;
      case MaskModeIntersect:
        if (!hasLoggedIntersectMasks) {
          Log.w(L.TAG, "Animation contains intersect masks. They are not supported but will be " +
                  "treated like add masks.");
          hasLoggedIntersectMasks = true;
        }
      case MaskModeAdd:
      default:
        // As a hack, we treat all non-subtract masks like add masks. This is not correct but it's
        // better than nothing.
        paint = addMaskPaint;
    }

    //noinspection ConstantConditions
    int size = mask.getMasks().size();

    boolean hasMask = false;
    for (int i = 0; i < size; i++) {
      if (mask.getMasks().get(i).getMaskMode() == maskMode) {
        hasMask = true;
        break;
      }
    }
    if (!hasMask) {
      return;
    }

    L.beginSection("Layer#drawMask");
    L.beginSection("Layer#saveLayer");
    saveLayerCompat(canvas, rect, paint);
    L.endSection("Layer#saveLayer");
    clearCanvas(canvas);

    for (int i = 0; i < size; i++) {
      Mask mask = this.mask.getMasks().get(i);
      if (mask.getMaskMode() != maskMode) {
        continue;
      }
      BaseKeyframeAnimation<?, Path> maskAnimation = this.mask.getMaskAnimations().get(i);
      Path maskPath = maskAnimation.getValue();
      path.set(maskPath);
      path.transform(matrix);
      BaseKeyframeAnimation<Integer, Integer> opacityAnimation =
          this.mask.getOpacityAnimations().get(i);
      int alpha = contentPaint.getAlpha();
      contentPaint.setAlpha((int) (opacityAnimation.getValue() * 2.55f));
      canvas.drawPath(path, contentPaint);
      contentPaint.setAlpha(alpha);
    }
    L.beginSection("Layer#restoreLayer");
    canvas.restore();
    L.endSection("Layer#restoreLayer");
    L.endSection("Layer#drawMask");
  }

  boolean hasMasksOnThisLayer() {
    return mask != null && !mask.getMaskAnimations().isEmpty();
  }

  private void setVisible(boolean visible) {
    if (visible != this.visible) {
      this.visible = visible;
      invalidateSelf();
    }
  }

  void setProgress(@FloatRange(from = 0f, to = 1f) float progress) {
    // Time stretch should not be applied to the layer transform.
    transform.setProgress(progress);
    if (layerModel.getTimeStretch() != 0) {
      progress /= layerModel.getTimeStretch();
    }
    if (matteLayer != null) {
      // The matte layer's time stretch is pre-calculated.
      float matteTimeStretch = matteLayer.layerModel.getTimeStretch();
      matteLayer.setProgress(progress * matteTimeStretch);
    }
    for (int i = 0; i < animations.size(); i++) {
      animations.get(i).setProgress(progress);
    }
  }

  private void buildParentLayerListIfNeeded() {
    if (parentLayers != null) {
      return;
    }
    if (parentLayer == null) {
      parentLayers = Collections.emptyList();
      return;
    }

    parentLayers = new ArrayList<>();
    BaseLayer layer = parentLayer;
    while (layer != null) {
      parentLayers.add(layer);
      layer = layer.parentLayer;
    }
  }

  @Override public String getName() {
    return layerModel.getName();
  }

  @Override public void setContents(List<Content> contentsBefore, List<Content> contentsAfter) {
    // Do nothing
  }

  @Override public void resolveKeyPath(
      KeyPath keyPath, int depth, List<KeyPath> accumulator, KeyPath currentPartialKeyPath) {
    if (!keyPath.matches(getName(), depth)) {
      return;
    }

    if (!"__container".equals(getName())) {
      currentPartialKeyPath = currentPartialKeyPath.addKey(getName());

      if (keyPath.fullyResolvesTo(getName(), depth)) {
        accumulator.add(currentPartialKeyPath.resolve(this));
      }
    }

    if (keyPath.propagateToChildren(getName(), depth)) {
      int newDepth = depth + keyPath.incrementDepthBy(getName(), depth);
      resolveChildKeyPath(keyPath, newDepth, accumulator, currentPartialKeyPath);
    }
  }

  void resolveChildKeyPath(
      KeyPath keyPath, int depth, List<KeyPath> accumulator, KeyPath currentPartialKeyPath) {
  }

  @CallSuper
  @Override
  public <T> void addValueCallback(T property, @Nullable LottieValueCallback<T> callback) {
    transform.applyValueCallback(property, callback);
  }
}