/*
    * #%L
    * wcm.io
    * %%
    * Copyright (C) 2019 wcm.io
    * %%
    * 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.
   * #L%
   */
  package io.wcm.handler.mediasource.dam;
  
  import static com.day.cq.commons.jcr.JcrConstants.JCR_CONTENT;
  import static com.day.cq.dam.api.DamConstants.EXIF_PIXELXDIMENSION;
  import static com.day.cq.dam.api.DamConstants.EXIF_PIXELYDIMENSION;
  import static com.day.cq.dam.api.DamConstants.METADATA_FOLDER;
  import static com.day.cq.dam.api.DamConstants.ORIGINAL_FILE;
  import static com.day.cq.dam.api.DamConstants.TIFF_IMAGELENGTH;
  import static com.day.cq.dam.api.DamConstants.TIFF_IMAGEWIDTH;
  import static io.wcm.handler.mediasource.dam.impl.metadata.RenditionMetadataNameConstants.NN_RENDITIONS_METADATA;
  import static io.wcm.handler.mediasource.dam.impl.metadata.RenditionMetadataNameConstants.PN_IMAGE_HEIGHT;
  import static io.wcm.handler.mediasource.dam.impl.metadata.RenditionMetadataNameConstants.PN_IMAGE_WIDTH;
  
  import java.io.IOException;
  import java.io.InputStream;
  
  import org.apache.commons.io.FilenameUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.commons.lang3.math.NumberUtils;
  import org.apache.sling.api.resource.Resource;
  import org.apache.sling.api.resource.ValueMap;
  import org.jetbrains.annotations.NotNull;
  import org.jetbrains.annotations.Nullable;
  import org.osgi.annotation.versioning.ProviderType;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.day.cq.dam.api.Asset;
  import com.day.cq.dam.api.Rendition;
  import com.day.image.Layer;
  
  import io.wcm.handler.media.Dimension;
  import io.wcm.handler.media.MediaFileType;
  import io.wcm.sling.commons.adapter.AdaptTo;
  
  /**
   * Helper methods for getting metadata for DAM renditions.
   */
  @ProviderType
  public final class AssetRendition {
  
    private static final Logger log = LoggerFactory.getLogger(AssetRendition.class);
  
    private AssetRendition() {
      // static methods only
    }
  
    /**
     * Get dimension (width, height) of given DAM rendition.
     *
     * <p>
     * It reads the dimension information from the
     * asset metadata for the original rendition, or from the rendition metadata generated by the
     * "DamRenditionMetadataService". If both is not available it gets the dimension from the renditions
     * binary file, but this is inefficient and should not happen under sound conditions.
     * </p>
     * @param rendition Rendition
     * @return Dimension or null if dimension could not be detected, not even in fallback mode
     */
    public static @Nullable Dimension getDimension(@NotNull Rendition rendition) {
      return getDimension(rendition, false);
    }
  
    /**
     * Get dimension (width, height) of given DAM rendition.
     *
     * <p>
     * It reads the dimension information from the
     * asset metadata for the original rendition, or from the rendition metadata generated by the
     * "DamRenditionMetadataService". If both is not available it gets the dimension from the renditions
     * binary file, but this is inefficient and should not happen under sound conditions.
     * </p>
     * @param rendition Rendition
     * @param suppressLogWarningNoRenditionsMetadata If set to true, no log warnings is generated when
     *          renditions metadata containing the width/height of the rendition does not exist (yet).
     * @return Dimension or null if dimension could not be detected, not even in fallback mode
     */
    public static @Nullable Dimension getDimension(@NotNull Rendition rendition,
        boolean suppressLogWarningNoRenditionsMetadata) {
  
     boolean isOriginal = isOriginal(rendition);
     String fileExtension = FilenameUtils.getExtension(getFilename(rendition));
 
     // get image width/height
     Dimension dimension = null;
     if (isOriginal) {
       // get width/height from metadata for original renditions
       dimension = getDimensionFromOriginal(rendition);
     }
 
     // dimensions for non-original renditions only supported for image binaries
     if (MediaFileType.isImage(fileExtension)) {
       if (dimension == null) {
         // check if rendition metadata is present in <rendition>/jcr:content/metadata provided by AEMaaCS asset compute
         dimension = getDimensionFromAemRenditionMetadata(rendition);
       }
 
       if (dimension == null) {
         // otherwise get from rendition metadata written by {@link DamRenditionMetadataService}
         dimension = getDimensionFromMediaHandlerRenditionMetadata(rendition);
       }
 
       // fallback: if width/height could not be read from either asset or rendition metadata load the image
       // into memory and get width/height from there - but log an warning because this is inefficient
       if (dimension == null) {
         dimension = getDimensionFromImageBinary(rendition, suppressLogWarningNoRenditionsMetadata);
       }
     }
 
     return dimension;
   }
 
   /**
    * Read dimension for original rendition from asset metadata.
    * @param rendition Rendition
    * @return Dimension or null
    */
   private static @Nullable Dimension getDimensionFromOriginal(@NotNull Rendition rendition) {
     Asset asset = rendition.getAsset();
     // asset may have stored dimension in different property names
     long width = getAssetMetadataValueAsLong(asset, TIFF_IMAGEWIDTH, EXIF_PIXELXDIMENSION);
     long height = getAssetMetadataValueAsLong(asset, TIFF_IMAGELENGTH, EXIF_PIXELYDIMENSION);
     return toValidDimension(width, height);
   }
 
   private static long getAssetMetadataValueAsLong(Asset asset, String... propertyNames) {
     for (String propertyName : propertyNames) {
       long value = NumberUtils.toLong(StringUtils.defaultString(asset.getMetadataValueFromJcr(propertyName), "0"));
       if (value > 0L) {
         return value;
       }
     }
     return 0L;
   }
 
   /**
    * Read dimension for non-original rendition from renditions metadata generated by "DamRenditionMetadataService".
    * @param rendition Rendition
    * @return Dimension or null
    */
   @SuppressWarnings("java:S1075") // not a file path
   private static @Nullable Dimension getDimensionFromMediaHandlerRenditionMetadata(@NotNull Rendition rendition) {
     Asset asset = rendition.getAsset();
     String metadataPath = JCR_CONTENT + "/" + NN_RENDITIONS_METADATA + "/" + rendition.getName();
     Resource metadataResource = AdaptTo.notNull(asset, Resource.class).getChild(metadataPath);
     if (metadataResource != null) {
       ValueMap props = metadataResource.getValueMap();
       long width = props.get(PN_IMAGE_WIDTH, 0L);
       long height = props.get(PN_IMAGE_HEIGHT, 0L);
       return toValidDimension(width, height);
     }
     return null;
   }
 
   /**
    * Asset Compute from AEMaaCS writes rendition metadata including width/height to jcr:content/metadata of the
    * rendition resource - try to read it from there (it may be missing for not fully processed assets, or in local
    * AEMaaCS SDK or AEM 6.5 instances).
    * @param rendition Rendition
    * @return Dimension or null
    */
   private static @Nullable Dimension getDimensionFromAemRenditionMetadata(@NotNull Rendition rendition) {
     Resource metadataResource = rendition.getChild(JCR_CONTENT + "/" + METADATA_FOLDER);
     if (metadataResource != null) {
       ValueMap props = metadataResource.getValueMap();
       long width = props.get(TIFF_IMAGEWIDTH, 0L);
       long height = props.get(TIFF_IMAGELENGTH, 0L);
       return toValidDimension(width, height);
     }
     return null;
   }
 
   /**
    * Fallback: Read dimension by loading image binary into memory.
    * @param rendition Rendition
    * @param suppressLogWarningNoRenditionsMetadata If set to true, no log warnings is generated when
    *          renditions metadata containing the width/height of the rendition does not exist (yet).
    * @return Dimension or null
    */
   @SuppressWarnings("PMD.GuardLogStatement")
   private static @Nullable Dimension getDimensionFromImageBinary(@NotNull Rendition rendition,
       boolean suppressLogWarningNoRenditionsMetadata) {
     try (InputStream is = rendition.getStream()) {
       if (is != null) {
         Layer layer = new Layer(is);
         long width = layer.getWidth();
         long height = layer.getHeight();
         Dimension dimension = toValidDimension(width, height);
         if (!suppressLogWarningNoRenditionsMetadata) {
           log.warn("Unable to detect rendition metadata for {}, "
               + "fallback to inefficient detection by loading image into in memory (detected dimension={}). "
               + "Please check if the service user for the bundle 'io.wcm.handler.media' is configured properly.",
               rendition.getPath(), dimension);
         }
         return dimension;
       }
       else {
         log.warn("Unable to get binary stream for rendition {}", rendition.getPath());
       }
     }
     catch (IOException ex) {
       log.warn("Unable to read binary stream to layer for rendition {}", rendition.getPath(), ex);
     }
     return null;
   }
 
   /**
    * Convert width/height to dimension.
    * @param width Width
    * @param height Height
    * @return Dimension or null if width or height are not valid
    */
   private static @Nullable Dimension toValidDimension(long width, long height) {
     if (width > 0L && height > 0L) {
       return new Dimension(width, height);
     }
     return null;
   }
 
   /**
    * Checks if the given rendition is the original file of the asset
    * @param rendition DAM rendition
    * @return true if rendition is the original
    */
   public static boolean isOriginal(@NotNull Rendition rendition) {
     return StringUtils.equals(rendition.getName(), ORIGINAL_FILE);
   }
 
   /**
    * Checks if the given rendition is a thumbnail rendition generated automatically by AEM
    * (with <code>cq5dam.thumbnail.</code> prefix).
    * @param rendition DAM rendition
    * @return true if rendition is a thumbnail rendition
    */
   public static boolean isThumbnailRendition(@NotNull Rendition rendition) {
     return AemRenditionType.THUMBNAIL_RENDITION.matches(rendition);
   }
 
   /**
    * Checks if the given rendition is a web rendition generated automatically by AEM for the image editor/cropping
    * (with <code>cq5dam.web.</code> prefix).
    * @param rendition DAM rendition
    * @return true if rendition is a web rendition
    */
   public static boolean isWebRendition(@NotNull Rendition rendition) {
     return AemRenditionType.WEB_RENDITION.matches(rendition);
   }
 
   /**
    * Get file name of given rendition. If it is the original rendition get asset name as file name.
    * @param rendition Rendition
    * @return File extension or null if it could not be detected
    */
   public static String getFilename(@NotNull Rendition rendition) {
     boolean isOriginal = isOriginal(rendition);
     if (isOriginal) {
       return rendition.getAsset().getName();
     }
     else {
       return rendition.getName();
     }
   }
 
 }