/*
    * Copyright (C) 2012 Alberto Irurueta Carro (alberto@irurueta.com)
    *
    * 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.
   */
  package com.irurueta.geometry.io;
  
  import java.io.File;
  import java.io.IOException;
  import java.util.HashSet;
  import java.util.Set;
  import java.util.StringTokenizer;
  
  /**
   * MaterialLoader implementation for OBJ files, which is capable of reading its
   * associated MTL file.
   */
  public class MaterialLoaderOBJ extends MaterialLoader {
  
      /**
       * Maximum allowed color value.
       */
      public static final short MAX_COLOR_VALUE = 255;
  
      /**
       * Set of materials loaded in MTL file.
       */
      private final Set<Material> materials = new HashSet<>();
  
      /**
       * Current material being loaded.
       */
      private MaterialOBJ currentMaterial = null;
  
      /**
       * Number of textures that have been found in MTL file.
       */
      private int textureCounter;
  
      /**
       * Default Constructor.
       */
      public MaterialLoaderOBJ() {
          super();
      }
  
      /**
       * Constructor.
       *
       * @param f material file to be read.
       * @throws IOException raised if provided file does not exist or an I/O
       *                     exception occurs.
       */
      public MaterialLoaderOBJ(final File f) throws IOException {
          super(f);
      }
  
      /**
       * Constructor.
       *
       * @param listener material listener to notify start, end and progress
       *                 events.
       */
      public MaterialLoaderOBJ(final MaterialLoaderListener listener) {
          super(listener);
      }
  
      /**
       * Constructor.
       *
       * @param f        material file to be read.
       * @param listener material listener to notify start, end and progress
       *                 events.
       * @throws IOException raised if provided file does not exist or an I/O
       *                     exception occurs.
       */
      public MaterialLoaderOBJ(final File f, final MaterialLoaderListener listener) throws IOException {
          super(f, listener);
      }
  
      /**
       * Indicates if material loader is ready to be used because a file has
       * already been provided.
       *
       * @return true if material loader is ready, false otherwise.
       */
      @Override
      public boolean isReady() {
          return hasFile();
     }
 
     /**
      * Starts the loading process of provided file.
      * This method returns a set containing all the materials that have been
      * loaded.
      *
      * @return a set containing all the materials that have been loaded.
      * @throws LockedException   raised if this instance is already locked.
      * @throws NotReadyException raised if this instance is not yet ready.
      * @throws IOException       if an I/O error occurs.
      * @throws LoaderException   if file is corrupted or cannot be interpreted.
      */
     @Override
     public Set<Material> load() throws LockedException, NotReadyException, IOException, LoaderException {
         if (!isReady()) {
             throw new NotReadyException();
         }
         if (isLocked()) {
             throw new LockedException();
         }
 
         setLocked(true);
 
         materials.clear();
         textureCounter = 0;
 
         if (listener != null) {
             listener.onLoadStart(this);
         }
 
         String line;
         do {
             line = reader.readLine();
             if (line != null) {
                 parseLine(line);
             }
         } while (line != null);
 
         currentMaterial.setId(materials.size());
         materials.add(currentMaterial);
 
         if (listener != null) {
             listener.onLoadEnd(this);
         }
 
         setLocked(false);
 
         return materials;
     }
 
     /**
      * Parses a line in an MTL file.
      *
      * @param line line being parsed.
      * @throws LoaderException if line cannot be interpreted.
      */
     @SuppressWarnings({"DuplicateExpressions", "DuplicatedCode"})
     private void parseLine(final String line) throws LoaderException {
         if (line == null || line.isEmpty()) {
             return;
         }
 
         try {
             final var tokenizer = new StringTokenizer(line);
             if (!tokenizer.hasMoreTokens()) {
                 // empty line or simply
                 // containing separators (tabs, line feeds, etc)
                 return;
             }
 
             final var command = tokenizer.nextToken();
 
             // search for command position
             final var commandPos = line.indexOf(command);
 
             if ("newmtl".equalsIgnoreCase(command)) {
                 if (currentMaterial != null) {
                     currentMaterial.setId(materials.size());
                     materials.add(currentMaterial);
                 }
                 final var name = line.substring(commandPos + command.length()).trim();
                 currentMaterial = new MaterialOBJ(name);
 
             } else if ("ka".equalsIgnoreCase(command)) {
                 if (currentMaterial == null) {
                     throw new LoaderException();
                 }
                 currentMaterial.setAmbientColor(
                         (short) (Float.parseFloat(tokenizer.nextToken()) * MAX_COLOR_VALUE),
                         (short) (Float.parseFloat(tokenizer.nextToken()) * MAX_COLOR_VALUE),
                         (short) (Float.parseFloat(tokenizer.nextToken()) * MAX_COLOR_VALUE));
 
             } else if ("kd".equalsIgnoreCase(command)) {
                 if (currentMaterial == null) {
                     throw new LoaderException();
                 }
                 currentMaterial.setDiffuseColor(
                         (short) (Float.parseFloat(tokenizer.nextToken()) * MAX_COLOR_VALUE),
                         (short) (Float.parseFloat(tokenizer.nextToken()) * MAX_COLOR_VALUE),
                         (short) (Float.parseFloat(tokenizer.nextToken()) * MAX_COLOR_VALUE));
 
             } else if ("Ks".equalsIgnoreCase(command)) {
                 if (currentMaterial == null) {
                     throw new LoaderException();
                 }
                 currentMaterial.setSpecularColor(
                         (short) (Float.parseFloat(tokenizer.nextToken()) * MAX_COLOR_VALUE),
                         (short) (Float.parseFloat(tokenizer.nextToken()) * MAX_COLOR_VALUE),
                         (short) (Float.parseFloat(tokenizer.nextToken()) * MAX_COLOR_VALUE));
 
             } else if ("Ns".equalsIgnoreCase(command) || "Ni".equalsIgnoreCase(command)) {
                 if (currentMaterial == null) {
                     throw new LoaderException();
                 }
                 currentMaterial.setSpecularCoefficient(Float.parseFloat(tokenizer.nextToken()));
 
             } else if ("d".equalsIgnoreCase(command) || "Tr".equalsIgnoreCase(command)) {
                 if (currentMaterial == null) {
                     throw new LoaderException();
                 }
                 currentMaterial.setTransparency((short) (Float.parseFloat(tokenizer.nextToken()) * MAX_COLOR_VALUE));
 
             } else if ("illum".equalsIgnoreCase(command)) {
                 if (currentMaterial == null) {
                     throw new LoaderException();
                 }
                 currentMaterial.setIllumination(Illumination.forValue(Integer.parseInt(tokenizer.nextToken())));
 
             } else if ("map_Kd".equalsIgnoreCase(command)) {
                 final var textureName = line.substring(commandPos + command.length()).trim();
                 final var tex = new Texture(textureName, textureCounter);
                 textureCounter++;
 
                 var valid = true;
                 if (textureValidationEnabled && listener != null) {
                     valid = listener.onValidateTexture(this, tex);
                 }
                 if (!valid) {
                     throw new InvalidTextureException();
                 }
 
                 currentMaterial.setDiffuseTextureMap(tex);
 
             } else if ("map_Ka".equalsIgnoreCase(command)) {
                 final var textureName = line.substring(commandPos + command.length()).trim();
                 final var tex = new Texture(textureName, textureCounter);
                 textureCounter++;
 
                 var valid = true;
                 if (textureValidationEnabled && listener != null) {
                     valid = listener.onValidateTexture(this, tex);
                 }
                 if (!valid) throw new InvalidTextureException();
 
                 currentMaterial.setAmbientTextureMap(tex);
 
             } else if ("map_Ks".equalsIgnoreCase(command)) {
                 final var textureName = line.substring(commandPos + command.length()).trim();
                 final var tex = new Texture(textureName, textureCounter);
                 textureCounter++;
 
                 var valid = true;
                 if (textureValidationEnabled && listener != null) {
                     valid = listener.onValidateTexture(this, tex);
                 }
                 if (!valid) {
                     throw new InvalidTextureException();
                 }
 
                 currentMaterial.setSpecularTextureMap(tex);
 
             } else if ("map_d".equalsIgnoreCase(command)) {
                 final var textureName = line.substring(commandPos + command.length()).trim();
                 final var tex = new Texture(textureName, textureCounter);
                 textureCounter++;
 
                 var valid = true;
                 if (textureValidationEnabled && listener != null) {
                     valid = listener.onValidateTexture(this, tex);
                 }
                 if (!valid) {
                     throw new InvalidTextureException();
                 }
 
                 currentMaterial.setAlphaTextureMap(tex);
 
             } else if ("map_bump".equalsIgnoreCase(command) || "bump".equalsIgnoreCase(command)) {
                 final var textureName = line.substring(commandPos + command.length()).trim();
                 final var tex = new Texture(textureName, textureCounter);
                 textureCounter++;
 
                 var valid = true;
                 if (textureValidationEnabled && listener != null) {
                     valid = listener.onValidateTexture(this, tex);
                 }
                 if (!valid) {
                     throw new InvalidTextureException();
                 }
 
                 currentMaterial.setBumpTextureMap(tex);
             }
         } catch (final Exception t) {
             throw new LoaderException(t);
         }
     }
 
     /**
      * Indicates if any material has been loaded already.
      *
      * @return true if materials have been loaded, false otherwise.
      */
     public boolean areMaterialsAvailable() {
         return !materials.isEmpty();
     }
 
     /**
      * Returns set of materials that have been read.
      *
      * @return set of materials that have been read.
      */
     public Set<Material> getMaterials() {
         return materials;
     }
 
     /**
      * Gets a material by its name, or null if material is not found.
      *
      * @param name name of material to be found.
      * @return a material having provided name or null if none is found.
      */
     public MaterialOBJ getMaterialByName(final String name) {
         if (name == null) {
             return null;
         }
 
         for (final var m : this.materials) {
             if (m instanceof MaterialOBJ m2) {
 
                 if (m2.getMaterialName() == null) {
                     continue;
                 }
 
                 if (m2.getMaterialName().equals(name)) {
                     return m2;
                 }
             }
         }
         return null;
     }
 
     /**
      * Indicates if material having provided name has been loaded or not.
      *
      * @param name name to search material by.
      * @return true if material having provided name exists, false otherwise.
      */
     public boolean containsMaterial(final String name) {
         return getMaterialByName(name) != null;
     }
 
     /**
      * Returns material by texture name.
      *
      * @param name name of texture.
      * @return texture that has been found or null if none has been found.
      */
     public Material getMaterialByTextureMapName(final String name) {
         if (name == null) {
             return null;
         }
 
         for (final Material m : this.materials) {
             if (m.getAlphaTextureMap() != null && m.getAlphaTextureMap().getFileName() != null
                     && m.getAlphaTextureMap().getFileName().equals(name)) {
                 return m;
             }
 
             if (m.getAmbientTextureMap() != null && m.getAmbientTextureMap().getFileName() != null
                     && m.getAmbientTextureMap().getFileName().equals(name)) {
                 return m;
             }
 
             if (m.getDiffuseTextureMap() != null && m.getDiffuseTextureMap().getFileName() != null
                     && m.getDiffuseTextureMap().getFileName().equals(name)) {
                 return m;
             }
 
             if (m.getSpecularTextureMap() != null && m.getSpecularTextureMap().getFileName() != null
                     && m.getSpecularTextureMap().getFileName().equals(name)) {
                 return m;
             }
         }
         return null;
     }
 }