/*
    * 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.
   */
  
  package org.apache.myfaces.tobago.layout;
  
  import org.apache.myfaces.tobago.internal.util.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.Serializable;
  import java.lang.invoke.MethodHandles;
  
  /**
   * In PDLs the class {@link org.apache.myfaces.tobago.layout.MeasureEditor} will convert the string literals.
   */
  public final class Measure implements Serializable {
  
    private static final long serialVersionUID = 1L;
  
    private static final Logger LOG = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
  
    public static final Measure ZERO = valueOf(0);
    public static final Measure AUTO = valueOf("auto");
    public static final Measure FRACTION1 = valueOf("1fr");
  
    private final float value;
    private final Unit unit;
  
    private Measure() {
      this.value = 0;
      this.unit = Unit.AUTO;
    }
  
    public Measure(final int i, final Unit unit) {
      this.value = i;
      this.unit = unit;
    }
  
    public Measure(final double d, final Unit unit) {
      this.value = (float) d;
      this.unit = unit;
    }
  
    public Measure(final String string, final Unit unit) {
      this.value = Float.parseFloat(string);
      this.unit = unit;
    }
  
    public static Measure valueOf(final Measure measure) {
      if (measure == null) {
        return ZERO;
      }
      return measure;
    }
  
    public static Measure valueOf(final int value) {
      return new Measure(value, Unit.PX);
    }
  
    public static Measure valueOf(final Integer i) {
      if (i == null) {
        return ZERO;
      }
      return valueOf(i.intValue());
    }
  
    public static Measure valueOf(final Number n) {
      if (n == null) {
        return ZERO;
      }
      return valueOf(n.doubleValue());
    }
  
    public static Measure valueOf(final String s) {
      return valueOf(s, Unit.PX);
    }
  
    public static Measure valueOf(final String s, final Unit defaultUnit) {
      try {
        if (StringUtils.isEmpty(s)) {
          return null;
        }
        final int length = s.length();
       if (s.endsWith("%")) {
         return new Measure(s.substring(0, length - 1), Unit.PERCENT);
       }
       if (s.endsWith("*")) {
         if (s.length() == 1) {
           return new Measure(1, Unit.FR);
         } else {
           return new Measure(s.substring(0, length - 1), Unit.FR);
         }
       }
       if (s.equals("auto")) {
         return new Measure();
       }
       for (int i = 4; i >= 2; i--) {
         final int pos = length - i;
         if (length >= i && Character.isLetter(s.charAt(pos))) {
           return new Measure(s.substring(0, pos), Unit.valueOf(s.substring(pos).toUpperCase()));
         }
       }
       return new Measure(s, defaultUnit);
 
     } catch (final RuntimeException e) {
       LOG.warn("Can't parse to any measure: '" + s + "'");
     }
     return null;
   }
 
   public static Measure valueOf(final Object object) {
     if (object == null) {
       return null;
     }
     if (object instanceof Measure) {
       return valueOf((Measure) object);
     }
     if (object instanceof Number) {
       return valueOf((Number) object);
     }
     if (object instanceof String) {
       return valueOf((String) object);
     }
     return valueOf(object.toString());
   }
 
   public String serialize() {
     final StringBuilder builder = new StringBuilder();
     if (unit != Unit.AUTO) {
       builder.append(value);
     }
     final int length = builder.length();
     if (length >= 3 && builder.charAt(length - 1) == '0' && builder.charAt(length - 2) == '.') {
       builder.deleteCharAt(length - 1);
       builder.deleteCharAt(length - 2);
     }
     builder.append(unit.getValue());
     return builder.toString();
   }
 
   public float getValue() {
     return value;
   }
 
   public Unit getUnit() {
     return unit;
   }
 
   public String toString() {
     return serialize();
   }
 
   @Override
   public boolean equals(final Object o) {
     if (this == o) {
       return true;
     }
     if (o == null || getClass() != o.getClass()) {
       return false;
     }
 
     final Measure measure = (Measure) o;
 
     if (Float.compare(measure.value, value) != 0) {
       return false;
     }
     return unit == measure.unit;
   }
 
   @Override
   public int hashCode() {
     int result = value != +0.0f ? Float.floatToIntBits(value) : 0;
     result = 31 * result + unit.hashCode();
     return result;
   }
 
   public enum Unit {
 
     EM,
     PX,
     EX,
     PT,
     CM,
     MM,
     IN,
     PC,
     CH, // Relative to width of the "0" (zero)
     REM, // Relative to font-size of the root element
     VW, // Relative to 1% of the width of the viewport*
     VH, // Relative to 1% of the height of the viewport*
     VMIN, // Relative to 1% of viewport's* smaller dimension
     VMAX, // Relative to 1% of viewport's* larger dimension
     PERCENT,
     FR, // Fraction - same as * in classic Tobago
     SEG, // Number of used columns in segment layout (Tobago specific)
     AUTO; // Marker for CSS 'auto', not a regular measure
 
     private final String value;
 
     Unit() {
       value = name().equals("PERCENT") ? "%" : name().toLowerCase();
     }
 
     String getValue() {
       return value;
     }
   }
 }