package org.hl7.fhir.dstu3.elementmodel;

/*
  Copyright (c) 2011+, HL7, Inc.
  All rights reserved.
  
  Redistribution and use in source and binary forms, with or without modification, 
  are permitted provided that the following conditions are met:
    
   * Redistributions of source code must retain the above copyright notice, this 
     list of conditions and the following disclaimer.
   * Redistributions in binary form must reproduce the above copyright notice, 
     this list of conditions and the following disclaimer in the documentation 
     and/or other materials provided with the distribution.
   * Neither the name of HL7 nor the names of its contributors may be used to 
     endorse or promote products derived from this software without specific 
     prior written permission.
  
  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 
  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 
  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
  POSSIBILITY OF SUCH DAMAGE.
  
 */



import static org.apache.commons.lang3.StringUtils.isNotBlank;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.apache.commons.lang3.Validate;
import org.hl7.fhir.dstu3.model.Base;
import org.hl7.fhir.dstu3.model.ElementDefinition;
import org.hl7.fhir.dstu3.model.ElementDefinition.TypeRefComponent;
import org.hl7.fhir.dstu3.model.StringType;
import org.hl7.fhir.dstu3.model.StructureDefinition;
import org.hl7.fhir.dstu3.model.Type;
import org.hl7.fhir.exceptions.FHIRException;
import org.hl7.fhir.utilities.Utilities;
import org.hl7.fhir.utilities.xhtml.XhtmlNode;

/**
 * This class represents the underlying reference model of FHIR
 * 
 * A resource is nothing but a set of elements, where every element has a 
 * name, maybe a stated type, maybe an id, and either a value or child elements 
 * (one or the other, but not both or neither)
 * 
 * @author Grahame Grieve
 *
 */
public class Element extends Base {


  public enum SpecialElement {
                CONTAINED, BUNDLE_ENTRY, BUNDLE_OUTCOME, PARAMETER;

    public static SpecialElement fromProperty(Property property) {
      if (property.getStructure().getIdElement().getIdPart().equals("Parameters"))
        return PARAMETER;
      if (property.getStructure().getIdElement().getIdPart().equals("Bundle") && property.getName().equals("resource"))
        return BUNDLE_ENTRY;
      if (property.getStructure().getIdElement().getIdPart().equals("Bundle") && property.getName().equals("outcome"))
        return BUNDLE_OUTCOME;
      if (property.getName().equals("contained")) 
        return CONTAINED;
      throw new Error("Unknown resource containing a native resource: "+property.getDefinition().getId());
    }
        }

        private List<String> comments;// not relevant for production, but useful in documentation
        private String name;
        private String type;
        private String value;
        private int index = -1;
        private List<Element> children;
        private Property property;
  private Property elementProperty; // this is used when special is set to true - it tracks the underlying element property which is used in a few places
        private int line;
        private int col;
        private SpecialElement special;
        private XhtmlNode xhtml; // if this is populated, then value will also hold the string representation

        public Element(String name) {
                super();
                this.name = name;
        }

  public Element(Element other) {
    super();
    name = other.name;
    type = other.type;
    property = other.property;
    elementProperty = other.elementProperty;
    special = other.special;
  }
  
  public Element(String name, Property property) {
                super();
                this.name = name;
                this.property = property;
        }

        public Element(String name, Property property, String type, String value) {
                super();
                this.name = name;
                this.property = property;
                this.type = type;
                this.value = value;
        }

        public void updateProperty(Property property, SpecialElement special, Property elementProperty) {
                this.property = property;
    this.elementProperty = elementProperty;
                this.special = special;
        }

        public SpecialElement getSpecial() {
                return special;
        }

        public String getName() {
                return name;
        }

        public String getType() {
                if (type == null)
                        return property.getType(name);
                else
                  return type;
        }

        public String getValue() {
                return value;
        }

        public boolean hasChildren() {
                return !(children == null || children.isEmpty());
        }

        public List<Element> getChildren() {
                if (children == null)
                        children = new ArrayList<Element>();
                return children;
        }

        public boolean hasComments() {
                return !(comments == null || comments.isEmpty());
        }

        public List<String> getComments() {
                if (comments == null)
                        comments = new ArrayList<String>();
                return comments;
        }

        public Property getProperty() {
                return property;
        }

        public void setValue(String value) {
                this.value = value;
        }

        public void setType(String type) {
                this.type = type;

        }

        public boolean hasValue() {
                return value != null;
        }

        public List<Element> getChildrenByName(String name) {
                List<Element> res = new ArrayList<Element>();
                if (hasChildren()) {
                        for (Element child : children)
                                if (name.equals(child.getName()))
                                        res.add(child);
                }
                return res;
        }

        public void numberChildren() {
                if (children == null)
                        return;
                
                String last = "";
                int index = 0;
                for (Element child : children) {
                        if (child.getProperty().isList()) {
                          if (last.equals(child.getName())) {
                                index++;
                          } else {
                                last = child.getName();
                                index = 0;
                          }
                        child.index = index;
                        } else {
                                child.index = -1;
                        }
                        child.numberChildren();
                }       
        }

        public int getIndex() {
                return index;
        }

        public boolean hasIndex() {
                return index > -1;
        }

        public void setIndex(int index) {
                this.index = index;
        }

        public String getChildValue(String name) {
                if (children == null)
                        return null;
                for (Element child : children) {
                        if (name.equals(child.getName()))
                                return child.getValue();
                }
        return null;
        }

  public void setChildValue(String name, String value) {
    if (children == null)
      children = new ArrayList<Element>();
    for (Element child : children) {
      if (name.equals(child.getName())) {
        if (!child.isPrimitive())
          throw new Error("Cannot set a value of a non-primitive type ("+name+" on "+this.getName()+")");
        child.setValue(value);
      }
    }
    try {
      setProperty(name.hashCode(), name, new StringType(value));
    } catch (FHIRException e) {
      throw new Error(e);
    }
  }

        public List<Element> getChildren(String name) {
                List<Element> res = new ArrayList<Element>(); 
                if (children != null)
                for (Element child : children) {
                        if (name.equals(child.getName()))
                                res.add(child);
                }
                return res;
        }

  public boolean hasType() {
    if (type == null)
      return property.hasType(name);
    else
      return true;
  }

  @Override
  public String fhirType() {
    return getType();
  }

  @Override
        public Base[] getProperty(int hash, String name, boolean checkValid) throws FHIRException {
        if (isPrimitive() && (hash == "value".hashCode()) && !Utilities.noString(value)) {
//              String tn = getType();
//              throw new Error(tn+" not done yet");
          Base[] b = new Base[1];
          b[0] = new StringType(value);
          return b;
        }
                
        List<Base> result = new ArrayList<Base>();
        if (children != null) {
        for (Element child : children) {
                if (child.getName().equals(name))
                        result.add(child);
                if (child.getName().startsWith(name) && child.getProperty().isChoice() && child.getProperty().getName().equals(name+"[x]"))
                        result.add(child);
        }
        }
        if (result.isEmpty() && checkValid) {
//              throw new FHIRException("not determined yet");
        }
        return result.toArray(new Base[result.size()]);
        }

        @Override
        protected void listChildren(List<org.hl7.fhir.dstu3.model.Property> childProps) {
          if (children != null) {
            for (Element c : children) {
              childProps.add(new org.hl7.fhir.dstu3.model.Property(c.getName(), c.fhirType(), c.getProperty().getDefinition().getDefinition(), c.getProperty().getDefinition().getMin(), maxToInt(c.getProperty().getDefinition().getMax()), c));
            }
          }
        }
        
  @Override
  public Base setProperty(int hash, String name, Base value) throws FHIRException {
    if (isPrimitive() && (hash == "value".hashCode())) {
      this.value = castToString(value).asStringValue();
      return this;
    }
    if ("xhtml".equals(getType()) && (hash == "value".hashCode())) {
      this.xhtml = castToXhtml(value);
      this.value =  castToXhtmlString(value);
      return this;
    }
    
    if (!value.isPrimitive() && !(value instanceof Element)) {
      if (isDataType(value)) 
        value = convertToElement(property.getChild(name), value);
      else
        throw new FHIRException("Cannot set property "+name+" on "+this.name+" - value is not a primitive type ("+value.fhirType()+") or an ElementModel type");
    }
    
    if (children == null)
      children = new ArrayList<Element>();
    Element childForValue = null;
    
    // look through existing children
    for (Element child : children) {
      if (child.getName().equals(name)) {
        if (!child.isList()) {
          childForValue = child;
          break;
        } else {
          Element ne = new Element(child);
          children.add(ne);
          numberChildren();
          childForValue = ne;
          break;
        }
      }
    }

    if (childForValue == null)
      for (Property p : property.getChildProperties(this.name, type)) {
        if (p.getName().equals(name) || p.getName().equals(name+"[x]")) {
          Element ne = new Element(name, p);
          children.add(ne);
          childForValue = ne;
          break;
        }
      }
    
    if (childForValue == null)
      throw new Error("Cannot set property "+name+" on "+this.name);
    else if (value.isPrimitive()) {
      if (childForValue.property.getName().endsWith("[x]"))
        childForValue.name = name+Utilities.capitalize(value.fhirType());
      childForValue.setValue(value.primitiveValue());
    } else {
      Element ve = (Element) value;
      childForValue.type = ve.getType();
      if (childForValue.property.getName().endsWith("[x]"))
        childForValue.name = name+Utilities.capitalize(childForValue.type);
      else if (value.isResource()) {
        if (childForValue.elementProperty == null)
          childForValue.elementProperty = childForValue.property;
        childForValue.property = ve.property;
        childForValue.special = SpecialElement.BUNDLE_ENTRY;
      }
      if (ve.children != null) {
        if (childForValue.children == null)
          childForValue.children = new ArrayList<Element>();
        else 
          childForValue.children.clear();
        childForValue.children.addAll(ve.children);
      }
    }
    return childForValue;
  }

  private Base convertToElement(Property prop, Base v) throws FHIRException {
    return new ObjectConverter(property.getContext()).convert(prop, (Type) v);
  }

  private boolean isDataType(Base v) {
    return v instanceof Type &&  property.getContext().getTypeNames().contains(v.fhirType());
  }

  @Override
  public Base makeProperty(int hash, String name) throws FHIRException {
    if (isPrimitive() && (hash == "value".hashCode())) {
      return new StringType(value);
    }

    if (children == null)
      children = new ArrayList<Element>();
    
    // look through existing children
    for (Element child : children) {
      if (child.getName().equals(name)) {
        if (!child.isList()) {
          return child;
        } else {
          Element ne = new Element(child);
          children.add(ne);
          numberChildren();
          return ne;
        }
      }
    }

    for (Property p : property.getChildProperties(this.name, type)) {
      if (p.getName().equals(name)) {
        Element ne = new Element(name, p);
        children.add(ne);
        return ne;
      }
    }
      
    throw new Error("Unrecognised name "+name+" on "+this.name); 
  }
  
        private int maxToInt(String max) {
    if (max.equals("*"))
      return Integer.MAX_VALUE;
    else
      return Integer.parseInt(max);
        }

        @Override
        public boolean isPrimitive() {
                return type != null ? property.isPrimitive(type) : property.isPrimitive(property.getType(name));
        }
        
  @Override
  public boolean isResource() {
    return property.isResource();
  }
  

        @Override
        public boolean hasPrimitiveValue() {
                return property.isPrimitiveName(name) || property.IsLogicalAndHasPrimitiveValue(name);
        }
        

        @Override
        public String primitiveValue() {
                if (isPrimitive())
                  return value;
                else {
                        if (hasPrimitiveValue() && children != null) {
                                for (Element c : children) {
                                        if (c.getName().equals("value"))
                                                return c.primitiveValue();
                                }
                        }
                        return null;
                }
        }
        
        // for the validator
  public int line() {
    return line;
  }

  public int col() {
    return col;
  }

        public Element markLocation(int line, int col) {
                this.line = line;
                this.col = col; 
                return this;
        }

        public void markValidation(StructureDefinition profile, ElementDefinition definition) {
        }
        
  public Element getNamedChild(String name) {
          if (children == null)
                return null;
          Element result = null;
          for (Element child : children) {
                if (child.getName().equals(name)) {
                        if (result == null)
                                result = child;
                        else 
                                throw new Error("Attempt to read a single element when there is more than one present ("+name+")");
                }
          }
          return result;
        }

  public void getNamedChildren(String name, List<Element> list) {
        if (children != null)
                for (Element child : children) 
                        if (child.getName().equals(name))
                                list.add(child);
  }

  public String getNamedChildValue(String name) {
        Element child = getNamedChild(name);
        return child == null ? null : child.value;
  }

  public void getNamedChildrenWithWildcard(String string, List<Element> values) {
          Validate.isTrue(string.endsWith("[x]"));
          
          String start = string.substring(0, string.length() - 3);
                if (children != null) {
                        for (Element child : children) { 
                                if (child.getName().startsWith(start)) {
                                        values.add(child);
                                }
                        }
                }
  }

  
        public XhtmlNode getXhtml() {
                return xhtml;
        }

        public Element setXhtml(XhtmlNode xhtml) {
                this.xhtml = xhtml;
                return this;
        }

        @Override
        public boolean isEmpty() {
                if (isNotBlank(value)) {
                        return false;
                }
                for (Element next : getChildren()) {
                        if (!next.isEmpty()) {
                                return false;
                        }
                }
                return true;
        }

  public Property getElementProperty() {
    return elementProperty;
  }

  public boolean hasElementProperty() {
    return elementProperty != null;
  }

  public boolean hasChild(String name) {
    return getNamedChild(name) != null;
  }

  @Override
  public String toString() {
    return name+"="+fhirType() + "["+(children == null || hasValue() ? value : Integer.toString(children.size())+" children")+"]";
  }

  @Override
  public String getIdBase() {
    return getChildValue("id");
  }

  @Override
  public void setIdBase(String value) {
    setChildValue("id", value);
  }


  @Override
  public boolean equalsDeep(Base other) {
    if (!super.equalsDeep(other))
      return false;
    if (isPrimitive() && other.isPrimitive())
      return primitiveValue().equals(other.primitiveValue());
    if (isPrimitive() || other.isPrimitive())
      return false;
    Set<String> processed  = new HashSet<String>();
    for (org.hl7.fhir.dstu3.model.Property p : children()) {
      String name = p.getName();
      processed.add(name);
      org.hl7.fhir.dstu3.model.Property o = other.getChildByName(name);
      if (!equalsDeep(p, o))
        return false;
    }
    for (org.hl7.fhir.dstu3.model.Property p : children()) {
      String name = p.getName();
      if (!processed.contains(name)) {
        org.hl7.fhir.dstu3.model.Property o = other.getChildByName(name);
        if (!equalsDeep(p, o))
          return false;
      }
    }
    return true;
  }

  private boolean equalsDeep(org.hl7.fhir.dstu3.model.Property p, org.hl7.fhir.dstu3.model.Property o) {
    if (o == null || p == null)
      return false;
    if (p.getValues().size() != o.getValues().size())
      return false;
    for (int i = 0; i < p.getValues().size(); i++)
      if (!Base.compareDeep(p.getValues().get(i), o.getValues().get(i), true))
        return false;
    return true;
  }

  @Override
  public boolean equalsShallow(Base other) {
    if (!super.equalsShallow(other))
      return false;
    if (isPrimitive() && other.isPrimitive())
      return primitiveValue().equals(other.primitiveValue());
    if (isPrimitive() || other.isPrimitive())
      return false;
    return true; //?
  }

  public Type asType() throws FHIRException {
    return new ObjectConverter(property.getContext()).convertToType(this);
  }

  @Override
  public boolean isMetadataBased() {
    return true;
  }

  public boolean isList() {
    if (elementProperty != null)
      return elementProperty.isList();
    else
      return property.isList();
  }
  
  @Override
  public String[] getTypesForProperty(int hash, String name) throws FHIRException {
    Property p = property.getChildSimpleName(this.name, name);
    if (p != null) {
      Set<String> types = new HashSet<String>();
      for (TypeRefComponent tr : p.getDefinition().getType()) {
        types.add(tr.getCode());
      }
      return types.toArray(new String[]{});
    }
    return super.getTypesForProperty(hash, name);

  }

  public void sort() {
    if (children != null) {
      List<Element> remove = new ArrayList<Element>();
      for (Element child : children) {
        child.sort();
        if (child.isEmpty())
          remove.add(child);
      }
      children.removeAll(remove);
      Collections.sort(children, new ElementSortComparator(this, this.property));
    }
  }

  public class ElementSortComparator implements Comparator<Element> {
    private List<ElementDefinition> children;
    public ElementSortComparator(Element e, Property property) {
      String tn = e.getType();
      StructureDefinition sd = property.getContext().fetchTypeDefinition(tn);
      if (sd != null && !sd.getAbstract())
        children = sd.getSnapshot().getElement();
      else
        children = property.getStructure().getSnapshot().getElement();
    }
    
    @Override
    public int compare(Element e0, Element e1) {
      int i0 = find(e0);
      int i1 = find(e1);
      return (i0 < i1) ? -1 : ((i0 == i1) ? 0 : 1);
    }
    private int find(Element e0) {
      int i =  e0.elementProperty != null ? children.indexOf(e0.elementProperty.getDefinition()) :  children.indexOf(e0.property.getDefinition());
      return i; 
    }

  }

}