package org.hl7.fhir.r5.profilemodel;

/*
  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 java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.hl7.fhir.exceptions.DefinitionException;
import org.hl7.fhir.r5.model.DataType;
import org.hl7.fhir.r5.model.ElementDefinition;
import org.hl7.fhir.r5.model.ElementDefinition.TypeRefComponent;
import org.hl7.fhir.r5.model.StructureDefinition;
import org.hl7.fhir.r5.model.ValueSet;
import org.hl7.fhir.utilities.CommaSeparatedStringBuilder;
import org.hl7.fhir.utilities.Utilities;

public abstract class PEDefinition {

  public enum PEDefinitionElementMode {
    Resource, Element, DataType, Extension
  }

  protected PEBuilder builder;
  protected String name;
  protected String path;
  protected StructureDefinition profile;
  protected ElementDefinition definition;
  protected List<PEType> types;
  protected Map<String, List<PEDefinition>> children = new HashMap<>();
  private boolean recursing;
  private boolean mustHaveValue;
  private boolean inFixedValue;
  private boolean isSlicer;
  private List<PEDefinition> slices; // if there are some...
  
//  /**
//   * Don't create one of these directly - always use the public methods on ProfiledElementBuilder
//   *  
//   * @param builder
//   * @param baseElement
//   * @param profiledElement
//   * @param data
//   */
//  protected PEDefinition(PEBuilder builder, String name, 
//      ElementDefinition definition, Base data) {
//    super();
//    this.builder = builder;
//    this.name = name;
//    this.definition = definition;
////    this.data = data;
//  }

  protected PEDefinition(PEBuilder builder, String name, StructureDefinition profile, ElementDefinition definition, String ppath) {
    this.builder = builder;
    this.name = name;
    this.profile = profile;
    this.definition = definition;
    this.path = ppath == null ? name : ppath+"."+name;
  }


  /** 
   * @return The name of the element or slice in the profile (always unique amongst children)
   */
  public String name() {
    return name;
  }

  /** 
   * @return The path of the element or slice in the profile (name.name.name...)
   */
  public String path() {
    return path;
  }

  /**
   * @return The name of the element in the resource (may be different to the slice name)
   */
  public String schemaName() {
    String n = definition.getName();
    return n;
  }
  
  /**
   * @return The name of the element in the resource (may be different to the slice name)
   */
  public String schemaNameWithType() {
    String n = definition.getName();
    if (n.endsWith("[x]") && types().size() == 1) {
      n = n.replace("[x]", Utilities.capitalize(types.get(0).getType()));
    }
    return n;
  }
  
  /**
   * @return a list of types. There is usually at least one type; it might be Element, Type, BackboneElement or BackboneType
   * 
   * The following elements don't have types (true primitives): Element.id. Extension.url, PrimitiveType.value
   */
  public List<PEType> types() {
    if (types == null) {
      List<PEType> ltypes = new ArrayList<>();
      listTypes(ltypes);
      types = ltypes;
    }
    return types;
  }
  
  protected abstract void listTypes(List<PEType> types);
  
  /**
   * @return The minimum number of repeats allowed
   */
  public int min() {
    return mustHaveValue ? 1 : definition.getMin();
  }
  
  /**
   * @return the maximum number of repeats allowed
   */
  public int max() {
    return definition.getMax() == null || "*".equals(definition.getMax()) ? Integer.MAX_VALUE : Integer.parseInt(definition.getMax());
  }
  
  /**
   * @return the definition of the element in the profile (fully populated)
   * 
   * Note that the profile definition might be the same as a base definition, when the tree runs off the end of what's profiled
   */
  public ElementDefinition definition() {
    return definition;
  }
  
  /**
   * @return the definition of the element in the base specification
   * 
   * Note that the profile definition might be the same as a base definition, when the tree runs off the end of what's profiled
   */
  public ElementDefinition baseDefinition() {
    String type = definition.getBase().getPath();
    if (type.contains(".")) {
      type= type.substring(0, type.indexOf("."));
    }
    StructureDefinition sd = builder.getContext().fetchTypeDefinition(type);
    return sd.getSnapshot().getElementByPath(definition.getBase().getPath());
  }
  
  /**
   * @return the short documentation of the definition (shown in the profile table view)
   */
  public String shortDocumentation() {
    return definition.getShort();
  }
  
  /**
   * @return the full definition of the element (markdown syntax)
   */
  public String documentation() {
    return definition.getDefinition();
  }
  
//  /**
//   * @return if the profiled definition has a value set, get the expansion 
//   */
//  public ValueSet expansion() {
//    throw new NotImplementedException("Not done yet");
//  }
//  
  /**
   * @param typeUrl - the url of one of the types listed in types()
   * @return - the list of children for the nominated type
   * 
   * Warning: profiles and resources can be recursive; you can't iterate this tree until you get 
   * to the leaves because you will never get to a child that doesn't have children (extensions have extensions etc)
   * 
   */
  public List<PEDefinition> children(String typeUrl) {
    return children(typeUrl, false);
  }
  
  public List<PEDefinition> children(String typeUrl, boolean allFixed) {
    if (children.containsKey(typeUrl+"$"+allFixed)) {
      return children.get(typeUrl+"$"+allFixed);      
    } 
    List<PEDefinition> res = new ArrayList<>();
    makeChildren(typeUrl, res, allFixed);
    children.put(typeUrl+"$"+allFixed, res);
    return res;    
  }
  
  public List<PEDefinition> children() {
    if (types().size() == 1) {
      return children(types.get(0).getUrl(), false);
    } else {
      throw new DefinitionException("Attempt to get children for an element that doesn't have a single type (element = "+path+", types = "+types()+")");
    }
  }
  
  public List<PEDefinition> children(boolean allFixed) {
    if (types().size() == 1) {
      return children(types.get(0).getUrl(), allFixed);
    } else {
      throw new DefinitionException("Attempt to get children for an element that doesn't have a single type (element = "+path+", types = "+types()+")");
    }
  }
  
  /**
   * @return True if the element has a fixed value. This will always be false if fixedProps = false when the builder is created
   */
  public boolean hasFixedValue() {
    return definition.hasFixed() || definition.hasPattern();
  }

  public DataType getFixedValue() {
    return definition.hasFixed() ? definition.getFixed() : definition.getPattern();
  }
  

  protected abstract void makeChildren(String typeUrl, List<PEDefinition> children, boolean allFixed);

  @Override
  public String toString() {
    return name+"("+schemaName()+"):"+types().toString()+" ["+min()+":"+(max() == Integer.MAX_VALUE ? "*" : max() )+"] \""+shortDocumentation()+"\"";
  }

  /**
   * @return true if the builder observes that this element is recursing (extensions have extensions)
   * 
   * Note that this is unreliable and may be withdrawn if it can't be fixed
   */
  public boolean isRecursing() {
    return recursing;
  }

  protected void setRecursing(boolean recursing) {
    this.recursing = recursing;
  }
  
  protected boolean isMustHaveValue() {
    return mustHaveValue;
  }

  protected void setMustHaveValue(boolean mustHaveValue) {
    this.mustHaveValue = mustHaveValue;
  }

  /**
   * @return true if this property is inside an element that has an assigned fixed value
   */
  public boolean isInFixedValue() {
    return inFixedValue;
  }


  protected void setInFixedValue(boolean inFixedValue) {
    this.inFixedValue = inFixedValue;
  }


  /** 
   * This is public to support unit testing - there's no reason to use it otherwise
   * 
   * @return used in the instance processor to differentiate slices
   */
  public abstract String fhirpath();


  public boolean isList() {
    return "*".equals(definition.getMax()) || (Utilities.parseInt(definition.getMax(), 2) > 1);
  }


  public boolean repeats() {
    return max() > 1;
  }
  
  public PEDefinitionElementMode mode() {
    if (builder.isResource(definition.getBase().getPath())) {
      return PEDefinitionElementMode.Resource;
    }
    for (TypeRefComponent tr : definition.getType()) {
      if ("Extension".equals(tr.getWorkingCode())) {
        return PEDefinitionElementMode.Extension;
      }
      if (!Utilities.existsInList(tr.getWorkingCode(), "Element", "BackboneElement")) {
        return PEDefinitionElementMode.DataType;
      }
    }
    return PEDefinitionElementMode.Element;
  }

  /**
   * @return true if this element is profiled one way or another
   */
  public boolean isProfiled() {
    return !profile.getUrl().startsWith("http://hl7.org/fhir/StructureDefinition");
  }


  public boolean isSlicer() {
    return isSlicer;
  }


  public void setSlicer(boolean isSlicer) {
    this.isSlicer = isSlicer;
  }


  public boolean isBaseList() {
    return !"1".equals(definition.getBase().getMax());
  }


  public StructureDefinition getProfile() {
    return profile;
  }


  public boolean isKeyElement() {
    boolean selfKey = definition.getMustSupport() || definition.getMustHaveValue() || min() > 0 || definition.hasCondition();
    if (isProfiled() && !selfKey) {
      if (types() != null && types().size() > 0) {
        for (PEDefinition child : children()) {
          if (child.isKeyElement()) {
            return true;
          }
        }
      }
    }
    return selfKey;
  }


  public boolean isPrimitive() {
    return types().size() == 1 && builder.getContext().isPrimitiveType(types.get(0).getName());
  }


  public boolean isBasePrimitive() {
    ElementDefinition ed = baseDefinition();
    return ed != null && ed.getType().size() == 1 && builder.getContext().isPrimitiveType(ed.getType().get(0).getWorkingCode());
  }


  // extensions do something different here 
  public List<PEDefinition> directChildren(boolean allFixed) {
    return children(allFixed);
  }


  public List<PEDefinition> getSlices() {
    return slices;
  }


  public void setSlices(List<PEDefinition> slices) {
    this.slices = slices;
  }


  public boolean isExtension() {
    return false;
  }

  public String getExtensionUrl() {
    return null;
  }

  public ValueSet valueSet() {
    if (definition.getBinding().hasValueSet()) {
      return builder.getContext().fetchResource(ValueSet.class, definition.getBinding().getValueSet());
    }
    return null;
  }


  public PEBuilder getBuilder() {
    return builder;
  }

  public String typeSummary() {
    CommaSeparatedStringBuilder b = new CommaSeparatedStringBuilder();
    for (PEType t : types()) {
      b.append(t.getName());
    }       
    return b.toString();
  }


  public boolean isSlice() {
    return definition.hasSliceName();
  }

}