package io.ebeaninternal.server.el;

import io.ebean.bean.EntityBean;
import io.ebean.plugin.Property;
import io.ebean.text.StringParser;
import io.ebean.util.SplitName;
import io.ebean.util.StringHelper;
import io.ebeaninternal.api.SpiExpressionRequest;
import io.ebeaninternal.server.deploy.BeanProperty;
import io.ebeaninternal.server.type.ScalarType;

import java.util.Arrays;


A ElGetValue based on a chain of properties.

Used to get the value for an compound expression like customer.name or
customer.shippingAddress.city etc.


Note that if any element in the chain returns null, then null is returned and
no further processing of the chain occurs.

/**
 * A ElGetValue based on a chain of properties.
 * <p>
 * Used to get the value for an compound expression like customer.name or
 * customer.shippingAddress.city etc.
 * </p>
 * <p>
 * Note that if any element in the chain returns null, then null is returned and
 * no further processing of the chain occurs.
 * </p>
 */
public class ElPropertyChain implements ElPropertyValue {

  private final String prefix;

  private final String placeHolder;
  private final String placeHolderEncrypted;

  private final String name;

  private final String expression;

  private final boolean containsMany;

  private final ElPropertyValue[] chain;

  private final boolean assocId;
  private final int last;
  private final BeanProperty lastBeanProperty;
  private final ScalarType<?> scalarType;

  private final ElPropertyValue lastElPropertyValue;

  public ElPropertyChain(boolean containsMany, boolean embedded, String expression, ElPropertyValue[] chain) {

    this.containsMany = containsMany;
    this.chain = chain;
    this.expression = expression;
    int dotPos = expression.lastIndexOf('.');
    if (dotPos > -1) {
      this.name = expression.substring(dotPos + 1);
      if (embedded) {
        int embPos = expression.lastIndexOf('.', dotPos - 1);
        this.prefix = embPos == -1 ? null : expression.substring(0, embPos);

      } else {
        this.prefix = expression.substring(0, dotPos);
      }
    } else {
      this.prefix = null;
      this.name = expression;
    }

    this.assocId = chain[chain.length - 1].isAssocId();

    this.last = chain.length - 1;
    this.lastBeanProperty = chain[chain.length - 1].getBeanProperty();
    if (lastBeanProperty != null) {
      this.scalarType = lastBeanProperty.getScalarType();
    } else {
      // case for nested compound type (non-scalar)
      this.scalarType = null;
    }
    this.lastElPropertyValue = chain[chain.length - 1];
    this.placeHolder = getElPlaceHolder(prefix, lastElPropertyValue, false);
    this.placeHolderEncrypted = getElPlaceHolder(prefix, lastElPropertyValue, true);
  }

  @Override
  public String toString() {
    return "expr:" + expression + " chain:" + Arrays.toString(chain);
  }

  @Override
  public int getFetchPreference() {
    return chain[0].getFetchPreference();
  }

  @Override
  public boolean isAggregation() {
    return false;
  }

  private String getElPlaceHolder(String prefix, ElPropertyValue lastElPropertyValue, boolean encrypted) {
    if (prefix == null) {
      return lastElPropertyValue.getElPlaceholder(encrypted);
    }

    String el = lastElPropertyValue.getElPlaceholder(encrypted);

    if (!el.contains("${}")) {
      // typically a secondary table property
      return StringHelper.replaceString(el, "${", "${" + prefix + ".");
    } else {
      return StringHelper.replaceString(el, ROOT_ELPREFIX, "${" + prefix + "}");
    }
  }

  
Return true if there is a many property from sinceProperty to
the end of this chain.
/**
   * Return true if there is a many property from sinceProperty to
   * the end of this chain.
   */
  @Override
  public boolean containsManySince(String sinceProperty) {
    if (sinceProperty == null) {
      return containsMany;
    }
    if (!expression.startsWith(sinceProperty)) {
      return containsMany;
    }

    int i = 1 + SplitName.count(sinceProperty);

    for (; i < chain.length; i++) {
      if (chain[i].getBeanProperty().containsMany()) {
        return true;
      }
    }

    return false;
  }

  @Override
  public boolean containsFormulaWithJoin() {
    // Not cascading the check at this stage
    return false;
  }

  @Override
  public boolean containsMany() {
    return containsMany;
  }

  @Override
  public String getElPrefix() {
    return prefix;
  }

  @Override
  public String getName() {
    return name;
  }

  @Override
  public String getElName() {
    return expression;
  }

  @Override
  public String getElPlaceholder(boolean encrypted) {
    return encrypted ? placeHolderEncrypted : placeHolder;
  }

  @Override
  public boolean isDbEncrypted() {
    return lastElPropertyValue.isDbEncrypted();
  }

  @Override
  public boolean isLocalEncrypted() {
    return lastElPropertyValue.isLocalEncrypted();
  }

  @Override
  public Object localEncrypt(Object value) {
    return lastElPropertyValue.localEncrypt(value);
  }

  @Override
  public String getAssocIsEmpty(SpiExpressionRequest request, String path) {
    return lastElPropertyValue.getAssocIsEmpty(request, path);
  }

  @Override
  public Object[] getAssocIdValues(EntityBean bean) {
    // Don't navigate the object graph as bean
    // is assumed to be the appropriate type
    return lastElPropertyValue.getAssocIdValues(bean);
  }

  @Override
  public String getAssocIdExpression(String prefix, String operator) {
    return lastElPropertyValue.getAssocIdExpression(expression, operator);
  }

  @Override
  public String getAssocIdInExpr(String prefix) {
    return lastElPropertyValue.getAssocIdInExpr(prefix);
  }

  @Override
  public String getAssocIdInValueExpr(boolean not, int size) {
    return lastElPropertyValue.getAssocIdInValueExpr(not, size);
  }

  @Override
  public boolean isAssocMany() {
    return lastElPropertyValue.isAssocMany();
  }

  @Override
  public Property getProperty() {
    return lastBeanProperty;
  }

  @Override
  public boolean isAssocId() {
    return assocId;
  }

  @Override
  public boolean isAssocProperty() {
    for (ElPropertyValue aChain : chain) {
      if (aChain.isAssocProperty()) {
        return true;
      }
    }
    return false;
  }

  @Override
  public String getDbColumn() {
    return lastElPropertyValue.getDbColumn();
  }

  @Override
  public BeanProperty getBeanProperty() {
    return lastBeanProperty;
  }


  @Override
  public boolean isDateTimeCapable() {
    return scalarType != null && scalarType.isDateTimeCapable();
  }

  @Override
  public int getJdbcType() {
    return scalarType == null ? 0 : scalarType.getJdbcType();
  }

  @Override
  public Object parseDateTime(long systemTimeMillis) {
    return scalarType.convertFromMillis(systemTimeMillis);
  }

  @Override
  public StringParser getStringParser() {
    return scalarType;
  }

  @Override
  public Object convert(Object value) {
    // just convert using the last one in the chain
    return lastElPropertyValue.convert(value);
  }

  @Override
  public Object pathGet(Object bean) {
    for (ElPropertyValue aChain : chain) {
      if (aChain.isAssocMany()) {
        throw new UnsupportedOperationException("pathGet not supported on [" + expression + "], because " + aChain + " is an assocMany property");
      }
      bean = aChain.pathGet(bean);
      if (bean == null) {
        return null;
      }
    }
    return bean;
  }

  @Override
  public Object pathGetNested(Object bean) {

    Object prevBean = bean;
    for (int i = 0; i < last; i++) {
      // always return non null prevBean
      prevBean = chain[i].pathGetNested(prevBean);
    }
    // try the last step in the chain
    return chain[last].pathGet(prevBean);
  }

  @Override
  public void pathSet(Object bean, Object value) {

    Object prevBean = bean;
    for (int i = 0; i < last; i++) {
      prevBean = chain[i].pathGetNested(prevBean);
    }
    if (prevBean != null) {
      if (lastBeanProperty != null) {
        // last chain element maps to a real scalar property
        lastBeanProperty.pathSet(prevBean, value);

      } else {
        // a non-scalar property of a Compound value object
        lastElPropertyValue.pathSet(prevBean, value);
      }
    }
  }


}