/*
 * 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.accumulo.core.client.impl;

import java.util.EnumSet;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.TreeMap;
import java.util.TreeSet;

import org.apache.accumulo.core.client.AccumuloException;
import org.apache.accumulo.core.client.AccumuloSecurityException;
import org.apache.accumulo.core.client.IteratorSetting;
import org.apache.accumulo.core.client.NamespaceNotFoundException;
import org.apache.accumulo.core.client.admin.NamespaceOperations;
import org.apache.accumulo.core.conf.Property;
import org.apache.accumulo.core.iterators.IteratorUtil.IteratorScope;

public abstract class NamespaceOperationsHelper implements NamespaceOperations {

  @Override
  public String systemNamespace() {
    return Namespace.ACCUMULO;
  }

  @Override
  public String defaultNamespace() {
    return Namespace.DEFAULT;
  }

  @Override
  public void attachIterator(String namespace, IteratorSetting setting)
      throws AccumuloSecurityException, AccumuloException, NamespaceNotFoundException {
    attachIterator(namespace, setting, EnumSet.allOf(IteratorScope.class));
  }

  @Override
  public void attachIterator(String namespace, IteratorSetting setting,
      EnumSet<IteratorScope> scopes)
      throws AccumuloSecurityException, AccumuloException, NamespaceNotFoundException {
    checkIteratorConflicts(namespace, setting, scopes);
    for (IteratorScope scope : scopes) {
      String root = String.format("%s%s.%s", Property.TABLE_ITERATOR_PREFIX,
          scope.name().toLowerCase(), setting.getName());
      for (Entry<String,String> prop : setting.getOptions().entrySet()) {
        this.setProperty(namespace, root + ".opt." + prop.getKey(), prop.getValue());
      }
      this.setProperty(namespace, root, setting.getPriority() + "," + setting.getIteratorClass());
    }
  }

  @Override
  public void removeIterator(String namespace, String name, EnumSet<IteratorScope> scopes)
      throws AccumuloSecurityException, AccumuloException, NamespaceNotFoundException {
    if (!exists(namespace))
      throw new NamespaceNotFoundException(null, namespace, null);
    Map<String,String> copy = new TreeMap<>();
    for (Entry<String,String> property : this.getProperties(namespace)) {
      copy.put(property.getKey(), property.getValue());
    }
    for (IteratorScope scope : scopes) {
      String root = String.format("%s%s.%s", Property.TABLE_ITERATOR_PREFIX,
          scope.name().toLowerCase(), name);
      for (Entry<String,String> property : copy.entrySet()) {
        if (property.getKey().equals(root) || property.getKey().startsWith(root + ".opt."))
          this.removeProperty(namespace, property.getKey());
      }
    }
  }

  @Override
  public IteratorSetting getIteratorSetting(String namespace, String name, IteratorScope scope)
      throws AccumuloSecurityException, AccumuloException, NamespaceNotFoundException {
    if (!exists(namespace))
      throw new NamespaceNotFoundException(null, namespace, null);
    int priority = -1;
    String classname = null;
    Map<String,String> settings = new HashMap<>();

    String root = String.format("%s%s.%s", Property.TABLE_ITERATOR_PREFIX,
        scope.name().toLowerCase(), name);
    String opt = root + ".opt.";
    for (Entry<String,String> property : this.getProperties(namespace)) {
      if (property.getKey().equals(root)) {
        String parts[] = property.getValue().split(",");
        if (parts.length != 2) {
          throw new AccumuloException("Bad value for iterator setting: " + property.getValue());
        }
        priority = Integer.parseInt(parts[0]);
        classname = parts[1];
      } else if (property.getKey().startsWith(opt)) {
        settings.put(property.getKey().substring(opt.length()), property.getValue());
      }
    }
    if (priority <= 0 || classname == null) {
      return null;
    }
    return new IteratorSetting(priority, name, classname, settings);
  }

  @Override
  public Map<String,EnumSet<IteratorScope>> listIterators(String namespace)
      throws AccumuloSecurityException, AccumuloException, NamespaceNotFoundException {
    if (!exists(namespace))
      throw new NamespaceNotFoundException(null, namespace, null);
    Map<String,EnumSet<IteratorScope>> result = new TreeMap<>();
    for (Entry<String,String> property : this.getProperties(namespace)) {
      String name = property.getKey();
      String[] parts = name.split("\\.");
      if (parts.length == 4) {
        if (parts[0].equals("table") && parts[1].equals("iterator")) {
          IteratorScope scope = IteratorScope.valueOf(parts[2]);
          if (!result.containsKey(parts[3]))
            result.put(parts[3], EnumSet.noneOf(IteratorScope.class));
          result.get(parts[3]).add(scope);
        }
      }
    }
    return result;
  }

  @Override
  public void checkIteratorConflicts(String namespace, IteratorSetting setting,
      EnumSet<IteratorScope> scopes)
      throws AccumuloException, NamespaceNotFoundException, AccumuloSecurityException {
    if (!exists(namespace))
      throw new NamespaceNotFoundException(null, namespace, null);
    for (IteratorScope scope : scopes) {
      String scopeStr = String.format("%s%s", Property.TABLE_ITERATOR_PREFIX,
          scope.name().toLowerCase());
      String nameStr = String.format("%s.%s", scopeStr, setting.getName());
      String optStr = String.format("%s.opt.", nameStr);
      Map<String,String> optionConflicts = new TreeMap<>();
      for (Entry<String,String> property : this.getProperties(namespace)) {
        if (property.getKey().startsWith(scopeStr)) {
          if (property.getKey().equals(nameStr))
            throw new AccumuloException(new IllegalArgumentException("iterator name conflict for "
                + setting.getName() + ": " + property.getKey() + "=" + property.getValue()));
          if (property.getKey().startsWith(optStr))
            optionConflicts.put(property.getKey(), property.getValue());
          if (property.getKey().contains(".opt."))
            continue;
          String parts[] = property.getValue().split(",");
          if (parts.length != 2)
            throw new AccumuloException("Bad value for existing iterator setting: "
                + property.getKey() + "=" + property.getValue());
          try {
            if (Integer.parseInt(parts[0]) == setting.getPriority())
              throw new AccumuloException(new IllegalArgumentException(
                  "iterator priority conflict: " + property.getKey() + "=" + property.getValue()));
          } catch (NumberFormatException e) {
            throw new AccumuloException("Bad value for existing iterator setting: "
                + property.getKey() + "=" + property.getValue());
          }
        }
      }
      if (optionConflicts.size() > 0)
        throw new AccumuloException(new IllegalArgumentException(
            "iterator options conflict for " + setting.getName() + ": " + optionConflicts));
    }
  }

  @Override
  public int addConstraint(String namespace, String constraintClassName)
      throws AccumuloException, AccumuloSecurityException, NamespaceNotFoundException {
    TreeSet<Integer> constraintNumbers = new TreeSet<>();
    TreeMap<String,Integer> constraintClasses = new TreeMap<>();
    int i;
    for (Entry<String,String> property : this.getProperties(namespace)) {
      if (property.getKey().startsWith(Property.TABLE_CONSTRAINT_PREFIX.toString())) {
        try {
          i = Integer.parseInt(
              property.getKey().substring(Property.TABLE_CONSTRAINT_PREFIX.toString().length()));
        } catch (NumberFormatException e) {
          throw new AccumuloException("Bad key for existing constraint: " + property);
        }
        constraintNumbers.add(i);
        constraintClasses.put(property.getValue(), i);
      }
    }
    i = 1;
    while (constraintNumbers.contains(i))
      i++;
    if (constraintClasses.containsKey(constraintClassName))
      throw new AccumuloException(
          "Constraint " + constraintClassName + " already exists for namespace " + namespace
              + " with number " + constraintClasses.get(constraintClassName));
    this.setProperty(namespace, Property.TABLE_CONSTRAINT_PREFIX.toString() + i,
        constraintClassName);
    return i;
  }

  @Override
  public void removeConstraint(String namespace, int number)
      throws AccumuloException, AccumuloSecurityException, NamespaceNotFoundException {
    this.removeProperty(namespace, Property.TABLE_CONSTRAINT_PREFIX.toString() + number);
  }

  @Override
  public Map<String,Integer> listConstraints(String namespace)
      throws AccumuloException, NamespaceNotFoundException, AccumuloSecurityException {
    Map<String,Integer> constraints = new TreeMap<>();
    for (Entry<String,String> property : this.getProperties(namespace)) {
      if (property.getKey().startsWith(Property.TABLE_CONSTRAINT_PREFIX.toString())) {
        if (constraints.containsKey(property.getValue()))
          throw new AccumuloException("Same constraint configured twice: " + property.getKey() + "="
              + Property.TABLE_CONSTRAINT_PREFIX + constraints.get(property.getValue()) + "="
              + property.getKey());
        try {
          constraints.put(property.getValue(), Integer.parseInt(
              property.getKey().substring(Property.TABLE_CONSTRAINT_PREFIX.toString().length())));
        } catch (NumberFormatException e) {
          throw new AccumuloException("Bad key for existing constraint: " + property);
        }
      }
    }
    return constraints;
  }
}