/*
Copyright (c) 2016 James Ahlborn

Licensed 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 com.healthmarketscience.jackcess.impl;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;

import com.healthmarketscience.jackcess.ColumnBuilder;
import com.healthmarketscience.jackcess.DataType;
import com.healthmarketscience.jackcess.IndexBuilder;

/**
 * Common helper class used to maintain state during table mutation.
 *
 * @author James Ahlborn
 * @usage _advanced_class_
 */
public abstract class TableMutator extends DBMutator
{
  private ColumnOffsets _colOffsets;

  protected TableMutator(DatabaseImpl database) {
    super(database);
  }

  public void setColumnOffsets(
      int fixedOffset, int varOffset, int longVarOffset) {
    if(_colOffsets == null) {
      _colOffsets = new ColumnOffsets();
    }
    _colOffsets.set(fixedOffset, varOffset, longVarOffset);
  }

  public ColumnOffsets getColumnOffsets() {
    return _colOffsets;
  }

  public IndexImpl.ForeignKeyReference getForeignKey(IndexBuilder idx) {
    return null;
  }

  protected void validateColumn(Set<String> colNames, ColumnBuilder column) {

      // FIXME for now, we can't create complex columns
      if(column.getType() == DataType.COMPLEX_TYPE) {
        throw new UnsupportedOperationException(withErrorContext(
            "Complex column creation is not yet implemented"));
      }
      
      column.validate(getFormat());
      if(!colNames.add(DatabaseImpl.toLookupName(column.getName()))) {
        throw new IllegalArgumentException(withErrorContext(
            "duplicate column name: " + column.getName()));
      }

      setColumnSortOrder(column);
  }

  protected void validateIndex(Set<String> colNames, Set<String> idxNames, 
                               boolean[] foundPk, IndexBuilder index) {
    
    index.validate(colNames, getFormat());
    if(!idxNames.add(DatabaseImpl.toLookupName(index.getName()))) {
      throw new IllegalArgumentException(withErrorContext(
          "duplicate index name: " + index.getName()));
    }
    if(index.isPrimaryKey()) {
      if(foundPk[0]) {
        throw new IllegalArgumentException(withErrorContext(
            "found second primary key index: " + index.getName()));
      }
      foundPk[0] = true;
    } else if(index.getType() == IndexImpl.FOREIGN_KEY_INDEX_TYPE) {
      if(getForeignKey(index) == null) {
        throw new IllegalArgumentException(withErrorContext(
            "missing foreign key info for " + index.getName()));
      }
    }
  }

  protected void validateAutoNumberColumn(Set<DataType> autoTypes, 
                                          ColumnBuilder column) 
  {
    if(!column.getType().isMultipleAutoNumberAllowed() &&
       !autoTypes.add(column.getType())) {
      throw new IllegalArgumentException(withErrorContext(
          "Can have at most one AutoNumber column of type " + column.getType() +
          " per table"));
    }    
  }

  private void setColumnSortOrder(ColumnBuilder column) {
      // set the sort order to the db default (if unspecified)
      if(column.getType().isTextual() && (column.getTextSortOrder() == null)) {
        column.setTextSortOrder(getDbSortOrder());
      }
  }

  abstract String getTableName();

  public abstract int getTdefPageNumber();

  abstract short getColumnNumber(String colName);

  public abstract ColumnState getColumnState(ColumnBuilder col);

  public abstract IndexDataState getIndexDataState(IndexBuilder idx);

  protected abstract String withErrorContext(String msg);

  /**
   * Maintains additional state used during column writing.
   * @usage _advanced_class_
   */
  static final class ColumnOffsets
  {
    private short _fixedOffset;
    private short _varOffset;
    private short _longVarOffset;

    public void set(int fixedOffset, int varOffset, int longVarOffset) {
      _fixedOffset = (short)fixedOffset;
      _varOffset = (short)varOffset;
      _longVarOffset = (short)longVarOffset;
    }
    
    public short getNextVariableOffset(ColumnBuilder col) {
      if(!col.getType().isLongValue()) {
        return _varOffset++;
      }
      return _longVarOffset++;
    }

    public short getNextFixedOffset(ColumnBuilder col) {
      short offset = _fixedOffset;
      _fixedOffset += col.getType().getFixedSize(col.getLength());
      return offset;
    }
  }

  /**
   * Maintains additional state used during column creation.
   * @usage _advanced_class_
   */
  static final class ColumnState
  {
    private byte _umapOwnedRowNumber;
    private byte _umapFreeRowNumber;
    // we always put both usage maps on the same page
    private int _umapPageNumber;

    public byte getUmapOwnedRowNumber() {
      return _umapOwnedRowNumber;
    }

    public void setUmapOwnedRowNumber(byte newUmapOwnedRowNumber) {
      _umapOwnedRowNumber = newUmapOwnedRowNumber;
    }

    public byte getUmapFreeRowNumber() {
      return _umapFreeRowNumber;
    }

    public void setUmapFreeRowNumber(byte newUmapFreeRowNumber) {
      _umapFreeRowNumber = newUmapFreeRowNumber;
    }

    public int getUmapPageNumber() {
      return _umapPageNumber;
    }

    public void setUmapPageNumber(int newUmapPageNumber) {
      _umapPageNumber = newUmapPageNumber;
    }
  }

  /**
   * Maintains additional state used during index data creation.
   * @usage _advanced_class_
   */
  static final class IndexDataState
  {
    private final List<IndexBuilder> _indexes = new ArrayList<IndexBuilder>();
    private int _indexDataNumber;
    private byte _umapRowNumber;
    private int _umapPageNumber;
    private int _rootPageNumber;

    public IndexBuilder getFirstIndex() {
      // all indexes which have the same backing IndexDataState will have
      // equivalent columns and flags.
      return _indexes.get(0);
    }

    public List<IndexBuilder> getIndexes() {
      return _indexes;
    }

    public void addIndex(IndexBuilder idx) {
      _indexes.add(idx);
    }

    public int getIndexDataNumber() {
      return _indexDataNumber;
    }

    public void setIndexDataNumber(int newIndexDataNumber) {
      _indexDataNumber = newIndexDataNumber;
    }

    public byte getUmapRowNumber() {
      return _umapRowNumber;
    }

    public void setUmapRowNumber(byte newUmapRowNumber) {
      _umapRowNumber = newUmapRowNumber;
    }

    public int getUmapPageNumber() {
      return _umapPageNumber;
    }

    public void setUmapPageNumber(int newUmapPageNumber) {
      _umapPageNumber = newUmapPageNumber;
    }

    public int getRootPageNumber() {
      return _rootPageNumber;
    }

    public void setRootPageNumber(int newRootPageNumber) {
      _rootPageNumber = newRootPageNumber;
    }
  }    
}