/*
   Copyright (c) 2018 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.text.DecimalFormat;
  import java.time.ZoneId;
  import java.time.format.DateTimeFormatter;
  import java.util.Map;
  import javax.script.Bindings;
  import javax.script.SimpleBindings;
  
  import com.healthmarketscience.jackcess.expr.EvalConfig;
  import com.healthmarketscience.jackcess.expr.FunctionLookup;
  import com.healthmarketscience.jackcess.expr.NumericConfig;
  import com.healthmarketscience.jackcess.expr.TemporalConfig;
  import com.healthmarketscience.jackcess.impl.expr.DefaultFunctions;
  import com.healthmarketscience.jackcess.impl.expr.Expressionator;
  import com.healthmarketscience.jackcess.impl.expr.NumberFormatter;
  import com.healthmarketscience.jackcess.impl.expr.RandomContext;
  
  /**
   *
   * @author James Ahlborn
   */
  public class DBEvalContext implements Expressionator.ParseContext, EvalConfig
  {
    private static final int MAX_CACHE_SIZE = 10;
  
    private final DatabaseImpl _db;
    private FunctionLookup _funcs = DefaultFunctions.LOOKUP;
    private Map<String,DateTimeFormatter> _sdfs;
    private Map<String,DecimalFormat> _dfs;
    private TemporalConfig _temporal = TemporalConfig.US_TEMPORAL_CONFIG;
    private NumericConfig _numeric = NumericConfig.US_NUMERIC_CONFIG;
    private final RandomContextl/expr/RandomContext.html#RandomContext">RandomContext _rndCtx = new RandomContext();
    private Bindings _bindings = new SimpleBindings();
  
    public DBEvalContext(DatabaseImpl db) {
      _db = db;
    }
  
    protected DatabaseImpl getDatabase() {
      return _db;
    }
  
    @Override
    public TemporalConfig getTemporalConfig() {
      return _temporal;
    }
  
    @Override
    public void setTemporalConfig(TemporalConfig temporal) {
      if(_temporal != temporal) {
        _temporal = temporal;
        _sdfs = null;
      }
    }
  
    @Override
    public ZoneId getZoneId() {
      return _db.getZoneId();
    }
  
    @Override
    public NumericConfig getNumericConfig() {
      return _numeric;
    }
  
    @Override
    public void setNumericConfig(NumericConfig numeric) {
      if(_numeric != numeric) {
        _numeric = numeric;
        _dfs = null;
      }
    }
  
    @Override
    public FunctionLookup getFunctionLookup() {
      return _funcs;
    }
  
    @Override
    public void setFunctionLookup(FunctionLookup lookup) {
      _funcs = lookup;
    }
 
   @Override
   public Bindings getBindings() {
     return _bindings;
   }
 
   @Override
   public void setBindings(Bindings bindings) {
     _bindings = bindings;
   }
 
   @Override
   public DateTimeFormatter createDateFormatter(String formatStr) {
     if(_sdfs == null) {
       _sdfs = new SimpleCache<String,DateTimeFormatter>(MAX_CACHE_SIZE);
     }
     DateTimeFormatter sdf = _sdfs.get(formatStr);
     if(sdf == null) {
       sdf = DateTimeFormatter.ofPattern(formatStr, _temporal.getLocale());
       _sdfs.put(formatStr, sdf);
     }
     return sdf;
   }
 
   @Override
   public DecimalFormat createDecimalFormat(String formatStr) {
     if(_dfs == null) {
       _dfs = new SimpleCache<String,DecimalFormat>(MAX_CACHE_SIZE);
     }
     DecimalFormat df = _dfs.get(formatStr);
     if(df == null) {
       df = new DecimalFormat(formatStr, _numeric.getDecimalFormatSymbols());
       df.setRoundingMode(NumberFormatter.ROUND_MODE);
       _dfs.put(formatStr, df);
     }
     return df;
   }
 
   public float getRandom(Integer seed) {
     return _rndCtx.getRandom(seed);
   }
 }