﻿/* Copyright (C) 2011  Jan Källman
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.

 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * The GNU Lesser General Public License can be viewed at http://www.opensource.org/licenses/lgpl-license.php
 * If you unfamiliar with this license or have questions about it, here is an http://www.gnu.org/licenses/gpl-faq.html
 *
 * All code and executables are provided "as is" with no warranty either express or implied.
 * The author accepts no liability for any damage or loss of business that this product may cause.
 *
 * Code change notes:
 *
 * Author							Change						Date
 *******************************************************************************
 * Mats Alm   		                Added		                2013-12-03
 *******************************************************************************/

using System.Collections.Generic;
using System.Linq;

namespace AppsheetEpplus;

public class Subtotal : ExcelFunction {
  private readonly Dictionary<int, HiddenValuesHandlingFunction> _functions = new();

  public Subtotal() {
    Initialize();
  }

  private void Initialize() {
    _functions[1] = new Average();
    _functions[2] = new Count();
    _functions[3] = new CountA();
    _functions[4] = new Max();
    _functions[5] = new Min();
    _functions[6] = new Product();
    _functions[7] = new Stdev();
    _functions[8] = new StdevP();
    _functions[9] = new Sum();
    _functions[10] = new Var();
    _functions[11] = new VarP();

    AddHiddenValueHandlingFunction(new Average(), 101);
    AddHiddenValueHandlingFunction(new Count(), 102);
    AddHiddenValueHandlingFunction(new CountA(), 103);
    AddHiddenValueHandlingFunction(new Max(), 104);
    AddHiddenValueHandlingFunction(new Min(), 105);
    AddHiddenValueHandlingFunction(new Product(), 106);
    AddHiddenValueHandlingFunction(new Stdev(), 107);
    AddHiddenValueHandlingFunction(new StdevP(), 108);
    AddHiddenValueHandlingFunction(new Sum(), 109);
    AddHiddenValueHandlingFunction(new Var(), 110);
    AddHiddenValueHandlingFunction(new VarP(), 111);
  }

  private void AddHiddenValueHandlingFunction(HiddenValuesHandlingFunction func, int funcNum) {
    func.IgnoreHiddenValues = true;
    _functions[funcNum] = func;
  }

  public override void BeforeInvoke(ParsingContext context) {
    base.BeforeInvoke(context);
    context.Scopes.Current.IsSubtotal = true;
  }

  public override CompileResult Execute(
      IEnumerable<FunctionArgument> arguments,
      ParsingContext context) {
    ValidateArguments(arguments, 2);
    var funcNum = ArgToInt(arguments, 0);
    if (context.Scopes.Current.Parent != null && context.Scopes.Current.Parent.IsSubtotal) {
      return CreateResult(0d, DataType.Decimal);
    }
    var actualArgs = arguments.Skip(1);
    var function = GetFunctionByCalcType(funcNum);
    var compileResult = function.Execute(actualArgs, context);
    compileResult.IsResultOfSubtotal = true;
    return compileResult;
  }

  private ExcelFunction GetFunctionByCalcType(int funcNum) {
    if (!_functions.ContainsKey(funcNum)) {
      ThrowExcelErrorValueException(eErrorType.Value);
      //throw new ArgumentException("Invalid funcNum " + funcNum + ", valid ranges are 1-11 and 101-111");
    }
    return _functions[funcNum];
  }
}