//---------------------------------------------------------------------------
//
//                 __________
//    _____   __ __\______   \_____  _______  ______  ____ _______
//   /     \ |  |  \|     ___/\__  \ \_  __ \/  ___/_/ __ \\_  __ |
//  |  Y Y  \|  |  /|    |     / __ \_|  | \/\___ \ \  ___/ |  | \/
//  |__|_|  /|____/ |____|    (____  /|__|  /____  > \___  >|__|
//        \/                       \/            \/      \/
//  (C) 2015 Ingo Berg
//
//  example1.cpp - using the parser as a static library
//
//---------------------------------------------------------------------------

#include "muParserTest.h"

#if defined(_WIN32) && defined(_DEBUG)
#define _CRTDBG_MAP_ALLOC
#include <crtdbg.h>
#include <stdlib.h>
#define CREATE_LEAKAGE_REPORT
#endif

#if defined(USINGDLL) && defined(_WIN32)
#error This sample can be used only with STATIC builds of muParser (on win32)
#endif

/** \brief This macro will enable mathematical constants like M_PI. */
#define _USE_MATH_DEFINES

#include <cmath>
#include <cstdlib>
#include <cstring>
#include <iomanip>
#include <ios>
#include <iostream>
#include <limits>
#include <locale>
#include <numeric>
#include <string>

#include "muParser.h"

using namespace std;
using namespace mu;

#if defined(CREATE_LEAKAGE_REPORT)

// Dumping memory leaks in the destructor of the static guard
// guarantees i won't get false positives from the ParserErrorMsg
// class wich is a singleton with a static instance.
struct DumpLeaks {
    ~DumpLeaks() { _CrtDumpMemoryLeaks(); }
} static LeakDumper;

#endif

// Operator callback functions
ValueOrError Mega(value_type a_fVal) { return a_fVal * 1e6; }
ValueOrError Milli(value_type a_fVal) { return a_fVal / (value_type)1e3; }
ValueOrError Rnd(value_type v) { return v * std::rand() / (value_type)(RAND_MAX + 1.0); }
ValueOrError Not(value_type v) { return v == 0; }
ValueOrError Add(value_type v1, value_type v2) { return v1 + v2; }
ValueOrError Mul(value_type v1, value_type v2) { return v1 * v2; }

//---------------------------------------------------------------------------
ValueOrError ThrowAnException(value_type) {
    throw std::runtime_error("This function does throw an exception.");
}

//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
ValueOrError Ping() {
    mu::console() << "ping\n";
    return 0;
}

//---------------------------------------------------------------------------
ValueOrError StrFun0(const char_type *szMsg) {
    if (szMsg) mu::console() << szMsg << std::endl;

    return 999;
}

//---------------------------------------------------------------------------
ValueOrError StrFun2(const char_type *v1, value_type v2, value_type v3) {
    mu::console() << v1 << std::endl;
    return v2 + v3;
}

//---------------------------------------------------------------------------
ValueOrError Debug(mu::value_type v1, mu::value_type v2) {
    ParserBase::EnableDebugDump(v1 != 0, v2 != 0);
    mu::console() << _T("Bytecode dumping ") << ((v1 != 0) ? _T("active") : _T("inactive"))
                  << _T("\n");
    return 1;
}

//---------------------------------------------------------------------------
// Factory function for creating new parser variables
// This could as well be a function performing database queries.
value_type *AddVariable(const char_type *a_szName, void *a_pUserData) {
    // I don't want dynamic allocation here, so i used this static buffer
    // If you want dynamic allocation you must allocate all variables dynamically
    // in order to delete them later on. Or you find other ways to keep track of
    // variables that have been created implicitely.
    static value_type afValBuf[100];
    static int iVal = -1;

    ++iVal;

    mu::console() << _T("Generating new variable \"") << a_szName << std::dec
                  << _T("\" (slots left: ") << 99 - iVal << _T(")")
                  << _T(" User data pointer is:") << std::hex << a_pUserData << endl;
    afValBuf[iVal] = 0;

    if (iVal >= 99)
        throw mu::ParserError(_T("Variable buffer overflow."));
    else
        return &afValBuf[iVal];
}

int IsHexValue(const char_type *a_szExpr, int *a_iPos, value_type *a_fVal) {
    if (a_szExpr[1] == 0 || (a_szExpr[0] != '0' || a_szExpr[1] != 'x')) return 0;

    unsigned iVal(0);

    // New code based on streams for UNICODE compliance:
    stringstream_type::pos_type nPos(0);
    stringstream_type ss(a_szExpr + 2);
    ss >> std::hex >> iVal;
    nPos = ss.tellg();

    if (nPos == (stringstream_type::pos_type)0) return 1;

    *a_iPos += (int)(2 + nPos);
    *a_fVal = (value_type)iVal;

    return 1;
}

//---------------------------------------------------------------------------
void Splash() {
    mu::console() << _T("                 __________                                       \n");
    mu::console() << _T("    _____   __ __\\______   \\_____  _______  ______  ____ _______\n");
    mu::console()
        << _T("   /     \\ |  |  \\|     ___/\\__  \\ \\_  __ \\/  ___/_/ __ \\\\_  __ \\ \n");
    mu::console()
        << _T("  |  Y Y  \\|  |  /|    |     / __ \\_|  | \\/\\___ \\ \\  ___/ |  | \\/ \n");
    mu::console() << _T("  |__|_|  /|____/ |____|    (____  /|__|  /____  > \\___  >|__|    \n");
    mu::console() << _T("        \\/                       \\/            \\/      \\/         \n");
    mu::console() << _T("  (C) 2015 Ingo Berg\n");
}

//---------------------------------------------------------------------------
ValueOrError SelfTest() {
    mu::console() << _T( "-----------------------------------------------------------\n");
    mu::console() << _T( "Running test suite:\n\n");

    // Skip the self test if the value type is set to an integer type.
    if (mu::TypeInfo<mu::value_type>::IsInteger()) {
        mu::console()
            << _T( "  Test skipped: integer data type are not compatible with the unit test!\n\n");
    } else {
        mu::Test::ParserTester pt;
        pt.Run();
    }

    return 0;
}

//---------------------------------------------------------------------------
ValueOrError Help() {
    mu::console() << _T( "-----------------------------------------------------------\n");
    mu::console() << _T( "Commands:\n\n");
    mu::console() << _T( "  list var     - list parser variables\n");
    mu::console() << _T( "  list exprvar - list expression variables\n");
    mu::console() << _T( "  list const   - list all numeric parser constants\n");
    mu::console() << _T( "  locale de    - switch to german locale\n");
    mu::console() << _T( "  locale en    - switch to english locale\n");
    mu::console() << _T( "  locale reset - reset locale\n");
    mu::console() << _T( "  quit         - exits the parser\n");
    mu::console() << _T( "\nConstants:\n\n");
    mu::console() << _T( "  \"_e\"   2.718281828459045235360287\n");
    mu::console() << _T( "  \"_pi\"  3.141592653589793238462643\n");
    mu::console() << _T( "-----------------------------------------------------------\n");
    return 0;
}

//---------------------------------------------------------------------------
/*
void CheckLocale()
{
  // Local names:
  // "C" - the classic C locale
  // "de_DE" - not for Windows?
  // "en_US" - not for Windows?
  // "German_germany" - For MSVC8
  try
  {
    std::locale loc("German_germany");
    console() << _T("Locale settings:\n");
    console() << _T("  Decimal point:  '") << std::use_facet<numpunct<char_type>
>(loc).decimal_point() << _T("'\n");
    console() << _T("  Thousands sep:  '") << std::use_facet<numpunct<char_type>
>(loc).thousands_sep() << _T("'\n");
    console() << _T("  Grouping:       '") << std::use_facet<numpunct<char_type> >(loc).grouping()
<< _T("'\n");
    console() << _T("  True is named:  '") << std::use_facet<numpunct<char_type> >(loc).truename()
<< _T("'\n");
    console() << _T("  False is named: '") << std::use_facet<numpunct<char_type> >(loc).falsename()
<< _T("'\n");
    console() << _T("-----------------------------------------------------------\n");
  }
  catch(...)
  {
    console() << _T("Locale settings:\n");
    console() << _T("  invalid locale name\n");
    console() << _T("-----------------------------------------------------------\n");
  }
}

//---------------------------------------------------------------------------
void CheckDiff()
{
  mu::Parser  parser;
  value_type x = 1,
             v1,
             v2,
             v3,
             eps(pow(std::numeric_limits<value_type>::epsilon(), 0.2));
  parser.DefineVar(_T("x"), &x);
  parser.SetExpr(_T("_e^-x*sin(x)"));

  v1 = parser.Diff(&x, 1),
  v2 = parser.Diff(&x, 1, eps);
  v3 = cos((value_type)1.0)/exp((value_type)1) - sin((value_type)1.0)/exp((value_type)1);
//-0.110793765307;
  mu::console() << parser.GetExpr() << _T("\n");
  mu::console() << _T("v1 = ") << v1 << _T("; v1-v3 = ") << v1-v3 << _T("\n");
  mu::console() << _T("v2 = ") << v2 << _T("; v2-v3 = ") << v2-v3 << _T("\n");
}
*/

//---------------------------------------------------------------------------
/** \brief Check for external keywords.
*/
int CheckKeywords(const mu::char_type *a_szLine, mu::Parser &a_Parser) {
    string_type sLine(a_szLine);

    if (sLine == _T("quit")) {
        return -1;
    } else if (sLine == _T("locale de")) {
        mu::console() << _T("Setting german locale: ArgSep=';' DecSep=',' ThousandsSep='.'\n");
        a_Parser.SetArgSep(';');
        a_Parser.SetDecSep(',');
        a_Parser.SetThousandsSep('.');
        return 1;
    } else if (sLine == _T("locale en")) {
        mu::console() << _T("Setting english locale: ArgSep=',' DecSep='.' ThousandsSep=''\n");
        a_Parser.SetArgSep(',');
        a_Parser.SetDecSep('.');
        a_Parser.SetThousandsSep();
        return 1;
    } else if (sLine == _T("locale reset")) {
        mu::console() << _T("Resetting locale\n");
        a_Parser.ResetLocale();
        return 1;
    }

    return 0;
}

//---------------------------------------------------------------------------
void Calc() {
    mu::Parser parser;

// Change locale settings if necessary
// function argument separator:   sum(2;3;4) vs. sum(2,3,4)
// decimal separator:             3,14       vs. 3.14
// thousands separator:           1000000    vs 1.000.000
//#define USE_GERMAN_LOCALE
#ifdef USE_GERMAN_LOCALE
    parser.SetArgSep(';');
    parser.SetDecSep(',');
    parser.SetThousandsSep('.');
#else
// this is the default, so i it's commented:
// parser.SetArgSep(',');
// parser.SetDecSep('.');
// parser.SetThousandsSep('');
#endif

    // Add some variables
    value_type vVarVal[] = {1, 2};  // Values of the parser variables
    parser.DefineVar(_T("a"),
                     &vVarVal[0]);  // Assign Variable names and bind them to the C++ variables
    parser.DefineVar(_T("b"), &vVarVal[1]);
    parser.DefineVar(_T("ft"), &vVarVal[1]);
    parser.DefineStrConst(_T("sVar1"), _T("Sample string 1"));
    parser.DefineStrConst(_T("sVar2"), _T("Sample string 2"));
    parser.AddValIdent(IsHexValue);

    // Add user defined unary operators
    parser.DefinePostfixOprt(_T("M"), Mega);
    parser.DefinePostfixOprt(_T("m"), Milli);
    parser.DefineInfixOprt(_T("!"), Not);
    parser.DefineFun(_T("strfun0"), StrFun0);
    parser.DefineFun(_T("strfun2"), StrFun2);
    parser.DefineFun(_T("ping"), Ping);
    parser.DefineFun(_T("rnd"), Rnd);
    parser.DefineFun(_T("throw"), ThrowAnException);

    parser.DefineOprt(_T("add"), Add, 0);
    parser.DefineOprt(_T("mul"), Mul, 1);

    // These are service and debug functions
    parser.DefineFun(_T("debug"), Debug);
    parser.DefineFun(_T("selftest"), SelfTest);
    parser.DefineFun(_T("help"), Help);

    parser.DefinePostfixOprt(_T("{ft}"), Milli);
    parser.DefinePostfixOprt(_T("ft"), Milli);
#ifdef _DEBUG
//  parser.EnableDebugDump(1, 0);
#endif

    // Define the variable factory
    parser.SetVarFactory(AddVariable, &parser);

    for (;;) {
        try {
            string_type sLine;
            std::getline(mu::console_in(), sLine);

            switch (CheckKeywords(sLine.c_str(), parser)) {
                case 0:
                    break;
                case 1:
                    continue;
                case -1:
                    return;
            }

            if (!sLine.length()) continue;

            parser.SetExpr(sLine);
            mu::console() << std::setprecision(12);

            // There are multiple ways to retrieve the result...
            // 1.) If you know there is only a single return value or in case you only need the last
            //     result of an expression consisting of comma separated subexpressions you can
            //     simply use:
            mu::console() << _T("ans=") << *parser.Eval() << _T("\n");

            // 2.) As an alternative you can also retrieve multiple return values using this API:
            int nNum = parser.GetNumResults();
            if (nNum > 1) {
                mu::console() << _T("Multiple return values detected! Complete list:\n");

                // this is the hard way if you need to retrieve multiple subexpression
                // results
                std::vector<ValueOrError> vs;
                parser.Eval(&vs);
                mu::console() << std::setprecision(12);
                for (const ValueOrError &v : vs) {
                    mu::console() << *v << _T("\n");
                }
            }
        } catch (mu::Parser::exception_type &e) {
            mu::console() << _T("\nError:\n");
            mu::console() << _T("------\n");
            mu::console() << _T("Message:     ") << e.GetMsg() << _T("\n");
            mu::console() << _T("Expression:  \"") << e.GetExpr() << _T("\"\n");
            mu::console() << _T("Token:       \"") << e.GetToken() << _T("\"\n");
            mu::console() << _T("Position:    ") << (int)e.GetPos() << _T("\n");
            mu::console() << _T("Errc:        ") << std::dec << e.GetCode() << _T("\n");
        }
    }  // while running
}

//---------------------------------------------------------------------------
int main(int, char **) {
    Splash();
    (void)SelfTest();
    (void)Help();

    //  CheckLocale();
    //  CheckDiff();

    mu::console() << _T("Enter an expression or a command:\n");

    try {
        Calc();
    } catch (Parser::exception_type &e) {
        // Only erros raised during the initialization will end up here
        // formula related errors are treated in Calc()
        console() << _T("Initialization error:  ") << e.GetMsg() << endl;
        console() << _T("aborting...") << endl;
        string_type sBuf;
        console_in() >> sBuf;
    } catch (std::exception & /*exc*/) {
        // there is no unicode compliant way to query exc.what()
        // so i'll leave it for this example.
        console() << _T("aborting...\n");
    }

    return 0;
}