/*
 Copyright (C) 2019-2022 Fredrik Öhrström (gpl-3.0-or-later)

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program 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 General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include"units.h"
#include"util.h"
#include<assert.h>
#include<math.h>

using namespace std;

#define LIST_OF_CONVERSIONS \
    X(Second, Minute, {vto=vfrom/60.0;}) \
    X(Minute, Second, {vto=vfrom*60.0;}) \
    X(Second, Hour, {vto=vfrom/3600.0;}) \
    X(Hour, Second, {vto=vfrom*3600.0;}) \
    X(Year, Second, {vto=vfrom*3600.0*24.0*365.2425;}) \
    X(Second, Year, {vto=vfrom/3600.0/24.0/365.2425;}) \
    X(Minute, Hour, {vto=vfrom/60.0;}) \
    X(Hour, Minute, {vto=vfrom*60.0;}) \
    X(Minute, Year, {vto=vfrom/60.0/24.0/365.2425;}) \
    X(Year, Minute, {vto=vfrom*60.0*24.0*365.2425;}) \
    X(Hour, Year, {vto=vfrom/24.0/365.2425;}) \
    X(Year, Hour, {vto=vfrom*24.0*365.2425;}) \
    X(Hour,  Day, {vto=vfrom/24.0;}) \
    X(Day,  Hour, {vto=vfrom*24.0;}) \
    X(Day,  Year, {vto=vfrom/365.2425;}) \
    X(Year,  Day, {vto=vfrom*365.2425;}) \
    X(KWH, GJ, {vto=vfrom*0.0036;})     \
    X(KWH, MJ, {vto=vfrom*0.0036*1000.0;})     \
    X(GJ,  KWH,{vto=vfrom/0.0036;}) \
    X(MJ,  GJ,  {vto=vfrom/1000.0;}) \
    X(MJ,  KWH,{vto=vfrom/1000.0/0.0036;}) \
    X(GJ,  MJ,  {vto=vfrom*1000.0;}) \
    X(M3,  L,  {vto=vfrom*1000.0;}) \
    X(M3H, LH, {vto=vfrom*1000.0;}) \
    X(L,   M3, {vto=vfrom/1000.0;}) \
    X(LH,  M3H,{vto=vfrom/1000.0;}) \
    X(C,   K,  {vto=vfrom+273.15;}) \
    X(K,   C,  {vto=vfrom-273.15;}) \
    X(C,   F,  {vto=(vfrom*9.0/5.0)+32.0;}) \
    X(F,   C,  {vto=(vfrom-32)*5.0/9.0;}) \


bool canConvert(Unit ufrom, Unit uto)
{
    if (ufrom == uto) return true;
#define X(from,to,code) if (Unit::from == ufrom && Unit::to == uto) return true;
LIST_OF_CONVERSIONS
#undef X
    return false;
}

double convert(double vfrom, Unit ufrom, Unit uto)
{
    double vto = -4711.0;
    if (ufrom == uto) { { vto = vfrom; } return vto; }

#define X(from,to,code) if (Unit::from == ufrom && Unit::to == uto) { code return vto; }
LIST_OF_CONVERSIONS
#undef X

    string from = unitToStringHR(ufrom);
    string to = unitToStringHR(uto);

    fprintf(stderr, "Cannot convert between units! from %s to %s\n", from.c_str(), to.c_str());
    assert(0);
    return 0;
}

bool isQuantity(Unit u, Quantity q)
{
#define X(cname,lcname,hrname,quantity,explanation) if (u == Unit::cname) return Quantity::quantity == q;
LIST_OF_UNITS
#undef X

    return false;
}

void assertQuantity(Unit u, Quantity q)
{
    if (!isQuantity(u, q))
    {
        error("Internal error! Unit is not of this quantity.\n");
    }
}

Unit defaultUnitForQuantity(Quantity q)
{
#define X(quantity,default_unit) if (q == Quantity::quantity) return Unit::default_unit;
LIST_OF_QUANTITIES
#undef X

    return Unit::Unknown;
}

const char *toString(Quantity q)
{
#define X(quantity,default_unit) if (q == Quantity::quantity) return #quantity;
LIST_OF_QUANTITIES
#undef X
    return "?";
}

Unit toUnit(string s)
{
#define X(cname,lcname,hrname,quantity,explanation) if (s == #cname) return Unit::cname;
LIST_OF_UNITS
#undef X

    return Unit::Unknown;
}

string unitToStringHR(Unit u)
{
#define X(cname,lcname,hrname,quantity,explanation) if (u == Unit::cname) return hrname;
LIST_OF_UNITS
#undef X

    return "?";
}

string unitToStringLowerCase(Unit u)
{
#define X(cname,lcname,hrname,quantity,explanation) if (u == Unit::cname) return #lcname;
LIST_OF_UNITS
#undef X

    return "?";
}

string unitToStringUpperCase(Unit u)
{
#define X(cname,lcname,hrname,quantity,explanation) if (u == Unit::cname) return #cname;
LIST_OF_UNITS
#undef X

    return "?";
}

string strWithUnitHR(double v, Unit u)
{
    string r = format3fdot3f(v);
    r += " "+unitToStringHR(u);
    return r;
}

string strWithUnitLowerCase(double v, Unit u)
{
    string r = format3fdot3f(v);
    r += " "+unitToStringLowerCase(u);
    return r;
}

Unit replaceWithConversionUnit(Unit u, vector<Unit> cs)
{
    for (Unit c : cs)
    {
        if (canConvert(u, c)) return c;
    }
    return u;
}

string valueToString(double v, Unit u)
{
    if (isnan(v))
    {
        return "null";
    }
    string s = to_string(v);
    while (s.size() > 0 && s.back() == '0') s.pop_back();
    if (s.back() == '.') {
        s.pop_back();
        if (s.length() == 0) return "0";
        return s;
    }
    if (s.length() == 0) return "0";
    return s;
}