/*
 *  The ManaPlus Client
 *  Copyright (C) 2009  The Mana World Development Team
 *  Copyright (C) 2009-2010  The Mana Developers
 *  Copyright (C) 2011-2019  The ManaPlus Developers
 *  Copyright (C) 2019-2021  Andrei Karas
 *
 *  This file is part of The ManaPlus Client.
 *
 *  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 2 of the License, or
 *  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 "resources/db/unitsdb.h"

#include "configuration.h"

#include "const/resources/currency.h"

#include "utils/cast.h"
#include "utils/checkutils.h"
#include "utils/stdmove.h"

#include "resources/beingcommon.h"

#include <climits>

#include "debug.h"

namespace
{
    struct UnitLevel final
    {
        A_DEFAULT_COPY(UnitLevel)

        std::string symbol;
        int count;
        int round;
        std::string separator;
    };

    struct UnitDescription final
    {
        A_DEFAULT_COPY(UnitDescription)

        STD_VECTOR<UnitLevel> levels;
        double conversion;
        bool mix;
    };

    UnitDescription defaultCurrency;
    UnitDescription defaultWeight;

    std::map<std::string, UnitDescription> mCurrencies;
}  // namespace

static std::string formatUnit(const int value,
                              const UnitDescription &ud);

static std::string splitNumber(std::string str,
                               const std::string &separator);

void UnitsDb::load()
{
    logger->log1("Initializing unit database...");
    {   // Setup default weight
        UnitDescription ud;

        ud.conversion = 1.0;
        ud.mix = false;

        const UnitLevel bu =
        {
            "g",
            1,
            0,
            ""
        };
        ud.levels.push_back(bu);

        const UnitLevel ul =
        {
            "kg",
            1000,
            2,
            ""
        };
        ud.levels.push_back(ul);

        defaultWeight = ud;
    }

    {   // Setup default currency
        UnitDescription ud;

        ud.conversion = 1.0;
        ud.mix = false;

        const UnitLevel bu = {"¤", 1, 0, ""};
        ud.levels.push_back(bu);

        defaultCurrency = ud;
    }

    loadXmlFile(paths.getStringValue("unitsFile"), SkipError_false);
    loadXmlFile(paths.getStringValue("unitsPatchFile"), SkipError_true);
    loadXmlDir("unitsPatchDir", loadXmlFile)
}

void UnitsDb::unload()
{
    logger->log1("Unloading unit database...");
    mCurrencies.clear();
}

static UnitDescription loadUnit(XmlNodePtr node)
{
    UnitDescription ud;
    int level = 1;
    ud.conversion = XML::getProperty(node, "conversion", 1);
    ud.mix = XML::getProperty(node, "mix", "no") == "yes";

    UnitLevel bu;
    bu.symbol = XML::getProperty(node, "base", "¤");
    bu.count = 1;
    bu.round = XML::getProperty(node, "round", 2);
    bu.separator = XML::getProperty(node, "separator", " ");

    ud.levels.push_back(bu);

    for_each_xml_child_node(uLevel, node)
    {
        if (xmlNameEqual(uLevel, "level"))
        {
            const UnitLevel ul =
            {
                XML::getProperty(uLevel, "symbol",
                                 strprintf("¤%d", level)),
                XML::getProperty(uLevel, "count", -1),
                XML::getProperty(uLevel, "round", bu.round),
                XML::getProperty(uLevel, "separator", bu.separator)
            };

            if (ul.count > 0)
            {
                ud.levels.push_back(ul);
                level++;
            }
            else
            {
                logger->log("Error bad unit count: %d for %s in %s",
                    ul.count,
                    ul.symbol.c_str(),
                    bu.symbol.c_str());
            }
        }
    }

    // Add one more level for saftey
    const UnitLevel lev =
    {
        "",
        INT_MAX,
        0,
        ""
    };
    ud.levels.push_back(lev);
    return ud;
}

static void loadCurrencies(XmlNodePtr parentNode)
{
    for_each_xml_child_node(node, parentNode)
    {
        if (xmlNameEqual(node, "unit"))
        {
            const std::string name = XML::getProperty(node, "name", "");
            if (name.empty())
            {
                reportAlways("Error: unknown currency name.")
                continue;
            }
            mCurrencies[name] = loadUnit(node);
            if (name == DEFAULT_CURRENCY)
                defaultCurrency = mCurrencies[name];
        }
    }
}

void UnitsDb::loadXmlFile(const std::string &fileName,
                          const SkipError skipError)
{
    XML::Document doc(fileName, UseVirtFs_true, skipError);
    XmlNodeConstPtrConst root = doc.rootNode();

    if ((root == nullptr) || !xmlNameEqual(root, "units"))
    {
        logger->log("Error loading unit definition file: "
            + paths.getStringValue("unitsFile"));
        return;
    }

    for_each_xml_child_node(node, root)
    {
        if (xmlNameEqual(node, "include"))
        {
            const std::string name = XML::getProperty(node, "name", "");
            if (!name.empty())
                loadXmlFile(name, skipError);
            continue;
        }
        else if (xmlNameEqual(node, "unit"))
        {
            const std::string type = XML::getProperty(node, "type", "");
            UnitDescription ud = loadUnit(node);
            if (type == "weight")
            {
                defaultWeight = ud;
            }
            else if (type == "currency")
            {
                defaultCurrency = ud;
                mCurrencies[DEFAULT_CURRENCY] = ud;
            }
            else
            {
                logger->log("Error unknown unit type: %s", type.c_str());
            }
        }
        else if (xmlNameEqual(node, "currency"))
        {
            loadCurrencies(node);
        }
    }
}

static std::string formatUnit(const int value,
                              const UnitDescription &ud)
{
    UnitLevel ul;

    // Shortcut for 0; do the same for values less than 0  (for now)
    if (value <= 0)
    {
        ul = ud.levels[0];
        return strprintf("0%s", ul.symbol.c_str());
    }

    double amount = ud.conversion * value;
    const unsigned int sz = CAST_U32(ud.levels.size());

    // If only the first level is needed, act like mix if false
    if (ud.mix && !ud.levels.empty() && ud.levels[1].count < amount)
    {
        std::string output;
        UnitLevel pl = ud.levels[0];
        ul = ud.levels[1];
        int levelAmount = CAST_S32(amount);
        int nextAmount = 0;

        if (ul.count != 0)
            levelAmount /= ul.count;

        amount -= static_cast<double>(levelAmount * ul.count);

        if (amount > 0)
        {
            output = splitNumber(strprintf("%.*f", pl.round,
                amount), pl.separator).append(pl.symbol);
        }

        for (unsigned int i = 2; i < sz; i++)
        {
            pl = ul;
            ul = ud.levels[i];

            if (ul.count != 0)
            {
                nextAmount = levelAmount / ul.count;
                levelAmount %= ul.count;
            }

            if (levelAmount > 0)
            {
                output = splitNumber(strprintf("%d", levelAmount),
                    pl.separator).append(pl.symbol).append(output);
            }

            if (nextAmount == 0)
                break;
            levelAmount = nextAmount;
        }

        return output;
    }

    ul.round = 0;
    for (unsigned int i = 0; i < sz; i++)
    {
        ul = ud.levels[i];
        if (amount < ul.count && ul.count > 0)
        {
            ul = ud.levels[i - 1];
            break;
        }
        if (ul.count != 0)
            amount /= ul.count;
    }

    return splitNumber(strprintf("%.*f", ul.round, amount),
        ul.separator).append(ul.symbol);
}

std::string UnitsDb::formatCurrency(const int value)
{
    return formatUnit(value, defaultCurrency);
}

std::string UnitsDb::formatCurrency64(const int64_t value)
{
    return formatUnit(CAST_S32(value),
        defaultCurrency);
}

std::string UnitsDb::formatCurrency(std::string name,
                                    const int value)
{
    if (mCurrencies.find(name) == mCurrencies.end())
        name = DEFAULT_CURRENCY;
    return formatUnit(value, mCurrencies[name]);
}

std::string UnitsDb::formatCurrency64(std::string name,
                                      const int64_t value)
{
    if (mCurrencies.find(name) == mCurrencies.end())
        name = DEFAULT_CURRENCY;
    return formatUnit(CAST_S32(value),
        mCurrencies[name]);
}

std::string UnitsDb::formatWeight(const int value)
{
    return formatUnit(value, defaultWeight);
}

bool UnitsDb::existsCurrency(const std::string &name)
{
    return mCurrencies.find(name) != mCurrencies.end();
}

static std::string splitNumber(std::string str,
                               const std::string &separator)
{
    std::string lastPart;
    const size_t point = str.find('.');
    if (point != std::string::npos)
    {
        lastPart = str.substr(point);
        str = str.substr(0, point);
    }
    std::string result;

    if (!str.empty())
    {
        size_t sz = str.size();
        while (sz >= 3)
        {
            if (sz >= 6)
            {
                result = std::string(separator).append(str.substr(
                    sz - 3)).append(result);
            }
            else
            {
                result = str.substr(sz - 3).append(result);
            }
            str = str.substr(0, str.size() - 3);
            sz = str.size();
        }
        if (!str.empty())
        {
            if (!result.empty())
                result = std::string(str).append(separator).append(result);
            else
                result = STD_MOVE(str);
        }
    }

    return result + lastPart;
}
