/*
 Author: Juan Rada-Vilela, Ph.D.
 Copyright (C) 2010-2014 FuzzyLite Limited
 All rights reserved

 This file is part of fuzzylite.

 fuzzylite 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 3 of the License, or (at your option)
 any later version.

 fuzzylite 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.

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

 fuzzylite™ is a trademark of FuzzyLite Limited.

 */

#include "fl/imex/FisImporter.h"

#include "fl/Headers.h"

#include <sstream>
#include <iostream>
#include <cctype>

namespace fl {

    FisImporter::FisImporter() : Importer() {
    }

    FisImporter::~FisImporter() {
    }

    std::string FisImporter::name() const {
        return "FisImporter";
    }

    Engine* FisImporter::fromString(const std::string& fis) const {
        FL_unique_ptr<Engine> engine(new Engine);

        std::istringstream fisReader(fis);
        std::string line;
        int lineNumber = 0;

        std::vector<std::string> sections;
        while (std::getline(fisReader, line)) {
            ++lineNumber;
            std::vector<std::string> comments;
            comments = Op::split(line, "//");
            if (comments.size() > 1) {
                line = comments.front();
            }
            comments = Op::split(line, "#");
            if (comments.size() > 1) {
                line = comments.front();
            }
            line = Op::trim(line);
            if (line.empty() or line.at(0) == '%' or line.at(0) == '#'
                    or (line.substr(0, 2) == "//")) {
                continue;
            }

            line = fl::Op::findReplace(line, "'", "");

            if ("[System]" == line.substr(0, std::string("[System]").size())
                    or "[Input" == line.substr(0, std::string("[Input").size())
                    or "[Output" == line.substr(0, std::string("[Output").size())
                    or "[Rules]" == line.substr(0, std::string("[Rules]").size())) {
                sections.push_back(line);
            } else {
                if (not sections.empty()) {
                    sections.at(sections.size() - 1) += "\n" + line;
                } else {
                    std::ostringstream ss;
                    ss << "[import error] line " << lineNumber << " <" << line + "> "
                            "does not belong to any section";
                    throw fl::Exception(ss.str(), FL_AT);
                }
            }
        }
        std::string andMethod, orMethod, impMethod, aggMethod, defuzzMethod;
        for (std::size_t i = 0; i < sections.size(); ++i) {
            if ("[System]" == sections.at(i).substr(0, std::string("[System]").size()))
                importSystem(sections.at(i), engine.get(),
                    andMethod, orMethod, impMethod, aggMethod, defuzzMethod);
            else if ("[Input" == sections.at(i).substr(0, std::string("[Input").size()))
                importInput(sections.at(i), engine.get());
            else if ("[Output" == sections.at(i).substr(0, std::string("[Output").size()))
                importOutput(sections.at(i), engine.get());
            else if ("[Rules]" == sections.at(i).substr(0, std::string("[Rules]").size()))
                importRules(sections.at(i), engine.get());
            else throw fl::Exception("[import error] section <"
                    + sections.at(i) + "> not recognized", FL_AT);
        }
        engine->configure(extractTNorm(andMethod), extractSNorm(orMethod),
                extractTNorm(impMethod), extractSNorm(aggMethod),
                extractDefuzzifier(defuzzMethod));
        return engine.release();
    }

    void FisImporter::importSystem(const std::string& section, Engine * engine,
            std::string& andMethod, std::string& orMethod,
            std::string& impMethod, std::string& aggMethod,
            std::string& defuzzMethod) const {
        std::istringstream reader(section);
        std::string line;
        std::getline(reader, line); //ignore first line [System]
        while (std::getline(reader, line)) {
            std::vector<std::string> keyValue = fl::Op::split(line, "=");

            std::string key = fl::Op::trim(keyValue.at(0));
            std::string value;
            for (std::size_t i = 1; i < keyValue.size(); ++i) {
                value += keyValue.at(i);
            }
            value = fl::Op::trim(value);
            if (key == "Name") engine->setName(value);
            else if (key == "AndMethod") andMethod = value;
            else if (key == "OrMethod") orMethod = value;
            else if (key == "ImpMethod") impMethod = value;
            else if (key == "AggMethod") aggMethod = value;
            else if (key == "DefuzzMethod") defuzzMethod = value;
            else if (key == "Type" or key == "Version"
                    or key == "NumInputs" or key == "NumOutputs"
                    or key == "NumRules" or key == "NumMFs") {
                //ignore because are redundant.
            } else throw fl::Exception("[import error] token <" + key + "> not recognized", FL_AT);
        }
    }

    void FisImporter::importInput(const std::string& section, Engine* engine) const {
        std::istringstream reader(section);
        std::string line;
        std::getline(reader, line); //ignore first line [Input#]

        InputVariable* input = new InputVariable;
        engine->addInputVariable(input);

        while (std::getline(reader, line)) {
            std::vector<std::string> keyValue = fl::Op::split(line, "=");
            if (keyValue.size() != 2)
                throw fl::Exception("[syntax error] expected a property of type "
                    "'key=value', but found <" + line + ">", FL_AT);
            std::string key = fl::Op::trim(keyValue.at(0));
            std::string value = fl::Op::trim(keyValue.at(1));

            if (key == "Name") input->setName(fl::Op::validName(value));
            else if (key == "Enabled") {
                input->setEnabled(Op::isEq(Op::toScalar(value), 1.0));
            } else if (key == "Range") {
                std::pair<scalar, scalar> minmax = range(value);
                input->setMinimum(minmax.first);
                input->setMaximum(minmax.second);
            } else if (key.substr(0, 2) == "MF") {
                input->addTerm(parseTerm(value, engine));
            } else if (key == "NumMFs") {
                //ignore
            } else {
                throw fl::Exception("[import error] token <" + key + "> not recognized", FL_AT);
            }
        }
    }

    void FisImporter::importOutput(const std::string& section, Engine* engine) const {
        std::istringstream reader(section);
        std::string line;
        std::getline(reader, line); //ignore first line [Output#]

        OutputVariable* output = new OutputVariable;
        engine->addOutputVariable(output);


        while (std::getline(reader, line)) {
            std::vector<std::string> keyValue = fl::Op::split(line, "=");
            if (keyValue.size() != 2)
                throw fl::Exception("[syntax error] expected a property of type "
                    "'key=value', but found < " + line + ">", FL_AT);
            std::string key = fl::Op::trim(keyValue.at(0));
            std::string value = fl::Op::trim(keyValue.at(1));

            if (key == "Name") output->setName(fl::Op::validName(value));
            else if (key == "Enabled") {
                output->setEnabled(Op::isEq(Op::toScalar(value), 1.0));
            } else if (key == "Range") {
                std::pair<scalar, scalar> minmax = range(value);
                output->setMinimum(minmax.first);
                output->setMaximum(minmax.second);
            } else if (key.substr(0, 2) == "MF") {
                output->addTerm(parseTerm(value, engine));
            } else if (key == "Default") {
                output->setDefaultValue(fl::Op::toScalar(value));
            } else if (key == "LockPrevious") {
                output->setLockPreviousOutputValue(fl::Op::isEq(fl::Op::toScalar(value), 1.0));
            } else if (key == "LockRange") {
                output->setLockOutputValueInRange(fl::Op::isEq(fl::Op::toScalar(value), 1.0));
            } else if (key == "NumMFs") {
                //ignore
            } else {
                throw fl::Exception("[import error] token <" + key + "> not recognized", FL_AT);
            }
        }
    }

    void FisImporter::importRules(const std::string& section, Engine* engine) const {
        std::istringstream reader(section);
        std::string line;
        std::getline(reader, line); //ignore first line [Rules]

        RuleBlock* ruleblock = new RuleBlock;
        engine->addRuleBlock(ruleblock);

        while (std::getline(reader, line)) {
            std::vector<std::string> inputsAndRest = fl::Op::split(line, ",");
            if (inputsAndRest.size() != 2)
                throw fl::Exception("[syntax error] expected rule to match pattern "
                    "<'i '+, 'o '+ (w) : '1|2'>, but found instead <" + line + ">", FL_AT);

            std::vector <std::string> outputsAndRest = fl::Op::split(inputsAndRest.at(1), ":");
            if (outputsAndRest.size() != 2)
                throw fl::Exception("[syntax error] expected rule to match pattern "
                    "<'i '+, 'o '+ (w) : '1|2'>, but found instead <" + line + ">", FL_AT);

            std::vector<std::string> inputs = fl::Op::split(inputsAndRest.at(0), " ");
            std::vector<std::string> outputs = fl::Op::split(outputsAndRest.at(0), " ");
            std::string weightInParenthesis = outputs.at(outputs.size() - 1);
            outputs.erase(outputs.begin() + outputs.size() - 1);
            std::string connector = fl::Op::trim(outputsAndRest.at(1));

            if ((int) inputs.size() != engine->numberOfInputVariables()) {
                std::ostringstream ss;
                ss << "[syntax error] expected <" << engine->numberOfInputVariables() << ">"
                        " input variables, but found <" << inputs.size() << ">"
                        " input variables in rule <" << line << ">";
                throw fl::Exception(ss.str(), FL_AT);
            }
            if ((int) outputs.size() != engine->numberOfOutputVariables()) {
                std::ostringstream ss;
                ss << "[syntax error] expected <" << engine->numberOfOutputVariables() << ">"
                        " output variables, but found <" << outputs.size() << ">"
                        " output variables in rule <" << line << ">";
                throw fl::Exception(ss.str(), FL_AT);
            }

            std::vector<std::string> antecedent, consequent;

            for (std::size_t i = 0; i < inputs.size(); ++i) {
                scalar inputCode = fl::Op::toScalar(inputs.at(i));
                if (fl::Op::isEq(inputCode, 0.0)) continue;
                std::ostringstream ss;
                ss << engine->getInputVariable(i)->getName() << " "
                        << fl::Rule::isKeyword() << " "
                        << translateProposition(inputCode, engine->getInputVariable(i));
                antecedent.push_back(ss.str());
            }

            for (std::size_t i = 0; i < outputs.size(); ++i) {
                scalar outputCode = fl::Op::toScalar(outputs.at(i));
                if (fl::Op::isEq(outputCode, 0.0)) continue;
                std::ostringstream ss;
                ss << engine->getOutputVariable(i)->getName() << " "
                        << fl::Rule::isKeyword() << " "
                        << translateProposition(outputCode, engine->getOutputVariable(i));
                consequent.push_back(ss.str());
            }

            std::ostringstream ruleText;

            ruleText << fl::Rule::ifKeyword() << " ";
            for (std::size_t i = 0; i < antecedent.size(); ++i) {
                ruleText << antecedent.at(i);
                if (i + 1 < antecedent.size()) {
                    ruleText << " ";
                    if (connector == "1") ruleText << fl::Rule::andKeyword() << " ";
                    else if (connector == "2") ruleText << fl::Rule::orKeyword() << " ";
                    else throw fl::Exception("[syntax error] connector <"
                            + connector + "> not recognized", FL_AT);
                }
            }

            ruleText << " " << fl::Rule::thenKeyword() << " ";
            for (std::size_t i = 0; i < consequent.size(); ++i) {
                ruleText << consequent.at(i);
                if (i + 1 < consequent.size()) {
                    ruleText << " " << fl::Rule::andKeyword() << " ";
                }
            }

            std::ostringstream ss;
            for (std::size_t i = 0; i < weightInParenthesis.size(); ++i) {
                if (weightInParenthesis.at(i) == '('
                        or weightInParenthesis.at(i) == ')'
                        or weightInParenthesis.at(i) == ' ') continue;
                ss << weightInParenthesis.at(i);
            }

            scalar weight = fl::Op::toScalar(ss.str());
            if (not fl::Op::isEq(weight, 1.0))
                ruleText << " " << fl::Rule::withKeyword() << " " << Op::str(weight);
            Rule* rule = new Rule(ruleText.str());
            try {
                rule->load(engine);
            } catch (...) {
                //ignore
            }
            ruleblock->addRule(rule);
        }
    }

    std::string FisImporter::translateProposition(scalar code, Variable* variable) const {
        int intPart = (int) std::floor(std::fabs(code)) - 1;
        scalar fracPart = std::fmod(std::fabs(code), 1.0);
        if (intPart >= variable->numberOfTerms()) {
            std::ostringstream ex;
            ex << "[syntax error] the code <" << code << "> refers to a term "
                    "out of range from variable <" << variable->getName() << ">";
            throw fl::Exception(ex.str(), FL_AT);
        }

        bool isAny = intPart < 0;
        std::ostringstream ss;
        if (code < 0) ss << Not().name() << " ";
        if (fl::Op::isEq(fracPart, 0.01)) ss << Seldom().name() << " ";
        else if (fl::Op::isEq(fracPart, 0.05)) ss << Somewhat().name() << " ";
        else if (fl::Op::isEq(fracPart, 0.2)) ss << Very().name() << " ";
        else if (fl::Op::isEq(fracPart, 0.3)) ss << Extremely().name() << " ";
        else if (fl::Op::isEq(fracPart, 0.4)) ss << Very().name() << " " << Very().name() << " ";
        else if (fl::Op::isEq(fracPart, 0.99)) ss << Any().name() << " ";
        else if (not fl::Op::isEq(fracPart, 0))
            throw fl::Exception("[syntax error] no hedge defined in FIS format for <"
                + fl::Op::str(fracPart) + ">", FL_AT);
        if (not isAny) {
            ss << variable->getTerm(intPart)->getName();
        }
        return ss.str();
    }

    std::string FisImporter::extractTNorm(const std::string & name) const {
        if (name.empty()) return "";
        if (name == "min") return Minimum().className();
        if (name == "prod") return AlgebraicProduct().className();
        if (name == "bounded_difference") return BoundedDifference().className();
        if (name == "drastic_product") return DrasticProduct().className();
        if (name == "einstein_product") return EinsteinProduct().className();
        if (name == "hamacher_product") return HamacherProduct().className();
        if (name == "nilpotent_minimum") return NilpotentMinimum().className();
        return name;
    }

    std::string FisImporter::extractSNorm(const std::string & name) const {
        if (name.empty()) return "";
        if (name == "max") return Maximum().className();
        if (name == "sum" or name == "probor") return AlgebraicSum().className();
        if (name == "bounded_sum") return BoundedSum().className();
        if (name == "normalized_sum") return NormalizedSum().className();
        if (name == "drastic_sum") return DrasticSum().className();
        if (name == "einstein_sum") return EinsteinSum().className();
        if (name == "hamacher_sum") return HamacherSum().className();
        if (name == "nilpotent_maximum") return NilpotentMaximum().className();
        return name;
    }

    std::string FisImporter::extractDefuzzifier(const std::string & name) const {
        if (name.empty()) return "";
        if (name == "centroid") return Centroid().className();
        if (name == "bisector") return Bisector().className();
        if (name == "lom") return LargestOfMaximum().className();
        if (name == "mom") return MeanOfMaximum().className();
        if (name == "som") return SmallestOfMaximum().className();
        if (name == "wtaver") return WeightedAverage().className();
        if (name == "wtsum") return WeightedSum().className();
        return name;
    }

    std::pair<scalar, scalar> FisImporter::range(const std::string& range) const {
        std::vector<std::string> parts = fl::Op::split(range, " ");
        if (parts.size() != 2)
            throw fl::Exception("[syntax error] expected range in format '[begin end]',"
                " but found <" + range + ">", FL_AT);
        std::string begin = parts.at(0), end = parts.at(1);
        if (begin.at(0) != '[' or end.at(end.size() - 1) != ']')
            throw fl::Exception("[syntax error] expected range in format '[begin end]',"
                " but found <" + range + ">", FL_AT);
        std::pair<scalar, scalar> result;
        result.first = fl::Op::toScalar(begin.substr(1));
        result.second = fl::Op::toScalar(end.substr(0, end.size() - 1));
        return result;
    }

    Term * FisImporter::parseTerm(const std::string & fis, const Engine* engine) const {
        std::ostringstream ss;
        for (std::size_t i = 0; i < fis.size(); ++i) {
            if (not (fis.at(i) == '[' or fis.at(i) == ']')) {
                ss << fis.at(i);
            }
        }
        std::string line = ss.str();

        std::vector<std::string> nameTerm = fl::Op::split(line, ":");
        if (nameTerm.size() != 2) {
            throw fl::Exception("[syntax error] expected term in format 'name':'class',[params], "
                    "but found <" + line + ">", FL_AT);
        }
        std::vector<std::string> termParams = fl::Op::split(nameTerm.at(1), ",");
        if (termParams.size() != 2) {
            throw fl::Exception("[syntax error] expected term in format 'name':'class',[params], "
                    "but found " + line, FL_AT);
        }

        std::vector<std::string> parameters = fl::Op::split(termParams.at(1), " ");
        for (std::size_t i = 0; i < parameters.size(); ++i) {
            parameters.at(i) = fl::Op::trim(parameters.at(i));
        }
        return createInstance(
                fl::Op::trim(termParams.at(0)),
                fl::Op::trim(nameTerm.at(0)),
                parameters, engine);
    }

    Term * FisImporter::createInstance(const std::string& mClass,
            const std::string& name, const std::vector<std::string>& params,
            const Engine* engine) const {
        std::map<std::string, std::string> mapping;
        mapping["discretemf"] = Discrete().className();
        mapping["concavemf"] = Concave().className();
        mapping["constant"] = Constant().className();
        mapping["cosinemf"] = Cosine().className();
        mapping["function"] = Function().className();
        mapping["gbellmf"] = Bell().className();
        mapping["gaussmf"] = Gaussian().className();
        mapping["gauss2mf"] = GaussianProduct().className();
        mapping["linear"] = Linear().className();
        mapping["pimf"] = PiShape().className();
        mapping["rampmf"] = Ramp().className();
        mapping["rectmf"] = Rectangle().className();
        mapping["smf"] = SShape().className();
        mapping["sigmf"] = Sigmoid().className();
        mapping["dsigmf"] = SigmoidDifference().className();
        mapping["psigmf"] = SigmoidProduct().className();
        mapping["spikemf"] = Spike().className();
        mapping["trapmf"] = Trapezoid().className();
        mapping["trimf"] = Triangle().className();
        mapping["zmf"] = ZShape().className();

        std::vector<std::string> sortedParams = params;

        if (mClass == "gbellmf" and params.size() >= 3) {
            sortedParams.at(0) = params.at(2);
            sortedParams.at(1) = params.at(0);
            sortedParams.at(2) = params.at(1);
        } else if (mClass == "gaussmf" and params.size() >= 2) {
            sortedParams.at(0) = params.at(1);
            sortedParams.at(1) = params.at(0);
        } else if (mClass == "gauss2mf" and params.size() >= 4) {
            sortedParams.at(0) = params.at(1);
            sortedParams.at(1) = params.at(0);
            sortedParams.at(2) = params.at(3);
            sortedParams.at(3) = params.at(2);
        } else if (mClass == "sigmf" and params.size() >= 2) {
            sortedParams.at(0) = params.at(1);
            sortedParams.at(1) = params.at(0);
        } else if (mClass == "dsigmf" and params.size() >= 4) {
            sortedParams.at(0) = params.at(1);
            sortedParams.at(1) = params.at(0);
            sortedParams.at(2) = params.at(2);
            sortedParams.at(3) = params.at(3);
        } else if (mClass == "psigmf" and params.size() >= 4) {
            sortedParams.at(0) = params.at(1);
            sortedParams.at(1) = params.at(0);
            sortedParams.at(2) = params.at(2);
            sortedParams.at(3) = params.at(3);
        }

        std::string flClass;
        std::map<std::string, std::string>::const_iterator it = mapping.find(mClass);
        if (it != mapping.end()) flClass = it->second;
        else flClass = mClass;

        FL_unique_ptr<Term> term;
        term.reset(FactoryManager::instance()->term()->constructObject(flClass));
        Term::updateReference(term.get(), engine);
        term->setName(Op::validName(name));
        std::string separator;
        if (not dynamic_cast<Function*> (term.get())) {
            separator = " ";
        }
        term->configure(Op::join(sortedParams, separator));
        return term.release();
    }

    FisImporter* FisImporter::clone() const {
        return new FisImporter(*this);
    }

}