#include <qpdf/QPDFLogger.hh>

#include <qpdf/Pl_Discard.hh>

#include <qpdf/Pl_OStream.hh>

#include <qpdf/QUtil.hh>

#include <iostream>

#include <stdexcept>

namespace

{

    class Pl_Track: public Pipeline

    {

      public:

        Pl_Track(char const* identifier, Pipeline* next) :

            Pipeline(identifier, next)

        {

            if (!next) {

                throw std::logic_error("Attempt to create Pl_Track with nullptr as next");

            }

        }

        void

        write(unsigned char const* data, size_t len) final

        {

            used = true;

            next()->write(data, len);

        }

        void

        finish() final

        {

            next()->finish();

        }

        bool

        getUsed() const

        {

            return used;

        }

      private:

        bool used{false};

    };

}; // namespace

QPDFLogger::Members::Members() :

    p_discard(new Pl_Discard()),

    p_real_stdout(new Pl_OStream("standard output", std::cout)),

    p_stdout(new Pl_Track("track stdout", p_real_stdout.get())),

    p_stderr(new Pl_OStream("standard error", std::cerr)),

    p_info(p_stdout),

    p_warn(nullptr),

    p_error(p_stderr),

    p_save(nullptr)

{

}

QPDFLogger::Members::~Members()

{

    p_stdout->finish();

    p_stderr->finish();

}

QPDFLogger::QPDFLogger() :

    m(new Members())

{

}

std::shared_ptr<QPDFLogger>

QPDFLogger::create()

{

    return std::shared_ptr<QPDFLogger>(new QPDFLogger);

}

std::shared_ptr<QPDFLogger>

QPDFLogger::defaultLogger()

{

    static auto l = create();

    return l;

}

void

QPDFLogger::info(char const* s)

{

    getInfo(false)->writeCStr(s);

}

void

QPDFLogger::info(std::string const& s)

{

    getInfo(false)->writeString(s);

}

std::shared_ptr<Pipeline>

QPDFLogger::getInfo(bool null_okay)

{

    return throwIfNull(m->p_info, null_okay);

}

void

QPDFLogger::warn(char const* s)

{

    getWarn(false)->writeCStr(s);

}

void

QPDFLogger::warn(std::string const& s)

{

    getWarn(false)->writeString(s);

}

std::shared_ptr<Pipeline>

QPDFLogger::getWarn(bool null_okay)

{

    if (m->p_warn) {

        return m->p_warn;

    }

    return getError(null_okay);

}

void

QPDFLogger::error(char const* s)

{

    getError(false)->writeCStr(s);

}

void

QPDFLogger::error(std::string const& s)

{

    getError(false)->writeString(s);

}

std::shared_ptr<Pipeline>

QPDFLogger::getError(bool null_okay)

{

    return throwIfNull(m->p_error, null_okay);

}

std::shared_ptr<Pipeline>

QPDFLogger::getSave(bool null_okay)

{

    return throwIfNull(m->p_save, null_okay);

}

std::shared_ptr<Pipeline>

QPDFLogger::standardOutput()

{

    return m->p_stdout;

}

std::shared_ptr<Pipeline>

QPDFLogger::standardError()

{

    return m->p_stderr;

}

std::shared_ptr<Pipeline>

QPDFLogger::discard()

{

    return m->p_discard;

}

void

QPDFLogger::setInfo(std::shared_ptr<Pipeline> p)

{

    if (p == nullptr) {

        if (m->p_save == m->p_stdout) {

            p = m->p_stderr;

        } else {

            p = m->p_stdout;

        }

    }

    m->p_info = p;

}

void

QPDFLogger::setWarn(std::shared_ptr<Pipeline> p)

{

    m->p_warn = p;

}

void

QPDFLogger::setError(std::shared_ptr<Pipeline> p)

{

    if (p == nullptr) {

        p = m->p_stderr;

    }

    m->p_error = p;

}

void

QPDFLogger::setSave(std::shared_ptr<Pipeline> p, bool only_if_not_set)

{

    if (only_if_not_set && (m->p_save != nullptr)) {

        return;

    }

    if (m->p_save == p) {

        return;

    }

    if (p == m->p_stdout) {

        auto pt = dynamic_cast<Pl_Track*>(p.get());

        if (pt->getUsed()) {

            throw std::logic_error(

                "QPDFLogger: called setSave on standard output after standard"

                " output has already been used");

        }

        if (m->p_info == m->p_stdout) {

            m->p_info = m->p_stderr;

        }

        QUtil::binary_stdout();

    }

    m->p_save = p;

}

void

QPDFLogger::saveToStandardOutput(bool only_if_not_set)

{

    setSave(standardOutput(), only_if_not_set);

}

void

QPDFLogger::setOutputStreams(std::ostream* out_stream, std::ostream* err_stream)

{

    if (out_stream == &std::cout) {

        out_stream = nullptr;

    }

    if (err_stream == &std::cerr) {

        err_stream = nullptr;

    }

    std::shared_ptr<Pipeline> new_out;

    std::shared_ptr<Pipeline> new_err;

    if (out_stream == nullptr) {

        if (m->p_save == m->p_stdout) {

            new_out = m->p_stderr;

        } else {

            new_out = m->p_stdout;

        }

    } else {

        new_out = std::make_shared<Pl_OStream>("output", *out_stream);

    }

    if (err_stream == nullptr) {

        new_err = m->p_stderr;

    } else {

        new_err = std::make_shared<Pl_OStream>("error output", *err_stream);

    }

    m->p_info = new_out;

    m->p_warn = nullptr;

    m->p_error = new_err;

}

std::shared_ptr<Pipeline>

QPDFLogger::throwIfNull(std::shared_ptr<Pipeline> p, bool null_okay)

{

    if (!(null_okay || p)) {

        throw std::logic_error("QPDFLogger: requested a null pipeline without null_okay == true");

    }

    return p;

}