// Copyright (C) 2016 xaizek <xaizek@posteo.net>
//
// This file is part of uncov.
//
// uncov is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// uncov 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with uncov.  If not, see <http://www.gnu.org/licenses/>.

#include "printing.hpp"

#include <cstddef>

#include <iomanip>
#include <memory>
#include <ostream>
#include <string>
#include <unordered_map>
#include <utility>

#include "utils/time.hpp"
#include "decoration.hpp"

namespace {

/**
 * @brief Settings for this unit.
 *
 * Must be set before using the unit.
 */
std::shared_ptr<PrintingSettings> settings;

//! Specification of terminal color scheme.
const std::unordered_map<std::string, decor::Decoration> highlightGroups = {
    { "linesbad",      decor::bold + decor::red_fg   },
    { "linesok",       decor::bold + decor::black_fg },
    { "linesgood",     decor::bold + decor::green_fg },
    { "lineschanged",  decor::yellow_fg },
    { "covbad",        decor::bold + decor::red_fg },
    { "covok",         decor::bold + decor::black_fg },
    { "covnormal",     decor::bold + decor::yellow_fg },
    { "covgood",       decor::bold + decor::green_fg },
    { "lineno",        decor::white_bg + decor::black_fg },
    { "missed",        decor::red_fg + decor::inv + decor::bold },
    { "covered",       decor::green_fg + decor::inv + decor::bold },
    { "silentmissed",  decor::red_fg + decor::bold },
    { "silentcovered", decor::green_fg + decor::bold },
    { "added",         decor::green_fg + decor::bold },
    { "removed",       decor::red_fg + decor::bold },
    { "retained",      decor::none },
    { "note",          decor::none },
    { "header",        decor::white_fg + decor::black_bg + decor::bold +
                       decor::inv },
    { "error",         decor::red_bg + decor::inv + decor::bold },
    { "label",         decor::bold },
    { "revision",      decor::none },
    { "time",          decor::none },
    { "hitcount",      decor::none },
};

/**
 * @brief Decorates text with highlighting (either ASCII codes or HTML classes).
 */
class Highlight
{
public:
    /**
     * @brief Initializes highlighting with a name of highlight group.
     *
     * @param groupName Name of the group.
     */
    explicit Highlight(std::string groupName) : groupName(std::move(groupName))
    {
    }

    /**
     * @brief Constructs a new object which extends previous one by one action.
     *
     * @param hi  Object to be extend.
     * @param app Action to append to list of actions.
     */
    Highlight(Highlight &&hi, std::function<void(std::ostream&)> app)
        : groupName(std::move(hi.groupName)), apps(std::move(hi.apps))
    {
        apps.push_back(app);
    }

public:
    /**
     * @brief Prints decorated output into the stream.
     *
     * @param os Output stream.
     *
     * @returns @p os
     */
    std::ostream & decorate(std::ostream &os) const
    {
        const bool isHtmlOutput = settings->isHtmlOutput();

        if (isHtmlOutput) {
            const auto width = os.width({});
            os << "<span class=\"" << groupName << "\">";
            static_cast<void>(os.width(width));
        } else {
            os << highlightGroups.at(groupName);
        }

        for (const auto app : apps) {
            app(os);
        }

        if (isHtmlOutput) {
            const auto width = os.width({});
            os << "</span>";
            static_cast<void>(os.width(width));
        } else {
            os << decor::def;
        }

        return os;
    }

private:
    const std::string groupName;                          //!< Highlight group.
    std::vector<std::function<void(std::ostream&)>> apps; //!< List of actions.
};

/**
 * @brief Appends element to the list of things to highlight.
 *
 * @tparam T Type of the element.
 *
 * @param hi  Highlight object.
 * @param val Element to append.
 *
 * @returns New highlight object.
 */
template <typename T>
Highlight
operator<<(Highlight &&hi, const T &val)
{
    return Highlight(std::move(hi), [val](std::ostream &os) { os << val; });
}

/**
 * @brief Outputs highlighted element into the stream.
 *
 * @param os Output stream.
 * @param hi Highlight object.
 *
 * @returns @p os
 */
inline std::ostream &
operator<<(std::ostream &os, const Highlight &hi)
{
    return hi.decorate(os);
}

/**
 * @brief Prints decorated number of hits.
 *
 * @param os     Output stream.
 * @param hits   Number of hits.
 * @param silent Whether to dim colors.
 *
 * @returns @p os
 */
std::ostream &
printHits(std::ostream &os, int hits, bool silent)
{
    std::string prefix = silent ? "silent" : "";

    if (hits == 0) {
        return os << (Highlight("hitcount") <<
                      (Highlight(prefix + "missed") << "x0" << ' '));
    } else if (hits > 0) {
        // 'x' and number must be output as a single unit here so that field
        // width applies correctly.
        return os << (Highlight("hitcount") <<
                      (Highlight(prefix + "covered")
                       << 'x' + std::to_string(hits) << ' '));
    } else {
        return os << (Highlight("hitcount") << "") << ' ';
    }
}

}

void
PrintingSettings::set(std::shared_ptr<PrintingSettings> settings)
{
    ::settings = std::move(settings);
}

std::ostream &
operator<<(std::ostream &os, const CLinesChange &change)
{
    if (change.data < 0) {
        // XXX: highlight this as "ok" if not covered lines were not changed and
        //      relevant lines reduced by the same amount?
        return os << (Highlight("linesbad") << change.data);
    } else if (change.data == 0) {
        return os << (Highlight("linesok") << change.data);
    } else {
        return os << std::showpos
                  << (Highlight("linesgood") << change.data)
                  << std::noshowpos;
    }
}

std::ostream &
operator<<(std::ostream &os, const MLinesChange &change)
{
    if (change.data > 0) {
        return os << std::showpos
                  << (Highlight("linesbad") << change.data)
                  << std::noshowpos;
    } else if (change.data == 0) {
        return os << (Highlight("linesok") << change.data);
    } else {
        return os << (Highlight("linesgood") << change.data);
    }
}

std::ostream &
operator<<(std::ostream &os, const RLinesChange &change)
{
    if (change.data > 0) {
        os << std::showpos;
    }
    return os << (Highlight("lineschanged") << change.data) << std::noshowpos;
}

std::ostream &
operator<<(std::ostream &os, const CoverageChange &change)
{
    if (change.data < 0) {
        return os << (Highlight("covbad") << change.data << '%');
    } else if (change.data == 0) {
        return os << (Highlight("covok") << change.data << '%');
    } else {
        return os << std::showpos
                  << (Highlight("covgood") << change.data << '%')
                  << std::noshowpos;
    }
}

std::ostream &
operator<<(std::ostream &os, const Coverage &coverage)
{
    if (coverage.data < settings->getMedLimit()) {
        return os << (Highlight("covbad") << coverage.data << '%');
    } else if (coverage.data < settings->getHiLimit()) {
        return os << (Highlight("covnormal") << coverage.data << '%');
    } else {
        return os << (Highlight("covgood") << coverage.data << '%');
    }
}

std::ostream &
operator<<(std::ostream &os, const Label &label)
{
    return os << (Highlight("label") << label.data);
}

std::ostream &
operator<<(std::ostream &os, const ErrorMsg &errMsg)
{
    return os << (Highlight("error") << errMsg.data);
}

std::ostream &
operator<<(std::ostream &os, const TableHeader &th)
{
    return os << (Highlight("header") << th.data);
}

std::ostream &
operator<<(std::ostream &os, const LineNo &lineNo)
{
    return os << (Highlight("lineno") << std::to_string(lineNo.data) << ' ');
}

std::ostream &
operator<<(std::ostream &os, const LineRetained &line)
{
    return os << (Highlight("retained") << ' ') << line.data;
}

std::ostream &
operator<<(std::ostream &os, const LineAdded &line)
{
    return os << (Highlight("added") << '+') << line.data;
}

std::ostream &
operator<<(std::ostream &os, const LineRemoved &line)
{
    return os << (Highlight("removed") << '-') << line.data;
}

std::ostream &
operator<<(std::ostream &os, const NoteMsg &line)
{
    return os << (Highlight("note") << " <<< " << line.data << " >>> ");
}

std::ostream &
operator<<(std::ostream &os, const HitsCount &hits)
{
    return printHits(os, hits.data, false);
}

std::ostream &
operator<<(std::ostream &os, const SilentHitsCount &hits)
{
    return printHits(os, hits.data, true);
}

std::ostream &
operator<<(std::ostream &os, const Revision &rev)
{
    return os << (Highlight("revision") << rev.data);
}

std::ostream &
operator<<(std::ostream &os, const Time &t)
{
    return os << (Highlight("time")
              << put_time(std::localtime(&t.data),
                          settings->getTimeFormat().c_str()));
}