// Copyright (C) 2015 xaizek <xaizek@posteo.net>
//
// This file is part of dit.
//
// dit is free software: you can redistribute it and/or modify
// it under the terms of version 3 of the GNU Affero General Public
// License as published by the Free Software Foundation.
//
// dit 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 dit.  If not, see <http://www.gnu.org/licenses/>.

#include <cstdlib>

#include <algorithm>
#include <ostream>
#include <string>
#include <unordered_set>
#include <vector>

#include "utils/contains.hpp"
#include "utils/strings.hpp"
#include "Command.hpp"
#include "Commands.hpp"
#include "Item.hpp"
#include "Project.hpp"
#include "Storage.hpp"
#include "completion.hpp"
#include "printing.hpp"

namespace {

/**
 * @brief Implementation of "show" command, which displays item information.
 */
class ShowCmd : public AutoRegisteredCommand<ShowCmd>
{
public:
    /**
     * @brief Constructs the command implementation.
     */
    ShowCmd();

public:
    /**
     * @copydoc Command::run()
     */
    virtual boost::optional<int> run(
        Project &project,
        const std::vector<std::string> &args) override;
    /**
     * @copydoc Command::complete()
     */
    virtual boost::optional<int> complete(
        Project &project,
        const std::vector<std::string> &args) override;

private:
    /**
     * @brief Prints out single record.
     *
     * @param name Name of the record (e.g. "type").
     * @param val Value of the record (e.g. "bug").
     */
    void printRecord(const std::string &name, const std::string &val);
};

}

ShowCmd::ShowCmd() : parent("show", "display item entries",
                            "Usage: show id [key...]")
{
}

boost::optional<int>
ShowCmd::run(Project &project, const std::vector<std::string> &args)
{
    if (args.size() < 1U) {
        err() << "Expected at least one argument (id).\n";
        return EXIT_FAILURE;
    }

    Config &config = project.getConfig();
    const std::string order = config.get("ui.show.order");

    const std::vector<std::string> ordering = split(order, ',');

    const std::string &id = args[0];
    std::unordered_set<std::string> filter(++args.cbegin(), args.cend());
    Item &item = project.getStorage().get(id);

    // Print known fields in specified order first.
    for (const std::string &field : ordering) {
        if (!filter.empty() && !contains(filter, field)) {
            continue;
        }

        const std::string &v = item.getValue(field);
        if (!v.empty()) {
            printRecord(field, v);
        }
    }

    // Print out the rest of the fields.
    for (const std::string &c : item.listRecordNames()) {
        if (!filter.empty() && !contains(filter, c)) {
            continue;
        }

        if (!contains(ordering, c)) {
            printRecord(c, item.getValue(c));;
        }
    }

    return EXIT_SUCCESS;
}

void
ShowCmd::printRecord(const std::string &name, const std::string &val)
{
    out() << Key{name} << Value{val} << '\n';
}

boost::optional<int>
ShowCmd::complete(Project &project, const std::vector<std::string> &args)
{
    if (args.size() <= 1U) {
        return completeIds(project.getStorage(), out());
    }

    try {
        const std::string &id = args[0];
        Item &item = project.getStorage().get(id);
        return completeKeys(item, out(), { ++args.cbegin(), args.cend() });
    } catch (std::runtime_error &) {
        return EXIT_FAILURE;
    }
}