remwharead/src/lib/sqlite.cpp

/*  This file is part of remwharead.
 *  Copyright © 2019 tastytea <tastytea@tastytea.de>
 *
 *  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, version 3.
 *
 *  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 <exception>
#include <iostream>
#include <algorithm>
#include <basedir.h>
#include <Poco/Data/Session.h>
#include <Poco/Data/SQLite/Connector.h>
#include "time.hpp"
#include "sqlite.hpp"

namespace remwharead
{
    using std::cerr;
    using std::endl;
    using namespace Poco::Data::Keywords;
    using Poco::Data::Statement;

    Database::Database()
        : _connected(false)
    {
        try
        {
            xdgHandle xdg;
            xdgInitHandle(&xdg);
            _dbpath = xdgDataHome(&xdg) / fs::path("remwharead");
            xdgWipeHandle(&xdg);

            if (!fs::exists(_dbpath))
            {
                fs::create_directories(_dbpath);
            }
            _dbpath /= "database.sqlite";

            Poco::Data::SQLite::Connector::registerConnector();
            _session = std::make_unique<Session>("SQLite", _dbpath);
            *_session << "CREATE TABLE IF NOT EXISTS remwharead("
                "uri TEXT, archive_uri TEXT, datetime TEXT, "
                "tags TEXT, title TEXT, description TEXT, fulltext TEXT);", now;

            _connected = true;
        }
        catch (std::exception &e)
        {
            cerr << "Error in " << __func__ << ": " << e.what() << endl;
        }
    }

    Database::operator bool() const
    {
        return _connected;
    }

    bool operator ==(const Database::entry &a, const Database::entry &b)
    {
        return (a.datetime == b.datetime);
    }

    const string Database::entry::fulltext_oneline() const
    {
        string oneline = fulltext;
        size_t pos = 0;
        while ((pos = oneline.find('\n', pos)) != string::npos)
        {
            oneline.replace(pos, 1, "\\n");
        }
        return oneline;
    }

    void Database::store(const Database::entry &data) const
    {
        try
        {
            const string strdatetime = timepoint_to_string(data.datetime, true);
            string strtags;
            Statement insert(*_session);

            for (const string &tag : data.tags)
            {
                strtags += tag;
                if (tag != *(data.tags.rbegin()))
                {
                    strtags += ",";
                }
            }

            // useRef() uses the const reference.
            insert << "INSERT INTO remwharead "
                "VALUES(?, ?, ?, ?, ?, ?, ?);",
                useRef(data.uri), useRef(data.archive_uri),
                useRef(strdatetime), useRef(strtags), useRef(data.title),
                useRef(data.description), useRef(data.fulltext);
            insert.execute();
        }
        catch (std::exception &e)
        {
            cerr << "Error in " << __func__ << ": " << e.what() << endl;
        }
    }

    const list<Database::entry> Database::retrieve(
        const time_point &start, const time_point &end) const
    {
        try
        {
            Database::entry entrybuf;
            string datetime, strtags;
            Statement select(*_session);

            // bind() copies the value.
            select << "SELECT * FROM remwharead WHERE datetime "
                "BETWEEN ? AND ? ORDER BY datetime DESC;",
                bind(timepoint_to_string(start, true)),
                bind(timepoint_to_string(end, true)),
                into(entrybuf.uri), into(entrybuf.archive_uri), into(datetime),
                into(strtags), into(entrybuf.title), into(entrybuf.description),
                into(entrybuf.fulltext), range(0, 1);

            list<entry> entries;

            while(!select.done() && select.execute() != 0)
            {
                entrybuf.datetime = string_to_timepoint(datetime, true);

                vector<string> tags;
                size_t pos = 0;
                while (pos != string::npos)
                {
                    const size_t newpos = strtags.find(',', pos);
                    const string tag = strtags.substr(pos, newpos - pos);
                    if (!tag.empty())
                    {
                        tags.push_back(tag);
                    }
                    pos = newpos;
                    if (pos != string::npos)
                    {
                        ++pos;
                    }
                }
                entrybuf.tags = tags;

                entries.push_back(entrybuf);
            }

            return entries;
        }
        catch (std::exception &e)
        {
            cerr << "Error in " << __func__ << ": " << e.what() << endl;
        }

        return {};
    }
}