/*
 * Copyright (C) 2008  Martin Hostettler
 *
 * 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; either version 2
 * of the License, or (at your option) any later version.
 *
 * 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 <https://www.gnu.org/licenses/>.
 *
 */

// manager mini command system

#include "mcmdmanager.h"

#include <QDebug>
#include <QRegularExpression>

MCmdSimpleState::MCmdSimpleState(QString name, QString prompt) : name_(name), prompt_(prompt), flags_(0) { }

MCmdSimpleState::MCmdSimpleState(QString name, QString prompt, int flags) : name_(name), prompt_(prompt), flags_(flags)
{
}

MCmdSimpleState::~MCmdSimpleState() { }

MCmdManager::MCmdManager(MCmdUiSiteIface *site_) : state_(nullptr), uiSite_(site_) {};

MCmdManager::~MCmdManager()
{
    for (MCmdProviderIface *prov : std::as_const(providers_)) {
        prov->mCmdSiteDestroyed();
    }
}

QStringList MCmdManager::parseCommand(const QString command, int pos, int &part, QString &partial, int &start, int &end,
                                      char &quotedAtPos)
{
    QStringList list;
    QString     item;
    bool        escape = false;
    int         quote  = 0; // "=1, '=2
    bool        space  = true;

    int partStart = 0;
    quotedAtPos   = 0;
    for (int i = 0; i < command.length(); i++) {
        if (i == pos) {
            part    = list.size();
            partial = item;
            end     = i;
            start   = partStart;
            if (quote)
                quotedAtPos = (quote == 1) ? '"' : '\'';
        }

        QChar ch = command[i];
        if (escape) {
            escape = false;
            item += ch;
        } else if (ch == '\\') {
            escape = true;
        } else if (quote != 0) {
            if ((quote == 1 && ch == '"') || (quote == 2 && ch == '\'')) {
                quote = 0;
            } else {
                item += ch;
            }
        } else if (ch == ' ') {
            partStart = i + 1;
            if (space) {
                continue;
            }
            list << item;
            item  = "";
            space = true;
            continue;
        } else if (ch == '\'') {
            quote = 2;
        } else if (ch == '"') {
            quote = 1;
        } else {
            item += ch;
        }
        space = false;
    }
    if (command.length() == pos) {
        part    = list.size();
        partial = item;
        end     = command.length();
        start   = partStart;
        if (quote)
            quotedAtPos = (quote == 1) ? '"' : '\'';
    }

    if (!space)
        list << item;
    return list;
}

QString MCmdManager::serializeCommand(const QStringList &list)
{
    QString            retval;
    bool               needspace = false;
    QRegularExpression specials("([\"\'\\\\ ])");
    for (QString item : list) {
        item.replace(specials, "\\\\1");
        if (item == "")
            item = "\"\"";
        if (needspace)
            retval += " ";
        retval += item;
        needspace = true;
    }
    return retval;
}

bool MCmdManager::processCommand(QString command)
{
    MCmdStateIface *tmpstate = nullptr;
    QStringList     preset;
    QStringList     items;
    if (state_->getFlags() & MCMDSTATE_UNPARSED) {
        items << command;
    } else {
        int     tmp_1;
        QString tmp_2;
        char    tmp_3;
        items = parseCommand(command, -1, tmp_1, tmp_2, tmp_1, tmp_1, tmp_3);
    }
    for (MCmdProviderIface *prov : std::as_const(providers_)) {
        if (prov->mCmdTryStateTransit(state_, items, tmpstate, preset)) {
            state_ = tmpstate;
            if (state_ != nullptr) {
                QString prompt = state_->getPrompt();
                QString def;
                if (state_->getFlags() & MCMDSTATE_UNPARSED) {
                    if (preset.size() == 1) {
                        def = preset.at(0);
                    }
                } else {
                    def = serializeCommand(preset);
                }
                uiSite_->mCmdReady(prompt, def);
            } else {
                uiSite_->mCmdClose();
            }
            return true;
        }
    }

    tmpstate = state_;
    bool ret = state_->unhandled(items);
    state_   = nullptr;
    if (state_ == nullptr) {
        tmpstate->dispose();
        uiSite_->mCmdClose();
    }
    return ret;
}

bool MCmdManager::open(MCmdStateIface *state, QStringList preset)
{
    if (nullptr != state_)
        state_->dispose();

    state_         = state;
    QString prompt = state->getPrompt();
    QString def;
    if (state_->getFlags() & MCMDSTATE_UNPARSED) {
        if (preset.size() == 1)
            def = preset.at(0);
    } else {
        def = serializeCommand(preset);
    }
    uiSite_->mCmdReady(prompt, def);
    return true;
}

QStringList MCmdManager::completeCommand(QString &command, int pos, int &start, int &end)
{
    int         part;
    QString     query;
    char        quotedAtPos;
    QStringList all;
    if (state_->getFlags() & MCMDSTATE_UNPARSED) {
        all << command;
        query = command.left(pos);
        part  = -1;
    } else {
        all = parseCommand(command, pos, part, query, start, end, quotedAtPos);
    }

    QStringList res;
    for (MCmdProviderIface *prov : std::as_const(providers_)) {
        res += prov->mCmdTryCompleteCommand(state_, query, all, part);
    }
    res.sort();

    QStringList quoted;
    if ((state_->getFlags() & MCMDSTATE_UNPARSED) == 0) {
        for (QString str : std::as_const(res)) {
            QString trail;
            if (str.size() > 1 && str.at(str.size() - 1) == QChar(0)) {
                str.chop(1);
                trail = " ";
            }
            str = str.replace("\\", "\\\\");
            if (quotedAtPos == 0) {
                quoted << str.replace(" ", "\\ ").replace("\"", "\\\"").replace("'", "\\'") + trail;
            } else {
                quoted << quotedAtPos + str.replace(quotedAtPos, QString("\\") + quotedAtPos) + trail;
            }
        }
    } else {
        quoted = res;
    }
    return quoted;
}

bool MCmdManager::isActive() { return state_ != nullptr; }

void MCmdManager::registerProvider(MCmdProviderIface *prov)
{
    if (!providers_.contains(prov)) {
        providers_ += prov;
    }
}
