/*
    This file is part of Kiten, a KDE Japanese Reference Tool
    SPDX-FileCopyrightText: 2001 Jason Katz-Brown <jason@katzbrown.com>
    SPDX-FileCopyrightText: 2006 Joseph Kerian <jkerian@gmail.com>
    SPDX-FileCopyrightText: 2006 Eric Kjeldergaard <kjelderg@gmail.com>
    SPDX-FileCopyrightText: 2011 Daniel E. Moctezuma <democtezuma@gmail.com>

    SPDX-License-Identifier: LGPL-2.0-or-later
*/

#include "dictfileedict.h"

#include <KConfigSkeleton>

#include <QFile>
#include <QList>
#include <QRegularExpression>
#include <QString>
#include <QStringDecoder>
#include <QTextStream>

#include "deinflection.h"
#include "dictfilefieldselector.h"
#include "dictquery.h"
#include "entryedict.h"
#include "entrylist.h"
#include "kitenmacros.h"

using namespace Qt::StringLiterals;

QString *DictFileEdict::deinflectionLabel = nullptr;
QStringList *DictFileEdict::displayFields = nullptr;
QString *DictFileEdict::wordType = nullptr;

/**
 * Per instructions in the super-class, this constructor basically sets the
 * dictionaryType member variable to identify this as an edict-type database handler.
 */
DictFileEdict::DictFileEdict()
    : DictFile(EDICT)
    , m_deinflection(nullptr)
    , m_hasDeinflection(false)
{
    m_dictionaryType = EDICT;
    m_searchableAttributes.insert(QStringLiteral("common"), QStringLiteral("common"));
}

/**
 * The destructor... ditch our memory maps and close our files here
 * (if they were open).
 */
DictFileEdict::~DictFileEdict()
{
    delete m_deinflection;
    m_deinflection = nullptr;
}

QMap<QString, QString> DictFileEdict::displayOptions() const
{
    QMap<QString, QString> list;
    list[QStringLiteral("Part of speech(type)")] = QStringLiteral("type");
    return list;
}

/**
 * Do a search, respond with a list of entries.
 * The general strategy will be to take the first word of the query, and do a
 * binary search on the dictionary for that item. Take all results and filter
 * them using the rest of the query with the validate method.
 */
EntryList *DictFileEdict::doSearch(const DictQuery &query)
{
    if (query.isEmpty() || !m_edictFile.valid()) // No query or dict, no results.
    {
        return new EntryList();
    }

    qDebug() << "Search from : " << getName();

    QString firstChoice = query.getWord();
    if (firstChoice.length() == 0) {
        firstChoice = query.getPronunciation();
        if (firstChoice.length() == 0) {
            firstChoice = query.getMeaning().split(' '_L1).first().toLower();
            if (firstChoice.length() == 0) {
                // The nastiest situation... we have to assemble a search string
                // from the first property
                QList<QString> keys = query.listPropertyKeys();
                if (keys.empty()) // Shouldn't happen... but maybe in the future
                {
                    return new EntryList();
                }
                firstChoice = keys[0];
                firstChoice = firstChoice + query.getProperty(firstChoice);
                // TODO: doSearch: some accommodation for searching for ranges and such of properties
            }
        }
    } else {
        // Only search for one kanji or the
        // binary lookup mechanism breaks
        firstChoice = firstChoice.at(0);
    }

    QList<QString> preliminaryResults = m_edictFile.findMatches(firstChoice);

    if (preliminaryResults.empty()) // If there were no matches... return an empty list
    {
        return new EntryList();
    }

    auto results = new EntryList();
    for (const QString &it : preliminaryResults) {
        //     qDebug() << "result: " << it << endl;
        Entry *result = makeEntry(it);
        auto resultEdict = static_cast<EntryEdict *>(result);
        if (result->matchesQuery(query) && resultEdict->matchesWordType(query)) {
            results->append(result);
        } else {
            delete result;
        }
    }

    // At this point we should have some preliminary results
    // and if there were no matches, it probably means the user
    // input was a verb or adjective, so we have to deinflect it.
    bool isAnyQuery = query.getMatchWordType() == DictQuery::Any;
    bool isVerbQuery = query.getMatchWordType() == DictQuery::Verb;
    bool isAdjectiveQuery = query.getMatchWordType() == DictQuery::Adjective;
    if (results->count() == 0 && (isAnyQuery || isVerbQuery || isAdjectiveQuery)) {
        delete results;
        results = m_deinflection->search(query, preliminaryResults);
        QString *label = m_deinflection->getDeinflectionLabel();
        if (!label->isEmpty() && !m_hasDeinflection) {
            deinflectionLabel = label;
            m_hasDeinflection = true;
            wordType = m_deinflection->getWordType();
        }
    } else {
        deinflectionLabel = nullptr;
        wordType = nullptr;
        m_hasDeinflection = false;
    }

    if (results) {
        auto common = new EntryList();
        auto uncommon = new EntryList();
        EntryList::EntryIterator i(*results);
        while (i.hasNext()) {
            auto entry = static_cast<EntryEdict *>(i.next());
            if (entry->isCommon()) {
                common->append(entry);
            } else {
                uncommon->append(entry);
            }
        }

        delete results;
        results = new EntryList();
        results->appendList(common);
        results->appendList(uncommon);
        delete common;
        delete uncommon;

        auto exact = new EntryList();
        auto beginning = new EntryList();
        auto ending = new EntryList();
        auto anywhere = new EntryList();
        EntryList::EntryIterator it(*results);
        while (it.hasNext()) {
            Entry *entry = it.next();

            if (entry->getWord() == query.getWord()) {
                exact->append(entry);
            } else if (entry->getWord().startsWith(query.getWord())) {
                beginning->append(entry);
            } else if (entry->getWord().endsWith(query.getWord())) {
                ending->append(entry);
            } else {
                anywhere->append(entry);
            }
        }

        delete results;
        results = new EntryList();
        results->appendList(exact);
        results->appendList(beginning);
        results->appendList(ending);
        results->appendList(anywhere);
        delete exact;
        delete beginning;
        delete ending;
        delete anywhere;
    }

    return results;
}

/**
 * Make a list of all the extra fields in our db.. Entry uses this to decide
 * what goes in the interpretations it gives.
 */
QStringList DictFileEdict::listDictDisplayOptions(QStringList x) const
{
    x += displayOptions().keys();
    return x;
}

/**
 * Load up the dictionary
 */
bool DictFileEdict::loadDictionary(const QString &fileName, const QString &dictName)
{
    if (m_edictFile.valid()) {
        return false; // Already loaded
    }

    if (m_edictFile.loadFile(fileName)) {
        m_dictionaryName = dictName;
        m_dictionaryFile = fileName;

        m_deinflection = new Deinflection(m_dictionaryName);
        m_deinflection->load();

        return true;
    }

    return false;
}

QMap<QString, QString> DictFileEdict::loadDisplayOptions() const
{
    QMap<QString, QString> list = displayOptions();
    list[QStringLiteral("Word/Kanji")] = QStringLiteral("Word/Kanji");
    list[QStringLiteral("Reading")] = QStringLiteral("Reading");
    list[QStringLiteral("Meaning")] = QStringLiteral("Meaning");
    list[QStringLiteral("--Newline--")] = QStringLiteral("--Newline--");

    return list;
}

QStringList *DictFileEdict::loadListType(KConfigSkeletonItem *item, QStringList *list, const QMap<QString, QString> &long2short)
{
    QStringList listFromItem;

    if (item != nullptr) {
        listFromItem = item->property().toStringList();
    }

    if (!listFromItem.isEmpty()) {
        delete list;

        list = new QStringList();
        for (const QString &it : listFromItem) {
            if (long2short.contains(it)) {
                list->append(long2short[it]);
            }
        }
    }

    return list;
}

void DictFileEdict::loadSettings()
{
    this->displayFields = new QStringList(loadDisplayOptions().values());
}

void DictFileEdict::loadSettings(KConfigSkeleton *config)
{
    QMap<QString, QString> long2short = displayOptions();
    long2short[QStringLiteral("Word/Kanji")] = QStringLiteral("Word/Kanji");
    long2short[QStringLiteral("Reading")] = QStringLiteral("Reading");
    long2short[QStringLiteral("Meaning")] = QStringLiteral("Meaning");
    long2short[QStringLiteral("--Newline--")] = QStringLiteral("--Newline--");

    KConfigSkeletonItem *item = config->findItem(getType() + "__displayFields"_L1);
    this->displayFields = loadListType(item, this->displayFields, long2short);
}

inline Entry *DictFileEdict::makeEntry(const QString &entry)
{
    return new EntryEdict(getName(), entry);
}

DictionaryPreferenceDialog *DictFileEdict::preferencesWidget(KConfigSkeleton *config, QWidget *parent)
{
    auto dialog = new DictFileFieldSelector(config, getType(), parent);
    dialog->addAvailable(listDictDisplayOptions(QStringList()));
    return dialog;
}

/**
 * Scan a potential file for the correct format, remembering to skip comment
 * characters. This is not a foolproof scan, but it should be checked before adding
 * a new dictionary.
 * Valid EDICT format is considered:
 * \<kanji or kana\>+ [\<kana\>] /latin characters & symbols/separated with slashes/
 * Comment lines start with... something... not remembering now.
 */
bool DictFileEdict::validDictionaryFile(const QString &filename)
{
    QFile file(filename);
    bool returnFlag = true;

    if (!file.exists() || !file.open(QIODevice::ReadOnly)) {
        return false;
    }

    // Now we can actually check the file
    QStringDecoder decoder("EUC-JP");
    const QString decoded = decoder(file.readAll());

    QTextStream fileStream(decoded.toUtf8());

    QString commentMarker(QStringLiteral("？？？？")); // Note: Don't touch this! vim seems to have
                                                       // An odd text codec error here too :(
    QRegularExpression formattedLine(QStringLiteral("^\\S+\\s+(\\[\\S+\\]\\s+)?/.*/$"));
    while (!fileStream.atEnd()) {
        QString line = fileStream.readLine();

        if (line.left(4) == commentMarker) {
            continue;
        }
        if (line.contains(formattedLine)) // If it matches our regex
        {
            continue;
        }

        returnFlag = false;
        break;
    }

    file.close();
    return returnFlag;
}

/**
 * Reject queries that specify anything we don't understand
 */
// TODO: Actually write this method (validQuery)
bool DictFileEdict::validQuery(const DictQuery &query)
{
    Q_UNUSED(query)
    return true;
}