/*
 *      gpgcontext.cpp
 *
 *      Copyright 2008 gpg4usb-team <gpg4usb@cpunk.de>
 *
 *      This file is part of gpg4usb.
 *
 *      Gpg4usb 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 3 of the License, or
 *      (at your option) any later version.
 *
 *      Gpg4usb 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 gpg4usb.  If not, see <http://www.gnu.org/licenses/>
 */

#include "gpgcontext.h"
#include "kgpg/gpgproc.h"
#include "kgpg/kgpginterface.h"
#include "kgpg/klinebufferedprocess.h"
#include "kgpg/core/kgpgkey.h"
#include "kgpg/transactions/kgpgencrypt.h"
#ifdef _WIN32
#include <windows.h>
#include <unistd.h>    /* contains read/write */
#endif


namespace GpgME
{

/** Constructor
 *  Set up gpgme-context, set paths to app-run path
 */
GpgContext::GpgContext()
{
    connect(this,SIGNAL(keyDBChanged()),this,SLOT(slotRefreshKeyList()));
    slotRefreshKeyList();
}

/** Destructor
 */
GpgContext::~GpgContext()
{

}

KgpgCore::KgpgKey GpgContext::getKeyDetails(QString uid) {

    KgpgCore::KgpgKeyList keys;
    keys = KgpgInterface::readPublicKeys(QStringList() << uid);
    KgpgCore::KgpgKey key = keys.first();
    return key;

}



/** List all availabe Keys (VERY much like kgpgme)
 */
GpgKeyList GpgContext::listKeys()
{

    GpgKeyList keys;

    foreach(KgpgCore::KgpgKey kkey, KgpgInterface::readPublicKeys()) {
        GpgKey key;
        key.email = kkey.email();
        //key.expired = kkey.expirationDate().toString();
        key.expired = false;
        key.fpr = kkey.fingerprint();
        key.id = kkey.id();
        key.fullid = kkey.fullId();
        key.name = kkey.name();
        key.revoked = false;
        keys.append(key);
    }

    foreach(KgpgCore::KgpgKey skey, KgpgInterface::readSecretKeys()) {
        // iterate keys, mark privates
        GpgKeyList::iterator it = keys.begin();
        while (it != keys.end()) {
            if (skey.id() == it->id) {
                it->privkey = true;
            }
            it++;
        }
    }

    return keys;
}

// TODO: do we really need to call gpg or could we use an already existing list
bool GpgContext::isSecretKey(QString uid) {

    foreach(KgpgCore::KgpgKey skey, KgpgInterface::readSecretKeys()) {
        if(skey.id() == uid) return true;
    }

    return false;

}

/** also from kgpgme.cpp, seems to clear password from mem */
void GpgContext::clearPasswordCache()
{
    if (mPasswordCache.size() > 0) {
        mPasswordCache.fill('\0');
        mPasswordCache.truncate(0);
    }
}

/*
 * if there is no '\n' before the PGP-Begin-Block, but for example a whitespace,
 * GPGME doesn't recognise the Message as encrypted. This function adds '\n'
 * before the PGP-Begin-Block, if missing.
 */
void GpgContext::preventNoDataErr(QByteArray *in)
{
    int block_start = in->indexOf(GpgConstants::PGP_CRYPT_BEGIN);
    if (block_start > 0 && in->at(block_start - 1) != '\n') {
        in->insert(block_start, '\n');
    }
    block_start = in->indexOf(GpgConstants::PGP_SIGNED_BEGIN);
    if (block_start > 0 && in->at(block_start - 1) != '\n') {
        in->insert(block_start, '\n');
    }
}

/*
  * isSigned returns:
  * - 0, if text isn't signed at all
  * - 1, if text is partially signed
  * - 2, if text is completly signed
  */
int GpgContext::textIsSigned(const QByteArray &text) {
    if (text.trimmed().startsWith(GpgConstants::PGP_SIGNED_BEGIN) && text.trimmed().endsWith(GpgConstants::PGP_SIGNED_END)) {
        return 2;
    }
    if (text.contains(GpgConstants::PGP_SIGNED_BEGIN) && text.contains(GpgConstants::PGP_SIGNED_END)) {
        return 1;
    }
    return 0;
}

QString GpgContext::beautifyFingerprint(QString fingerprint)
{
    uint len = fingerprint.length();
    if ((len > 0) && (len % 4 == 0))
        for (uint n = 0; 4 *(n + 1) < len; ++n)
            fingerprint.insert(5 * n + 4, ' ');
    return fingerprint;
}

void GpgContext::slotRefreshKeyList() {
    mKeyList = this->listKeys();
}

/**
 * note: privkey status is not returned
 */
GpgKey GpgContext::getKeyByFpr(QString fpr) {

    foreach  (GpgKey key, mKeyList) {
        if(key.fpr == fpr) {
            return key;
        }
    }

    return GpgKey();
}

/**
 * note: privkey status is not returned
 * TODO: Long Ids also should be supported
 */
GpgKey GpgContext::getKeyById(QString id) {

    foreach  (GpgKey key, mKeyList) {
        if(key.id == id || key.fullid == id) {
            return key;
        }
    }

    return GpgKey();
}

void GpgContext::emitKeyDBChanged() {
    emit keyDBChanged();
}

// TODO: from kgpgverify, merge back
static QString
sigTimeMessage(const QString &sigtime)
{
    QDateTime stamp;
    if (sigtime.contains(QLatin1Char('T'))) {
        stamp = QDateTime::fromString(sigtime, Qt::ISODate);
    } else {
        bool ok;
        qint64 secs = sigtime.toLongLong(&ok);
        if (ok)
            stamp = QDateTime::fromMSecsSinceEpoch(secs * 1000);
    }

    if (!stamp.isValid())
        return QString();

    return QObject::tr("The signature was created at %1 %2")
            .arg(stamp.date().toString())
            .arg(stamp.time().toString() + QLatin1String("<br/>")
                 , "first argument is formatted date, second argument is formatted time");

}

QString GpgContext::getReport(const QStringList &log)
{
    QString result;
    // newer versions of GnuPG emit both VALIDSIG and GOODSIG
    // for a good signature. Since VALIDSIG has more information
    // we use that.
    const QRegExp validsig(QLatin1String("^\\[GNUPG:\\] VALIDSIG([ ]+[^ ]+){10,}.*$"));
    //const bool useGoodSig = (model != NULL) && (log.indexOf(validsig) == -1);
    const bool useGoodSig = log.indexOf(validsig) == -1;
    QString sigtime;	// timestamp of signature creation

    foreach (const QString &line, log) {
        if (!line.startsWith(QLatin1String("[GNUPG:] ")))
            continue;

        const QString msg = line.mid(9);

        if (msg.startsWith(QLatin1String("VALIDSIG ")) && !useGoodSig) {
            // from GnuPG source, doc/DETAILS:
            //   VALIDSIG    <fingerprint in hex> <sig_creation_date> <sig-timestamp>
            //                <expire-timestamp> <sig-version> <reserved> <pubkey-algo>
            //                <hash-algo> <sig-class> <primary-key-fpr>
            const QStringList vsig = msg.mid(9).split(QLatin1Char(' '), QString::SkipEmptyParts);
            Q_ASSERT(vsig.count() >= 10);

            //result += vsig[9];

            GpgKey key = getKeyByFpr(vsig[9]);

            // ignore for now if this is signed with the primary id (vsig[0] == vsig[9]) or not
            if (key.email.isEmpty()) {
                result += tr("<qt>Good signature from:<br /><b>%1</b><br />Key ID: %2<br /></qt>")
                        .arg(key.name).arg(vsig[9]);
            } else {
                result += tr("Good signature from: NAME <EMAIL>, Key ID: HEXID",
                        "<qt>Good signature from:<br /><b>%1 &lt;%2&gt;</b><br />Key ID: %3<br /></qt>")
                        .arg(key.name).arg(key.email).arg(vsig[9]);
            }
            result += sigTimeMessage(vsig[2]);


/*			const KGpgKeyNode *node = model->findKeyNode(vsig[9]);

            if (node != NULL) {
                // ignore for now if this is signed with the primary id (vsig[0] == vsig[9]) or not
                if (node->getEmail().isEmpty())
                    result += tr("<qt>Good signature from:<br /><b>%1</b><br />Key ID: %2<br /></qt>")
                            .arg(node->getName()).arg(vsig[9]);
                else
                    result += tr("Good signature from: NAME <EMAIL>, Key ID: HEXID",
                            "<qt>Good signature from:<br /><b>%1 &lt;%2&gt;</b><br />Key ID: %3<br /></qt>")
                            .arg(node->getName()).arg(node->getEmail()).arg(vsig[9]);

                result += sigTimeMessage(vsig[2]);
            } else {
                // this should normally never happen, but one could delete
                // the key just after the verification. Brute force solution:
                // do the whole report generation again, but this time make
                // sure GOODSIG is used.
                return getReport(log, NULL);
            }*/
        } else if (msg.startsWith(QLatin1String("UNEXPECTED")) ||
                msg.startsWith(QLatin1String("NODATA"))) {
            result += tr("No signature found.") + QLatin1Char('\n');
        } else if (useGoodSig && msg.startsWith(QLatin1String("GOODSIG "))) {
            int sigpos = msg.indexOf( ' ' , 8);
            const QString keyid = msg.mid(8, sigpos - 8);

            // split the name/email pair to give translators more power to handle this
            QString email;
            QString name = msg.mid(sigpos + 1);

            int oPos = name.indexOf(QLatin1Char('<'));
            int cPos = name.indexOf(QLatin1Char('>'));
            if ((oPos >= 0) && (cPos >= 0)) {
                email = name.mid(oPos + 1, cPos - oPos - 1);
                name = name.left(oPos).simplified();
            }

            if (email.isEmpty())
                result += tr("<qt>Good signature from:<br /><b>%1</b><br />Key ID: %2<br /></qt>")
                        .arg(name).arg(keyid);
            else
                result += tr("Good signature from: NAME <EMAIL>, Key ID: HEXID",
                             "<qt>Good signature from:<br /><b>%1 &lt;%2&gt;</b><br />Key ID: %3<br /></qt>")
                        .arg(name).arg(email).arg(keyid);
            if (!sigtime.isEmpty()) {
                result += sigTimeMessage(sigtime);
                sigtime.clear();
            }
        } else if (msg.startsWith(QLatin1String("SIG_ID "))) {
            const QStringList parts = msg.simplified().split(QLatin1Char(' '));
            if (parts.count() > 2)
                sigtime = parts[2];
        } else if (msg.startsWith(QLatin1String("BADSIG"))) {
            int sigpos = msg.indexOf( ' ', 7);
            result += tr("<qt><b>BAD signature</b> from:<br /> %1<br />Key id: %2<br /><br /><b>The file is corrupted</b><br /></qt>")
                    .arg(msg.mid(sigpos + 1).replace(QLatin1Char('<'), QLatin1String("&lt;")))
                    .arg(msg.mid(7, sigpos - 7));
        } else  if (msg.startsWith(QLatin1String("TRUST_UNDEFINED"))) {
            result += tr("<qt>The signature is valid, but the key is untrusted<br /></qt>");
        } else if (msg.startsWith(QLatin1String("TRUST_ULTIMATE"))) {
            result += tr("<qt>The signature is valid, and the key is ultimately trusted<br /></qt>");
        }
    }

    return result;
}

}