/*
 * SPDX-License-Identifier: GPL-3.0-or-later
 */
#include "plumbmsg.h"

QString PlumbMsg::lookup(const QString &name) const
{
    for (const PlumbAttr &a : attr) {
        if (a.name == name)
            return a.value;
    }
    return QString();
}

void PlumbMsg::setAttr(const QString &name, const QString &value)
{
    for (PlumbAttr &a : attr) {
        if (a.name == name) {
            a.value = value;
            return;
        }
    }
    attr.append(PlumbAttr{name, value});
}

// Quote one attribute value if it contains space, ', = or tab
static QString quoteAttrValue(const QString &v)
{
    bool needsQuote = false;
    for (const QChar c : v) {
        if (c == QLatin1Char(' ') || c == QLatin1Char('\'')
            || c == QLatin1Char('=') || c == QLatin1Char('\t')) {
            needsQuote = true;
            break;
        }
    }
    if (!needsQuote)
        return v;
    QString out;
    out.reserve(v.size() + 2);
    out.append(QLatin1Char('\''));
    for (const QChar c : v) {
        out.append(c);
        if (c == QLatin1Char('\''))
            out.append(c); // double it
    }
    out.append(QLatin1Char('\''));
    return out;
}

QByteArray packPlumbAttr(const QList<PlumbAttr> &attr)
{
    QString s;
    bool first = true;
    for (const PlumbAttr &a : attr) {
        if (!first)
            s.append(QLatin1Char(' '));
        first = false;
        s.append(a.name);
        s.append(QLatin1Char('='));
        s.append(quoteAttrValue(a.value));
    }
    return s.toUtf8();
}

QList<PlumbAttr> unpackPlumbAttr(const QByteArray &line)
{
    QList<PlumbAttr> out;
    const QString s = QString::fromUtf8(line);
    int i = 0;
    const int n = s.size();
    while (i < n) {
        while (i < n && (s[i] == QLatin1Char(' ') || s[i] == QLatin1Char('\t')))
            i++;
        if (i >= n)
            break;
        int nameStart = i;
        while (i < n && s[i] != QLatin1Char('=') && s[i] != QLatin1Char(' ')
               && s[i] != QLatin1Char('\t'))
            i++;
        if (i >= n || s[i] != QLatin1Char('='))
            break;
        const QString name = s.mid(nameStart, i - nameStart);
        i++; // skip '='
        QString value;
        bool quoting = false;
        while (i < n) {
            const QChar c = s[i];
            if (quoting) {
                if (c == QLatin1Char('\'')) {
                    if (i + 1 < n && s[i + 1] == QLatin1Char('\'')) {
                        i++;
                    } else {
                        quoting = false;
                        i++;
                        continue;
                    }
                }
            } else {
                if (c == QLatin1Char(' ') || c == QLatin1Char('\t'))
                    break;
                if (c == QLatin1Char('\'')) {
                    quoting = true;
                    i++;
                    continue;
                }
            }
            value.append(c);
            i++;
        }
        out.append(PlumbAttr{name, value});
    }
    return out;
}

QByteArray PlumbMsg::pack() const
{
    QByteArray buf;
    buf.append(src.toUtf8());
    buf.append('\n');
    buf.append(dst.toUtf8());
    buf.append('\n');
    buf.append(wdir.toUtf8());
    buf.append('\n');
    buf.append(type.toUtf8());
    buf.append('\n');
    buf.append(packPlumbAttr(attr));
    buf.append('\n');
    buf.append(QByteArray::number(data.size()));
    buf.append('\n');
    buf.append(data);
    return buf;
}

bool PlumbMsg::unpack(const QByteArray &buf, PlumbMsg *out)
{
    if (!out)
        return false;
    int pos = 0;
    const int n = buf.size();
    auto nextLine = [&](QByteArray *line) -> bool {
        int nl = buf.indexOf('\n', pos);
        if (nl < 0)
            return false;
        *line = buf.mid(pos, nl - pos);
        pos = nl + 1;
        return true;
    };

    QByteArray srcL, dstL, wdirL, typeL, attrL, ndataL;
    if (!nextLine(&srcL) || !nextLine(&dstL) || !nextLine(&wdirL)
        || !nextLine(&typeL) || !nextLine(&attrL) || !nextLine(&ndataL))
        return false;

    PlumbMsg m;
    m.src = QString::fromUtf8(srcL);
    m.dst = QString::fromUtf8(dstL);
    m.wdir = QString::fromUtf8(wdirL);
    m.type = QString::fromUtf8(typeL);
    m.attr = unpackPlumbAttr(attrL);

    bool ok = false;
    ndataL.trimmed().toInt(&ok);
    if (!ok)
        return false;
    m.data = buf.mid(pos, n - pos);

    *out = m;
    return true;
}