#include "gitstatusmodel.h"

#include <QFont>
#include <QIcon>

GitStatusModel::GitStatusModel(QObject *parent)
    : QAbstractItemModel(parent)
{
    m_nodeNames[NodeStaged] = QStringLiteral("Staged");
    m_nodeNames[NodeChanged] = QStringLiteral("Changed");
    m_nodeNames[NodeUntracked] = QStringLiteral("Untracked");

    m_nodeIcons[NodeStaged] = QIcon::fromTheme(QStringLiteral("vcs-added"));
    m_nodeIcons[NodeChanged] = QIcon::fromTheme(QStringLiteral("vcs-locally-modified"));
    m_nodeIcons[NodeUntracked] = QIcon::fromTheme(QStringLiteral("vcs-added"));
}

QModelIndex GitStatusModel::index(int row, int column, const QModelIndex &parent) const
{
    if (column != 0)
        return {};

    if (!parent.isValid()) {
        // Top-level nodes
        if (row >= 0 && row < NodeCount)
            return createIndex(row, 0, TopLevelId);
        return {};
    }

    // Child items — parent's internalId is TopLevelId, parent's row gives the node type
    if (parent.internalId() == TopLevelId) {
        int nodeType = parent.row();
        if (nodeType >= 0 && nodeType < NodeCount && row >= 0 && row < m_entries[nodeType].size())
            return createIndex(row, 0, quintptr(nodeType));
    }

    return {};
}

QModelIndex GitStatusModel::parent(const QModelIndex &child) const
{
    if (!child.isValid())
        return {};

    if (child.internalId() == TopLevelId)
        return {}; // top-level has no parent

    // internalId is the node type
    int nodeType = int(child.internalId());
    if (nodeType >= 0 && nodeType < NodeCount)
        return createIndex(nodeType, 0, TopLevelId);

    return {};
}

int GitStatusModel::rowCount(const QModelIndex &parent) const
{
    if (!parent.isValid())
        return NodeCount;

    if (parent.internalId() == TopLevelId) {
        int nodeType = parent.row();
        if (nodeType >= 0 && nodeType < NodeCount)
            return m_entries[nodeType].size();
    }

    return 0;
}

int GitStatusModel::columnCount(const QModelIndex &) const
{
    return 1;
}

QVariant GitStatusModel::data(const QModelIndex &index, int role) const
{
    if (!index.isValid())
        return {};

    // Top-level nodes
    if (index.internalId() == TopLevelId) {
        int nodeType = index.row();
        if (nodeType < 0 || nodeType >= NodeCount)
            return {};

        switch (role) {
        case Qt::DisplayRole:
            return QStringLiteral("%1 (%2)").arg(m_nodeNames[nodeType]).arg(m_entries[nodeType].size());
        case Qt::DecorationRole:
            return m_nodeIcons[nodeType];
        case Qt::FontRole: {
            QFont f;
            f.setBold(true);
            return f;
        }
        case NodeTypeRole:
            return nodeType;
        default:
            return {};
        }
    }

    // File entries
    int nodeType = int(index.internalId());
    if (nodeType < 0 || nodeType >= NodeCount)
        return {};

    int row = index.row();
    if (row < 0 || row >= m_entries[nodeType].size())
        return {};

    const auto &entry = m_entries[nodeType][row];

    switch (role) {
    case Qt::DisplayRole:
        return entry.file;
    case Qt::DecorationRole: {
        // Status char icon
        QChar sc = (nodeType == NodeStaged) ? entry.indexStatus : entry.workStatus;
        if (sc == QLatin1Char('M'))
            return QIcon::fromTheme(QStringLiteral("vcs-locally-modified"));
        if (sc == QLatin1Char('A') || sc == QLatin1Char('?'))
            return QIcon::fromTheme(QStringLiteral("vcs-added"));
        if (sc == QLatin1Char('D'))
            return QIcon::fromTheme(QStringLiteral("vcs-removed"));
        if (sc == QLatin1Char('R'))
            return QIcon::fromTheme(QStringLiteral("vcs-locally-modified"));
        return QIcon::fromTheme(QStringLiteral("text-plain"));
    }
    case Qt::ToolTipRole: {
        QChar sc = (nodeType == NodeStaged) ? entry.indexStatus : entry.workStatus;
        return QStringLiteral("[%1] %2").arg(sc).arg(entry.file);
    }
    case FilePathRole:
        return entry.file;
    case NodeTypeRole:
        return nodeType;
    default:
        return {};
    }
}

Qt::ItemFlags GitStatusModel::flags(const QModelIndex &index) const
{
    if (!index.isValid())
        return Qt::NoItemFlags;

    if (index.internalId() == TopLevelId)
        return Qt::ItemIsEnabled; // top-level nodes not selectable

    return Qt::ItemIsEnabled | Qt::ItemIsSelectable;
}

void GitStatusModel::parseStatus(const QByteArray &raw)
{
    if (raw == m_lastRaw)
        return;
    m_lastRaw = raw;

    beginResetModel();

    for (int i = 0; i < NodeCount; ++i)
        m_entries[i].clear();

    const auto lines = raw.split('\n');
    for (const auto &line : lines) {
        if (line.size() < 4)
            continue;

        // Format: XY <space> filename
        // or XY <space> old -> new (for renames)
        QChar x = QLatin1Char(line.at(0));
        QChar y = QLatin1Char(line.at(1));
        // line[2] is space
        QString file = QString::fromUtf8(line.mid(3));

        // Handle renames: "R  old -> new"
        int arrowIdx = file.indexOf(QStringLiteral(" -> "));
        if (arrowIdx >= 0)
            file = file.mid(arrowIdx + 4);

        GitStatusEntry entry{file, x, y};

        // Staged: X is not ' ', '?' or '!'
        if (x != QLatin1Char(' ') && x != QLatin1Char('?') && x != QLatin1Char('!')) {
            m_entries[NodeStaged].append(entry);
        }

        // Changed (working tree): Y is not ' ', '?' or '!'
        if (y == QLatin1Char('?')) {
            m_entries[NodeUntracked].append(entry);
        } else if (y != QLatin1Char(' ') && y != QLatin1Char('!')) {
            m_entries[NodeChanged].append(entry);
        }
    }

    endResetModel();
}