#include "tagpanel.h"
#include <QHeaderView>
#include <QRegularExpression>
#include <QApplication>
#include <QClipboard>
#include <QDateTime>
#include <QScrollBar>
#include <QFont>
#include <QTextCursor>

TagPanel::TagPanel(const QString &tag, QWidget *parent)
    : QGroupBox(QStringLiteral("[%1]").arg(tag), parent)
    , m_tag(tag)
{
    auto *layout = new QVBoxLayout(this);
    layout->setContentsMargins(6, 14, 6, 6);
    layout->setSpacing(4);

    m_tabs = new QTabWidget(this);

    // ── "Aktuell" tab: latest value(s), updates in-place ───────────────
    auto *currentTab = new QWidget(m_tabs);
    auto *currentLayout = new QVBoxLayout(currentTab);
    currentLayout->setContentsMargins(0, 4, 0, 0);
    currentLayout->setSpacing(4);

    m_table = new QTableWidget(0, 2, currentTab);
    m_table->setHorizontalHeaderLabels({tr("Key"), tr("Value")});
    m_table->horizontalHeader()->setStretchLastSection(true);
    m_table->verticalHeader()->hide();
    m_table->setEditTriggers(QAbstractItemView::NoEditTriggers);
    m_table->setAlternatingRowColors(true);
    m_table->setMaximumHeight(220);
    m_table->verticalHeader()->setDefaultSectionSize(22);
    currentLayout->addWidget(m_table);

    m_rawLabel = new QLabel(currentTab);
    m_rawLabel->setWordWrap(true);
    m_rawLabel->setStyleSheet("font-family: monospace;");
    m_rawLabel->hide();
    currentLayout->addWidget(m_rawLabel);

    m_tabs->addTab(currentTab, tr("Aktuell"));

    // ── "Verlauf" tab: every value ever received, timestamped ──────────
    auto *historyTab = new QWidget(m_tabs);
    auto *historyLayout = new QVBoxLayout(historyTab);
    historyLayout->setContentsMargins(0, 4, 0, 0);
    historyLayout->setSpacing(4);

    m_historyEdit = new QPlainTextEdit(historyTab);
    m_historyEdit->setReadOnly(true);
    m_historyEdit->setMaximumHeight(220);
    m_historyEdit->setLineWrapMode(QPlainTextEdit::NoWrap);
    QFont mono("Monospace");
    mono.setStyleHint(QFont::Monospace);
    mono.setPointSize(9);
    m_historyEdit->setFont(mono);
    historyLayout->addWidget(m_historyEdit);

    auto *historyBtnRow = new QHBoxLayout();
    auto *clearHistBtn = new QPushButton(tr("Verlauf leeren"), historyTab);
    clearHistBtn->setToolTip(tr("Nur den Verlauf dieses Tags leeren (Panel bleibt bestehen)"));
    connect(clearHistBtn, &QPushButton::clicked, this, &TagPanel::clearHistory);
    historyBtnRow->addStretch();
    historyBtnRow->addWidget(clearHistBtn);
    historyLayout->addLayout(historyBtnRow);

    m_tabs->addTab(historyTab, tr("Verlauf"));

    layout->addWidget(m_tabs);

    auto *btnRow = new QHBoxLayout();
    btnRow->addStretch();
    auto *copyBtn = new QPushButton(tr("📋 Copy"), this);
    copyBtn->setToolTip(tr("Copy the active tab's content to clipboard"));
    copyBtn->setMaximumWidth(90);
    connect(copyBtn, &QPushButton::clicked, this, &TagPanel::copyToClipboard);
    btnRow->addWidget(copyBtn);
    layout->addLayout(btnRow);
}

void TagPanel::update(const QString &value)
{
    appendHistory(value);

    static const QRegularExpression kvRe(R"((\w+)=(\S+))");
    if (kvRe.match(value).hasMatch()) {
        parseKeyValue(value);
        m_rawLabel->hide();
        m_table->show();
    } else {
        showRaw(value);
        m_table->hide();
        m_rawLabel->show();
    }
}

void TagPanel::appendHistory(const QString &value)
{
    const QString ts = QDateTime::currentDateTime().toString("hh:mm:ss.zzz");
    m_historyEdit->appendPlainText(QStringLiteral("[%1]  %2").arg(ts, value));
    m_historyEdit->verticalScrollBar()->setValue(
        m_historyEdit->verticalScrollBar()->maximum());

    ++m_historyCount;
    if (m_historyCount > kMaxHistoryEntries) {
        // Drop the oldest entry (topmost line) to keep memory use bounded
        // for very chatty or long-running tags.
        QTextCursor cursor(m_historyEdit->document());
        cursor.movePosition(QTextCursor::Start);
        cursor.movePosition(QTextCursor::Down, QTextCursor::KeepAnchor);
        cursor.removeSelectedText();
        --m_historyCount;
    }
}

void TagPanel::clearHistory()
{
    m_historyEdit->clear();
    m_historyCount = 0;
}

void TagPanel::parseKeyValue(const QString &value)
{
    static const QRegularExpression kvRe(R"((\w+)=(\S+))");
    auto it = kvRe.globalMatch(value);
    while (it.hasNext()) {
        const auto match = it.next();
        const QString key   = match.captured(1);
        const QString raw   = match.captured(2);

        // Split on ';' -> list of values. A plain (non-list) value yields
        // a QStringList with exactly one element, which still goes through
        // the same code path for consistency.
        QStringList values = raw.split(';', Qt::SkipEmptyParts);
        if (values.isEmpty())
            values << raw;   // preserve even an empty/odd value as-is

        setKeyValues(key, values);
    }
}

void TagPanel::setKeyValues(const QString &key, const QStringList &values)
{
    const int newCount = values.size();

    if (m_keyRanges.contains(key)) {
        // Key already exists – remove its current rows, then re-insert at
        // the same starting position with the new row count.
        const KeyRange old = m_keyRanges[key];
        for (int i = 0; i < old.count; ++i)
            m_table->removeRow(old.firstRow);

        // Shift all OTHER key ranges that started after this one
        for (auto it = m_keyRanges.begin(); it != m_keyRanges.end(); ++it) {
            if (it.key() != key && it->firstRow > old.firstRow)
                it->firstRow += (newCount - old.count);
        }

        int insertAt = old.firstRow;
        for (int i = 0; i < newCount; ++i) {
            m_table->insertRow(insertAt + i);
            auto *keyItem = new QTableWidgetItem(i == 0 ? key : QString());
            auto *valItem = new QTableWidgetItem(values[i]);
            valItem->setBackground(QColor(0x2d, 0x5a, 0x2d));   // flash green on update
            m_table->setItem(insertAt + i, 0, keyItem);
            m_table->setItem(insertAt + i, 1, valItem);
        }
        m_keyRanges[key] = {insertAt, newCount};
    } else {
        // New key – append at the bottom
        const int insertAt = m_table->rowCount();
        for (int i = 0; i < newCount; ++i) {
            m_table->insertRow(insertAt + i);
            auto *keyItem = new QTableWidgetItem(i == 0 ? key : QString());
            auto *valItem = new QTableWidgetItem(values[i]);
            valItem->setBackground(QColor(0x2d, 0x5a, 0x2d));
            m_table->setItem(insertAt + i, 0, keyItem);
            m_table->setItem(insertAt + i, 1, valItem);
        }
        m_keyRanges[key] = {insertAt, newCount};
    }
}

void TagPanel::showRaw(const QString &value)
{
    m_rawLabel->setText(value);
}

void TagPanel::copyToClipboard()
{
    QStringList lines;
    lines << QStringLiteral("[%1]").arg(m_tag);

    if (m_tabs->currentIndex() == 1) {
        // "Verlauf" tab active - copy the full timestamped history as-is.
        QApplication::clipboard()->setText(
            lines.join('\n') + '\n' + m_historyEdit->toPlainText());
        return;
    }

    if (m_table->isVisible()) {
        QString lastKey;
        for (int r = 0; r < m_table->rowCount(); ++r) {
            const QString key = m_table->item(r, 0)->text();
            const QString val = m_table->item(r, 1)->text();
            if (!key.isEmpty()) {
                lines << QStringLiteral("  %1 = %2").arg(key, val);
                lastKey = key;
            } else {
                lines << QStringLiteral("      %1").arg(val);   // continuation row
            }
        }
    } else {
        lines << QStringLiteral("  %1").arg(m_rawLabel->text());
    }

    QApplication::clipboard()->setText(lines.join('\n'));
}