#include "about_dialog.h"

#include <QApplication>
#include <QCoreApplication>
#include <QDialogButtonBox>
#include <QHBoxLayout>
#include <QLabel>
#include <QTextBrowser>
#include <QVBoxLayout>

namespace {
// palette(mid) is meant for 3D bevel/shadow decoration, not text — it has
// poor contrast against the window background in dark themes (barely
// legible). Blend the widget's actual text and window colors instead, so
// the result is reliably readable — de-emphasized relative to full-strength
// text, but never low-contrast — in either a light or dark theme.
QColor mutedTextColor(const QWidget* widget)
{
    const QPalette pal = widget->palette();
    const QColor text = pal.color(QPalette::WindowText);
    const QColor background = pal.color(QPalette::Window);
    constexpr qreal kTextWeight = 0.65;

    auto blend = [kTextWeight](int textChannel, int backgroundChannel) {
        return qBound(0,
                      qRound(textChannel * kTextWeight + backgroundChannel * (1.0 - kTextWeight)),
                      255);
    };

    return QColor(blend(text.red(), background.red()),
                  blend(text.green(), background.green()),
                  blend(text.blue(), background.blue()));
}
}

AboutDialog::AboutDialog(QWidget* parent) : QDialog(parent)
{
    setWindowTitle(QStringLiteral("About OrbitHub"));
    setWindowIcon(QApplication::windowIcon());
    resize(760, 560);

    auto* layout = new QVBoxLayout(this);
    layout->setContentsMargins(16, 16, 16, 16);
    layout->setSpacing(12);

    auto* headerRow = new QHBoxLayout();
    headerRow->setSpacing(12);

    auto* iconLabel = new QLabel(this);
    iconLabel->setFixedSize(80, 80);
    iconLabel->setPixmap(QApplication::windowIcon().pixmap(80, 80));
    iconLabel->setAlignment(Qt::AlignCenter);

    auto* titleColumn = new QVBoxLayout();
    titleColumn->setSpacing(4);

    auto* title = new QLabel(QStringLiteral("<h1 style='margin:0'>OrbitHub</h1>"), this);
    auto* subtitle = new QLabel(
        QStringLiteral("Unified remote session manager for SSH, RDP, and VNC workflows."),
        this);
    subtitle->setWordWrap(true);
    subtitle->setStyleSheet(QStringLiteral("color: %1;").arg(mutedTextColor(this).name()));

    const QString version = QCoreApplication::applicationVersion().trimmed().isEmpty()
        ? QStringLiteral("Development build")
        : QCoreApplication::applicationVersion().trimmed();
    auto* buildLine = new QLabel(
        QStringLiteral("Version: %1 | Qt runtime linked dynamically").arg(version),
        this);
    buildLine->setStyleSheet(QStringLiteral("color: %1;").arg(mutedTextColor(this).name()));

    titleColumn->addWidget(title);
    titleColumn->addWidget(subtitle);
    titleColumn->addWidget(buildLine);
    titleColumn->addStretch();

    headerRow->addWidget(iconLabel, 0, Qt::AlignTop);
    headerRow->addLayout(titleColumn, 1);

    auto* browser = new QTextBrowser(this);
    browser->setOpenExternalLinks(true);
    browser->setStyleSheet(QStringLiteral(
        "QTextBrowser { border: 1px solid palette(midlight); border-radius: 8px; padding: 8px; }"));
    browser->setHtml(QStringLiteral(R"(
<h3 style="margin-top:0">Third-Party Libraries</h3>
<p>OrbitHub uses the following external libraries:</p>
<table cellspacing="0" cellpadding="6" border="1" style="border-collapse:collapse; width:100%;">
  <tr><th align="left">Library</th><th align="left">License</th><th align="left">Upstream</th></tr>
  <tr><td>Qt 6 (Widgets / SQL)</td><td>LGPLv3 / GPLv3 / Commercial</td><td><a href="https://www.qt.io/licensing">qt.io/licensing</a></td></tr>
  <tr><td>KodoTerm</td><td>MIT</td><td><a href="https://github.com/diegoiast/KodoTerm">github.com/diegoiast/KodoTerm</a></td></tr>
  <tr><td>libvterm</td><td>MIT</td><td><a href="https://github.com/neovim/libvterm">github.com/neovim/libvterm</a></td></tr>
  <tr><td>FreeRDP / WinPR</td><td>Apache License 2.0</td><td><a href="https://github.com/FreeRDP/FreeRDP">github.com/FreeRDP/FreeRDP</a></td></tr>
</table>

<h3>License Links</h3>
<ul>
  <li><a href="https://www.gnu.org/licenses/lgpl-3.0.html">GNU LGPLv3 (gnu.org)</a></li>
  <li><a href="https://opensource.org/licenses/MIT">MIT License (opensource.org)</a></li>
  <li><a href="https://www.apache.org/licenses/LICENSE-2.0">Apache License 2.0 (apache.org)</a></li>
</ul>

<h3>License Files In This Repository</h3>
<ul>
  <li><code>third_party/KodoTerm/LICENSE</code></li>
  <li><code>third_party/FreeRDP/LICENSE</code></li>
  <li><code>LICENSE</code> (project license)</li>
</ul>
)"));

    auto* buttons = new QDialogButtonBox(QDialogButtonBox::Close, this);
    connect(buttons, &QDialogButtonBox::rejected, this, &QDialog::reject);
    connect(buttons, &QDialogButtonBox::accepted, this, &QDialog::accept);

    layout->addLayout(headerRow);
    layout->addWidget(browser, 1);
    layout->addWidget(buttons);
}