#include "inputbar.h"
#include "emojipanel.h"
#include "debug_ui.h"
#include <QDebug>
#include <QTextEdit>
#include <QPushButton>
#include <QHBoxLayout>
#include <QVBoxLayout>
#include <QFileDialog>
#include <QKeyEvent>
#include <QFontMetrics>
#include <QScrollBar>
#include <QApplication>

static QPushButton *makeIconBtn(const QString &text, const QString &tooltip, QWidget *parent) {
    auto *btn = new QPushButton(text, parent);
    btn->setFixedSize(34, 34);
    btn->setCursor(Qt::PointingHandCursor);
    btn->setToolTip(tooltip);
    btn->setStyleSheet(
        "QPushButton { border: none; border-radius: 4px; font-size: 18px; background: transparent; }"
        "QPushButton:hover { background: palette(light); }"
    );
    return btn;
}

static QWidget *wrapBottomBtn(QPushButton *btn, int pad) {
    auto *w = new QWidget(btn->parentWidget());
    auto *l = new QVBoxLayout(w);
    l->setContentsMargins(0, 0, 0, 0);
    l->setSpacing(0);
    l->addWidget(btn);
    l->addSpacing(pad);
    return w;
}

InputBar::InputBar(EmojiPanel *emojiPanel, QWidget *parent)
    : QWidget(parent)
    , m_input(new QTextEdit(this))
    , m_emojiBtn(nullptr)
    , m_emojiPanel(emojiPanel)
{
    auto *layout = new QHBoxLayout(this);
    layout->setContentsMargins(8, 4, 8, 4);
    layout->setSpacing(4);

    auto *attachBtn = makeIconBtn(QString::fromUtf8("\xF0\x9F\x93\x8E"),
                                  QString::fromUtf8("Прикрепить"), this);
    connect(attachBtn, &QPushButton::clicked, this, [this]() {
        QString path = QFileDialog::getOpenFileName(this, QString::fromUtf8("Прикрепить файл"));
        if (!path.isEmpty()) {
            qDebug() << "Attached:" << path;
        }
    });
    layout->addWidget(wrapBottomBtn(attachBtn, 3), 0, Qt::AlignBottom);

    m_input->setAcceptRichText(false);
    m_input->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    m_input->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    m_input->setTabChangesFocus(true);
    m_input->setStyleSheet(
        "QTextEdit { border: 1px solid palette(mid); border-radius: 6px;"
        " padding: 4px 8px; background: palette(base); }"
    );
    m_input->installEventFilter(this);
    QFontMetrics fm(m_input->font());
    m_input->setFixedHeight(fm.lineSpacing() + 12);
    layout->addWidget(m_input, 1);

    m_emojiBtn = makeIconBtn(QString::fromUtf8("\xF0\x9F\x99\x82"),
                             QString::fromUtf8("Смайлики"), this);
    layout->addWidget(wrapBottomBtn(m_emojiBtn, 3), 0, Qt::AlignBottom);

    auto *sendBtn = makeIconBtn(QString::fromUtf8("\xE2\x9E\xA4"),
                                QString::fromUtf8("Отправить"), this);
    sendBtn->setStyleSheet(sendBtn->styleSheet() +
        "QPushButton { color: palette(highlight); font-weight: bold; }");
    layout->addWidget(sendBtn, 0, Qt::AlignBottom);

    connect(m_input, &QTextEdit::textChanged, this, &InputBar::adjustInputHeight);
    connect(sendBtn, &QPushButton::clicked,   this, &InputBar::onSendClicked);

    if (m_emojiPanel) {
        connect(m_emojiBtn, &QPushButton::clicked, this, [this]() {
            m_emojiPanel->setVisible(!m_emojiPanel->isVisible());
        });
        connect(m_emojiPanel, &EmojiPanel::emojiSelected, this, [this](const QString &emoji) {
            m_input->insertPlainText(emoji);
            m_input->setFocus();
        });
    }
}

bool InputBar::eventFilter(QObject *obj, QEvent *event) {
    if (obj == m_input && event->type() == QEvent::KeyPress) {
        auto *ke = static_cast<QKeyEvent *>(event);
        if (ke->key() == Qt::Key_Return || ke->key() == Qt::Key_Enter) {
            if (ke->modifiers() & Qt::ControlModifier) {
                m_input->insertPlainText("\n");
                return true;
            } else {
                onSendClicked();
                return true;
            }
        }
    }
    return QWidget::eventFilter(obj, event);
}

void InputBar::adjustInputHeight() {
    m_input->document()->adjustSize();

    int lineSpacing = m_input->fontMetrics().lineSpacing();
    int docH = (int)m_input->document()->size().height() + 12;
    int maxH = 12 * lineSpacing + 12;
    int h = qBound(lineSpacing + 12, docH, maxH);
    m_input->setFixedHeight(h);

    bool needScroll = docH > maxH;
    m_input->setVerticalScrollBarPolicy(needScroll ? Qt::ScrollBarAlwaysOn
                                                   : Qt::ScrollBarAlwaysOff);
    if (needScroll) {
        QTextCursor c = m_input->textCursor();
        if (c.atEnd())
            m_input->verticalScrollBar()->setValue(m_input->verticalScrollBar()->maximum());
        else
            m_input->ensureCursorVisible();
    }
}

void InputBar::onSendClicked() {
    QString text = m_input->toPlainText();
    GUI_INFO("send: len=%d hasLF=%d text='%s'",
             text.length(), text.contains('\n'), qPrintable(text));
    while (!text.isEmpty() && (text.back() == ' ' || text.back() == '\t'))
        text.chop(1);
    if (text.isEmpty()) return;
    emit sendMessage(text);
    m_input->clear();
    if (m_emojiPanel) m_emojiPanel->hide();
    m_input->setFocus();
}