#include "MultiSelectComboBox.h"

#include <QDebug>
#include <QEvent>
#include <QLineEdit>
#include <QMouseEvent>
#include <QStandardItem>
#include <QStandardItemModel>
#include <QStyleOptionComboBox>
#include <QStylePainter>

MultiSelectComboBox::MultiSelectComboBox(QWidget *parent) : QComboBox(parent), skipNextHide(false) { initialize(); }

MultiSelectComboBox::~MultiSelectComboBox() {}

void MultiSelectComboBox::initialize() {
    // Set up the model
    setModel(new QStandardItemModel(this));

    // Set up the view
    QListView *listView = new QListView(this);
    setView(listView);

    // Make the combo box read-only but clickable
    setEditable(true);
    setInsertPolicy(QComboBox::NoInsert);
    lineEdit()->setReadOnly(true);

    // 设置输入框样式，使其看起来可点击
    lineEdit()->setCursor(Qt::PointingHandCursor);
    lineEdit()->setStyleSheet("QLineEdit { background-color: white; }");

    // Install event filter to handle mouse events
    view()->viewport()->installEventFilter(this);
    lineEdit()->installEventFilter(this);

    // Connect to the item changed signal
    connect(model(), &QStandardItemModel::itemChanged, this, &MultiSelectComboBox::onItemChanged);

    // Set minimum width for better display
    setMinimumWidth(150);

    // Set the default text
    updateText();
}

void MultiSelectComboBox::addItem(const QString &key, const QString &value) {
    QStandardItem *item = new QStandardItem(value);
    item->setFlags(Qt::ItemIsUserCheckable | Qt::ItemIsEnabled);
    item->setData(Qt::Unchecked, Qt::CheckStateRole);
    item->setData(key, Qt::UserRole);

    model()->appendRow(item);
    updateText();
}

void MultiSelectComboBox::addItems(const QList<QPair<QString, QString>> &items) {
    for (const auto &item : items) {
        addItem(item.first, item.second);
    }
}

QStringList MultiSelectComboBox::checkedKeys() const {
    QStringList keys;
    for (int i = 0; i < model()->rowCount(); ++i) {
        QStandardItem *item = model()->item(i);
        if (item->checkState() == Qt::Checked) {
            keys.append(item->data(Qt::UserRole).toString());
        }
    }
    return keys;
}

QList<QPair<QString, QString>> MultiSelectComboBox::checkedItemsWithKeys() const {
    QList<QPair<QString, QString>> items;
    for (int i = 0; i < model()->rowCount(); ++i) {
        QStandardItem *item = model()->item(i);
        if (item->checkState() == Qt::Checked) {
            items.append({item->data(Qt::UserRole).toString(), item->text()});
        }
    }
    return items;
}

void MultiSelectComboBox::setCheckedKeys(const QStringList &keys) {
    for (int i = 0; i < model()->rowCount(); ++i) {
        QStandardItem *item = model()->item(i);
        QString key = item->data(Qt::UserRole).toString();
        item->setData(keys.contains(key) ? Qt::Checked : Qt::Unchecked, Qt::CheckStateRole);
    }
    updateText();
}

bool MultiSelectComboBox::eventFilter(QObject *object, QEvent *event) {
    if (object == view()->viewport()) {
        if (event->type() == QEvent::MouseButtonPress) {
            QMouseEvent *mouseEvent = static_cast<QMouseEvent *>(event);
            if (mouseEvent->button() == Qt::LeftButton) {
                QModelIndex index = view()->indexAt(mouseEvent->pos());
                if (index.isValid()) {
                    // 切换选中状态
                    QStandardItem *item = model()->itemFromIndex(index);
                    if (item) {
                        Qt::CheckState currentState =
                            static_cast<Qt::CheckState>(item->data(Qt::CheckStateRole).toInt());
                        Qt::CheckState newState = (currentState == Qt::Checked) ? Qt::Unchecked : Qt::Checked;
                        item->setData(newState, Qt::CheckStateRole);

                        // 防止点击选项后立即关闭弹出菜单
                        skipNextHide = true;
                        return true;  // 阻止默认处理
                    }
                }
            }
        }
        if (event->type() == QEvent::MouseButtonRelease) {
            // 防止点击选项后立即关闭弹出菜单
            skipNextHide = true;
            return false;
        }
    } else if (object == lineEdit()) {
        if (event->type() == QEvent::MouseButtonPress) {
            QMouseEvent *mouseEvent = static_cast<QMouseEvent *>(event);
            if (mouseEvent->button() == Qt::LeftButton) {
                if (!view()->isVisible()) {
                    showPopup();
                } else {
                    hidePopup();
                }
                return true;  // 事件已处理
            }
        }
    }
    return QComboBox::eventFilter(object, event);
}

void MultiSelectComboBox::showPopup() { QComboBox::showPopup(); }

void MultiSelectComboBox::hidePopup() {
    if (skipNextHide) {
        skipNextHide = false;
        return;
    }
    QComboBox::hidePopup();
}

void MultiSelectComboBox::mousePressEvent(QMouseEvent *event) {
    // 如果点击的是输入框区域，显示弹出菜单
    if (event->button() == Qt::LeftButton) {
        if (!view()->isVisible()) {
            showPopup();
        } else {
            hidePopup();
        }
        event->accept();
        return;
    }

    // 其他情况调用父类方法
    QComboBox::mousePressEvent(event);
}

void MultiSelectComboBox::onItemChanged(QStandardItem *item) {
    Q_UNUSED(item);
    updateText();
}

void MultiSelectComboBox::updateText() {
    QStringList texts;
    for (int i = 0; i < model()->rowCount(); ++i) {
        QStandardItem *item = model()->item(i);
        if (item->checkState() == Qt::Checked) {
            texts.append(item->text());
        }
    }

    displayText = texts.isEmpty() ? "请选择..." : texts.join(", ");
    setEditText(displayText);
    emit selectionChanged();
}

void MultiSelectComboBox::paintEvent(QPaintEvent *event) {
    Q_UNUSED(event);
    QStylePainter painter(this);
    painter.setPen(palette().color(QPalette::Text));

    // Draw the combobox frame, focusrect and selected etc.
    QStyleOptionComboBox opt;
    initStyleOption(&opt);

    // If we have selected items, use displayText, otherwise use placeholderText
    if (!displayText.isEmpty()) {
        opt.currentText = displayText;
    } else {
        opt.currentText = "Select items...";
    }

    painter.drawComplexControl(QStyle::CC_ComboBox, opt);
    painter.drawControl(QStyle::CE_ComboBoxLabel, opt);
}

QStandardItemModel *MultiSelectComboBox::model() const {
    return qobject_cast<QStandardItemModel *>(QComboBox::model());
}