/* Вид истории сообщений: фон, выделение строк/текста, копирование и прокрутка вниз.
 * MessageDelegate рисует содержимое; ChatView обрабатывает мышь и клавиатуру. */
#pragma once

#include <QListView>
#include <QPersistentModelIndex>
#include <QPoint>
#include <QPushButton>
#include <QSet>
#include <functional>

struct ChatTextSelection {
    QPersistentModelIndex index;
    QPoint clickPos;
    QPoint dragPos;
    int startChar = -1;
    int endChar = -1;
    bool active = false;
};

class ChatView : public QListView {
    Q_OBJECT
public:
    explicit ChatView(QWidget *parent = nullptr);

    void setBackgroundImage(const QString &path);
    void setHistoricalWindow(bool enabled);

    bool hasSelection() const { return m_selStart.isValid(); }
    QModelIndex selStart() const { return QModelIndex(m_selStart); }
    QModelIndex selEnd()   const { return QModelIndex(m_selEnd); }
    bool isSelecting()     const { return m_selecting; }
    const ChatTextSelection &textSelection() const { return m_textSel; }

    bool isRowSelected(const QModelIndex &idx) const;
    void setTextSelChars(int start, int end) { m_textSel.startChar = start; m_textSel.endChar = end; }
    void setLinkHitTest(std::function<QString(const QModelIndex&, const QPoint&)> fn) { m_linkHitTest = std::move(fn); }

signals:
    void animationTriggered();
    void linkActivated(const QString& link);
    void latestRequested();

protected:
    bool viewportEvent(QEvent *event) override;
    void paintEvent(QPaintEvent *event) override;
    void resizeEvent(QResizeEvent *event) override;
    void scrollContentsBy(int dx, int dy) override;
    void mousePressEvent(QMouseEvent *event) override;
    void mouseMoveEvent(QMouseEvent *event) override;
    void mouseReleaseEvent(QMouseEvent *event) override;
    void keyPressEvent(QKeyEvent *event) override;

private:
    void copySelection();
    void updateScrollDownBtn();

    QPixmap m_background;
    QPersistentModelIndex m_selStart;
    QPersistentModelIndex m_selEnd;
    ChatTextSelection m_textSel;
    QPersistentModelIndex m_lastHovered;
    QSet<QString> m_visibleAnimations;
    QPersistentModelIndex m_pressIndex;
    QPoint m_pressPos;
    bool m_selecting = false;
    bool m_historicalWindow = false;
    std::function<QString(const QModelIndex&, const QPoint&)> m_linkHitTest;
    QPushButton *m_scrollDownBtn = nullptr;
};