#pragma once

#include "mappresent_global.h"
#include <QWidget>
#include <memory>
#include <QMap>


/// <summary>
/// 绘制索引
/// </summary>
struct MAPPRESENT_EXPORT PresentIndex {
	/// <summary>
	/// 行号
	/// </summary>
	int row = INT_MAX;
	/// <summary>
	/// 列号
	/// </summary>
	int col = INT_MAX;

	bool isValid() const;

	PresentIndex& operator+=(const PresentIndex& other);
	bool operator!=(const PresentIndex& other) const;
	bool operator==(const PresentIndex& other) const;
	bool operator<(const PresentIndex& other) const;
};

/// <summary>
/// 绘制选项
/// </summary>
struct MAPPRESENT_EXPORT PresentOption {
	/// <summary>
	/// 当前所绘制索引
	/// </summary>
	PresentIndex index;
	/// <summary>
	/// 当前绘制外缘
	/// </summary>
	QRectF outline;

	PresentOption& operator=(const PresentOption& other);
};

/// <summary>
/// 单元绘制委托
/// </summary>
class MAPPRESENT_EXPORT UnitPresentDelegate : public QObject {
	Q_OBJECT
public:
	UnitPresentDelegate(QObject* parent = nullptr);
	virtual ~UnitPresentDelegate() = default;

	/// <summary>
	/// 匹配单元类型
	/// </summary>
	/// <returns></returns>
	virtual int unitType() const = 0;
	/// <summary>
	/// 绘制本单元瓦片
	/// </summary>
	/// <param name="p"></param>
	/// <param name="option"></param>
	virtual void paint(QPainter* p, const PresentOption& option) = 0;

signals:
	/// <summary>
	/// 更新通知/重绘请求
	/// </summary>
	void updateRequest(const PresentIndex &idx);
};

/// <summary>
/// 基础瓦片地图绘制
/// </summary>
class MAPPRESENT_EXPORT MapPresent : public QWidget
{
	Q_OBJECT
private:
	/// <summary>
	/// 初级区域矩形变长
	/// </summary>
	const float _primitive_region_len = 64;
	/// <summary>
	/// 缩放倍数
	/// </summary>
	double _scale_times = 1;
	/// <summary>
	/// 当前瓦片地图中心索引
	/// </summary>
	PresentIndex _center_index;

	// ===================================
	/// <summary>
	/// 绘制中转缓冲区
	/// </summary>
	QPixmap _paint_buffer;
	/// <summary>
	/// 试图核心索引
	/// </summary>
	QMap<PresentIndex, PresentOption> _visible_units;
	/// <summary>
	/// 被更新的单元索引
	/// </summary>
	QList<PresentIndex> _updated_units;

	/// <summary>
	/// 可视化单元整理
	/// </summary>
	void visible_units_tidy();
	/// <summary>
	/// 可视化索引填充
	/// </summary>
	/// <param name="a"></param>
	/// <param name="b"></param>
	/// <returns></returns>
	QList<PresentIndex> item_supply(const PresentIndex& a, const PresentIndex& b) const;

	// ===================================
	/// <summary>
	/// 类型化绘制委托
	/// </summary>
	QHash<int, UnitPresentDelegate*> _type_present_delegate;
	void unit_option_paint(QPainter& widget_painter, const PresentOption &opt);


public:
	MapPresent(QWidget* parent = nullptr);

	void zoomTo(double percent);
	double zoomTimes() const;

	/// <summary>
	/// 通过widget上定位获取绘制索引
	/// </summary>
	/// <param name="pos"></param>
	/// <returns></returns>
	PresentIndex indexGet(const QPointF& pos) const;
	/// <summary>
	/// 通过绘制索引获取指定单元外接矩形
	/// </summary>
	/// <param name="idx"></param>
	/// <returns></returns>
	QRectF outlineGet(const PresentIndex& idx) const;
	/// <summary>
	/// 获取周围包裹单元
	/// </summary>
	/// <param name="center">核心单元索引</param>
	/// <param name="dist">单元距离</param>
	/// <returns></returns>
	QList<PresentIndex> siblingsGet(const PresentIndex& center, uint16_t dist = 1) const;

signals:
	void mouseIn();
	void mouseOut();
	void mouseHover(const PresentIndex& unit_index);

protected:
	void paintEvent(QPaintEvent* ev) override;
	void resizeEvent(QResizeEvent* event) override;

	void mouseMoveEvent(QMouseEvent* event) override;
	void enterEvent(QEvent* event) override;
	void leaveEvent(QEvent* event) override;

};