#ifndef LH_ELEMENT_H
#define LH_ELEMENT_H

#include <functional>
#include <memory>
#include <tuple>
#include <list>
#include "types.h"
#include "stylesheet.h"
#include "css_properties.h"

namespace litehtml
{
	class line_box;
	class dumper;
	class render_item;

	class element : public std::enable_shared_from_this<element>
	{
		friend class line_box;
		friend class html_tag;
		friend class el_table;
		friend class document;
	public:
		typedef std::shared_ptr<element>		ptr;
		typedef std::shared_ptr<const element>	const_ptr;
		typedef std::weak_ptr<element>			weak_ptr;
	protected:
		std::weak_ptr<element>					m_parent;
		std::weak_ptr<document>					m_doc;
		elements_list							m_children;
		css_properties							m_css;
		std::list<std::weak_ptr<render_item>>	m_renders;
		used_selector::vector					m_used_styles;

		virtual void select_all(const css_selector& selector, elements_list& res);
		element::ptr _add_before_after(int type, const style& style);

	private:
		std::map<string_id, int>	m_counter_values;

	public:
		explicit element(const std::shared_ptr<document>& doc);
		virtual ~element() = default;

		const css_properties&		css() const;
		css_properties&				css_w();

		bool						in_normal_flow()			const;
		bool						is_inline()					const;	// returns true if element is inline
		bool						is_inline_box()				const;	// returns true if element is inline box (inline-table, inline-box, inline-flex)
		bool						is_block_box()				const;
		position					get_placement()				const;
		bool						is_positioned()				const;
		bool						is_float()					const;
		bool						is_block_formatting_context() const;

		pixel_t						v_scroll(pixel_t dy)		const;
		pixel_t						h_scroll(pixel_t dx)		const;

		bool						is_root() const;
		element::ptr				parent() const;
		void						parent(const element::ptr& par);
		// returns true for elements inside a table (but outside cells) that don't participate in table rendering
		bool						is_table_skip() const;

		std::shared_ptr<document>	get_document() const;
		const std::list<std::shared_ptr<element>>& children() const;

		std::shared_ptr<render_item> get_render_item();

		virtual elements_list		select_all(const string& selector);
		virtual elements_list		select_all(const css_selector& selector);

		virtual element::ptr		select_one(const string& selector);
		virtual element::ptr		select_one(const css_selector& selector);

		virtual bool				appendChild(const ptr &el);
		virtual bool				removeChild(const ptr &el);
		virtual void				clearRecursive();

		virtual string_id			id() const;
		virtual string_id			tag() const;
		virtual const char*			get_tagName() const;
		virtual void				set_tagName(const char* tag);
		virtual void				set_data(const char* data);

		virtual void				set_attr(const char* name, const char* val);
		virtual const char*			get_attr(const char* name, const char* def = nullptr) const;
		virtual void				apply_stylesheet(const litehtml::css& stylesheet);
		virtual void				refresh_styles();
		virtual bool				is_white_space() const;
		virtual bool				is_space() const;
		virtual bool				is_comment() const;
		virtual bool				is_body() const;
		virtual bool				is_break() const;
		virtual bool				is_text() const;

		virtual bool				on_mouse_over();
		virtual bool				on_mouse_leave();
		virtual bool				on_lbutton_down();
		virtual bool				on_lbutton_up(bool is_click = true);
		virtual void				on_click();
		virtual bool				set_pseudo_class(string_id cls, bool add);
		virtual bool				set_class(const char* pclass, bool add);
		virtual bool				is_replaced() const;
		virtual void				compute_styles(bool recursive = true);
		virtual void				draw(uint_ptr hdc, pixel_t x, pixel_t y, const position *clip, const std::shared_ptr<render_item>& ri);
		virtual void				draw_background(uint_ptr hdc, pixel_t x, pixel_t y, const position *clip, const std::shared_ptr<render_item> &ri);

		virtual void				get_text(string& text) const;
		virtual void				parse_attributes();
		virtual int					select(const css_selector::vector& selector_list, bool apply_pseudo = true);
		virtual int					select(const string& selector);
		virtual int					select(const css_selector& selector, bool apply_pseudo = true);
		virtual int					select(const css_element_selector& selector, bool apply_pseudo = true);
		virtual element::ptr		find_ancestor(const css_selector& selector, bool apply_pseudo = true, bool* is_pseudo = nullptr);
		virtual bool				is_ancestor(const ptr &el) const;
		virtual element::ptr		find_adjacent_sibling(const element::ptr& el, const css_selector& selector, bool apply_pseudo = true, bool* is_pseudo = nullptr);
		virtual element::ptr		find_sibling(const element::ptr& el, const css_selector& selector, bool apply_pseudo = true, bool* is_pseudo = nullptr);
		virtual void				get_content_size(size& sz, pixel_t max_width);
		virtual bool				is_nth_child(const element::ptr& el, int num, int off, bool of_type, const css_selector::vector& selector_list = {}) const;
		virtual bool				is_nth_last_child(const element::ptr& el, int num, int off, bool of_type, const css_selector::vector& selector_list = {}) const;
		virtual bool				is_only_child(const element::ptr& el, bool of_type) const;
		virtual void				add_style(const style& style);
		virtual const background*	get_background(bool own_only = false);

		virtual string				dump_get_name();
		virtual std::vector<std::tuple<string, string>> dump_get_attrs();
		void						dump(litehtml::dumper& cout);

		std::tuple<element::ptr, element::ptr, element::ptr> split_inlines();
		virtual std::shared_ptr<render_item> create_render_item(const std::shared_ptr<render_item>& parent_ri);
		bool requires_styles_update();
		void add_render(const std::shared_ptr<render_item>& ri);
		bool find_styles_changes( position::vector& redraw_boxes);
		element::ptr add_pseudo_before(const style& style)
		{
			return _add_before_after(0, style);
		}
		element::ptr add_pseudo_after(const style& style)
		{
			return _add_before_after(1, style);
		}

		string				get_counter_value(const string& counter_name);
		string				get_counters_value(const string_vector& parameters);
		void				increment_counter(const string_id& counter_name_id, const int increment = 1);
		void				reset_counter(const string_id& counter_name_id, const int value = 0);

		void				run_on_renderers(const std::function<bool(const std::shared_ptr<render_item>&)>& func);

	private:
		std::vector<element::ptr> get_siblings_before() const;
		bool				find_counter(const string_id& counter_name_id, std::map<string_id, int>::iterator& map_iterator);
		void				parse_counter_tokens(const string_vector& tokens, const int default_value, std::function<void(const string_id&, const int)> handler) const;
	};

	//////////////////////////////////////////////////////////////////////////
	//							INLINE FUNCTIONS							//
	//////////////////////////////////////////////////////////////////////////

	inline bool litehtml::element::in_normal_flow() const
	{
		if(css().get_position() != element_position_absolute &&
		   css().get_display() != display_none &&
		   css().get_position() != element_position_fixed)
		{
			return true;
		}
		return false;
	}

	inline bool litehtml::element::is_root() const
	{
		return m_parent.expired();
	}

	inline element::ptr litehtml::element::parent() const
	{
		return m_parent.lock();
	}

	inline void litehtml::element::parent(const element::ptr& par)
	{
		m_parent = par;
	}

	inline bool litehtml::element::is_positioned()	const
	{
		return (css().get_position() > element_position_static);
	}

	inline bool litehtml::element::is_float()	const
	{
		return (css().get_float() != float_none);
	}

	inline std::shared_ptr<document> element::get_document() const
	{
		return m_doc.lock();
	}

	inline const css_properties& element::css() const
	{
		return m_css;
	}

	inline css_properties& element::css_w()
	{
		return m_css;
	}

	inline bool element::is_block_box() const
	{
		if (css().get_display() == display_block ||
			css().get_display() == display_flex ||
			css().get_display() == display_table ||
			css().get_display() == display_list_item)
		{
			return true;
		}
		return false;
	}

	inline const std::list<std::shared_ptr<element>>& element::children() const
	{
		return m_children;
	}

	inline std::shared_ptr<render_item> element::get_render_item()
	{
		if(m_renders.empty())
		{
			return nullptr;
		}
		return m_renders.front().lock();
	}
}

#endif  // LH_ELEMENT_H