#pragma once

#include <SFML/Graphics/VertexArray.hpp>
#include <SFML/Graphics/Font.hpp>
#include <SFML/Graphics/RenderTarget.hpp>
#include <SFML/Window/Event.hpp>
#include <SFML/System/String.hpp>
#include <SFML/System/Clock.hpp>
#include <vector>
#include "types.hpp"
#include <assert.h>

namespace QuickMedia
{
    struct StringViewUtf32 {
        const u32 *data;
        size_t size;

        StringViewUtf32() : data(nullptr), size(0) {}
        StringViewUtf32(const u32 *data, usize size) : data(data), size(size) {}

        size_t find(const StringViewUtf32 &other, size_t offset = 0) const;

        u32 operator [] (usize index) const {
            assert(index < size);
            return data[index];
        }
    };

    struct TextElement
    {
        enum class Type
        {
            TEXT
        };
        
        TextElement() {}
        TextElement(const StringViewUtf32 &_text, Type _type) : text(_text), type(_type), ownLine(false) {}
        
        StringViewUtf32 text;
        sf::Vector2f position;
        Type type;
        bool ownLine; // Currently only used for emoji, to make emoji bigger when it's the only thing on a line
    };
    
    class Text
    {
    public:
        Text(const sf::Font *font);
        Text(const sf::String &str, const sf::Font *font, unsigned int characterSize, float maxWidth, bool plainText = true);
        
        void setString(const sf::String &str);
        const sf::String& getString() const;
        
        void setPosition(float x, float y);
        void setPosition(const sf::Vector2f &position);
        sf::Vector2f getPosition() const;
        
        void setMaxWidth(float maxWidth);
        float getMaxWidth() const;
        
        void setCharacterSize(unsigned int characterSize);
        unsigned int getCharacterSize() const;
        
        const sf::Font* getFont() const;
        
        void setFillColor(sf::Color color);
        void setLineSpacing(float lineSpacing);
        void setCharacterSpacing(float characterSpacing);
        void setEditable(bool editable);
        
        // Warning: won't update until @draw is called
        float getHeight() const;
        
        void processEvent(const sf::Event &event);
        
        // Performs culling. @updateGeometry is called even if text is not visible if text is dirty, because updateGeometry might change the dimension of the text and make is visible.
        // Returns true if text was drawn on screen (if text is within window borders)
        bool draw(sf::RenderTarget &target);

        void updateGeometry(bool update_even_if_not_dirty = false);
    private:
        enum class CaretMoveDirection : u8
        {
            NONE,
            UP,
            DOWN,
            HOME,
            END
        };
        
        void updateCaret();
        bool isCaretAtEnd() const;
        int getStartOfLine(int startIndex) const;
        int getEndOfLine(int startIndex) const;
        int getRowByPosition(const sf::Vector2f &position) const;
        
        int getPreviousLineClosestPosition(int startIndex) const;
        int getNextLineClosestPosition(int startIndex) const;
    private:
        sf::String str;
        const sf::Font *font;
        unsigned int characterSize;
        sf::VertexArray vertices;
        float maxWidth;
        sf::Vector2f position;
        sf::Color color;
        sf::Color urlColor;
        bool dirty;
        bool dirtyText;
        bool dirtyCaret;
        bool plainText;
        bool editable;
        bool visible;
        CaretMoveDirection caretMoveDirection;
        sf::FloatRect boundingBox;
        float lineSpacing;
        float characterSpacing;
        std::vector<TextElement> textElements;
        
        int caretIndex;
        sf::Vector2f caretPosition;
        sf::Clock lastSeenTimer;
        sf::Vector2u renderTargetSize;
    };
}