#pragma once

#include "NetUtils.hpp"
#include <mglpp/system/FloatRect.hpp>
#include <mglpp/system/vec.hpp>
#include <mglpp/graphics/Color.hpp>
#include <mglpp/graphics/VertexBuffer.hpp>
#include <mglpp/graphics/Vertex.hpp>
#include <mglpp/system/Clock.hpp>
#include <vector>
#include <string_view>
#include <array>

namespace mgl {
    class Font;
    class Event;
    class Window;
}

namespace QuickMedia
{
    static constexpr size_t FONT_ARRAY_SIZE = 6;

    enum FormattedTextFlag : uint8_t {
        FORMATTED_TEXT_FLAG_NONE        = 0,
        //FORMATTED_TEXT_FLAG_BOLD        = 1 << 0,
        FORMATTED_TEXT_FLAG_CODE        = 1 << 1,
        FORMATTED_TEXT_FLAG_COLOR       = 1 << 2
    };

    struct TextElement
    {
        enum class Type {
            TEXT,
            FORMAT_START,
            FORMAT_END,
            IMAGE
        };

        enum class TextType {
            TEXT,
            EMOJI
        };
        
        TextElement() {}

        void create_text(std::string_view text) {
            this->text = text;
            text_type = TextType::TEXT;
            type = Type::TEXT;
        }

        // If size is {0, 0} then the image is drawn at its original size
        void create_image(std::string url, bool local, mgl::vec2i size, std::string alt) {
            this->url = std::move(url);
            this->alt = std::move(alt);
            this->local = local;
            this->size = size;
            type = Type::IMAGE;
        }

        // TODO: Remove some fields
        
        // TODO: union grouped
        std::string_view text;
        TextType text_type = TextType::TEXT;
        mgl::Color color = mgl::Color(255, 255, 255, 255);
        uint8_t text_flags = FORMATTED_TEXT_FLAG_NONE; // FormattedTextFlag

        // TODO: Remove these
        std::string url;
        std::string alt;
        bool local = false;
        mgl::vec2i pos;
        mgl::vec2i size;
        int vertex_ref_index = 0; // Note: only used temporary within updateGeometry
        int text_num_bytes = 0; // Note: only used temporary within updateGeometry

        Type type;
    };

    struct VertexRef {
        int vertices_index;     // index to |vertices| VertexArray
        int index;              // index within vertices[vertices_index]
        int line;
        int text_num_bytes;
        uint32_t codepoint;
    };
    
    class Text
    {
    public:
        Text(std::string str, bool bold_font, unsigned int characterSize, float maxWidth, bool highlight_urls = false);
        
        void setString(std::string str);
        const std::string& getString() const;
        void appendText(const std::string &str);
        // size = {0, 0} = keep original image size
        static std::string formatted_image(const std::string &url, bool local, mgl::vec2i size, const std::string &alt);
        // text_flags is bit-or of FormattedTextFlag
        static std::string formatted_text(const std::string &text, mgl::Color color, uint8_t text_flags);
        void insert_text_at_caret_position(const std::string &str);
        // Set to 0 to disable max lines
        void set_max_lines(int max_lines);

        static std::string to_printable_string(const std::string &str);
        
        void set_position(float x, float y);
        void set_position(const mgl::vec2f &position);
        mgl::vec2f get_position() const;
        
        void setMaxWidth(float maxWidth);
        float getMaxWidth() const;
        
        void setCharacterSize(unsigned int characterSize);
        unsigned int get_character_size() const;

        void replace(size_t start_index, size_t length, const std::string &insert_str);
        int getCaretIndex() const;
        int getNumLines() const;
        
        void set_color(mgl::Color color, bool force_color = false);
        void setLineSpacing(float lineSpacing);
        void setCharacterSpacing(float characterSpacing);
        void setEditable(bool editable);
        bool isEditable() const;
        // Note: only call after initial updateGeometry or draw. TODO: Automatically do this internally
        void moveCaretToEnd();

        // Note: won't update until @draw is called
        float getWidth() const;
        
        // Note: won't update until @draw is called
        float getHeight() const;
        
        void processEvent(mgl::Window &window, const mgl::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(mgl::Window &target);

        void updateGeometry(bool update_even_if_not_dirty = false);

        bool single_line_edit = false;
    private:
        enum class CaretMoveDirection : uint8_t
        {
            NONE,
            UP,
            DOWN,
            HOME,
            END,
            LEFT,
            RIGHT,
            LEFT_WORD,
            RIGHT_WORD
        };

        Text();
        void updateCaret();
        int getStartOfLine(int startIndex) const;
        int getEndOfLine(int startIndex) const;
        int getStartOfWord(int startIndex) const;
        int getEndOfWord(int startIndex) const;
        
        int getPreviousLineClosestPosition(int startIndex) const;
        int getNextLineClosestPosition(int startIndex) const;

        static void split_text_by_type(std::vector<TextElement> &text_elements, std::string_view str, float vspace);
        void split_text_by_type();

        float font_get_real_height(mgl::Font *font);
        float get_text_quad_left_side(const VertexRef &vertex_ref) const;
        float get_text_quad_right_side(const VertexRef &vertex_ref) const;
        float get_text_quad_top_side(const VertexRef &vertex_ref) const;
        float get_text_quad_bottom_side(const VertexRef &vertex_ref) const;
        float get_text_quad_height(const VertexRef &vertex_ref) const;
        void move_vertex_lines_by_largest_items(int vertices_linear_end);
        // If the index is past the end, then the caret offset is the right side of the last character, rather than the left side
        float get_caret_offset_by_caret_index(int index) const;
        VertexRef& get_vertex_ref_clamp(int index);
        // Takes into consideration if index is the last vertex and the last vertex is a newline, then it should be on its own line
        int get_vertex_line(int index) const;
        uint32_t get_vertex_codepoint(int index) const;
        size_t get_string_index_from_caret_index(size_t caret_index) const;
    private:
        std::string str; // TODO: Remove this for non-editable text???
        bool bold_font;
        unsigned int characterSize;
        std::array<std::vector<mgl::Vertex>, FONT_ARRAY_SIZE> vertices;
        std::array<mgl::VertexBuffer, FONT_ARRAY_SIZE> vertex_buffers;
        float maxWidth;
        mgl::vec2f position;
        mgl::Color color;
        bool force_color = false;
        bool dirty;
        bool dirtyText;
        bool dirtyCaret;
        bool editable;
        bool highlight_urls;
        CaretMoveDirection caretMoveDirection;
        mgl::FloatRect boundingBox;
        int num_lines;
        float lineSpacing;
        float characterSpacing;
        std::vector<TextElement> textElements;
        
        int caretIndex;
        float caret_offset_x;
        mgl::vec2f caretPosition;

        int max_lines = 0;
        std::vector<VertexRef> vertices_linear; // TODO: Use textElements instead
        std::vector<Range> url_ranges;
    };
}