#include "SDL.h"
#include "SDL_ttf.h"

#include <map>
#include <vector>


enum class Style: Uint16
{
    BOLD      = 1 << 0,  // bold font
    UNDERLINE = 1 << 1,  // underline text
    STANDOUT  = 1 << 2,  // inverse bg/fg
    BLINK     = 1 << 3,  // blinking
};


class ColorMap
{
private:
    Uint8 _map[16][3] = {
        {0,0,0},        // 0 - black
        {23,23,178},    // 1 - blue
        {23,178,23},    // 2 - green
        {23,178,178},   // 3 - cyan
        {178,23,23},    // 4 - red
        {178,23,178},   // 5 - magenta
        {178,103,23},   // 6 - brown
        {178,178,178},  // 7 - light gray
        {104,104,104},  // 8 - gray
        {84,84,255},    // 9 - light blue
        {84,255,84},    // 10 - light green
        {84,255,255},   // 11 - light cyan
        {255,84,84},    // 12 - light red
        {255,84,255},   // 13 - light magenta
        {255,255,84},   // 14 - yellow
        {255,255,255},  // 15 - white
    };

public:
    void index_to_rgb(int index, SDL_Color &color);
};


class GlyphCache
{
public:
    SDL_Surface *lookup_glyph(Uint16 ch);
    void put_glyph(Uint16 ch, SDL_Surface *srf);
    void flush();

private:
    std::map<Uint16, SDL_Surface*> _glyph_map;
};


class GlyphRenderer
{
public:
    GlyphRenderer();
    ~GlyphRenderer();

    void open_font(const char *fname_regular, const char *fname_bold, int ptsize);
    void close_font();

    // do not free surface returned!
    SDL_Surface *render_cell(Uint16 ch, Uint16 attr);

    int get_cell_width() { return _cell_width; };
    int get_cell_height() { return _cell_height; };

private:
    TTF_Font *_font_regular;
    TTF_Font *_font_bold;
    int _cell_width;
    int _cell_height;
    GlyphCache _cache;
    ColorMap _colormap;
};


struct TerminalCell
{
    Uint16 ch;
    Uint16 attr;
    bool operator !=(const TerminalCell &rhs) const { return ch != rhs.ch || attr != rhs.attr; };
};


class TerminalScreen
{
public:
    TerminalScreen():
        _screen_surface(NULL), _cells_front(0), _cells_back(0), _render(),
        _pixel_width(0), _pixel_height(0), _width(0), _height(0),
        _cell_width(0), _cell_height(0) {};
    ~TerminalScreen() {};

    void select_font(const char *fname_regular, const char *fname_bold, int ptsize);
    void resize(int pxwidth, int pxheight);

    void erase();
    void putch(int x, int y, Uint16 ch, Uint16 attr);
    void commit();

    int get_width() { return _width; };
    int get_height() { return _height; };
    int get_cell_width() { return _cell_width; };
    int get_cell_height() { return _cell_height; };

private:
    SDL_Surface *_screen_surface;
    std::vector<TerminalCell> _cells_front;
    std::vector<TerminalCell> _cells_back;
    GlyphRenderer _render;

    int _pixel_width;  // terminal window width in pixels
    int _pixel_height;
    int _width;  // width in characters
    int _height; // height in characters
    int _cell_width;  // character cell width in pixels
    int _cell_height;

    void _reset_cells();
};


struct Event
{
    enum { QUIT, RESIZE, KEYPRESS, MOUSEDOWN, MOUSEUP, MOUSEMOVE, MOUSEWHEEL };
    int type;

    union
    {
        struct
        {
            char keyname[10];
            Uint16 unicode;
        } key;
        struct
        {
            int x, y;
            int button;
        } mouse;
    };
};


class Terminal
{
public:
    Terminal();
    ~Terminal();

    void select_font(const char *fname_regular, const char *fname_bold, int ptsize)
        { _screen.select_font(fname_regular, fname_bold, ptsize); };
    void resize(int pxwidth, int pxheight) { _screen.resize(pxwidth, pxheight); };

    void erase() { _screen.erase(); };
    void putch(int x, int y, Uint16 ch) { _screen.putch(x, y, ch, _attr); };
    void commit() { _screen.commit(); };

    Uint16 prepare_attr(Uint8 fg, Uint8 bg, Uint8 style) { return fg | bg << 4 | style << 8; };
    void set_attr(Uint16 value) { _attr = value; };

    void set_cursor(int x, int y) { _cursor_x = x; _cursor_y = y; };
    void show_cursor(bool visible) { _cursor_visible = visible; };

    void get_next_event(Event &event);

    int get_width() { return _screen.get_width(); };
    int get_height() { return _screen.get_height(); };

private:
    TerminalScreen _screen;
    Uint16 _attr;
    int _cursor_x;
    int _cursor_y;
    bool _cursor_visible;

    int _mousemove_last_x;
    int _mousemove_last_y;

    const char *_translate_keyname(SDLKey sym);
};