#include "SDL.h"

#include "SDL_ttf.h"

#include <map>

#include <string>

#include <vector>

#include <exception>

namespace Style

{

    enum {

        BOLD      = 1 << 24,  // bold font

        UNDERLINE = 1 << 25,  // underline text

        STANDOUT  = 1 << 26,  // inverse bg/fg

        BLINK     = 1 << 27,  // blinking

    };

};

namespace KeyMod

{

    enum {

        SHIFT = 1<<0,

        ALT   = 1<<1,

        CTRL  = 1<<2,

        META  = 1<<3,

    };

};

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) const;

};

class GlyphCache

{

public:

    // lookup glyph in cache, id is combined char and attr

    SDL_Surface *lookup_glyph(Uint64 id);

    void put_glyph(Uint64 id, SDL_Surface *srf);

    void flush();

private:

    std::map<Uint64, SDL_Surface*> _glyph_map;

};

/* TTF font glyph renderer

 *

 * Renders uniformly sized cells with single character.

 * Wraps SDL_ttf functions, see its documentation here:

 *

 * http://www.libsdl.org/projects/SDL_ttf/docs/SDL_ttf.html

 *

 */

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(Uint32 ch, Uint32 attr, bool blink_state);

    int get_cell_width() const { return _cell_width; };

    int get_cell_height() const { return _cell_height; };

private:

    TTF_Font *_font_regular;

    TTF_Font *_font_bold;

    int _cell_width;

    int _cell_height;

    GlyphCache _cache;

    ColorMap _colormap;

    void _render_glyph(SDL_Surface *cell_surface, TTF_Font *font, Uint32 ch,

            SDL_Color fgcolor, SDL_Color bgcolor);

};

/* One cell of terminal window

 *

 * Each cell contains one character, its color and attributes.

 * Character is encoded in 32bit unicode.

 * Other 32 bits are attributes:

 *   0-7   (8b) - foreground color index

 *   8-15  (8b) - background color index

 *   16-23 (8b) - RESERVED for alpha channel

 *   24    (1b) - bold font

 *   25    (1b) - underline

 *   26    (1b) - standout (swap fg/bg color)

 *   27    (1b) - blink

 *   28-31 (4b) - RESERVED

 */

struct TerminalCell

{

    Uint32 ch;

    Uint32 attr;

    TerminalCell() : ch(0), attr(7) {};

    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), _blink_state(1) {};

    ~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, Uint32 ch, Uint32 attr);

    void toggle_cursor(int x, int y);

    void toggle_blink() { _blink_state = !_blink_state; _draw_blink(); };

    void commit();

    // force full redraw on next commit()

    void redraw();

    int get_width() const { return _width; };

    int get_height() const { return _height; };

    int get_cell_width() const { return _cell_width; };

    int get_cell_height() const { 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;

    int _blink_state; // 0 - blink chars hidden, 1 - visible

    void _reset_cells();

    void _draw_blink();

};

struct Event

{

    enum { QUIT, RESIZE, KEYPRESS, MOUSEDOWN, MOUSEUP, MOUSEMOVE, MOUSEHOVER, MOUSEWHEEL };

    int type;

    union

    {

        struct

        {

            char keyname[10];

            Uint32 unicode;

            int mod;

        } key;

        struct

        {

            int x, y;

            int relx, rely;

            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, Uint32 ch) { _screen.putch(x, y, ch, _attr); };

    void commit();

    Uint32 prepare_attr(Uint8 fg, Uint8 bg, Uint32 style) { return (Uint32)fg | (Uint32)bg << 8 | (style & 0xFF000000); };

    void set_attr(Uint32 value) { _attr = value; };

    void show_cursor(int x, int y) { _cursor_x = x; _cursor_y = y; _cursor_visible = true; };

    void hide_cursor() { _cursor_visible = false; };

    /* Wait for an event.

     *

     * Timeout is in miliseconds, zero means wait indefinitely.

     * Returns false on timeout, true on event.

     */

    bool wait_event(Event &event, Uint32 timeout);

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

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

private:

    TerminalScreen _screen;

    Uint32 _attr;

    int _cursor_x;

    int _cursor_y;

    bool _cursor_visible;

    int _mousemove_last_x;

    int _mousemove_last_y;

    bool _handle_event(const SDL_Event &sdl_event, Event &event);

    const char *_translate_keyname(SDLKey sym);

    int _translate_mod(SDLMod mod);

    static Uint32 _wait_event_callback(Uint32 interval, void *param);

    static Uint32 _blink_toggle_callback(Uint32 interval, void *param);

};

class SDLTermError: public std::exception

{

public:

    SDLTermError(const std::string &a_msg)

        : std::exception(), _msg(a_msg) {};

    virtual ~SDLTermError() throw() {};

    virtual const char *what() const throw() { return _msg.c_str(); };

private:

    std::string _msg;

};