// The OS/K Team licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

#include <pc/console.h>

#define KEYBUFSIZE      8192

typedef uint keycode_t;

keycode_t keybuf[KEYBUFSIZE] = { 0 };
keycode_t *keybuf_last = &keybuf[0];
keycode_t *keybuf_ptr = &keybuf[0];

void console_addkey(keycode_t key)
{
    *keybuf_ptr++ = key;

    if (keybuf_ptr == keybuf + KEYBUFSIZE)
        keybuf_ptr = &keybuf[0];
}

keycode_t console_getkey(void)
{
    keycode_t rc = *keybuf_last++;

    if (keybuf_last == keybuf + KEYBUFSIZE)
        keybuf_last = &keybuf[0];

    return rc;
}

keycode_t console_scankeybuf(void)
{
    if (keybuf_last != keybuf_ptr)
        return console_getkey();

    return 0;
}

void console_flushkeybuf(void)
{
    memset(keybuf, 0, KEYBUFSIZE);
    keybuf_last = keybuf_ptr = &keybuf[0];
}

#define QKEY(key, c, cshift, cmode, calt, cgui)                             \
_QKEY(SDLK_##key, c, cshift, cmode, calt, cgui)

#define _QKEY(key, c, cshift, cmode, calt, cgui)                            \
        case key:                                                           \
            if (__builtin_expect((mod &                                     \
                    (KMOD_SHIFT|KMOD_ALT|KMOD_MODE|KMOD_GUI)) == 0, 1))     \
                 code = c;                                                  \
            else if ((mod & KMOD_SHIFT)) code = cshift;                     \
            else if ((mod & KMOD_LALT)) code = calt;                        \
            else if ((mod & KMOD_RALT)) code = cmode;                       \
            else if ((mod & KMOD_GUI)) code = cgui;                         \
            break;

void console_handle_input(SDL_Keycode key)
{
    keycode_t code = 0;

    SDL_Keymod mod = SDL_GetModState();

    if (mod & KMOD_CTRL)
    {
        if (key == SDLK_c)
            _except(E_BRK, "Ctrl+C received");

        return;
    }

    switch (key)
    {
        case SDLK_SPACE:        code = ' ';     break;
        case SDLK_BACKSPACE:    code = '\b';    break;

        case SDLK_ESCAPE:       code = 0x1B;    break;

        case SDLK_RETURN:
        case SDLK_RETURN2:
            code = '\n';
            break;

        case SDLK_TAB:          code = '\t';    break;

        // COMMON

        QKEY(a,             'a', 'A',   0,  0,  0);
        QKEY(b,             'b', 'B',   0,  0,  0);
        QKEY(c,             'c', 'C',   0,  0,  0);
        QKEY(d,             'd', 'D',   0,  0,  0);
        QKEY(e,             'e', 'E',   0,  0,  0);
        QKEY(f,             'f', 'F',   0,  0,  0);
        QKEY(g,             'g', 'G',   0,  0,  0);
        QKEY(h,             'h', 'H',   0,  0,  0);
        QKEY(i,             'i', 'I',   0,  0,  0);
        QKEY(j,             'j', 'J',   0,  0,  0);
        QKEY(k,             'k', 'K',   0,  0,  0);
        QKEY(l,             'l', 'L',   0,  0,  0);
        QKEY(m,             'm', 'M',   0,  0,  0);
        QKEY(n,             'n', 'N',   0,  0,  0);
        QKEY(o,             'o', 'O',   0,  0,  0);
        QKEY(p,             'p', 'P',   0,  0,  0);
        QKEY(q,             'q', 'Q',   0,  0,  0);
        QKEY(r,             'r', 'R',   0,  0,  0);
        QKEY(s,             's', 'S',   0,  0,  0);
        QKEY(t,             't', 'T',   0,  0,  0);
        QKEY(u,             'u', 'U',   0,  0,  0);
        QKEY(v,             'v', 'V',   0,  0,  0);
        QKEY(w,             'w', 'W',   0,  0,  0);
        QKEY(x,             'x', 'X',   0,  0,  0);
        QKEY(y,             'y', 'Y',   0,  0,  0);
        QKEY(z,             'z', 'Z',   0,  0,  0);

        // AZERTY

        QKEY(EXCLAIM,       '!',  0,    0,  0,  0);
        QKEY(DOLLAR,        '$',  0,    0,  0,  0);
        QKEY(ASTERISK,      '*',  0,    0,  0,  0);
        QKEY(COLON,         ':', '/',   0,  0,  0);
        QKEY(LESS,          '<', '>',   0,  0,  0);
        QKEY(CARET,         '^',  0,    0,  0,  0);

        QKEY(AMPERSAND,     '&', '1',  0,   0,  0);
        QKEY(QUOTEDBL,      '"', '3', '#',  0,  0);
        QKEY(LEFTPAREN,     '(', '5', '[',  0,  0);
        QKEY(UNDERSCORE,    '_', '8', '\\', 0,  0);
        QKEY(RIGHTPAREN,    ')',  0,  ']',  0,  0);

        // QWERTY

        QKEY(BACKSLASH,     '\\', '|',  0,  0,  0);
        QKEY(PERIOD,        '.', '>',   0,  0,  0);
        QKEY(SLASH,         '/', '?',   0,  0,  0);
        QKEY(LEFTBRACKET,   '[', '{',   0,  0,  0);
        QKEY(RIGHTBRACKET,  ']', '}',   0,  0,  0);
        QKEY(BACKQUOTE,     '`', '~',   0,  0,  0);

        // MIXED

#ifdef QWERTY

        QKEY(QUOTE,         '\'', '"',  0,  0,  0);
        QKEY(COMMA,         ',', '<',   0,  0,  0);
        QKEY(SEMICOLON,     ';', ':',   0,  0,  0);
        QKEY(EQUALS,        '=', '+',   0,  0,  0);
        QKEY(MINUS,         '-', '_',   0,  0,  0);
        QKEY(1,             '1', '!',   0,  0,  0);
        QKEY(2,             '2', '@',   0,  0,  0);
        QKEY(3,             '3', '#',   0,  0,  0);
        QKEY(4,             '4', '$',   0,  0,  0);
        QKEY(5,             '5', '%',   0,  0,  0);
        QKEY(6,             '6', '^',   0,  0,  0);
        QKEY(7,             '7', '&',   0,  0,  0);
        QKEY(8,             '8', '*',   0,  0,  0);
        QKEY(9,             '9', '(',   0,  0,  0);
        QKEY(0,             '0', ')',   0,  0,  0);

#else

        QKEY(QUOTE,         '\'', '4', '{', 0,  0);
        QKEY(COMMA,         ',', '?',  0,   0,  0);
        QKEY(SEMICOLON,     ';', '.',  0,   0,  0);
        QKEY(EQUALS,        '=', '+', '}',  0,  0);
        QKEY(MINUS,         '-', '6', '|',  0,  0);
        QKEY(1,             '&', '1',  0,   0,  0);
        QKEY(2,              0,  '2', '~',  0,  0);
        QKEY(3,             '"', '3', '#',  0,  0);
        QKEY(4,             '\'','4', '{',  0,  0);
        QKEY(5,             '(', '5', '[',  0,  0);
        QKEY(6,             '-', '6', '|',  0,  0);
        QKEY(7,              0,  '7', '`',  0,  0);
        QKEY(8,             '_', '8', '\\', 0,  0);
        QKEY(9,              0,  '9', '^',  0,  0);
        QKEY(0,              0,  '0', '@',  0,  0);

#endif

        // Other
        
        QKEY(HASH,          '#', 0, 0, 0, 0);
        QKEY(PERCENT,       '%', 0, 0, 0, 0);
        QKEY(PLUS,          '+', 0, 0, 0, 0);
        QKEY(GREATER,       '>', 0, 0, 0, 0);
        QKEY(QUESTION,      '?', 0, 0, 0, 0);
        QKEY(AT,            '@', 0, 0, 0, 0);

        // Found experimentally

        _QKEY(231,           0, '0', '@', 0, 0);
        _QKEY(232,           0, '7', '`', 0, 0);
        _QKEY(233,           0, '2', '~', 0, 0);
        _QKEY(249,           0, '%',  0,  0, 0);

        default:
            return;
    }

    if (code != 0)
        console_addkey(code);
}