/* vt100.c - simple subset of vt100 that should work on all terminals */
/* PUBLIC DOMAIN - October 10, 2006 - Jon Mayo */
/* this is actually a subset of ECMA-48/ISO 6429/ANSI X3.64 */

#define VT_COLOR_IGNORE -1  /* ignore this parameter */
#define VT_COLOR_BLACK 0
#define VT_COLOR_RED 1
#define VT_COLOR_GREEN 2
#define VT_COLOR_BROWN 3
#define VT_COLOR_BLUE 4
#define VT_COLOR_MAGENTA 5
#define VT_COLOR_CYAN 6
#define VT_COLOR_WHITE 7
#define VT_COLOR_DEFAULT 9  /* use the terminals default color */

#define VT_ATTR_IGNORE -1   /* ignore this parameter */
#define VT_ATTR_OFF 0
#define VT_ATTR_ON 1

#define VT_ERASE_END 1      /* erase to end of line or end of screen */
#define VT_ERASE_ALL 2      /* erase everything */

#define VT_RESET_TERMINAL "\033c"

/*!
 * paramters:
 * mode - VT_ERASE_END to erase cursor to end-of-screen, VT_ERASE_ALL to erase screen
 */
void vt_erase_screen(int mode) {
    printf("\033[%uJ", mode);
    fflush(stdout);
}

/*!
 * paramters:
 * mode - VT_ERASE_END to erase cursor to end-of-line, VT_ERASE_ALL to erase entire line
 */
void vt_erase_line(int mode) {
    printf("\033[%uK", mode);
    fflush(stdout);
}

/*!
 * description: saves the current cursor position
 * parameters:
 * old - non-zero to use old vt100 style code, zero uses ECMA-48 which is fairly portable
 */
void vt_cursor_save(int old) {
    if(old) {
        /* old */
        printf("\0337");
    } else {
        /* ECMA-48 */
        printf("\033[s");
    }
    fflush(stdout);
}

/*!
 * description: restore the last saved cursor position
 * parameters:
 * old - non-zero to use old vt100 style code, zero uses ECMA-48 which is fairly portable
 */
void vt_cursor_restore(int old) {
    if(old) {
        /* old */
        printf("\0338");
    } else {
        /* ECMA-48 */
        printf("\033[u");
    }
    fflush(stdout);
}

/*!
 * description: send code to move the cursor position.
 */
void vt_moveto(unsigned x, unsigned y) {
    printf("\033[%u;%uH", y, x);
    fflush(stdout);
}

/*!
 * description: sets a scroll region
 */
void vt_setwindow(unsigned top, unsigned bottom) {
    printf("\033[%u;%ur", top, bottom);
    fflush(stdout);
}

/*!
 * description: clears the scroll region, making the scrolling full screen again
 */
void vt_setwindow_clear() {
    printf("\033[r");
    fflush(stdout);
}

void vt_init() {
    vt_setwindow_clear();
    vt_color(VT_COLOR_DEFAULT, VT_COLOR_DEFAULT);
}

/*!
 * description: set colors
 * parameters:
 * fg - foreground color (use VT_COLOR_XXX macro), negative means ignore
 * bg - background color (use VT_COLOR_XXX macro), negative means ignore
 *
 */
void vt_color(int fg, int bg) {
    if(fg<0 && bg<0) { /* -1,-1 we'll use for reset */
        printf("\033[0m", bg+40);
    } else if(fg<0) {
        printf("\033[%um", bg+40);
    } else if(bg<0) {
        printf("\033[%um", fg+30);
    } else {
        printf("\033[0;%u;%um", fg+30, bg+40);
    }
    fflush(stdout);
}

/*!
 * description: set special video attributes
 * parameters:
 * reverse - use reverse video (VT_ATTR_IGNORE, VT_ATTR_OFF, VT_ATTR_ON)
 * bold - use bold video (VT_ATTR_IGNORE, VT_ATTR_OFF, VT_ATTR_ON)
 */
void vt_attr(int reverse, int bold) {
    int count;
    count=(reverse!=VT_ATTR_IGNORE)+(bold!=VT_ATTR_IGNORE);
    printf("\033[");
    if(reverse!=VT_ATTR_IGNORE) {
        printf("%u", reverse==VT_ATTR_OFF?27:7);
        if(--count) printf(";");
    }
    if(bold!=VT_ATTR_IGNORE) {
        printf("%u", bold==VT_ATTR_OFF?22:1);
        if(--count) printf(";");
    }
    printf("m");
    fflush(stdout);
}

/*!
 * description: turns on xterm style mouse reporting
 * parameters:
 * enable - non-zero to enable, zero to disable reporting
 */
void vt_xterm_mouse(int enable) {
    printf("\033[?1000%c", enable?'h':'l');
    fflush(stdout);
}

/*!
 * description: enables/disables full screen reverse video, useful for visual bell effect
 * parameters:
 * enable - non-zero to have reverse video, zero to have normal video
 */
void vt_reverse_video(int enable) {
    printf("\033[?5%c", enable?'h':'l');
}