/*
  fixMargins for TI-Nspire OS 3.6
  Copyright (C) 2014 Levak

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#define asm __asm__ /* std=c99 */
#include <os.h>

#define PROG_NAME "fixMargins"

static const char *error_title = "Error " PROG_NAME;
static const char *title = PROG_NAME;
static const char *successHook = "Hook successfully installed !";
static const char *alreadyInstalled = "Hook already installed !";
static const char *notAppliableHook = "Hook is not appliable to that TI-Nspire model nor OS version.";

static const int hook_getPos_addrs[] = {0x0, 0x0,  // Clickpad / Touchpad 3.1
                                        0x0, 0x0,  // CX 3.1
                                        0x0, 0x0,  // CM 3.1
                                        0x10004ecc, 0x10004e9c,  // Clickpad / Touchpad 3.6
                                        0x10004E64, 0x10004E64}; // CX 3.6

static const int hook_getPos_values[] = {0x0, 0x0,
                                         0x0, 0x0,
                                         0x0, 0x0,
                                         0xE3520000, 0xE3520000,
                                         0xE3520000, 0xE3520000};

static const int hook_callee_addrs[] = {0x0, 0x0,
                                        0x0, 0x0,
                                        0x0, 0x0,
                                        0x10120274, 0x1012089c,
                                        0x1011fcb8, 0x10120310};

#define HOOK_GETPOS_ADDR (nl_osvalue((int*)hook_getPos_addrs, sizeof(hook_getPos_addrs)/sizeof(hook_getPos_addrs[0])))
#define HOOK_GETPOS_VALUE (nl_osvalue((int*)hook_getPos_values, sizeof(hook_getPos_values)/sizeof(hook_getPos_values[0])))
#define HOOK_CALLEE_ADDR (nl_osvalue((int*)hook_callee_addrs, sizeof(hook_callee_addrs)/sizeof(hook_callee_addrs[0])))

static unsigned D2Editor_move_addrs[] = {0x0, 0x0,
                                         0x0, 0x0,
                                         0x0, 0x0,
                                         0x10044ee4, 0x10044e44,
                                         0x10044434, 0x100443C4};
#define D2Editor_move SYSCALL_CUSTOM(D2Editor_move_addrs, void, void * /* D2Editor */, int /* x */, int /* y */)

static unsigned int *callee = NULL;

HOOK_DEFINE(hook_getPos) {
    unsigned int *r2 = (unsigned int*)(HOOK_SAVED_REGS(hook_getPos)[2] /* r2 */);
    unsigned int *r3 = (unsigned int*)(HOOK_SAVED_REGS(hook_getPos)[3] /* r3 */);
    unsigned int *lr = (unsigned int*)(HOOK_SAVED_REGS(hook_getPos)[13] /* lr */);

    /* If we have a warning icon, offset by 0x12 the D2Editor. */
    if (lr == callee)
    {
        void **histRow = (void **)(HOOK_SAVED_REGS(hook_getPos)[4] /* r4 */);
        if (histRow != NULL)
        {
            void **d2editor = histRow[0x24 / 4];
            if (d2editor != NULL)
                D2Editor_move(d2editor, 0x12, (int)(d2editor[0x8 / 4]));
        }
    }

    /* Always assign margin to 0 */
    *r2 = 0x0;
    *r3 = 0x10;
    HOOK_RESTORE_RETURN(hook_getPos);
}

int main(int argc, char* argv[]) {
    if(argc < 1) return 0;
    argv = argv;

    callee = (unsigned int*) HOOK_CALLEE_ADDR;

    /* If hook is not appliable */
    if (((int)HOOK_GETPOS_VALUE) == 0)
        show_msgbox(error_title, notAppliableHook);
    else
    {
        /* If hook isn't already installed */
        if (*((int*)HOOK_GETPOS_ADDR) == HOOK_GETPOS_VALUE)
        {
            /* Remove everything */
            unsigned int *p = (unsigned int *) HOOK_GETPOS_ADDR;
            for (unsigned int i = 0; i < 8; ++i)
                p[i] = 0;

            /* Install hook */
            HOOK_INSTALL(HOOK_GETPOS_ADDR, hook_getPos);
            nl_set_resident();

            if (!nl_isstartup())
                show_msgbox(title, successHook);
        }
        else
            show_msgbox(error_title, alreadyInstalled);
    }

    return 0;
}