//----------------------------------------------------------------------------//
//                           GNU GPL OS/K                                     //
//                                                                            //
//  Desc:       Kernel shell                                                  //
//                                                                            //
//                                                                            //
//  Copyright © 2018-2019 The OS/K Team                                       //
//                                                                            //
//  This file is part of OS/K.                                                //
//                                                                            //
//  OS/K 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         //
//  any later version.                                                        //
//                                                                            //
//  OS/K 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 OS/K.  If not, see <https://www.gnu.org/licenses/>.            //
//----------------------------------------------------------------------------//

#include <vers.h>
#include <mm/mm.h>
#include <io/ata.h>
#include <io/vga.h>
#include <io/spkr.h>
#include <ke/time.h>
#include <lib/buf.h>
#include <sh/shell.h>
#include <po/shtdwn.h>

static Command_t testcmdtable[];

error_t CmdTest(int argc, char **argv, char *cmdline)
{
    ExecuteCommand(cmdline+5, testcmdtable);
    KernLog ("\n");

    return EOK;
}

error_t CmdArgs(int argc, char **argv, char *cmdline)
{
    int i;

    KernLog("cmdline: '%s'\nargc: %d\n", cmdline, argc);

    for (i = 0; i < argc; i++) {
        KernLog("argv[%d]: '%s'\n", i, argv[i]);
    }

    return EOK;
}

error_t CmdAtoi(int argc, char **argv, char *cmdline)
{
    int i;

    KernLog("cmdline: '%s'\nargc: %d\n", cmdline, argc);

    for (i = 0; i < argc; i++) {
        KernLog("argv[%d]: '%u'\n", i, atoi(argv[i]));
    }

    return EOK;
}

error_t CmdDumpATASect(int argc, char **argv, char *cmdline)
{
    char sector[512] = {0};
    int sectNumber = atoi(argv[1]);
    int nb = 1; //atoi(argv[2]);
    int x = 0;
    int step = 16;

    if (sectNumber <= 0 || sectNumber > 255) {
        KernLog("Bad argument\n\n");
        return EINVAL;
    }

    if (!nb) nb = 1;

    KernLog("Sector begin: %d\n", (sectNumber - 1)*512);

    IoReadATA(sector, nb, sectNumber);

    while(x < 512*nb) {
        KernLog("%C", shcol);
        for (int i = 0; i < step; i++) {
            KernLog("%02x ", (uchar)sector[i+x]);
        }
        KernLog("   %C ", VGA_COLOR_LIGHT_BLUE);
        for (int i = 0; i < step; i++) {
            if (isprint(sector[i+x]))
                KernLog("%c",
                        sector[i+x]
                        );
            else
                KernLog("%c", 0);
        }
        KernLog("\n");
        x += step;
    }

    KernLog("\n\n");
    return EOK;
}

error_t CmdDumpMem(int argc, char **argv, char *cmdline)
{
    char sector[1024] = {0};
    char *address = (char*)atol(argv[1]);
    int nb = 1; //atoi(argv[2]);
    int x = 0;
    int step = 16;

    KernLog("Address begin: %p\n", address);

    for (int i = 0; i < 1024*nb; i++) {
        sector[i] = *address++;
    }

    while(x < 1024*nb) {
        KernLog("%C", shcol);
        for (int i = 0; i < step; i++) {
            KernLog("%02x ", (uchar)sector[i+x]);
        }
        KernLog("   %C ", VGA_COLOR_LIGHT_BLUE);
        for (int i = 0; i < step; i++) {
            if (isprint(sector[i+x]))
                KernLog("%c",
                        sector[i+x]
                        );
            else
                KernLog("%c", 0);
        }
        KernLog("\n");
        x += step;
    }

    KernLog("\n\n");
    return EOK;
}

error_t CmdFloatDiv(int argc, char **argv, char *cmdline)
{
    double a = (double)atoi(argv[1]);
    double b = (double)atoi(argv[2]);

    double number = a / b;
    double number_ent = (double)(ulong)number;
    double dec = number - number_ent;
    double sub = 0.0;

    char res[17];   // 10e-16 is the max precision

    for(int i = 0; i < 16; i++) {
        dec = (dec * 10.0) - (sub * 10.0);
        sub = (double)(ulong)dec;

        snprintf(&res[i], 17-i, "%d", (ulong)dec);
    }

    KernLog("%d / %d = %d.%s \n", (ulong)a, (ulong)b, (ulong)number_ent, res);

    return EOK;
}

error_t CmdHelpTest(int argc, char **argv, char *cmdline)
{
    uint i, count = 0;
    Command_t *cmd;

    if (argc == 1) {
        KernLog("List of all test built-ins:\n");
        for (cmd = testcmdtable; cmd->name != NULL; cmd++, count++) {
            KernLog("\t%s", cmd->name);
            for (i = strlen(cmd->name)/4; i<3; i++) {
                KernLog("\t");
            }
            KernLog("%C%s%C\n", VGA_COLOR_DARK_GREY, cmd->help, shcol);
        }
        KernLog("End of list; %u commands total\n", count);
    }

    return EOK;
}

error_t CmdPF(int argc, char **argv, char *cmdline)
{
    ulong *address = (ulong*)(ulong)atoi(argv[1]);

    KernLog("Provoking Page Fault at %#x\n", address);

    KernLog("It contained %#x\n", *address);
    *address = 1;
    KernLog("Now it contains %#x\n", *address);

    KernLog("No page fault : address was valid/present\n");

    return EOK;
}

error_t CmdShell(int argc, char **argv, char *cmdline)
{
    ShStartShell();
    return EOK;
}

error_t CmdStackOverflow(int argc, char **argv, char *cmdline)
{
    CmdStackOverflow(0, 0, 0);
    return EOK;
}

error_t CmdStackUnderflow(int argc, char **argv, char *cmdline)
{
    for (int i = 0 ;; i++) {
        asm volatile ("pop %rax\n");
    }

    return EOK;
}

error_t CmdTimerTest(int argc, char **argv, char *cmdline)
{
    int delay = atoi(argv[1]);

    Timer_t *timer = KeSetTimer(delay);

    while(!(KeGetTimer(timer))) {
        bprintf(BStdOut,".");
        BStdOut->flusher(BStdOut);
    }

    KernLog("Finished !\n");

    return EOK;
}

static Command_t testcmdtable[] =
{
    { "args",       CmdArgs,           "Print command line"                   },
    { "atoi",       CmdAtoi,           "Print command line atoised"           },
    { "dmpsec",     CmdDumpATASect,    "Dump an ATA sector on screen"         },
    { "dmp",        CmdDumpMem,        "Dump 1MB of memory starting from addr"},
    { "help",       CmdHelpTest,       "Show this message"                    },
    { "div",        CmdFloatDiv,     "Float div. Usage : div a b. Returns a/b"},
    { "pf",         CmdPF,             "Provoke a PF. Usage: pfault <address>"},
    { "shell",      CmdShell,          "Start a new shell (nested)",          },
    { "stkov",      CmdStackOverflow,  "Provoke a stack overflow"             },
    { "stkun",      CmdStackUnderflow, "Provoke a stack underflow"            },
    { "timer",      CmdTimerTest,      "test timer of x ms"                   },
    { NULL, NULL, NULL }
};