//----------------------------------------------------------------------------//
//                           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[];

static inline int ShAtoi(char* str)
{
    int res = 0;

    for (int i = 0; str[i] != 0; ++i)
        res = res * 10 + str[i] - '0';

    return res;
}

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 CmdBeep(int argc, char **argv, char *cmdline)
{
    IoDoBeep();
    return EOK;
}

error_t CmdClear(int argc, char **argv, char *cmdline)
{
    BLockBuf(BStdOut);

    BStdOut->wp = BStdOut->rp = BStdOut->buf;
    BStdOut->lastLF = 0;

    BUnlockBuf(BStdOut);

    return EOK;
}

error_t CmdColor(int argc, char **argv, char *cmdline)
{
    int col = 0;
    char *p;

    if (argc > 2) {
        KernLog("Usage: 'color [#|list]'\n");
        return EINVAL;
    }

    if (argc == 1) {
        KernLog("Current color: %s (%d)\n", RtlColorNames[shcol], shcol);
    }

    else if (!strcmp(argv[1], "list")) {
        KernLog("Available colors:\n");
        for (col = 0; col <= VGA_COLOR_WHITE; col++) {
            KernLog("%d - %s\n", col, RtlColorNames[col]);
        }
    }

    else {
        p = argv[1];

        while (isdigit(*p) && col < VGA_COLOR_WHITE) {
            col = 10 * col + *p++ - '0';
        }

        if (*p || col < VGA_COLOR_BLACK || col > VGA_COLOR_WHITE) {
            KernLog("Invalid color: %d\n", col);
            KernLog("Usage: 'color [#|list]'\n");
            return EINVAL;
        }

        else {
            shcol = col;
        }

    }
    return EOK;
}

error_t CmdDate(int argc, char **argv, char *cmdline)
{
    KernLog("%.10s\n", KeFormatCurTime());
    return EOK;
}

error_t CmdDumpATASect(int argc, char **argv, char *cmdline)
{
    char sector[512] = {0};
    int sectNumber = ShAtoi(argv[1]);
    int nb = 1; //ShAtoi(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 CmdFloatDiv(int argc, char **argv, char *cmdline)
{
    double a = (double)ShAtoi(argv[1]);
    double b = (double)ShAtoi(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 CmdHelp(int argc, char **argv, char *cmdline)
{
    uint i, count = 0;
    Command_t *cmd;

    if (argc == 1) {
        KernLog("List of all shell built-ins:\n");
        for (cmd = shcmdtable; 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 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 CmdMemMap(int argc, char **argv, char *cmdline)
{
    MmPrintMemoryMap();
    return EOK;
}

error_t CmdMemUsage(int argc, char **argv, char *cmdline);

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

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

    *address = 1;

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

    return EOK;
}

error_t CmdPsTest(int argc, char **argv, char *cmdline)
{
    // pstest();
    return EOK;
}

error_t CmdQuit(int argc, char **argv, char *cmdline)
{
    PoShutdown();
    return EOK;
}

error_t CmdReloadPage(int argc, char **argv, char *cmdline)
{
    MmReloadPaging();
    return EOK;
}

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

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

    KeSleep(delay);
    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 CmdStarWars(int argc, char **argv, char *cmdline)
{
    IoDoStarWars();

    return EOK;
}

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

    return EOK;
}

error_t CmdTime(int argc, char **argv, char *cmdline)
{
    KernLog("%s\n", &KeFormatCurTime()[13]);
    return EOK;
}

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

    Timer_t *timer = KeSetTimer(delay);

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

    KernLog("Finished !\n");

    return EOK;
}

error_t CmdVersion(int argc, char **argv, char *cmdline)
{
    int CH = VGA_COLOR_LIGHT_BLUE;
    int CN = shcol;

    KernLog("OS/K version %C%s (x86-64)%C\n",
            CH,
            _KALEID_VERSION,
            CN
            );

    KernLog("Copyright (C) 2018-2019 The OS/K Team\n\n");
    KernLog("This program is free software, released under the\n");
    KernLog("terms of the GNU GPL version 3 or later as published\n");
    KernLog("by the Free Software Foundation.\n");
    KernLog("You are free to change and redistribute it.\n");
    KernLog("There is NO WARRANTY, to the extent permitted by law.\n");
    KernLog("See <http://gnu.org/licenses/gpl.html>\n\n");

    return EOK;
}

//----------------------------------------------------------------------------//

static Command_t testcmdtable[] =
{
    { "args",       CmdArgs,           "Print command line"                   },
    { "dmpsec",     CmdDumpATASect,    "Dump an ATA sector on screen"         },
    { "help",       CmdHelpTest,       "Show this message"                    },
    { "pf",         CmdPF,             "Provoke a PF. Usage: pfault <address>"},
    { "ps",         CmdPsTest,         "Scheduler test routine"               },
    { "div",        CmdFloatDiv,     "Float div. Usage : div a b. Returns a/b"},
    { "rpag",       CmdReloadPage,     "Reload the pages directory"           },
    { "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 }
};

Command_t shcmdtable[] =
{
    { "beep",       CmdBeep,           "Make a beep"                          },
    { "cls",        CmdClear,          "Clears standard output"               },
    { "color",      CmdColor,          "Change shell text color"              },
    { "date",       CmdDate,           "Print date"                           },
    { "exit",       CmdQuit,           "Initiate shutdown"                    },
    { "help",       CmdHelp,           "Show this message"                    },
    { "march",      CmdStarWars,       "Play the Imperial March"              },
    { "mmap",       CmdMemMap,         "Show memory map"                      },
    { "musage",     CmdMemUsage,       "Show memory statistics"               },
    { "quit",       CmdQuit,           "Alias for 'exit'"                     },
    { "shell",      CmdShell,          "Start a new shell (nested)",          },
    { "sleep",      CmdSleep,          "Sleep x ms"                           },
    { "time",       CmdTime,           "Print time"                           },
    { "test",       CmdTest,           "Launch the x test"                    },
    { "ver",        CmdVersion,        "Version and legal infos"              },
    { NULL, NULL, NULL }
};