//----------------------------------------------------------------------------//
//                                OS on Kaleid                                //
//                                                                            //
//  Desc:       Kernel shell                                                  //
//                                                                            //
//                                                                            //
//  Copyright © 2018-2021 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/paging.h>
#include <mm/palloc.h>
#include <mm/map.h>
#include <drivers/ata.h>
#include <io/vga.h>
#include <io/spkr.h>
#include <ke/time.h>
#include <ke/syscall.h>
#include <libbuf.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 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 CmdPageTranslateVirtToPhy(int argc, char **argv, char *cmdline)
{
    void *address = (void*)atoul(argv[1]);

    if (!(void*)strtoul(argv[1], NULL, 16)) {
        KernLog("No argument : translating the userspace address\n");
        address = (void *)0x80000000;
    }

    void *translation = MmTransVirtToPhyAddr(address);

    KernLog("Translation of %p is %p\n", address, translation);
    return EOK;
}

error_t CmdPageTranslatePhyToVirt(int argc, char **argv, char *cmdline)
{
     void *address = (void*)strtoul(argv[1], NULL, 16);

    /* if (!(void*)atoul(argv[1])) { */
    /*     address = (ulong *)0x80000000; */
    /* } */

    void *translation = MmTransPhyToVirtAddr(address);

    KernLog("Translation of %p is %p\n", address, translation);
    return EOK;
}

error_t CmdPageMap(int argc, char **argv, char *cmdline)
{
    void *virtual = (void*)strtoul(argv[1], NULL, 16);
    void *physical = (void*)strtoul(argv[2], NULL, 16);

    MmMapPage(virtual, physical, PRESENT | READWRITE);

    return EOK;
}

error_t CmdPageUnmap(int argc, char **argv, char *cmdline)
{
    void *virtual = (void*)strtoul(argv[1], NULL, 16);

    MmUnmapPage(virtual);

    return EOK;
}

error_t CmdPageAlloc(int argc, char **argv, char *cmdline)
{
    if (argc != 4) {
        KernLog("Invalid arguments !\n");
        return EINVAL;
    }

    size_t size = (size_t)atol(argv[1]);
    void *virtaddr = (void *)strtol(argv[2], NULL, 16);
    ulong flags = (ulong)atol(argv[3]);

    KernLog("Allocating %u o...\n", size);
    ulong id = MmAllocPageFrame(size, false);
    KernLog("Allocated with id : %lu\n", id);

    KernLog("Mapping pages id %d at %p (flags %#x)...\n", id, virtaddr, flags);
    error_t err = MmMapPageFrame(id, virtaddr, flags);
    if (err == EOK)
        KernLog("Successful mapped.\n");
    else
        KernLog("Failed to map !\n");

    return EOK;
}

error_t CmdPageFree(int argc, char **argv, char *cmdline)
{
    if (argc != 2) {
        KernLog("Invalid arguments !\n");
        return EINVAL;
    }

    ulong id = (ulong)atol(argv[1]);

    KernLog("Unmapping pages id %d...\n", id);
    error_t err = MmUnmapPageFrame(id);
    if (err == EOK)
        KernLog("Success unmaping.\n");
    else {
        KernLog("Failed to unmap !\n");
        return EFAILED;
    }

    KernLog("Freeing pages id %d...\n", id);
    MmFreePageFrame(id);

    return EOK;
}

error_t CmdPF(int argc, char **argv, char *cmdline)
{
    register ulong *address = (ulong*)(ulong)strtoul(argv[1], NULL, 16);

    KernLog("Test provoking a fault at %p\n", address);

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

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

    return EOK;
}

extern void pstest(void);

error_t CmdPS(int argc, char **argv, char *cmdline)
{
    pstest();
    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;
}

error_t CmdSyscallTest(int argc, char **argv, char *cmdline)
{
    if (argc != 2) {
        KernLog("Invalid arguments !\n");
        return EINVAL;
    }

    ulong code = (ulong)atol(argv[1]);
    
    error_t err = KeSyscall(code);

    KernLog("Exit : %s\n", strerror(err));
    
    return err;
}

error_t CmdRing3Test(int argc, char **argv, char *cmdline)
{
    size_t size = 1*KPAGESIZE;
    void *entryPoint = (void*)USERSPACE;
    ulong flags = PRESENT | READWRITE | USERMODE;

    KernLog("Allocating %u o...\n", size);
    ulong id = MmAllocPageFrame(size, false);
    KernLog("Allocated with id : %lu\n", id);

    KernLog("Mapping pages id %d at %p (flags %#x)...\n", id, entryPoint, flags);
    error_t err = MmMapPageFrame(id, entryPoint, flags);
    if (err == EOK)
        KernLog("Successfully mapped.\n");
    else {
        KernLog("Failed to map !\n");
        return ENOMEM;
    }
    
    size = 1*KPAGESIZE;
    void *stackAddr = (void*)USERSPACE + 4*KPAGESIZE;
    flags = PRESENT | READWRITE | USERMODE;

    KernLog("Allocating %u o...\n", size);
    id = MmAllocPageFrame(size, false);
    KernLog("Allocated with id : %lu\n", id);

    KernLog("Mapping pages id %d at %p (flags %#x)...\n", id, stackAddr, flags);
    err = MmMapPageFrame(id, stackAddr, flags);
    if (err == EOK)
        KernLog("Successfully mapped.\n");
    else {
        KernLog("Failed to map !\n");
        return ENOMEM;
    }
    
    KernLog("Entrypoint : %p, stack address : %p\n", entryPoint, stackAddr+size);
        
    extern void UserTest();
    
    memmove(entryPoint, UserTest, KPAGESIZE);

    KeJumpToUserspace(0, entryPoint, stackAddr+size);

    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"         },
    { "help",       CmdHelpTest,       "Show this message"                    },
    { "div",        CmdFloatDiv,     "Float div. Usage : div a b. Returns a/b"},
    { "transvtp",   CmdPageTranslateVirtToPhy,  "Translate a virtual to"
                                                  " physical address (paging)"},
    { "transptv",   CmdPageTranslatePhyToVirt,  "Translate a physical to"
                                                   " virtual address (paging)"},
    { "pmap",       CmdPageMap,        "Map a page to given physical addr"    },
    { "punmap",     CmdPageUnmap,      "Unmap a page"                         },
    { "palloc",     CmdPageAlloc,      "Alloc x B of pages at y address"
                                                                "with z flags"},
    { "pfree",      CmdPageFree,       "Free a page block of id x"            },
    { "pf",         CmdPF,             "Provoke a PF. Usage: pfault <address>"},
    { "ps",         CmdPS,             "Scheduler algorithm test"             },
    { "ring3",      CmdRing3Test,      "Jump to a userspace function"         },
    { "shell",      CmdShell,          "Start a new shell (nested)",          },
    { "stkov",      CmdStackOverflow,  "Provoke a stack overflow"             },
    { "stkun",      CmdStackUnderflow, "Provoke a stack underflow"            },
    { "syscall",    CmdSyscallTest,    "Trigger a system call"                },
    { "timer",      CmdTimerTest,      "test timer of x ms"                   },
    { NULL, NULL, NULL }
};