/*
*   This file is part of Luma3DS
*   Copyright (C) 2016-2020 Aurora Wright, TuxSH
*
*   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/>.
*
*   Additional Terms 7.b and 7.c of GPLv3 apply to this file:
*       * Requiring preservation of specified reasonable legal notices or
*         author attributions in that material or in the Appropriate Legal
*         Notices displayed by works containing it.
*       * Prohibiting misrepresentation of the origin of that material,
*         or requiring that modified versions of such material be marked in
*         reasonable ways as different from the original version.
*/

#include "fs.h"
#include "memory.h"
#include "fmt.h"
#include "crypto.h"
#include "cache.h"
#include "screen.h"
#include "draw.h"
#include "utils.h"
#include "fatfs/ff.h"
#include "buttons.h"
#include "firm.h"
#include "crypto.h"
#include "strings.h"

static FATFS sdFs,
             nandFs;

static bool switchToMainDir(bool isSd)
{
    const char *mainDir = isSd ? "/luma" : "/rw/luma";

    switch(f_chdir(mainDir))
    {
        case FR_OK:
            return true;
        case FR_NO_PATH:
            return f_mkdir(mainDir) == FR_OK && switchToMainDir(isSd);
        default:
            return false;
    }
}

bool mountFs(bool isSd, bool switchToCtrNand)
{
    return isSd ? f_mount(&sdFs, "0:", 1) == FR_OK && switchToMainDir(true) :
                  f_mount(&nandFs, "1:", 1) == FR_OK && (!switchToCtrNand || (f_chdrive("1:") == FR_OK && switchToMainDir(false)));
}

u32 fileRead(void *dest, const char *path, u32 maxSize)
{
    FIL file;
    FRESULT result = FR_OK;
    u32 ret = 0;

    if(f_open(&file, path, FA_READ) != FR_OK) return ret;

    u32 size = f_size(&file);
    if(dest == NULL) ret = size;
    else if(size <= maxSize)
        result = f_read(&file, dest, size, (unsigned int *)&ret);
    result |= f_close(&file);

    return result == FR_OK ? ret : 0;
}

u32 getFileSize(const char *path)
{
    return fileRead(NULL, path, 0);
}

bool fileWrite(const void *buffer, const char *path, u32 size)
{
    FIL file;
    FRESULT result = FR_OK;

    switch(f_open(&file, path, FA_WRITE | FA_OPEN_ALWAYS))
    {
        case FR_OK:
        {
            unsigned int written;
            result = f_write(&file, buffer, size, &written);
            if(result == FR_OK) result = f_truncate(&file);
            result |= f_close(&file);

            return result == FR_OK && (u32)written == size;
        }
        case FR_NO_PATH:
            for(u32 i = 1; path[i] != 0; i++)
                if(path[i] == '/')
                {
                    char folder[i + 1];
                    memcpy(folder, path, i);
                    folder[i] = 0;
                    result = f_mkdir(folder);
                }

            return result == FR_OK && fileWrite(buffer, path, size);
        default:
            return false;
    }
}

bool fileDelete(const char *path)
{
    return f_unlink(path) == FR_OK;
}

bool findPayload(char *path, u32 pressed)
{
    const char *pattern;

    if(pressed & BUTTON_LEFT) pattern = PATTERN("left");
    else if(pressed & BUTTON_RIGHT) pattern = PATTERN("right");
    else if(pressed & BUTTON_UP) pattern = PATTERN("up");
    else if(pressed & BUTTON_DOWN) pattern = PATTERN("down");
    else if(pressed & BUTTON_START) pattern = PATTERN("start");
    else if(pressed & BUTTON_B) pattern = PATTERN("b");
    else if(pressed & BUTTON_X) pattern = PATTERN("x");
    else if(pressed & BUTTON_Y) pattern = PATTERN("y");
    else if(pressed & BUTTON_R1) pattern = PATTERN("r");
    else if(pressed & BUTTON_A) pattern = PATTERN("a");
    else pattern = PATTERN("select");

    DIR dir;
    FILINFO info;
    FRESULT result;

    result = f_findfirst(&dir, &info, "payloads", pattern);

    if(result != FR_OK) return false;

    f_closedir(&dir);

    if(!info.fname[0]) return false;

    sprintf(path, "payloads/%s", info.fname);

    return true;
}

bool payloadMenu(char *path)
{
    DIR dir;

    if(f_opendir(&dir, "payloads") != FR_OK) return false;

    FILINFO info;
    u32 payloadNum = 0;
    char payloadList[20][49];

    while(f_readdir(&dir, &info) == FR_OK && info.fname[0] != 0 && payloadNum < 20)
    {
        if(info.fname[0] == '.') continue;

        u32 nameLength = strlen(info.fname);

        if(nameLength < 6 || nameLength > 52) continue;

        nameLength -= 5;

        if(memcmp(info.fname + nameLength, ".firm", 5) != 0) continue;

        memcpy(payloadList[payloadNum], info.fname, nameLength);
        payloadList[payloadNum][nameLength] = 0;
        payloadNum++;
    }

    if(f_closedir(&dir) != FR_OK || !payloadNum) return false;

    u32 pressed = 0,
        selectedPayload = 0;

    if(payloadNum != 1)
    {
        initScreens();

        drawString(true, 10, 10, COLOR_TITLE, "Luma3DS chainloader");
        drawString(true, 10, 10 + SPACING_Y, COLOR_TITLE, "Press A to select, START to quit");

        for(u32 i = 0, posY = 10 + 3 * SPACING_Y, color = COLOR_RED; i < payloadNum; i++, posY += SPACING_Y)
        {
            drawString(true, 10, posY, color, payloadList[i]);
            if(color == COLOR_RED) color = COLOR_WHITE;
        }

        while(pressed != BUTTON_A && pressed != BUTTON_START)
        {
            do
            {
                pressed = waitInput(true) & MENU_BUTTONS;
            }
            while(!pressed);

            u32 oldSelectedPayload = selectedPayload;

            switch(pressed)
            {
                case BUTTON_UP:
                    selectedPayload = !selectedPayload ? payloadNum - 1 : selectedPayload - 1;
                    break;
                case BUTTON_DOWN:
                    selectedPayload = selectedPayload == payloadNum - 1 ? 0 : selectedPayload + 1;
                    break;
                case BUTTON_LEFT:
                    selectedPayload = 0;
                    break;
                case BUTTON_RIGHT:
                    selectedPayload = payloadNum - 1;
                    break;
                default:
                    continue;
            }

            if(oldSelectedPayload == selectedPayload) continue;

            drawString(true, 10, 10 + (3 + oldSelectedPayload) * SPACING_Y, COLOR_WHITE, payloadList[oldSelectedPayload]);
            drawString(true, 10, 10 + (3 + selectedPayload) * SPACING_Y, COLOR_RED, payloadList[selectedPayload]);
        }
    }

    if(pressed != BUTTON_START)
    {
        sprintf(path, "payloads/%s.firm", payloadList[selectedPayload]);

        return true;
    }

    while(HID_PAD & MENU_BUTTONS);
    wait(2000ULL);

    return false;
}

u32 firmRead(void *dest, u32 firmType)
{
    static const char *firmFolders[][2] = {{"00000002", "20000002"},
                                           {"00000102", "20000102"},
                                           {"00000202", "20000202"},
                                           {"00000003", "20000003"},
                                           {"00000001", "20000001"}};

    char folderPath[35],
         path[48];

    sprintf(folderPath, "1:/title/00040138/%s/content", firmFolders[firmType][ISN3DS ? 1 : 0]);

    DIR dir;
    u32 firmVersion = 0xFFFFFFFF;

    if(f_opendir(&dir, folderPath) != FR_OK) goto exit;

    FILINFO info;

    //Parse the target directory
    while(f_readdir(&dir, &info) == FR_OK && info.fname[0] != 0)
    {
        //Not a cxi
        if(info.fname[9] != 'a' || strlen(info.fname) != 12) continue;

        u32 tempVersion = hexAtoi(info.altname, 8);

        //Found an older cxi
        if(tempVersion < firmVersion) firmVersion = tempVersion;
    }

    if(f_closedir(&dir) != FR_OK || firmVersion == 0xFFFFFFFF) goto exit;

    //Complete the string with the .app name
    sprintf(path, "%s/%08lx.app", folderPath, firmVersion);

    if(fileRead(dest, path, 0x400000 + sizeof(Cxi) + 0x200) <= sizeof(Cxi) + 0x400) firmVersion = 0xFFFFFFFF;

exit:
    return firmVersion;
}

void findDumpFile(const char *folderPath, char *fileName)
{
    DIR dir;
    FRESULT result;

    for(u32 n = 0; n <= 99999999; n++)
    {
        FILINFO info;

        sprintf(fileName, "crash_dump_%08lu.dmp", n);
        result = f_findfirst(&dir, &info, folderPath, fileName);

        if(result != FR_OK || !info.fname[0]) break;
    }

    if(result == FR_OK) f_closedir(&dir);
}