#include "draw.h"
#include "fs.h"
#include "fatfs/ff.h"
#include "fatfs/nandio.h"

// don't use this area for anything else!
static FATFS* fs = (FATFS*)0x20316000; 
// reserve one MB for this, just to be safe
static DirStruct* curdir_contents = (DirStruct*)0x21000000;
// this is the main buffer
// static u8* main_buffer = (u8*)0x21100000;
// number of currently open file systems
static u32 numfs = 0;

bool InitFS()
{
    #ifndef EXEC_GATEWAY
    // TODO: Magic?
    *(u32*)0x10000020 = 0;
    *(u32*)0x10000020 = 0x340;
    #endif
    u32 emunand_state = CheckEmuNand();
    for (numfs = 0; numfs < 16; numfs++) {
        char fsname[8];
        snprintf(fsname, 8, "%lu:", numfs);
        int res = f_mount(fs + numfs, fsname, 1);
        if (res != FR_OK) {
            if (numfs >= 4) break;
            ShowError("Initialising failed! (%lu/%s/%i)", numfs, fsname, res);
            DeinitFS();
            return false;
        }
    }
    ShowError("Mounted: %i partitions", numfs);
    return true;
}

void DeinitFS()
{
    for (u32 i = 0; i < numfs; i++) {
        char fsname[8];
        snprintf(fsname, 7, "%lu:", numfs);
        f_mount(NULL, fsname, 1);
    }
    numfs = 0;
}

bool GetRootDirContentsWorker(DirStruct* contents)
{
    static const char* drvname[16] = {
        "SDCARD",
        "SYSCTRN", "SYSTWLN", "SYSTWLP",
        "EMU0CTRN", "EMU0TWLN", "EMU0TWLP",
        "EMU1CTRN", "EMU1TWLN", "EMU1TWLP",
        "EMU2CTRN", "EMU2TWLN", "EMU2TWLP",
        "EMU3CTRN", "EMU3TWLN", "EMU3TWLP"
    };
    
    for (u32 pdrv = 0; (pdrv < numfs) && (pdrv < MAX_ENTRIES); pdrv++) {
        memset(contents->entry[pdrv].path, 0x00, 16);
        snprintf(contents->entry[pdrv].path + 0,  4, "%lu:", pdrv);
        snprintf(contents->entry[pdrv].path + 4, 16, "[%lu:] (%s)", pdrv, drvname[pdrv]);
        contents->entry[pdrv].name = contents->entry[pdrv].path + 4;
        contents->entry[pdrv].size = 0;
        contents->entry[pdrv].type = T_FAT_ROOT;
    }
    contents->n_entries = numfs;
    
    return contents->n_entries;
}

bool GetDirContentsWorker(DirStruct* contents, char* fpath, int fsize, bool recursive)
{
    DIR pdir;
    FILINFO fno;
    char* fname = fpath + strnlen(fpath, fsize - 1);
    bool ret = false;
    
    if (f_opendir(&pdir, fpath) != FR_OK)
        return false;
    (fname++)[0] = '/';
    fno.lfname = fname;
    fno.lfsize = fsize - (fname - fpath);
    
    while (f_readdir(&pdir, &fno) == FR_OK) {
        if ((strncmp(fno.fname, ".", 2) == 0) || (strncmp(fno.fname, "..", 3) == 0))
            continue; // filter out virtual entries
        if (fname[0] == 0)
            strncpy(fname, fno.fname, (fsize - 1) - (fname - fpath));
        if (fno.fname[0] == 0) {
            ret = true;
            break;
        } else {
            DirEntry* entry = &(contents->entry[contents->n_entries]);
            snprintf(entry->path, 256, "%s", fpath);
            entry->name = entry->path + (fpath - fname);
            if (fno.fattrib & AM_DIR) {
                entry->type = T_FAT_DIR;
                entry->size = 0;
            } else {
                entry->type = T_FAT_FILE;
                entry->size = fno.fsize;
            }
            contents->n_entries++;
            if (contents->n_entries >= MAX_ENTRIES)
                break;
        }
        if (recursive && (fno.fattrib & AM_DIR)) {
            if (!GetDirContentsWorker(contents, fpath, fsize, recursive))
                break;
        }
    }
    f_closedir(&pdir);
    
    return ret;
}

DirStruct* GetDirContents(const char* path)
{
    curdir_contents->n_entries = 0;
    if (strncmp(path, "", 256) == 0) { // root directory
        if (!GetRootDirContentsWorker(curdir_contents))
            curdir_contents->n_entries = 0; // not required, but so what?
    } else {
        char fpath[256]; // 256 is the maximum length of a full path
        strncpy(fpath, path, 256);
        if (!GetDirContentsWorker(curdir_contents, fpath, 256, false))
            curdir_contents->n_entries = 0;
    }
    
    return curdir_contents;
}

/*static uint64_t ClustersToBytes(FATFS* fs, DWORD clusters)
{
    uint64_t sectors = clusters * fs->csize;
#if _MAX_SS != _MIN_SS
    return sectors * fs->ssize;
#else
    return sectors * _MAX_SS;
#endif
}

uint64_t RemainingStorageSpace()
{
    DWORD free_clusters;
    FATFS *fs2;
    FRESULT res = f_getfree("0:", &free_clusters, &fs2);
    if (res)
        return -1;

    return ClustersToBytes(&fs, free_clusters);
}

uint64_t TotalStorageSpace()
{
    return ClustersToBytes(&fs, fs.n_fatent - 2);
}*/