/**
 * @file lv_fs_pc.c
 *
 */

/*********************
 *      INCLUDES
 *********************/
#include "lvgl.h"
#include "lv_fs_if.h"
#if LV_USE_FS_IF
#if LV_FS_IF_PC != '\0'

#include <stdio.h>
#include <errno.h>
#include <dirent.h>
#include <unistd.h>
#ifdef WIN32
#include <windows.h>
#endif

/**********************
 *      TYPEDEFS
 **********************/

/* Create a type to store the required data about your file. */
typedef FILE* file_t;

/*Similarly to `file_t` create a type for directory reading too */
#ifndef WIN32
typedef DIR* dir_t;
#else
typedef HANDLE dir_t;
#endif

/**********************
 *  STATIC PROTOTYPES
 **********************/
static lv_fs_res_t fs_open(lv_fs_drv_t* drv, void* file_p, const char* path, lv_fs_mode_t mode);
static lv_fs_res_t fs_close(lv_fs_drv_t* drv, void* file_p);
static lv_fs_res_t fs_read(lv_fs_drv_t* drv, void* file_p, void* buf, uint32_t btr, uint32_t* br);
static lv_fs_res_t fs_write(lv_fs_drv_t* drv, void* file_p, const void* buf, uint32_t btw, uint32_t* bw);
static lv_fs_res_t fs_seek(lv_fs_drv_t* drv, void* file_p, uint32_t pos);
static lv_fs_res_t fs_size(lv_fs_drv_t* drv, void* file_p, uint32_t* size_p);
static lv_fs_res_t fs_tell(lv_fs_drv_t* drv, void* file_p, uint32_t* pos_p);
static lv_fs_res_t fs_remove(lv_fs_drv_t* drv, const char* path);
static lv_fs_res_t fs_trunc(lv_fs_drv_t* drv, void* file_p);
static lv_fs_res_t fs_rename(lv_fs_drv_t* drv, const char* oldname, const char* newname);
static lv_fs_res_t fs_free(lv_fs_drv_t* drv, uint32_t* total_p, uint32_t* free_p);
static lv_fs_res_t fs_dir_open(lv_fs_drv_t* drv, void* dir_p, const char* path);
static lv_fs_res_t fs_dir_read(lv_fs_drv_t* drv, void* dir_p, char* fn);
static lv_fs_res_t fs_dir_close(lv_fs_drv_t* drv, void* dir_p);

/**********************
 *  STATIC VARIABLES
 **********************/

/**********************
 *      MACROS
 **********************/

/**********************
 *   GLOBAL FUNCTIONS
 **********************/

/**
 * Register a driver for the File system interface
 */
void lv_fs_if_pc_init(char letter, const char* path)
{
    /*---------------------------------------------------
     * Register the file system interface  in LittlevGL
     *--------------------------------------------------*/

    /* Add a simple drive to open images */
    lv_fs_drv_t fs_drv; /*A driver descriptor*/
    lv_fs_drv_init(&fs_drv);

    /*Set up fields...*/
    fs_drv.file_size     = sizeof(file_t);
    fs_drv.letter        = letter;
    fs_drv.open_cb       = fs_open;
    fs_drv.close_cb      = fs_close;
    fs_drv.read_cb       = fs_read;
    fs_drv.write_cb      = fs_write;
    fs_drv.seek_cb       = fs_seek;
    fs_drv.tell_cb       = fs_tell;
    fs_drv.free_space_cb = fs_free;
    fs_drv.size_cb       = fs_size;
    fs_drv.remove_cb     = fs_remove;
    fs_drv.rename_cb     = fs_rename;
    fs_drv.trunc_cb      = fs_trunc;

    fs_drv.rddir_size   = sizeof(dir_t);
    fs_drv.dir_close_cb = fs_dir_close;
    fs_drv.dir_open_cb  = fs_dir_open;
    fs_drv.dir_read_cb  = fs_dir_read;

    fs_drv.user_data = path;

    lv_fs_drv_register(&fs_drv);

    // char cur_path[512] = "";
    // getcwd(cur_path, sizeof(cur_path));
    LV_LOG_USER("LV_FS_PC ready");
    // LV_LOG_USER("The following path is considered as root directory:\n%s", cur_path);
}

/**********************
 *   STATIC FUNCTIONS
 **********************/

/**
 * Open a file
 * @param drv pointer to a driver where this function belongs
 * @param file_p pointer to a file_t variable
 * @param path path to the file beginning with the driver letter (e.g. S:/folder/file.txt)
 * @param mode read: FS_MODE_RD, write: FS_MODE_WR, both: FS_MODE_RD | FS_MODE_WR
 * @return LV_FS_RES_OK or any error from lv_fs_res_t enum
 */
static lv_fs_res_t fs_open(lv_fs_drv_t* drv, void* file_p, const char* path, lv_fs_mode_t mode)
{
    (void)drv; /*Unused*/
    errno = 0;

    const char* flags = "";

    if(mode == LV_FS_MODE_WR)
        flags = "wb";
    else if(mode == LV_FS_MODE_RD)
        flags = "rb";
    else if(mode == (LV_FS_MODE_WR | LV_FS_MODE_RD))
        flags = "rb+";

        /*Make the path relative to the current directory (the projects root folder)*/

#ifndef WIN32
    char buf[256];
    sprintf(buf, "%s/%s", drv->user_data, path);
#else
    char buf[256];
    sprintf(buf, "%s\\%s", drv->user_data, path);
#endif

    LV_LOG_USER(buf);

    file_t f = fopen(buf, flags);
    if(f == NULL) return LV_FS_RES_UNKNOWN;

    /*Be sure we are the beginning of the file*/
    fseek(f, 0, SEEK_SET);

    /* 'file_p' is pointer to a file descriptor and
     * we need to store our file descriptor here*/
    file_t* fp = file_p; /*Just avoid the confusing casings*/
    *fp        = f;

    return LV_FS_RES_OK;
}

/**
 * Close an opened file
 * @param drv pointer to a driver where this function belongs
 * @param file_p pointer to a file_t variable. (opened with lv_ufs_open)
 * @return LV_FS_RES_OK: no error, the file is read
 *         any error from lv_fs_res_t enum
 */
static lv_fs_res_t fs_close(lv_fs_drv_t* drv, void* file_p)
{
    (void)drv;           /*Unused*/
    file_t* fp = file_p; /*Just avoid the confusing casings*/
    fclose(*fp);
    return LV_FS_RES_OK;
}

/**
 * Read data from an opened file
 * @param drv pointer to a driver where this function belongs
 * @param file_p pointer to a file_t variable.
 * @param buf pointer to a memory block where to store the read data
 * @param btr number of Bytes To Read
 * @param br the real number of read bytes (Byte Read)
 * @return LV_FS_RES_OK: no error, the file is read
 *         any error from lv_fs_res_t enum
 */
static lv_fs_res_t fs_read(lv_fs_drv_t* drv, void* file_p, void* buf, uint32_t btr, uint32_t* br)
{
    (void)drv;           /*Unused*/
    file_t* fp = file_p; /*Just avoid the confusing casings*/
    *br        = fread(buf, 1, btr, *fp);
    return LV_FS_RES_OK;
}

/**
 * Write into a file
 * @param drv pointer to a driver where this function belongs
 * @param file_p pointer to a file_t variable
 * @param buf pointer to a buffer with the bytes to write
 * @param btr Bytes To Write
 * @param br the number of real written bytes (Bytes Written). NULL if unused.
 * @return LV_FS_RES_OK or any error from lv_fs_res_t enum
 */
static lv_fs_res_t fs_write(lv_fs_drv_t* drv, void* file_p, const void* buf, uint32_t btw, uint32_t* bw)
{
    (void)drv;           /*Unused*/
    file_t* fp = file_p; /*Just avoid the confusing casings*/
    *bw        = fwrite(buf, 1, btw, *fp);
    return LV_FS_RES_OK;
}

/**
 * Set the read write pointer. Also expand the file size if necessary.
 * @param drv pointer to a driver where this function belongs
 * @param file_p pointer to a file_t variable. (opened with lv_ufs_open )
 * @param pos the new position of read write pointer
 * @return LV_FS_RES_OK: no error, the file is read
 *         any error from lv_fs_res_t enum
 */
static lv_fs_res_t fs_seek(lv_fs_drv_t* drv, void* file_p, uint32_t pos)
{
    (void)drv;           /*Unused*/
    file_t* fp = file_p; /*Just avoid the confusing casings*/
    fseek(*fp, pos, SEEK_SET);
    return LV_FS_RES_OK;
}

/**
 * Give the size of a file bytes
 * @param drv pointer to a driver where this function belongs
 * @param file_p pointer to a file_t variable
 * @param size pointer to a variable to store the size
 * @return LV_FS_RES_OK or any error from lv_fs_res_t enum
 */
static lv_fs_res_t fs_size(lv_fs_drv_t* drv, void* file_p, uint32_t* size_p)
{
    (void)drv;           /*Unused*/
    file_t* fp = file_p; /*Just avoid the confusing casings*/

    uint32_t cur = ftell(*fp);

    fseek(*fp, 0L, SEEK_END);
    *size_p = ftell(*fp);

    /*Restore file pointer*/
    fseek(*fp, cur, SEEK_SET);

    return LV_FS_RES_OK;
}

/**
 * Give the position of the read write pointer
 * @param drv pointer to a driver where this function belongs
 * @param file_p pointer to a file_t variable.
 * @param pos_p pointer to to store the result
 * @return LV_FS_RES_OK: no error, the file is read
 *         any error from lv_fs_res_t enum
 */
static lv_fs_res_t fs_tell(lv_fs_drv_t* drv, void* file_p, uint32_t* pos_p)
{
    (void)drv;           /*Unused*/
    file_t* fp = file_p; /*Just avoid the confusing casings*/
    *pos_p     = ftell(*fp);
    return LV_FS_RES_OK;
}

/**
 * Delete a file
 * @param drv pointer to a driver where this function belongs
 * @param path path of the file to delete
 * @return  LV_FS_RES_OK or any error from lv_fs_res_t enum
 */
static lv_fs_res_t fs_remove(lv_fs_drv_t* drv, const char* path)
{
    (void)drv; /*Unused*/
    lv_fs_res_t res = LV_FS_RES_NOT_IMP;

    /* Add your code here*/

    return res;
}

/**
 * Truncate the file size to the current position of the read write pointer
 * @param drv pointer to a driver where this function belongs
 * @param file_p pointer to an 'ufs_file_t' variable. (opened with lv_fs_open )
 * @return LV_FS_RES_OK: no error, the file is read
 *         any error from lv_fs_res_t enum
 */
static lv_fs_res_t fs_trunc(lv_fs_drv_t* drv, void* file_p)
{
    (void)drv;           /*Unused*/
    file_t* fp = file_p; /*Just avoid the confusing casings*/

    fflush(*fp); /*If not syncronized fclose can write the truncated part*/
    uint32_t p = ftell(*fp);
    //  ftruncate(fileno(*fp), p);
    return LV_FS_RES_OK;
}

/**
 * Rename a file
 * @param drv pointer to a driver where this function belongs
 * @param oldname path to the file
 * @param newname path with the new name
 * @return LV_FS_RES_OK or any error from 'fs_res_t'
 */
static lv_fs_res_t fs_rename(lv_fs_drv_t* drv, const char* oldname, const char* newname)
{
    (void)drv; /*Unused*/
    static char new[512];
    static char old[512];

    sprintf(old, "%s/%s", drv->user_data, oldname);
    sprintf(new, "%s/%s", drv->user_data, newname);

    int r = rename(old, new);

    if(r == 0)
        return LV_FS_RES_OK;
    else
        return LV_FS_RES_UNKNOWN;
}

/**
 * Get the free and total size of a driver in kB
 * @param drv pointer to a driver where this function belongs
 * @param letter the driver letter
 * @param total_p pointer to store the total size [kB]
 * @param free_p pointer to store the free size [kB]
 * @return LV_FS_RES_OK or any error from lv_fs_res_t enum
 */
static lv_fs_res_t fs_free(lv_fs_drv_t* drv, uint32_t* total_p, uint32_t* free_p)
{
    (void)drv; /*Unused*/
    lv_fs_res_t res = LV_FS_RES_NOT_IMP;

    /* Add your code here*/

    return res;
}

#ifdef WIN32
static char next_fn[256];
#endif

/**
 * Initialize a 'fs_read_dir_t' variable for directory reading
 * @param drv pointer to a driver where this function belongs
 * @param dir_p pointer to a 'fs_read_dir_t' variable
 * @param path path to a directory
 * @return LV_FS_RES_OK or any error from lv_fs_res_t enum
 */
static lv_fs_res_t fs_dir_open(lv_fs_drv_t* drv, void* dir_p, const char* path)
{
    (void)drv; /*Unused*/
    dir_t d;
#ifndef WIN32
    /*Make the path relative to the current directory (the projects root folder)*/
    char buf[256];
    sprintf(buf, "%s/%s", drv->user_data, path);
    if((d = opendir(buf)) == NULL) {
        return LV_FS_RES_FS_ERR;
    } else {
        /* 'dir_p' is pointer to a file descriptor and
         * we need to store our file descriptor here*/
        dir_t* dp = dir_p; /*Just avoid the confusing casings*/
        *dp       = d;
    }
#else
    d = INVALID_HANDLE_VALUE;
    WIN32_FIND_DATA fdata;

    /*Make the path relative to the current directory (the projects root folder)*/
    char buf[256];
    sprintf(buf, "%s\\%s\\*", drv->user_data, path);

    strcpy(next_fn, "");
    d = FindFirstFile(buf, &fdata);
    do {
        if(strcmp(fdata.cFileName, ".") == 0 || strcmp(fdata.cFileName, "..") == 0) {
            continue;
        } else {

            if(fdata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
                sprintf(next_fn, "/%s", fdata.cFileName);
            } else {
                sprintf(next_fn, "%s", fdata.cFileName);
            }
            break;
        }
    } while(FindNextFileA(d, &fdata));

    dir_t* dp = dir_p; /*Just avoid the confusing casings*/
    *dp       = d;

#endif

    return LV_FS_RES_OK;
}

/**
 * Read the next filename form a directory.
 * The name of the directories will begin with '/'
 * @param drv pointer to a driver where this function belongs
 * @param dir_p pointer to an initialized 'fs_read_dir_t' variable
 * @param fn pointer to a buffer to store the filename
 * @return LV_FS_RES_OK or any error from lv_fs_res_t enum
 */
static lv_fs_res_t fs_dir_read(lv_fs_drv_t* drv, void* dir_p, char* fn)
{
    (void)drv;         /*Unused*/
    dir_t* dp = dir_p; /*Just avoid the confusing casings*/

#ifndef WIN32
    struct dirent* entry;
    do {
        entry = readdir(*dp);

        if(entry) {
            if(entry->d_type == DT_DIR)
                sprintf(fn, "/%s", entry->d_name);
            else
                strcpy(fn, entry->d_name);
        } else {
            strcpy(fn, "");
        }
    } while(strcmp(fn, "/.") == 0 || strcmp(fn, "/..") == 0);
#else
    strcpy(fn, next_fn);

    strcpy(next_fn, "");
    WIN32_FIND_DATA fdata;

    if(FindNextFile(*dp, &fdata) == false) return LV_FS_RES_OK;
    do {
        if(strcmp(fdata.cFileName, ".") == 0 || strcmp(fdata.cFileName, "..") == 0) {
            continue;
        } else {

            if(fdata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
                sprintf(next_fn, "/%s", fdata.cFileName);
            } else {
                sprintf(next_fn, "%s", fdata.cFileName);
            }
            break;
        }
    } while(FindNextFile(*dp, &fdata));

#endif
    return LV_FS_RES_OK;
}

/**
 * Close the directory reading
 * @param drv pointer to a driver where this function belongs
 * @param dir_p pointer to an initialized 'fs_read_dir_t' variable
 * @return LV_FS_RES_OK or any error from lv_fs_res_t enum
 */
static lv_fs_res_t fs_dir_close(lv_fs_drv_t* drv, void* dir_p)
{
    (void)drv; /*Unused*/
    dir_t* dp = dir_p;
#ifndef WIN32
    closedir(*dp);
#else
    FindClose(*dp);
    *dp = INVALID_HANDLE_VALUE;
#endif
    return LV_FS_RES_OK;
}

#endif /*LV_USE_FS_IF*/
#endif /*LV_FS_IF_FATFS*/