#include "c_stdio.h"
#include "platform.h"
#include "spiffs.h"

/*
 * With the intoduction of a unified FatFS and SPIFFS support (#1397), the SPIFFS
 * interface is now abstracted through a uses a single SPIFFS entry point
 * myspiffs_realm() which returns a vfs_fs_fns object (as does myfatfs_realm()).
 * All other functions and data are static.
 *
 * Non-OS SDK V3.0 introduces a flash partition table (PT) and SPIFFS has now been
 * updated to support this:
 *   -  SPIFFS limits search to the specifed SPIFFS0 address and size.
 *   -  Any headroom / offset from other partitions is reflected in the PT allocations.
 *   -  Unforced mounts will attempt to mount any valid SPIFSS found in this range
 *      (NodeMCU uses the SPIFFS_USE_MAGIC setting to make existing FS discoverable).
 *   -  Subject to the following, no offset or FS search is done.  The FS is assumed
 *      to be at the first valid location at the start of the partition.
 */
#include "spiffs_nucleus.h"

static spiffs fs;

#define LOG_PAGE_SIZE       	256
#define LOG_BLOCK_SIZE		(INTERNAL_FLASH_SECTOR_SIZE * 2)
#define LOG_BLOCK_SIZE_SMALL_FS	(INTERNAL_FLASH_SECTOR_SIZE)
#define MIN_BLOCKS_FS		4
#define MASK_1MB (0x100000-1)
#define ALIGN (0x2000)

static u8_t spiffs_work_buf[LOG_PAGE_SIZE*2];
static u8_t spiffs_fds[sizeof(spiffs_fd) * SPIFFS_MAX_OPEN_FILES];
#if SPIFFS_CACHE
static u8_t myspiffs_cache[20 + (LOG_PAGE_SIZE+20)*4];
#endif

static s32_t my_spiffs_read(u32_t addr, u32_t size, u8_t *dst) {
  platform_flash_read(dst, addr, size);
  return SPIFFS_OK;
}

static s32_t my_spiffs_write(u32_t addr, u32_t size, u8_t *src) {
  platform_flash_write(src, addr, size);
  return SPIFFS_OK;
}

static int erase_cnt = -1;  // If set to >=0 then erasing gives a ... feedback
static s32_t my_spiffs_erase(u32_t addr, u32_t size) {
  u32_t sect_first = platform_flash_get_sector_of_address(addr);
  u32_t sect_last = sect_first;
  while( sect_first <= sect_last ) {
    if (erase_cnt >= 0 && (erase_cnt++ & 0xF) == 0) {
      dbg_printf(".");
    }
    if( platform_flash_erase_sector( sect_first ++ ) == PLATFORM_ERR ) {
      return SPIFFS_ERR_INTERNAL;
    }
  }
  return SPIFFS_OK;
}

void myspiffs_check_callback(spiffs_check_type type, spiffs_check_report report, u32_t arg1, u32_t arg2){
  // if(SPIFFS_CHECK_PROGRESS == report) return;
  // NODE_ERR("type: %d, report: %d, arg1: %d, arg2: %d\n", type, report, arg1, arg2);
}

/*******************
 * Note that the W25Q32BV array is organized into 16,384 programmable pages of 256-bytes 
 * each. Up to 256 bytes can be programmed at a time.  Pages can be erased in groups of 
 * 16 (4KB sector erase), groups of 128 (32KB block erase), groups of 256 (64KB block 
 * erase) or the entire chip (chip erase). The W25Q32BV has 1,024 erasable sectors and 
 * 64 erasable blocks respectively. The small 4KB sectors allow for greater flexibility 
 * in applications that require data and parameter storage. 
 *
 * Returns  TRUE if FS was found.
 */
static bool myspiffs_set_cfg(spiffs_config *cfg, bool force_create) {
  uint32 pt_start, pt_size, pt_end;

  pt_size = platform_flash_get_partition (NODEMCU_SPIFFS0_PARTITION, &pt_start);
  if (pt_size == 0) {
    return FALSE;
  }
  pt_end = pt_start + pt_size;

  cfg->hal_read_f = my_spiffs_read;
  cfg->hal_write_f = my_spiffs_write;
  cfg->hal_erase_f = my_spiffs_erase;
  cfg->phys_erase_block = INTERNAL_FLASH_SECTOR_SIZE;
  cfg->log_page_size = LOG_PAGE_SIZE;
  cfg->phys_addr = (pt_start + ALIGN - 1) & ~(ALIGN - 1);
  cfg->phys_size = (pt_end & ~(ALIGN - 1)) - cfg->phys_addr;
  
  if (cfg->phys_size < MIN_BLOCKS_FS * LOG_BLOCK_SIZE_SMALL_FS) {
    return FALSE;
  } else if (cfg->phys_size < MIN_BLOCKS_FS * LOG_BLOCK_SIZE_SMALL_FS) {
    cfg->log_block_size = LOG_BLOCK_SIZE_SMALL_FS;
  } else  {
    cfg->log_block_size = LOG_BLOCK_SIZE;
  }

#ifdef SPIFFS_USE_MAGIC_LENGTH
  if (!force_create) {
    int size = SPIFFS_probe_fs(cfg);

    if (size > 0 && size < cfg->phys_size) {
      NODE_DBG("Overriding size:%x\n",size);
      cfg->phys_size = size;
    }
    if (size <= 0) {
      return FALSE;
    }
  }
#endif

  NODE_DBG("myspiffs set cfg block: %x  %x  %x  %x  %x  %x\n", pt_start, pt_end,
           cfg->phys_size, cfg->phys_addr, cfg->phys_size, cfg->log_block_size);

  return TRUE;
}


static bool myspiffs_mount(bool force_mount) {
  spiffs_config cfg;
  if (!myspiffs_set_cfg(&cfg, force_mount) && !force_mount) {
    return FALSE;
  }

  fs.err_code = 0;

  int res = SPIFFS_mount(&fs,
    &cfg,
    spiffs_work_buf,
    spiffs_fds,
    sizeof(spiffs_fds),
#if SPIFFS_CACHE
    myspiffs_cache,
    sizeof(myspiffs_cache),
#else
    0, 0,
#endif
    // myspiffs_check_callback);
    0);
  NODE_DBG("mount res: %d, %d\n", res, fs.err_code);
  return res == SPIFFS_OK;
}

void myspiffs_unmount() {
  SPIFFS_unmount(&fs);
}

// FS formatting function
// Returns 1 if OK, 0 for error
int myspiffs_format( void )
{
  SPIFFS_unmount(&fs);
  myspiffs_mount(TRUE);
  SPIFFS_unmount(&fs);

  NODE_DBG("Formatting: size 0x%x, addr 0x%x\n", fs.cfg.phys_size, fs.cfg.phys_addr);
  erase_cnt = 0;
  int status = SPIFFS_format(&fs);
  erase_cnt = -1;

  return status < 0 ? 0 : myspiffs_mount(FALSE);
}


// ***************************************************************************
// vfs API
// ***************************************************************************

#include <c_stdlib.h>
#include "vfs_int.h"

#define MY_LDRV_ID "FLASH"

// default current drive
static int is_current_drive = TRUE;

// forward declarations
static sint32_t myspiffs_vfs_close( const struct vfs_file *fd );
static sint32_t myspiffs_vfs_read( const struct vfs_file *fd, void *ptr, size_t len );
static sint32_t myspiffs_vfs_write( const struct vfs_file *fd, const void *ptr, size_t len );
static sint32_t myspiffs_vfs_lseek( const struct vfs_file *fd, sint32_t off, int whence );
static sint32_t myspiffs_vfs_eof( const struct vfs_file *fd );
static sint32_t myspiffs_vfs_tell( const struct vfs_file *fd );
static sint32_t myspiffs_vfs_flush( const struct vfs_file *fd );
static uint32_t myspiffs_vfs_size( const struct vfs_file *fd );
static sint32_t myspiffs_vfs_ferrno( const struct vfs_file *fd );

static sint32_t  myspiffs_vfs_closedir( const struct vfs_dir *dd );
static sint32_t  myspiffs_vfs_readdir( const struct vfs_dir *dd, struct vfs_stat *buf );

static vfs_vol  *myspiffs_vfs_mount( const char *name, int num );
static vfs_file *myspiffs_vfs_open( const char *name, const char *mode );
static vfs_dir  *myspiffs_vfs_opendir( const char *name );
static sint32_t  myspiffs_vfs_stat( const char *name, struct vfs_stat *buf );
static sint32_t  myspiffs_vfs_remove( const char *name );
static sint32_t  myspiffs_vfs_rename( const char *oldname, const char *newname );
static sint32_t  myspiffs_vfs_fsinfo( uint32_t *total, uint32_t *used );
static sint32_t  myspiffs_vfs_fscfg( uint32_t *phys_addr, uint32_t *phys_size );
static sint32_t  myspiffs_vfs_format( void );
static sint32_t  myspiffs_vfs_errno( void );
static void      myspiffs_vfs_clearerr( void );

static sint32_t myspiffs_vfs_umount( const struct vfs_vol *vol );

// ---------------------------------------------------------------------------
// function tables
//
static vfs_fs_fns myspiffs_fs_fns = {
  .mount    = myspiffs_vfs_mount,
  .open     = myspiffs_vfs_open,
  .opendir  = myspiffs_vfs_opendir,
  .stat     = myspiffs_vfs_stat,
  .remove   = myspiffs_vfs_remove,
  .rename   = myspiffs_vfs_rename,
  .mkdir    = NULL,
  .fsinfo   = myspiffs_vfs_fsinfo,
  .fscfg    = myspiffs_vfs_fscfg,
  .format   = myspiffs_vfs_format,
  .chdrive  = NULL,
  .chdir    = NULL,
  .ferrno   = myspiffs_vfs_errno,
  .clearerr = myspiffs_vfs_clearerr
};

static vfs_file_fns myspiffs_file_fns = {
  .close     = myspiffs_vfs_close,
  .read      = myspiffs_vfs_read,
  .write     = myspiffs_vfs_write,
  .lseek     = myspiffs_vfs_lseek,
  .eof       = myspiffs_vfs_eof,
  .tell      = myspiffs_vfs_tell,
  .flush     = myspiffs_vfs_flush,
  .size      = myspiffs_vfs_size,
  .ferrno    = myspiffs_vfs_ferrno
};

static vfs_dir_fns myspiffs_dd_fns = {
  .close     = myspiffs_vfs_closedir,
  .readdir   = myspiffs_vfs_readdir
};


// ---------------------------------------------------------------------------
// specific struct extensions
//
struct myvfs_file {
  struct vfs_file vfs_file;
  spiffs_file fh;
};

struct myvfs_dir {
  struct vfs_dir vfs_dir;
  spiffs_DIR d;
};


// ---------------------------------------------------------------------------
// volume functions
//
static sint32_t myspiffs_vfs_umount( const struct vfs_vol *vol ) {
  // not implemented

  return VFS_RES_ERR;
}


// ---------------------------------------------------------------------------
// dir functions
//
#define GET_DIR_D(descr) \
  const struct myvfs_dir *mydd = (const struct myvfs_dir *)descr; \
  spiffs_DIR *d = (spiffs_DIR *)&(mydd->d);

static sint32_t myspiffs_vfs_closedir( const struct vfs_dir *dd ) {
  GET_DIR_D(dd);

  sint32_t res = SPIFFS_closedir( d );

  // free descriptor memory
  c_free( (void *)dd );
}

static sint32_t myspiffs_vfs_readdir( const struct vfs_dir *dd, struct vfs_stat *buf ) {
  GET_DIR_D(dd);
  struct spiffs_dirent dirent;

  if (SPIFFS_readdir( d, &dirent )) {
    c_memset( buf, 0, sizeof( struct vfs_stat ) );

    // copy entries to  item
    // fill in supported stat entries
    c_strncpy( buf->name, dirent.name, FS_OBJ_NAME_LEN+1 );
    buf->name[FS_OBJ_NAME_LEN] = '\0';
    buf->size = dirent.size;
    return VFS_RES_OK;
  }

  return VFS_RES_ERR;
}


// ---------------------------------------------------------------------------
// file functions
//
#define GET_FILE_FH(descr) \
  const struct myvfs_file *myfd = (const struct myvfs_file *)descr; \
  spiffs_file fh = myfd->fh;

static sint32_t myspiffs_vfs_close( const struct vfs_file *fd ) {
  GET_FILE_FH(fd);

  sint32_t res = SPIFFS_close( &fs, fh );

  // free descriptor memory
  c_free( (void *)fd );

  return res;
}

static sint32_t myspiffs_vfs_read( const struct vfs_file *fd, void *ptr, size_t len ) {
  GET_FILE_FH(fd);

  sint32_t n = SPIFFS_read( &fs, fh, ptr, len );

  return n >= 0 ? n : VFS_RES_ERR;
}

static sint32_t myspiffs_vfs_write( const struct vfs_file *fd, const void *ptr, size_t len ) {
  GET_FILE_FH(fd);

  sint32_t n = SPIFFS_write( &fs, fh, (void *)ptr, len );

  return n >= 0 ? n : VFS_RES_ERR;
}

static sint32_t myspiffs_vfs_lseek( const struct vfs_file *fd, sint32_t off, int whence ) {
  GET_FILE_FH(fd);
  int spiffs_whence;

  switch (whence) {
  default:
  case VFS_SEEK_SET:
    spiffs_whence = SPIFFS_SEEK_SET;
    break;
  case VFS_SEEK_CUR:
    spiffs_whence = SPIFFS_SEEK_CUR;
    break;
  case VFS_SEEK_END:
    spiffs_whence = SPIFFS_SEEK_END;
    break;
  }

  sint32_t res = SPIFFS_lseek( &fs, fh, off, spiffs_whence );
  return res >= 0 ? res : VFS_RES_ERR;
}

static sint32_t myspiffs_vfs_eof( const struct vfs_file *fd ) {
  GET_FILE_FH(fd);

  return SPIFFS_eof( &fs, fh );
}

static sint32_t myspiffs_vfs_tell( const struct vfs_file *fd ) {
  GET_FILE_FH(fd);

  return SPIFFS_tell( &fs, fh );
}

static sint32_t myspiffs_vfs_flush( const struct vfs_file *fd ) {
  GET_FILE_FH(fd);

  return SPIFFS_fflush( &fs, fh ) >= 0 ? VFS_RES_OK : VFS_RES_ERR;
}

static uint32_t myspiffs_vfs_size( const struct vfs_file *fd ) {
  GET_FILE_FH(fd);

  int32_t curpos = SPIFFS_tell( &fs, fh );
  int32_t size = SPIFFS_lseek( &fs, fh, 0, SPIFFS_SEEK_END );
  (void) SPIFFS_lseek( &fs, fh, curpos, SPIFFS_SEEK_SET );

   return size;
}

static sint32_t myspiffs_vfs_ferrno( const struct vfs_file *fd ) {
  return SPIFFS_errno( &fs );
}


static int fs_mode2flag(const char *mode){
  if(c_strlen(mode)==1){
  	if(c_strcmp(mode,"w")==0)
  	  return SPIFFS_WRONLY|SPIFFS_CREAT|SPIFFS_TRUNC;
  	else if(c_strcmp(mode, "r")==0)
  	  return SPIFFS_RDONLY;
  	else if(c_strcmp(mode, "a")==0)
  	  return SPIFFS_WRONLY|SPIFFS_CREAT|SPIFFS_APPEND;
  	else
  	  return SPIFFS_RDONLY;
  } else if (c_strlen(mode)==2){
  	if(c_strcmp(mode,"r+")==0)
  	  return SPIFFS_RDWR;
  	else if(c_strcmp(mode, "w+")==0)
  	  return SPIFFS_RDWR|SPIFFS_CREAT|SPIFFS_TRUNC;
  	else if(c_strcmp(mode, "a+")==0)
  	  return SPIFFS_RDWR|SPIFFS_CREAT|SPIFFS_APPEND;
  	else
  	  return SPIFFS_RDONLY;
  } else {
  	return SPIFFS_RDONLY;
  }
}

// ---------------------------------------------------------------------------
// filesystem functions
//
static vfs_file *myspiffs_vfs_open( const char *name, const char *mode ) {
  struct myvfs_file *fd;
  int flags = fs_mode2flag( mode );

  if (fd = (struct myvfs_file *)c_malloc( sizeof( struct myvfs_file ) )) {
    if (0 < (fd->fh = SPIFFS_open( &fs, name, flags, 0 ))) {
      fd->vfs_file.fs_type = VFS_FS_SPIFFS;
      fd->vfs_file.fns     = &myspiffs_file_fns;
      return (vfs_file *)fd;
    } else {
      c_free( fd );
    }
  }

  return NULL;
}

static vfs_dir *myspiffs_vfs_opendir( const char *name ){
  struct myvfs_dir *dd;

  if (dd = (struct myvfs_dir *)c_malloc( sizeof( struct myvfs_dir ) )) {
    if (SPIFFS_opendir( &fs, name, &(dd->d) )) {
      dd->vfs_dir.fs_type = VFS_FS_SPIFFS;
      dd->vfs_dir.fns     = &myspiffs_dd_fns;
      return (vfs_dir *)dd;
    } else {
      c_free( dd );
    }
  }

  return NULL;
}

static sint32_t myspiffs_vfs_stat( const char *name, struct vfs_stat *buf ) {
  spiffs_stat stat;

  if (0 <= SPIFFS_stat( &fs, name, &stat )) {
    c_memset( buf, 0, sizeof( struct vfs_stat ) );

    // fill in supported stat entries
    c_strncpy( buf->name, stat.name, FS_OBJ_NAME_LEN+1 );
    buf->name[FS_OBJ_NAME_LEN] = '\0';
    buf->size = stat.size;

    return VFS_RES_OK;
  } else {
    return VFS_RES_ERR;
  }
}

static sint32_t myspiffs_vfs_remove( const char *name ) {
  return SPIFFS_remove( &fs, name );
}

static sint32_t myspiffs_vfs_rename( const char *oldname, const char *newname ) {
  return SPIFFS_rename( &fs, oldname, newname );
}

static sint32_t myspiffs_vfs_fsinfo( uint32_t *total, uint32_t *used ) {
  return SPIFFS_info( &fs, total, used );
}

static sint32_t myspiffs_vfs_fscfg( uint32_t *phys_addr, uint32_t *phys_size ) {
  *phys_addr = fs.cfg.phys_addr;
  *phys_size = fs.cfg.phys_size;
  return VFS_RES_OK;
}

static vfs_vol  *myspiffs_vfs_mount( const char *name, int num ) {
  // volume descriptor not supported, just return TRUE / FALSE
  return myspiffs_mount(FALSE) ? (vfs_vol *)1 : NULL;
}

static sint32_t myspiffs_vfs_format( void ) {
  return myspiffs_format();
}

static sint32_t myspiffs_vfs_errno( void ) {
  return SPIFFS_errno( &fs );
}

static void myspiffs_vfs_clearerr( void ) {
  SPIFFS_clearerr( &fs );
}


// ---------------------------------------------------------------------------
// VFS interface functions
//

vfs_fs_fns *myspiffs_realm( const char *inname, char **outname, int set_current_drive ) {
  if (inname[0] == '/') {
    // logical drive is specified, check if it's our id
    if (0 == c_strncmp(inname + 1, MY_LDRV_ID, sizeof(MY_LDRV_ID)-1)) {
      *outname = (char *)(inname + sizeof(MY_LDRV_ID));
      if (*outname[0] == '/') {
        // skip leading /
        (*outname)++;
      }

      if (set_current_drive) is_current_drive = TRUE;
      return &myspiffs_fs_fns;
    }
  } else {
    // no logical drive in patchspec, are we current drive?
    if (is_current_drive) {
      *outname = (char *)inname;
      return &myspiffs_fs_fns;
    }
  }

  if (set_current_drive) is_current_drive = FALSE;
  return NULL;
}