#pragma once

/*
Stupid cpio-like tool to make read-only 'filesystems' that live on the flash SPI chip of the module.
Can (will) use lzf compression (when I come around to it) to make shit quicker. Aligns names, files,
headers on 4-byte boundaries so the SPI abstraction hardware in the ESP8266 doesn't crap on itself
when trying to do a <4byte or unaligned read.
*/

/*
The idea 'borrows' from cpio: it's basically a concatenation of {header, filename, file} data.
Header, filename and file data is 32-bit aligned. The last file is indicated by data-less header
with the FLAG_LASTFILE flag set.
*/

#include <stdint.h>

/// Last file in the filesystem image
#define EFS_FLAG_LASTFILE (1<<0)
/// Gzipped file. This does not affect espfs, it's a user-level flag; un-gzip is not implemented as part
/// of the FS or CGI - gzipped files are sent directly to the browser with the appropriate header -
/// saving bandwidth and getting us better compression ratios than heatshrink can achieve for larger files.
#define EFS_FLAG_GZIP (1<<1)
/// No filesystem level compression
#define EFS_COMPRESS_NONE 0
/// The file is stored as compressed
#define EFS_COMPRESS_HEATSHRINK 1
/// Magic number leading each file record
#define EFS_MAGIC 0x73665345 /* ASCII sequence of bytes 'E' 'S' 'f' 's' interpreted as a little endian uint32_t */

/* 16 bytes long for alignment */
typedef struct {
  /// Magic number
  uint32_t magic;
  /// File flags
  uint8_t flags;
  /// Filesystem-level compression used
  uint8_t compression;
  /// Length of the file name
  uint16_t nameLen;
  /// Compressed file length (differs from the decompressed size if either gzip or heatshrink is used)
  uint32_t fileLenComp;
  /// Decompressed file length
  uint32_t fileLenDecomp;
} __attribute__((packed)) EspFsHeader;