#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include "sp_file.h"

#include "memfile.h"

void *mf_open(const char *name);

void mf_close(void *handle);

size_t mf_write(const void *buf, size_t size, size_t count, void *handle);

size_t mf_read(void *buf, size_t size, size_t count, void *handle);

size_t mf_getpos(void *handle);

int mf_setpos(void *handle, size_t pos);

sp_writefuncs_t cstd_funcs = 

{

	mf_open,

	mf_close,

	mf_write,

	mf_read,

	mf_getpos,

	mf_setpos

};

sp_file_t *spfw_create(const char *name, sp_writefuncs_t *optfuncs)

{

	sp_file_t file;

	sp_file_t *pFile;

	if (!optfuncs)

	{

		optfuncs = &cstd_funcs;

	}

	file.handle = optfuncs->fnOpen(name);

	if (!file.handle)

	{

		return NULL;

	}

	pFile = (sp_file_t *)malloc(sizeof(sp_file_t));

	pFile->handle = file.handle;

	memcpy(&pFile->funcs, optfuncs, sizeof(sp_writefuncs_t));

	pFile->curoffs = 0;

	pFile->header.magic = SPFILE_MAGIC;

	pFile->header.sections = 0;

	pFile->header.stringtab = 0;

	pFile->header.version = SPFILE_VERSION;

	pFile->header.imagesize = 0;

	pFile->header.disksize = 0;

	pFile->header.compression = SPFILE_COMPRESSION_NONE;

	pFile->header.dataoffs = 0;

	pFile->lastsection = 0;

	pFile->offsets = NULL;

	pFile->sections = NULL;

	pFile->state = -1;

	pFile->nametab = NULL;

	pFile->nametab_idx = 0;

	return pFile;

}

void spfw_destroy(sp_file_t *spf)

{

	free(spf->sections);

	free(spf->nametab);

	free(spf->offsets);

	spf->funcs.fnClose(spf->handle);

	free(spf);

}

uint8_t spfw_add_section(sp_file_t *spf, const char *name)

{

	size_t namelen;

	uint8_t s;

	if (spf->state != -1)

	{

		return 0;

	}

	namelen = strlen(name) + 1;

	if (spf->header.sections == 0)

	{

		/** allocate for first section */

		spf->sections = (sp_file_section_t *)malloc(sizeof(sp_file_section_t));

		spf->offsets = (size_t *)malloc(sizeof(size_t));

		spf->nametab = (char *)malloc(namelen);

	} else {

		uint16_t num = spf->header.sections + 1;

		spf->sections = (sp_file_section_t *)realloc(spf->sections, sizeof(sp_file_section_t) * num);

		spf->offsets = (size_t *)realloc(spf->offsets, sizeof(size_t) * num);

		spf->nametab = (char *)realloc(spf->nametab, spf->nametab_idx + namelen);

	}

	s = spf->header.sections;

	spf->sections[s].nameoffs = spf->nametab_idx;

	/** 

	 * "fix" offset will be the second uint2 slot, which is after the previous sections after the header.

	 */

	spf->offsets[s] = sizeof(spf->header) + (sizeof(sp_file_section_t) * spf->header.sections) + sizeof(uint32_t);

	strcpy(&spf->nametab[spf->nametab_idx], name);

	spf->nametab_idx += namelen;

	return ++spf->header.sections;

}

int spfw_finalize_header(sp_file_t *spf)

{

	uint32_t size;

	if (spf->state != -1)

	{

		return -1;

	}

	size = sizeof(sp_file_section_t) * spf->header.sections;

	spf->header.stringtab = sizeof(spf->header) + size;

	spf->header.dataoffs = spf->header.stringtab + spf->nametab_idx;

	if (spf->funcs.fnWrite(&spf->header, sizeof(spf->header), 1, spf->handle) != 1)

	{

		return -1;

	}

	if (spf->funcs.fnWrite(spf->sections, sizeof(sp_file_section_t), spf->header.sections, spf->handle) != 

		spf->header.sections)

	{

		return -1;

	}

	if (spf->funcs.fnWrite(spf->nametab, sizeof(char), spf->nametab_idx, spf->handle) != spf->nametab_idx)

	{

		return -1;

	}

	spf->curoffs = spf->funcs.fnGetPos(spf->handle);

	spf->lastsection = spf->curoffs;

	spf->state++;

	return 0;

}

int spfw_next_section(sp_file_t *spf)

{

	uint8_t s;

	uint32_t rest[2];

	if (spf->state < 0 || spf->state > spf->header.sections)

	{

		return -1;

	}

	if (spf->state == (int)spf->header.sections)

	{

		return 0;

	}

	s = (uint8_t)spf->state;

	spf->curoffs = spf->funcs.fnGetPos(spf->handle);

	spf->funcs.fnSetPos(spf->handle, spf->offsets[s]);

	rest[0] = spf->lastsection;

	rest[1] = spf->curoffs - spf->lastsection;

	if (spf->funcs.fnWrite(rest, sizeof(uint32_t), 2, spf->handle) != 2)

	{

		return -1;

	}

	spf->funcs.fnSetPos(spf->handle, spf->curoffs);

	spf->lastsection = spf->curoffs;

	spf->state++;

	return 1;

}

int spfw_finalize_all(sp_file_t *spf)

{

	uint8_t offs;

	if (spf->state < spf->header.sections)

	{

		return -1;

	}

	offs = offsetof(sp_file_hdr_t, imagesize);

	spf->header.disksize = spf->funcs.fnGetPos(spf->handle);

	spf->header.imagesize = spf->funcs.fnGetPos(spf->handle);

	spf->funcs.fnSetPos(spf->handle, offs);

	spf->funcs.fnWrite(&spf->header.imagesize, sizeof(uint32_t), 1, spf->handle);

	spf->funcs.fnSetPos(spf->handle, spf->header.imagesize);

	return 1;

}

/**

 * More memory file operations

 */

void *mf_open(const char *name)

{

	return memfile_creat(name, 1024);

}

void mf_close(void *handle)

{

	memfile_destroy((memfile_t *)handle);

}

size_t mf_write(const void *buf, size_t size, size_t count, void *handle)

{

	if (!count)

	{

		return 0;

	}

	if (memfile_write((memfile_t *)handle, buf, size*count))

	{

		return count;

	}

	return 0;

}

size_t mf_read(void *buf, size_t size, size_t count, void *handle)

{

	return memfile_read((memfile_t *)handle, buf, size*count) / count;

}

size_t mf_getpos(void *handle)

{

	return (long)memfile_tell((memfile_t *)handle);

}

int mf_setpos(void *handle, size_t pos)

{

	memfile_seek((memfile_t *)handle, (long)pos);

	return 1;

}

#if UNUSED_FOR_NOW

/**

 * Default file operations...

 * Based on C standard library calls.

 */

void *fp_open(const char *name)

{

	return fopen(name, "wb");

}

void fp_close(void *handle)

{

	fclose((FILE *)handle);

}

size_t fp_write(const void *buf, size_t size, size_t count, void *handle)

{

	return fwrite(buf, size, count, (FILE *)handle);

}

size_t fp_read(void *buf, size_t size, size_t count, void *handle)

{

	return fread(buf, size, count, (FILE *)handle);

}

size_t fp_getpos(void *handle)

{

	return (size_t)ftell((FILE *)handle);

}

int fp_setpos(void *handle, size_t pos)

{

	return fseek((FILE *)handle, (long)pos, SEEK_SET);

}

#endif