/* radare - LGPL - Copyright 2007-2010 pancake<nopcode.org> */

#include <r_io.h>

#if 0
* TODO:
* - make path of indirections shortr (io->undo.foo is slow) */
* - Plugin changes in write and seeks
* - Per-fd history log
#endif

R_API int r_io_undo_init(struct r_io_t *io) {
	io->undo.w_init = 0;
	io->undo.w_enable = 0;
	io->undo.idx = 0;
	io->undo.limit = 0;
	io->undo.s_enable = 0;
	io->undo.w_enable = 0;
	INIT_LIST_HEAD(&(io->undo.w_list));
	return R_TRUE;
}

R_API void r_io_undo_enable(struct r_io_t *io, int s, int w) {
	io->undo.s_enable = s;
	io->undo.w_enable = w;
}

R_API ut64 r_io_sundo_last(struct r_io_t *io) {
	return (io->undo.idx>0)?
		io->undo.seek[io->undo.idx-2] : io->off;
}

R_API int r_io_sundo(struct r_io_t *io) {
	io->undo.idx--;
	if (io->undo.idx<0)
		return io->undo.idx = 0;
	io->off = io->undo.seek[io->undo.idx-1];
	return R_TRUE;
}

R_API int r_io_sundo_redo(struct r_io_t *io) {
	if (io->undo.idx<io->undo.limit) {
		io->undo.idx += 2;
		if (io->undo.idx>=R_IO_UNDOS) {
			io->undo.idx -= 2;
			return R_FALSE;
		} else io->off = io->undo.seek[io->undo.idx];
		r_io_sundo(io);
		return R_TRUE;
	}
	return R_FALSE;
}

R_API void r_io_sundo_push(RIO *io) {
	ut64 off = (io->va && !list_empty (&io->sections))? 
		r_io_section_offset_to_vaddr (io, io->off) : io->off;
	if (!io->undo.s_enable)
		return;
	if (io->undo.seek[io->undo.idx-1] == off)
		return;
	io->undo.seek[io->undo.idx] = off;
	if (++io->undo.idx==R_IO_UNDOS-1)
		io->undo.idx--;
	if (io->undo.limit<io->undo.idx)
		io->undo.limit = io->undo.idx;
}

R_API void r_io_sundo_reset(struct r_io_t *io) {
	io->undo.idx = 0;
}

R_API void r_io_sundo_list(struct r_io_t *io) {
	int i;
	if (io->undo.idx>0) {
		io->printf ("f undo_idx @ %d\n", io->undo.idx);
		for(i=io->undo.idx-1;i!=0;i--)
			io->printf ("f undo_%d @ 0x%"PFMT64x"\n",
				io->undo.idx-1-i, io->undo.seek[i-1]);
	} else eprintf("-no seeks done-\n");
}

/* undo writez */

R_API void r_io_wundo_new(struct r_io_t *io, ut64 off, const ut8 *data, int len) {
	struct r_io_undo_w_t *uw;

	if (!io->undo.w_enable)
		return;

	/* undo write changes */
	uw = R_NEW(struct r_io_undo_w_t);
	uw->set = R_TRUE;
	uw->off = off;
	uw->len = len;
	uw->n = (ut8*) malloc(len);
	memcpy(uw->n, data, len);
	uw->o = (ut8*) malloc(len);
	r_io_read_at(io, off, uw->o, len);
	list_add_tail(&(uw->list), &(io->undo.w_list));
}

R_API void r_io_wundo_clear(struct r_io_t *io) {
	// XXX memory leak
	INIT_LIST_HEAD(&(io->undo.w_list));
}

// rename to r_io_undo_length ?
R_API int r_io_wundo_size(struct r_io_t *io) {
	struct list_head *p;
	int i = 0;
	if (io->undo.w_init)
		list_for_each_prev(p, &(io->undo.w_list))
			i++;
	return i;
}

// TODO: Deprecate or so? iterators must be language-wide, but helpers are useful
R_API void r_io_wundo_list(struct r_io_t *io) {
#define BW 8 /* byte wrap */
	struct list_head *p;
	int i = 0, j, len;

	if (io->undo.w_init)
	list_for_each_prev(p, &(io->undo.w_list)) {
		struct r_io_undo_w_t *u = list_entry(p, struct r_io_undo_w_t, list);
		io->printf ("%02d %c %d %08"PFMT64x": ", i, u->set?'+':'-', u->len, u->off);
		len = (u->len>BW)?BW:u->len;
		for(j=0;j<len;j++) io->printf ("%02x ", u->o[j]);
		if (len == BW) io->printf (".. ");
		io->printf ("=> ");
		for(j=0;j<len;j++) io->printf ("%02x ", u->n[j]);
		if (len == BW) io->printf (".. ");
		io->printf ("\n");
		i++;
	}
}

R_API int r_io_wundo_apply(struct r_io_t *io, struct r_io_undo_w_t *u, int set) {
	int orig = io->undo.w_enable;
	io->undo.w_enable = 0;
	if (set) {
		r_io_write_at(io, u->off, u->n, u->len);
		u->set = R_TRUE;
	} else {
		r_io_write_at(io, u->off, u->o, u->len);
		u->set = R_FALSE;
	}
	io->undo.w_enable = orig;
	return 0;
}

R_API void r_io_wundo_apply_all(struct r_io_t *io, int set) {
	struct list_head *p;

	list_for_each_prev (p, &(io->undo.w_list)) {
		struct r_io_undo_w_t *u = list_entry (p, struct r_io_undo_w_t, list);
		r_io_wundo_apply (io, u, set); //UNDO_WRITE_UNSET);
		eprintf ("%s 0x%08"PFMT64x"\n", set?"redo":"undo", u->off);
	}
}

/* sets or unsets the writes done */
/* if ( set == 0 ) unset(n) */
R_API int r_io_wundo_set(struct r_io_t *io, int n, int set) {
	struct r_io_undo_w_t *u = NULL;
	struct list_head *p;
	int i = 0;
	if (io->undo.w_init) {
		list_for_each_prev(p, &(io->undo.w_list)) {
			if (i++ == n) {
				u = list_entry(p, struct r_io_undo_w_t, list);
				break;
			}
		}
		if (u) {
			r_io_wundo_apply(io, u, set);
			return R_TRUE;
		} else eprintf ("invalid undo-write index\n");
	} else eprintf ("no writes done\n");
	return R_FALSE;
}