/* radare - LGPL - Copyright 2015-2023 - pancake, rkx1209 */

#include <r_anal.h>

#define DB esil->trace->db
#define KEY(x) r_strf ("%d."x, esil->trace->idx)
#define KEYAT(x,y) r_strf ("%d."x".0x%"PFMT64x, esil->trace->idx, y)
#define KEYREG(x,y) r_strf ("%d."x".%s", esil->trace->idx, y)
#define CMP_REG_CHANGE(x, y) ((x) - ((REsilRegChange *)y)->idx)
#define CMP_MEM_CHANGE(x, y) ((x) - ((REsilMemChange *)y)->idx)

static R_TH_LOCAL int ocbs_set = false;
static R_TH_LOCAL REsilCallbacks ocbs = {0};

static void htup_vector_free(HtUPKv *kv) {
	if (kv) {
		r_vector_free (kv->value);
	}
}

R_API REsilTrace *r_esil_trace_new(REsil *esil) {
	r_return_val_if_fail (esil, NULL);
	if (!esil->stack_addr || !esil->stack_size) {
		// R_LOG_ERROR ("Run `aeim` to initialize a stack for the ESIL vm");
		return NULL;
	}
	size_t i;
	REsilTrace *trace = R_NEW0 (REsilTrace);
	if (!trace) {
		return NULL;
	}
	trace->registers = ht_up_new (NULL, htup_vector_free, NULL);
	if (!trace->registers) {
		goto error;
	}
	trace->memory = ht_up_new (NULL, htup_vector_free, NULL);
	if (!trace->memory) {
		goto error;
	}
	trace->db = sdb_new0 ();
	if (!trace->db) {
		goto error;
	}
	// Save initial ESIL stack memory
	trace->stack_addr = esil->stack_addr;
	trace->stack_size = esil->stack_size;
	trace->stack_data = malloc (esil->stack_size);
	if (!trace->stack_data) {
		goto error;
	}
	esil->anal->iob.read_at (esil->anal->iob.io, trace->stack_addr,
		trace->stack_data, trace->stack_size);
	// Save initial registers arenas
	for (i = 0; i < R_REG_TYPE_LAST; i++) {
		RRegArena *a = esil->anal->reg->regset[i].arena;
		RRegArena *b = r_reg_arena_new (a->size);
		if (!b) {
			goto error;
		}
		if (b->bytes && a->bytes && b->size > 0) {
			memcpy (b->bytes, a->bytes, b->size);
		}
		trace->arena[i] = b;
	}
	return trace;
error:
	R_LOG_ERROR ("trace initialization failed");
	r_esil_trace_free (trace);
	return NULL;
}

R_API void r_esil_trace_free(REsilTrace *trace) {
	size_t i;
	if (trace) {
		ht_up_free (trace->registers);
		ht_up_free (trace->memory);
		for (i = 0; i < R_REG_TYPE_LAST; i++) {
			r_reg_arena_free (trace->arena[i]);
		}
		free (trace->stack_data);
		// eprintf ("sdb free %p%c", trace->db, 10);
		sdb_free (trace->db);
		trace->db = NULL;
		R_FREE (trace);
	}
}

static void add_reg_change(REsilTrace *trace, int idx, RRegItem *ri, ut64 data) {
	r_return_if_fail (trace && ri);
	ut64 addr = ri->offset | (ri->arena << 16);
	RVector *vreg = ht_up_find (trace->registers, addr, NULL);
	if (!vreg) {
		vreg = r_vector_new (sizeof (REsilRegChange), NULL, NULL);
		if (!vreg) {
			R_LOG_ERROR ("creating a register vector");
			return;
		}
		ht_up_insert (trace->registers, addr, vreg);
	}
	REsilRegChange reg = { idx, data };
	r_vector_push (vreg, &reg);
}

static void add_mem_change(REsilTrace *trace, int idx, ut64 addr, ut8 data) {
	r_return_if_fail (trace);
	RVector *vmem = ht_up_find (trace->memory, addr, NULL);
	if (!vmem) {
		vmem = r_vector_new (sizeof (REsilMemChange), NULL, NULL);
		if (!vmem) {
			R_LOG_ERROR ("creating a memory vector");
			return;
		}
		ht_up_insert (trace->memory, addr, vmem);
	}
	REsilMemChange mem = { idx, data };
	r_vector_push (vmem, &mem);
}

static bool trace_hook_reg_read(REsil *esil, const char *name, ut64 *res, int *size) {
	r_return_val_if_fail (esil && name && res, -1);
	r_strf_buffer (128);
	bool ret = false;
	if (*name == '0') {
		// eprintf ("Register not found in profile\n");
		return false;
	}
	if (ocbs.hook_reg_read) {
		REsilCallbacks cbs = esil->cb;
		esil->cb = ocbs;
		ret = ocbs.hook_reg_read (esil, name, res, size);
		esil->cb = cbs;
	}
	if (!ret && esil->cb.reg_read) {
		ret = esil->cb.reg_read (esil, name, res, size);
	}
	if (ret) {
		ut64 val = *res;
		// eprintf ("[ESIL] REG READ %s 0x%08"PFMT64x"\n", name, val);
		sdb_array_add (DB, KEY ("reg.read"), name, 0); // XXX this is very slow and memory hungry
		sdb_num_set (DB, KEYREG ("reg.read", name), val, 0);
		// eprintf ("select it %p%c", DB, 10);
	}
	return ret;
}

static bool trace_hook_reg_write(REsil *esil, const char *name, ut64 *val) {
	r_strf_buffer (128);
	bool ret = false;
	// eprintf ("[ESIL] REG WRITE %s 0x%08"PFMT64x"\n", name, *val);
	RRegItem *ri = r_reg_get (esil->anal->reg, name, -1);
	if (ri) {
		sdb_array_add (DB, KEY ("reg.write"), name, 0);
		sdb_num_set (DB, KEYREG ("reg.write", name), *val, 0);
		add_reg_change (esil->trace, esil->trace->idx + 1, ri, *val);
		if (ocbs.hook_reg_write) {
			REsilCallbacks cbs = esil->cb;
			esil->cb = ocbs;
			ret = ocbs.hook_reg_write (esil, name, val);
			esil->cb = cbs;
		}
		r_unref (ri);
	}
	return ret;
}

static bool trace_hook_mem_read(REsil *esil, ut64 addr, ut8 *buf, int len) {
	char *hexbuf = calloc ((1 + len), 4);
	r_strf_buffer (128);
	int ret = 0;
	if (esil->cb.mem_read) {
		ret = esil->cb.mem_read (esil, addr, buf, len);
	}
	sdb_array_add_num (DB, KEY ("mem.read"), addr, 0);
	r_hex_bin2str (buf, len, hexbuf);
	sdb_set (DB, KEYAT ("mem.read.data", addr), hexbuf, 0);
	//eprintf ("[ESIL] MEM READ 0x%08"PFMT64x" %s\n", addr, hexbuf);
	free (hexbuf);

	if (ocbs.hook_mem_read) {
		REsilCallbacks cbs = esil->cb;
		esil->cb = ocbs;
		ret = ocbs.hook_mem_read (esil, addr, buf, len);
		esil->cb = cbs;
	}
	return ret;
}

static bool trace_hook_mem_write(REsil *esil, ut64 addr, const ut8 *buf, int len) {
	size_t i;
	int ret = 0;
	char *hexbuf = r_hex_bin2strdup (buf, len);
	if (!hexbuf) {
		return false;
	}
	r_strf_buffer (128);
	sdb_array_add_num (DB, KEY ("mem.write"), addr, 0);
	sdb_set (DB, KEYAT ("mem.write.data", addr), hexbuf, 0);
	//eprintf ("[ESIL] MEM WRITE 0x%08"PFMT64x" %s\n", addr, hexbuf);
	free (hexbuf);
	for (i = 0; i < len; i++) {
		add_mem_change (esil->trace, esil->trace->idx + 1, addr + i, buf[i]);
	}

	if (ocbs.hook_mem_write) {
		REsilCallbacks cbs = esil->cb;
		esil->cb = ocbs;
		ret = ocbs.hook_mem_write (esil, addr, buf, len);
		esil->cb = cbs;
	}
	return ret != 0;
}

R_API void r_esil_trace_op(REsil *esil, RAnalOp *op) {
	r_return_if_fail (esil && op);
	r_strf_buffer (128);
	const char *expr = r_strbuf_get (&op->esil);
	if (!esil->trace) {
		esil->trace = r_esil_trace_new (esil);
		if (!esil->trace) {
			R_LOG_ERROR ("Cannot initialize the esil trace class");
			return;
		}
	}
	if (R_STR_ISEMPTY (expr)) {
		// do nothing
		return;
	}
	/* restore from trace when `idx` is not at the end */
	if (esil->trace->idx != esil->trace->end_idx) {
		// eprintf ("j %d\n", esil->trace->idx);
		r_esil_trace_restore (esil, esil->trace->idx + 1);
		return;
	}
	/* save old callbacks */
	if (ocbs_set) {
		R_LOG_WARN ("r_esil_trace_op: Cannot call recursively");
	}
	ocbs = esil->cb;
	ocbs_set = true;
	sdb_num_set (DB, "idx", esil->trace->idx, 0);
	sdb_num_set (DB, KEY ("addr"), op->addr, 0);
	RRegItem *pc_ri = r_reg_get (esil->anal->reg, "PC", -1);
	add_reg_change (esil->trace, esil->trace->idx, pc_ri, op->addr);
//	sdb_set (DB, KEY ("opcode"), op->mnemonic, 0);
//	sdb_set (DB, KEY ("addr"), expr, 0);
	//eprintf ("[ESIL] ADDR 0x%08"PFMT64x"\n", op->addr);
	//eprintf ("[ESIL] OPCODE %s\n", op->mnemonic);
	//eprintf ("[ESIL] EXPR = %s\n", expr);
	/* set hooks */
	esil->cb.hook_reg_read = trace_hook_reg_read;
	esil->cb.hook_reg_write = trace_hook_reg_write;
	esil->cb.hook_mem_read = trace_hook_mem_read;
	esil->cb.hook_mem_write = trace_hook_mem_write;
	/* evaluate esil expression */
	const int esil_verbose = esil->verbose;
	esil->verbose = 0; // disable verbose logs when tracing
	r_esil_parse (esil, expr);
	r_esil_stack_free (esil);
	esil->verbose = esil_verbose;
	/* restore hooks */
	esil->cb = ocbs;
	ocbs_set = false;
	/* increment idx */
	esil->trace->idx++;
	esil->trace->end_idx++;
}

static bool restore_memory_cb(void *user, const ut64 key, const void *value) {
	size_t index;
	REsil *esil = user;
	RVector *vmem = (RVector *)value;

	r_vector_upper_bound (vmem, esil->trace->idx, index, CMP_MEM_CHANGE);
	if (index > 0 && index <= vmem->len) {
		REsilMemChange *c = r_vector_index_ptr (vmem, index - 1);
		esil->anal->iob.write_at (esil->anal->iob.io, key, &c->data, 1);
	}
	return true;
}

static bool restore_register(REsil *esil, RRegItem *ri, int idx) {
	size_t index;
	RVector *vreg = ht_up_find (esil->trace->registers, ri->offset | (ri->arena << 16), NULL);
	if (vreg) {
		r_vector_upper_bound (vreg, idx, index, CMP_REG_CHANGE);
		if (index > 0 && index <= vreg->len) {
			REsilRegChange *c = r_vector_index_ptr (vreg, index - 1);
			if (c) {
				r_reg_set_value (esil->anal->reg, ri, c->data);
			}
		}
	}
	return true;
}

R_API void r_esil_trace_restore(REsil *esil, int idx) {
	size_t i;
	REsilTrace *trace = esil->trace;
	// Restore initial state when going backward
	if (idx < esil->trace->idx) {
		// Restore initial registers value
		for (i = 0; i < R_REG_TYPE_LAST; i++) {
			RRegArena *a = esil->anal->reg->regset[i].arena;
			RRegArena *b = trace->arena[i];
			if (a && b) {
				memcpy (a->bytes, b->bytes, a->size);
			}
		}
		// Restore initial stack memory
		esil->anal->iob.write_at (esil->anal->iob.io, trace->stack_addr,
			trace->stack_data, trace->stack_size);
	}
	// Apply latest changes to registers and memory
	esil->trace->idx = idx;
	RListIter *iter;
	RRegItem *ri;
	r_list_foreach (esil->anal->reg->allregs, iter, ri) {
		restore_register (esil, ri, idx);
	}
	ht_up_foreach (trace->memory, restore_memory_cb, esil);
}

static int cmp_strings_by_leading_number(void *data1, void *data2) {
	const char* a = sdbkv_key ((const SdbKv *)data1);
	const char* b = sdbkv_key ((const SdbKv *)data2);
	int i = 0;
	int j = 0;
	int k = 0;
	while (isdigit (a[i])) {
		i++;
	}
	while (isdigit (b[j])) {
		j++;
	}
	if (!i || !j) {
		return 1;
	}
	i--;
	j--;
	if (i > j) {
		return 1;
	}
	if (j > i) {
		return -1;
	}
	while (k <= i) {
		if (a[k] < b[k]) {
			return -1;
		}
		if (a[k] > b[k]) {
			return 1;
		}
		k++;
	}
	for (; a[i] && b[i]; i++) {
		if (a[i] > b[i]) {
			return 1;
		}
		if (a[i] < b[i]) {
			return -1;
		}
	}
	if (!a[i] && b[i]) {
		return -1;
	}
	if (!b[i] && a[i]) {
		return 1;
	}
	return 0;
}

R_API void r_esil_trace_list(REsil *esil) {
	r_return_if_fail (esil && esil->anal);
	PrintfCallback p = esil->anal->cb_printf;
	SdbKv *kv;
	SdbListIter *iter;
	if (esil->trace) {
		SdbList *list = sdb_foreach_list (esil->trace->db, true);
		ls_sort (list, (SdbListComparator) cmp_strings_by_leading_number);
		ls_foreach (list, iter, kv) {
			p ("%s=%s\n", sdbkv_key (kv), sdbkv_value (kv));
		}
		ls_free (list);
	}
}

R_API void r_esil_trace_show(REsil *esil, int idx) {
	r_strf_buffer (128);
	PrintfCallback p = esil->anal->cb_printf;
	if (!esil->trace) {
		return;
	}
	int trace_idx = esil->trace->idx;
	esil->trace->idx = idx;

	const char *str2 = sdb_const_get (DB, KEY ("addr"), 0);
	if (!str2) {
		return;
	}
	p ("ar PC = %s\n", str2);
	/* registers */
	const char *str = sdb_const_get (DB, KEY ("reg.read"), 0);
	if (R_STR_ISNOTEMPTY (str)) {
		char regname[32];
		const char *next, *ptr = str;
		do {
			next = sdb_const_anext (ptr);
			int len = next? (int)(size_t)(next - ptr) - 1 : strlen (ptr);
			if (len < sizeof (regname)) {
				memcpy (regname, ptr, len);
				regname[len] = 0;
				str2 = sdb_const_get (DB, KEYREG ("reg.read", regname), 0);
				p ("ar %s = %s\n", regname, str2);
			} else {
				R_LOG_ERROR ("Invalid entry in reg.read");
			}
			ptr = next;
		} while (next);
	}
	/* memory */
	str = sdb_const_get (DB, KEY ("mem.read"), 0);
	if (R_STR_ISNOTEMPTY (str)) {
		char addr[64];
		const char *next, *ptr = str;
		do {
			next = sdb_const_anext (ptr);
			int len = next? (int)(size_t)(next - ptr) - 1 : strlen (ptr);
			if (len < sizeof (addr)) {
				memcpy (addr, ptr, len);
				addr[len] = 0;
				str2 = sdb_const_get (DB, KEYAT ("mem.read.data",
					r_num_get (NULL, addr)), 0);
				p ("wx %s @ %s\n", str2, addr);
			} else {
				R_LOG_ERROR ("Invalid entry in reg.read");
			}
			ptr = next;
		} while (next);
	}
	esil->trace->idx = trace_idx;
}
