#include <assert.h>
#include <ctype.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>

#include "node.h"

void node_print_atom(node_t *n, FILE *fp)
{
	switch (n->atom.atype) {
	case A_IDENT:
		fputs(n->atom.ident, fp);
		break;
	case A_NUM:
		fprintf(fp, "%#"PRIx64, n->atom.num);
		break;
	case A_STRING:
		fprintf(fp, "\"%s\"", n->atom.string);
		break;

	default:
		fputs("INVALID_ATOM", fp);
	}
}

void node_print_expr(node_t *n, FILE *fp)
{
	if (!isprint(n->expr.etype)) {
		fputs("INVALID_EXPR", fp);
		return;
	}

	fputc(n->expr.etype, fp);
}

void node_print(node_t *n, FILE *fp)
{
	switch (n->ntype) {
	case N_ATOM:
		node_print_atom(n, fp);
		break;
	case N_EXPR:
		node_print_expr(n, fp);
		break;

	default:
		fputs("INVALID_NODE", fp);
	}
}

int __node_dump_pre(node_t *n, void *_info)
{
	node_dump_info_t *info = _info;

	fprintf(info->fp, "%*s", info->indent, "");
	node_print(n, info->fp);
	fputc('\n', info->fp);

	if (n->ntype == N_EXPR) {
		info->indent += 2;
	}
	return 0;
}

int __node_dump_post(node_t *n, void *_info)
{
	node_dump_info_t *info = _info;
	node_t *next;

	if (n->ntype == N_EXPR)
		info->indent -= 2;

	if (n->up && n->up->ntype == N_EXPR && n->up->expr.arg == n) {
		for (next = n->next; next; next = next->next) {
			node_dump(next, info);
		}
	}

	return 0;
}

void node_dump(node_t *n, node_dump_info_t *info)
{

	node_walk(n, __node_dump_pre, __node_dump_post, info);
}

int node_walk(node_t *n,
	      int (*pre)(node_t *, void *),
	      int (*post)(node_t *, void *),
	      void *ctx)
{
	int err = 0;
	
	if (pre && (err = pre(n, ctx)))
		return err;

	if (n->ntype == N_EXPR) {
		err = node_walk(n->expr.arg, pre, post, ctx);
		if (err)
			return err;
	}

	if (post && (err = post(n, ctx)))
		return err;

	return 0;
}

static node_t *__node(ntype_t ntype)
{
	node_t *n = calloc(1, sizeof(*n));
	assert(n);

	n->ntype = ntype;
	return n;
}

node_t *node_ident(char *name)
{
	node_t *n = __node(N_ATOM);

	n->atom.atype = A_IDENT;
	n->atom.ident = name;
	return n;
}

node_t *node_num(int64_t num)
{
	node_t *n = __node(N_ATOM);

	n->atom.atype = A_NUM;
	n->atom.num = num;
	return n;
}

node_t *node_string(char *string)
{
	node_t *n = __node(N_ATOM);

	n->atom.atype = A_STRING;
	n->atom.string = string;
	return n;
}

node_t *node_expr(etype_t etype, node_t *arg)
{
	node_t *n = __node(N_EXPR);
	node_t *next;

	n->expr.etype = etype;
	n->expr.arg = arg;

	for (next = arg; next; next = next->next)
		next->up = n;

	return n;
}

node_t *node_cons(node_t *head, node_t *tail)
{
	node_t *next;

	assert(!head->next);
	head->next = tail;

	for (next = tail; next; next = next->next)
		next->up = head->up;

	return head;
}