#include <string.h>
#include <stdio.h>

#include "wv_dom.h"

wv_ref wv_node_new(struct wv_arena *arena, wv_node_type type)
{
	wv_ref ref;
	struct wv_node *node;

	ref = wv_alloc(arena, sizeof(struct wv_node));
	node = (struct wv_node *)WV_ADDR(arena, ref);
	memset(node, 0, sizeof(struct wv_node));
	node->type = type;

	return ref;
}

void wv_node_append(struct wv_arena *arena, wv_ref parent_ref, 
	wv_ref child_ref)
{
	struct wv_node *p, *c, *last;

	if (!parent_ref || !child_ref)
		return;

	p = (struct wv_node *)WV_ADDR(arena, parent_ref);
	c = (struct wv_node *)WV_ADDR(arena, child_ref);

	c->parent = parent_ref;

	if (!p->first_child) {
		/* This is the parent's only child */
		p->first_child = child_ref;
	} else {
		/* Link to the current tail of the child list */
		last = (struct wv_node *)WV_ADDR(arena, p->last_child);
		last->next_sibling = child_ref;
		c->prev_sibling = p->last_child;
	}

	p->last_child = child_ref;
}

void wv_attr_set(struct wv_arena *arena, wv_ref node_ref, 
	wv_ref key_str, wv_ref val_str)
{
	wv_ref attr_ref;
	struct wv_node *n;
	struct wv_attr *a;

	n = (struct wv_node *)WV_ADDR(arena, node_ref);
	if (n->type != WV_NODE_ELEMENT) return;

	attr_ref = wv_alloc(arena, sizeof(struct wv_attr));
	a = (struct wv_attr *)WV_ADDR(arena, attr_ref);

	a->key = key_str;
	a->val = val_str;
	
	// Link attribute to the head of the list (prepend)
	a->next = n->u.element.attr_head;
	n->u.element.attr_head = attr_ref;
}

wv_ref wv_attr_get(struct wv_arena *arena, wv_ref node_ref, 
	const char *key_name)
{
	wv_ref curr;
	struct wv_node *n;
	struct wv_attr *a;

	n = (struct wv_node *)WV_ADDR(arena, node_ref);
	if (n->type != WV_NODE_ELEMENT)
		return 0;

	curr = n->u.element.attr_head;
	while (curr != 0) {
		a = (struct wv_attr *)WV_ADDR(arena, curr);
		const char *attr_key = (const char *)WV_ADDR(arena, a->key);
		if (strcmp(attr_key, key_name) == 0)
			return a->val;
		curr = a->next;
	}

	return 0;
}