#include <stdlib.h>

#include "syntax.h"

bool se_istraversable(tSyntaxElement* syntaxtree) {
	return syntaxtree->type == TREE && syntaxtree->content != NULL;
}

tSyntaxElement* se_create(void) {
	tSyntaxElement* syntaxelement = malloc(sizeof(tSyntaxElement));
	syntaxelement->type = NONE;
	syntaxelement->content = NULL;
	syntaxelement->next = NULL;
	syntaxelement->top = NULL;
	return syntaxelement;

}

tSyntaxElement* se_bottom(tSyntaxElement* syntaxelement) {
	syntaxelement->content = se_create();
	((tSyntaxElement*)syntaxelement->content)->top = syntaxelement;
	return ((tSyntaxElement*)syntaxelement->content);
}

tSyntaxElement* se_next(tSyntaxElement* syntaxelement) {
	syntaxelement->next = se_create();
	syntaxelement->next->top = syntaxelement->top;
	return syntaxelement->next;
}

void se_free(tSyntaxElement* syntaxtree) {
	switch (syntaxtree->type) {
		case NONE:
			free(syntaxtree);
			return;
		case TREE:
			if (syntaxtree->content != NULL) {
				se_free((tSyntaxElement*)syntaxtree->content);
			}
			break;
		default:
			free(syntaxtree->content);
			break;
	}
	if (syntaxtree->next != NULL) {
		se_free(syntaxtree->next);
	}
	free(syntaxtree);
}

// Remove NONEs from the syntax tree.
void se_clean(tSyntaxElement* syntaxtree) {
	if (syntaxtree->next != NULL) {
		switch (syntaxtree->next->type) {
			case NONE:
				free(syntaxtree->next);
				syntaxtree->next = NULL;
				break;
			default:
				se_clean(syntaxtree->next);
				break;
		}
	}
	if (syntaxtree->content != NULL && (syntaxtree->type == TREE)) {
		switch (((tSyntaxElement*)syntaxtree->content)->type) {
			case NONE:
				free(syntaxtree->content);
				syntaxtree->content = NULL;
				break;
			default:
				se_clean((tSyntaxElement*)syntaxtree->content);
				break;
		}
	}
}