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

#include "sxmlclib.h"

void print_article_title(XMLNode *root);

int process(char *fn) {
	XMLDoc *doc = malloc(sizeof(XMLDoc));
	if (!doc) {
		fprintf(stderr, "Could not allocate memory for the XMLDoc when trying to parse %s.\n", fn);
		exit(1);
	}

	XMLDoc_init(doc);

	int ret = XMLDoc_parse_file_DOM(fn, doc);
	if (!ret) {
		fprintf(stderr, "Error when parsing file '%s'.\n", fn);
		return 1;
	}

	// Apparently ill-formed XML is not an error but the library
	// can't find the root node afterwards...
	if (doc->i_root < 0) {
		fprintf(stderr, "i_root was negative. Skipping file '%s'.\n", fn);
		return 1;
	}

	XMLNode *root = doc->nodes[doc->i_root];
	if (!root) {
		fprintf(stderr, "Root was NULL. Exiting.\n");
		return 1;
	}

	print_article_title(root);

	XMLDoc_free(doc);
	return 0;
}

XMLNode* find_child_node(XMLNode *node, const char* tagname) {
	XMLNode** children = node->children;
	XMLNode* next = NULL;

	for (int i = 0; i < node->n_children; i++) {
		if (!strcmp(children[i]->tag, tagname)) {
			next = children[i];
			break;
		}
	}

	return next;
}

void print_article_title(XMLNode *root) {
	XMLNode* next = root;
	static const char *path[] = {"front", "article-meta", "title-group", "article-title", NULL};

	for (int i = 0; path[i]; i++) {
		next = find_child_node(next, path[i]);
		if (!next) {
			fprintf(stderr, "Could not find '%s' tag.\n", path[i]);
			return;
		}
	}

	printf("article-title: %s\n", next->text);
}

int main(int argc, char *argv[]) {

	for (int i = 1; i < argc; i++) {
		process(argv[i]);
	}

	return 0;
}