#include <assert.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>


typedef __uint32_t art_id;


static int
cmpstring_pp_pp(const void *p1, const void *p2)
{
	return strcasecmp(* (char * const *) p1, * (char * const *) p2);
}

static int
cmpstring_p_pp(const void *p1, const void *p2)
{
	return strcasecmp((char * const) p1, * (char * const *) p2);
}




int main()
{
	FILE *in_file;
	FILE *out_file;

	char **title = NULL;
	art_id titles = 0;
	art_id titles_alloc = 0;

	art_id **link;
	art_id *links;

	art_id link_titles_done = 0;

	art_id i;


	/*
	 * Read all titles into memory
	 */

	in_file = fopen("titles.txt", "r");
	while (!feof(in_file)) {
		char *in_line = NULL;
		ssize_t in_line_len = 0;
		size_t zero = 0;

		if (titles == titles_alloc) {
			titles_alloc += 100000;
			title = realloc(title, titles_alloc * sizeof(title[0]));
		}

		in_line_len = getline(&in_line, &zero, in_file);

		/* Ignore empty lines and errors */
		if (in_line_len < 2) {
			continue;
		}

		/* Delete trailing newline */
		in_line[in_line_len - 1] = '\0';

		title[titles] = in_line;
		titles++;
	}
	fclose(in_file);

	qsort(title, titles, sizeof(title[0]), cmpstring_pp_pp);

	printf("Sorting done.\n");



	link = malloc(titles * sizeof(art_id*));
	links = malloc(titles * sizeof(art_id));

	in_file = fopen("enwiki-links-plain.txt", "r");
	while (!feof(in_file)) {
		char *in_line = NULL;
		ssize_t in_line_len = 0;
		size_t zero = 0;

		in_line_len = getline(&in_line, &zero, in_file);

		/* Ignore empty lines and errors */
		if (in_line_len < 2) {
			//printf("%d\n", links[i]);
			if (in_line)
				free(in_line);
			continue;
		}

		/* Delete trailing newline */
		in_line[in_line_len - 1] = '\0';

		if (in_line_len > 5
		    && !memcmp(in_line, "~~~~", 4)) {
			/* Title */
			char **cur_title = bsearch(&in_line[4], title,
						titles, sizeof(title[0]),
						cmpstring_p_pp);

			if (!cur_title) {
				printf("TITLE NOT FOUND: %s\n", in_line);
				assert(cur_title);
			}

			i = cur_title - title;
			//printf("%s\n", title[i]);

			link_titles_done++;
			if (0 == (link_titles_done % 100000)) {
				printf("%d\n", link_titles_done);
			}
		} else {
			/* Link */

			/* Delete trailing anchor */
			strtok(in_line, "#");

			char **cur_link = bsearch(&in_line[0], title,
						titles, sizeof(title[0]),
						cmpstring_p_pp);

			if (!cur_link) {
				//printf("LINK NOT FOUND: %s\n", in_line);
				free(in_line);
				continue;
			}

			links[i]++;
			link[i] = realloc(link[i], links[i] * sizeof(art_id));

			link[i][links[i] - 1] = cur_link - title;

			//printf("%s -- %d\n", title[i], links[i]);
		}

		free(in_line);
	}
	fclose(in_file);

	printf("Links identified.\n");



	out_file = fopen("titles-sorted.txt", "w");
	for (i = 0; i < titles; i++) {
		fputs(title[i], out_file);
		fputs("\n", out_file);
	}
	fclose(out_file);

	printf("Titles written.\n");



	out_file = fopen("links-outgoing.bin", "wb");
	fwrite(&titles, sizeof(titles), 1, out_file);
	for (i = 0; i < titles; i++) {
		art_id j;

		fwrite(&links[i], sizeof(links[i]), 1, out_file);

		for (j = 0; j < links[i]; j++) {
			fwrite(&link[i][j], sizeof(link[i][j]), 1, out_file);
		}
	}
	fclose(out_file);

	printf("Links written.\n");
}