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

/* A majority of lines in files.json
are less than 80 characters long. */
#define GUESS 80
/* Each informative line has 6 spaces,
a quote, then the data type, then a quote,
then a colon, then a space, then a quote,
then the data, terminated by a quote.
The length of the data type's name plus
11 characters precedes the data on each line. */
#define PREFIX 11

void
stripquote(char *str)
{
	int i;
	for (i = 0; str[i] != '\0'; ++i)
		if (str[i] == '"') {
			str[i] = '\0';
			break;
		}
}

int
dircmp(char *dir, char *str)
{
	int slashes = 0, i;
	for (i = 0; str[i] != '\0'; ++i)
		if (str[i] == '/')
			++slashes;
	if (dir == NULL) {
		if (! slashes)
			return 1;
		return 0;
	}

	int diff = 0, dirslashes = 0, dirlen = 0;
	for (i = 0; dir[i] != '\0'; ++i) {
		if (dir[i] != str[i]) {
			diff = 1;
			break;
		}
		if (dir[i] == '/')
			++dirslashes;
		++dirlen;
	}
	if (diff)
		return 0;

	/* Account for a trailing slash. */
	if (dir[dirlen - 1] == '/')
		--dirslashes;
	if (slashes - dirslashes < 2)
		return 1;
	return 0;
}

void
printentry(int long_format, int size, char *path, int is_directory,
	char *sha1_hash, char *updated_at)
{
	if (long_format) {
		/* The longest 31-bit int is 10 digits.
		If the file size is larger, there's worse problems. */
		printf("%10d ", size);
		int i;
		for (i = 0; i < 20; ++i)
			putchar(updated_at[5 + i]);
		putchar(' ');
	}
	printf("%s", path);
	if (is_directory)
		putchar('/');
	putchar('\n');
}

char *infn = "files.json";
/* neols [-l] [wildcard] */
int
main(int argc, char **argv)
{
	FILE *in = fopen(infn, "r");
	if (in == NULL) {
		puts("files.json isn't in the working directory.");
		return 1;
	}
	int i;
	int long_format = 0;
	char *dir = NULL;
	for (i = 1; i < argc; ++i) {
		if (strcmp(argv[i], "-l") == 0)
			long_format = 1;
		else
			dir = argv[i];
	}
	char *line;
	/* The various statistics related to each entry are stored,
	one entry at a time. A path may be any size, so each line need
	be handled by realloc. */
	char *path = NULL, *updated_at = NULL, *sha1_hash = NULL;
	int is_directory = 0, size = 0;
	int end, len;
	for (end = 0; ! end;) {
		line = storeline(in, &end, &len, GUESS);
		/* Only on lines terminating an entry, '}' is the
		fifth character. The ninth character of each data
		line is unique. */
		if (line[4] == '}') {
			char *p = path + PREFIX + strlen("size");
			if (dircmp(dir, p)) {
				printentry(long_format, size, p,
					is_directory, sha1_hash + PREFIX
					+ strlen("sha1_hash"),
					updated_at + PREFIX +
					strlen("updated_at"));
			}
			free(path);
			free(updated_at);
			free(sha1_hash);
			sha1_hash = NULL;
			size = 0;
			free(line);
		} else if (line[8] == 'a') {
			path = line;
			stripquote(path + strlen("path") + PREFIX);
		} else if (line[8] == 's') {
			if (strstr(line, "false") == 0)
				is_directory = 1;
			else
				is_directory = 0;
			free(line);
		} else if (line[8] == 'i') {
			line[len - 1] = '\0';
			size = atoi(line + PREFIX + strlen("size"));
			free(line);
		} else if (line[8] == 'p') {
			updated_at = line;
			stripquote(updated_at);
		} else if (line[8] == 'h') {
			sha1_hash = line;
		}
	}
	return 0;
}