#include <stdio.h>
#include <unistd.h>
#include "agenda_entry.h"
#define BS 100 //blocksize for buffers

void destroy_entry_array(entry *array, int elements) {
	for (int i = 0; i < elements; i++)
		destroy_entry(array[i]);
	free(array);
}

char *read_file_to_buffer(char *filename) {
    FILE *fd = fopen(filename, "r");
    int bufsize = BS,
        bufread = 0;
    char *buf = (char *)malloc(bufsize);
    char *newbuf;

    while (fread(buf + bufread, 1, 100, fd) == BS) {
        newbuf = (char *)malloc(bufsize + BS);
        strncpy(newbuf, buf, bufsize);
        free(buf);
        buf = newbuf;
        bufsize += BS;
        bufread += BS;
    }
    fclose(fd);
    return buf;
}

// this function does not work... to debug!
entry *read_entries_to_array(char *buffer, int *entries) {
	int numentries = 5,
		idx = 0;
	entry *ret = (entry *)malloc(numentries * sizeof(entry));
	char *cursor = buffer;
	while (cursor) {
		if (idx == numentries) {
			entry *newret = (entry *)malloc((numentries + 5) * sizeof(entry));
			memcpy(newret, ret, (idx)*sizeof(entry));
			free(ret);
			ret = newret;
			numentries += 5;
		}
		ret[idx++] = read_agenda_entry(cursor);
		cursor = next_entry(cursor);
	}
	*entries = idx;
	return ret;
}

int main(int argc, char **argv) {
	// unbuffering stdout in order to prevent leaks
	// has the added benefit of reducing memory usage too
	setvbuf(stdout, NULL, _IONBF, 0);
	if (argc <= 1) {
		printf("no agenda file supplied!\nUsage: otc <agendafile>\n");
		return -1;
	}
	
	// read file into buf 
	char *buf = read_file_to_buffer(argv[1]);
	if (strlen(buf) == 0) return -1; // don't do empty buffers
	
	// read entries into array
	int idx = 0;
	entry *agenda = read_entries_to_array(buf, &idx);
	free(buf);
	/*char *tmp = buf;
	entry *agenda;
	int numentries = 10,
		idx = 0,
        buflen = strlen(buf);
	agenda = (entry *)malloc(numentries * sizeof(entry));
	while (buf) {
		agenda[idx++] = read_agenda_entry(buf);
		tmp = next_entry(buf);
		if (tmp == NULL) buflen = 0;
		else buflen -= (tmp - buf);
		buf = tmp;
		}*/

	// sort entries
	sort_entry_array(agenda, idx);

	// format nicely
	char *e;
	Date td = today();
	Date nw = nextweek(td);
	Date last_date = agenda[0].date;
	if (!zero(last_date)) {
		e = print_date_to_string(last_date);
		if (smaller(last_date, td))
			printf("\n%s [OUTATIME]:\n", e);
		else if (smaller(last_date, nw))
			printf("\n%s:\n", e);
		free(e);
	}
	for (int i = 0; i < idx; i++) {
		if (!eql(agenda[i].date, last_date)) {
			last_date = agenda[i].date;
			if (!zero(last_date)) {
				e = print_date_to_string(last_date);
				if (smaller(last_date, td))
					printf("\n%s [OUTATIME]:\n", e);
				else if (smaller(last_date, nw))
					printf("\n%s:\n", e);
				free(e);
			} else {
				printf("\nUnscheduled:\n");
			}
		}
		e = format_entry(agenda[i]);
		if (zero(agenda[i].date) || smaller(agenda[i].date, nw)) puts(e);
		free(e);
	}

	// free up the memory
	fclose(stdout);
	destroy_entry_array(agenda, idx);
	return 0;
}