#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <stdbool.h>
#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>
#include <unistd.h>
#include <time.h>

typedef enum topic {NOTHING, MATH, PHYSICS, ENGLISH, FRENCH, INFO} topic;
// colles subjects

typedef struct date {int hour; int day; int month; int year;} date; /* format is {hour, day, month, year} */
// nothing to say here

typedef struct creneau {date date; int group; char* name; topic mat;} creneau;
// one créneau de colle
// /!\ creneau has to be sorted by ascending dates
// with edt being a creneau*, it is required to have edt[0] be a Monday and edt[len(edt)-1] has to be a Friday

typedef struct colleur {char* name; topic mat; date* disp; int n_disp;} colleur;
// available creneaux for the colleurs

typedef struct array {int* a; int len; int memlen;} array;
// yes

static int width = 1200;
static int height = 900;

int date_dist(date d1, date d2) { /* returns distance between d1 and d2 in days
     if d2 is sooner than d1, it will return -1 */
    if(d2.month == d1.month && d2.year == d1.year) {
        if(d2.day < d1.day) {
            return -1;
        }
        return d2.day - d1.day;
    } else {
        int is_31 = 0;
        if(d1.month == 1 || d1.month == 3 || d1.month == 5 || d1.month == 7 || d1.month == 8 || d1.month == 10 || d1.month == 12) {
            is_31 = 1;
        } else {
            is_31 = (d1.month == 2)*(-2) + (d1.month == 2 && d1.year%4 == 0 && d1.year%100 != 0);
        }
        if(d2.month - d1.month < 0 && d2.year <= d1.year) {
            return -1;
        } else if(d2.month - d1.month == 1 && d2.year == d1.year) {
            return d2.day + (30 + is_31 - d1.day);
        } else {
            date copy;
            copy.day = d1.day;
            copy.month = d1.month;
            copy.year = d1.year;
            copy.month = (copy.month + 1);
            if(copy.month == 13) {
                copy.month = 1;
                copy.year += 1;
            }
            return (30 + is_31 + date_dist(copy, d2));
        }
    }
}

bool is_sorted(creneau* edt, int len) {
    for(int i = 1; i < len; i++) {
        if(date_dist(edt[i-1].date, edt[i].date) == -1) {
            printf("Anomaly detected at lane %d (dates are not sorted in ascending order)\n", i);
            return false;
        }
    }
    printf("No problem detected\n");
    return true;
}

creneau* import_creneaux(char* filename, int size) {
    // import creneau data from a file 
    // see file.txt for an example
    FILE* ptr = fopen(filename, "r");
    char c = fgetc(ptr);

    creneau* edt = malloc(sizeof(creneau)*size);
    int i = 0;
    int to_fill = 0;

    int buffer = 0;

    while(c != EOF && c != '$') {
        if((int)(c) >= 48 && (int)(c) <= 57) {
            buffer *= 10;
            buffer += (int)(c) - 48;
        } else {
            if(to_fill == 0) {
                edt[i].date.hour = buffer;
                edt[i].group = 0;
                edt[i].name = "empty";
                edt[i].mat = NOTHING;
            } else if(to_fill == 1) {
                edt[i].date.day = buffer;
            } else if(to_fill == 2) {
                edt[i].date.month = buffer;
            } else {
                edt[i].date.year = buffer;
            }
            to_fill++;
            buffer = 0;
            if(c == '\n') {
                i++;
                to_fill = 0;
            }
        }
        c = fgetc(ptr);
    }

    fclose(ptr);

    if(!is_sorted(edt, size)) {
        assert(0);
    }
    return edt;
}

bool str_equal(char* s1, char* s2) {
    // note : s1 and s2 must be valid strings (aka have (int)(0) at the end)
    if((int)(s1[0]) == 0 || (int)(s2[0]) == 0) {
        return ((int)(s1[0]) == 0 && (int)(s2[0]) == 0);
    } else if(s1[0] != s2[0]) {
        return false;
    }
    return str_equal(&s1[1], &s2[1]);
}