initial proper of seasons

src/builder.c

@@ -0,0 +1,505 @@
+#include "builder.h"
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+//helper to add days to a date
+static struct tm add_days(struct tm date, int days) {
+	date.tm_mday += days;
+	mktime(&date);
+	return date;
+}
+
+//helper to compare dates (return negative if d1 < d2, 0 if equal, positive if d1 > d2)
+static int compare_dates(struct tm d1, struct tm d2) {
+	if (d1.tm_year != d2.tm_year) return d1.tm_year - d2.tm_year;
+	if (d1.tm_mon != d2.tm_mon) return d1.tm_mon - d2.tm_mon;
+	return d1.tm_mday - d2.tm_mday;
+}
+
+/// Computus algorithm to calculate Easter Sunday
+static ChurchDay easter_for_year(int year) {
+    int a = year % 19;
+    int b = year / 100;
+    int c = year % 100;
+    int d = b / 4;
+    int e = b % 4;
+    int f = (b + 8) / 25;
+    int g = (b - f + 1) / 3;
+    int h = (19 * a + b - d - g + 15) % 30;
+    int i = c / 4;
+    int k = c % 4;
+    int l = (32 + 2 * e + 2 * i - h - k) % 7;
+    int m = (a + 11 * h + 22 * l) / 451;
+    int month = (h + l - 7 * m + 114) / 31;
+    int day = (h + l - 7 * m + 114) % 31 + 1;
+    
+    return church_day_new(year, month, day, SOLEMNITY, EASTER,
+                         "Easter Sunday of the Resurrection of the Lord");
+}
+
+static ChurchDay ash_wednesday(const ChurchDay *easter) {
+    struct tm date = add_days(easter->date, -46);
+    ChurchDay cd;
+    cd.date = date;
+    cd.class = SOLEMNITY;
+    cd.season = LENT;
+    strcpy(cd.description, "Ash Wednesday");
+    return cd;
+}
+
+static ChurchDay first_sunday_advent(int year) {
+    struct tm dec_first = {0};
+    dec_first.tm_year = year - 1900;
+    dec_first.tm_mon = 11; // December
+    dec_first.tm_mday = 1;
+    mktime(&dec_first);
+    
+    int days_to_subtract;
+    switch (dec_first.tm_wday) {
+        case 0: days_to_subtract = 0; break;  // Sunday
+        case 1: days_to_subtract = 1; break;  // Monday
+        case 2: days_to_subtract = 2; break;  // Tuesday
+        case 3: days_to_subtract = 3; break;  // Wednesday
+        case 4: days_to_subtract = 4; break;  // Thursday
+        case 5: days_to_subtract = -2; break; // Friday
+        case 6: days_to_subtract = -1; break; // Saturday
+        default: days_to_subtract = 0; break;
+    }
+    
+    struct tm date = add_days(dec_first, -days_to_subtract);
+    ChurchDay cd;
+    cd.date = date;
+    cd.class = SUNDAY;
+    cd.season = ADVENT;
+    strcpy(cd.description, "1st Sunday of Advent");
+    return cd;
+}
+
+static ChurchDay epiphany(int year) {
+    for (int day = 2; day <= 8; day++) {
+        struct tm date = {0};
+        date.tm_year = year - 1900;
+        date.tm_mon = 0; // January
+        date.tm_mday = day;
+        mktime(&date);
+        
+        if (date.tm_wday == 0) { // Sunday
+            return church_day_new(year, 1, day, SOLEMNITY, CHRISTMAS,
+                                "The Epiphany of the Lord");
+        }
+    }
+    // Fallback (shouldn't happen)
+    return church_day_new(year, 1, 6, SOLEMNITY, CHRISTMAS, "The Epiphany of the Lord");
+}
+
+static ChurchDay baptism(ChurchDay epiphany_day) {
+    struct tm date = add_days(epiphany_day.date, 7);
+    ChurchDay cd;
+    cd.date = date;
+    cd.class = FEAST;
+    cd.season = CHRISTMAS;
+    strcpy(cd.description, "The Baptism of the Lord");
+    return cd;
+}
+
+static ChurchDay pentecost(ChurchDay easter) {
+    struct tm date = add_days(easter.date, 49);
+    ChurchDay cd;
+    cd.date = date;
+    cd.class = SOLEMNITY;
+    cd.season = EASTER;
+    strcpy(cd.description, "Pentecost Sunday");
+    return cd;
+}
+
+static const char* ordinal_suffix(int number) {
+    char str[16];
+    snprintf(str, sizeof(str), "%d", number);
+    
+    if (strstr(str, "11") == str + strlen(str) - 2 ||
+        strstr(str, "12") == str + strlen(str) - 2 ||
+        strstr(str, "13") == str + strlen(str) - 2) {
+        return "th";
+    }
+    
+    switch (str[strlen(str) - 1]) {
+        case '1': return "st";
+        case '2': return "nd";
+        case '3': return "rd";
+        default: return "th";
+    }
+}
+
+static const char* day_string(int wday) {
+    switch (wday) {
+        case 0: return "Sunday";
+        case 1: return "Monday";
+        case 2: return "Tuesday";
+        case 3: return "Wednesday";
+        case 4: return "Thursday";
+        case 5: return "Friday";
+        case 6: return "Saturday";
+        default: return "Unknown";
+    }
+}
+
+static void calculate_advent(ChurchYear *cy, const ChurchDay *start) {
+    ChurchDay current = *start;
+    int sunday_counter = 1;
+    
+    church_year_add(cy, current);
+    
+    while (1) {
+        if (current.date.tm_mon == 11 && current.date.tm_mday == 24) {
+            break;
+        }
+        
+        current.date = add_days(current.date, 1);
+        
+        if (current.date.tm_wday == 0) {
+            sunday_counter++;
+        }
+        
+        current.season = ADVENT;
+        current.class = (current.date.tm_wday == 0) ? SUNDAY : SEASONAL_WEEKDAY;
+        
+        if (current.date.tm_mday >= 17 && current.date.tm_mon == 11) {
+            snprintf(current.description, sizeof(current.description),
+                    "December %d%s", current.date.tm_mday,
+                    ordinal_suffix(current.date.tm_mday));
+        } else if (current.date.tm_wday == 0) {
+            snprintf(current.description, sizeof(current.description),
+                    "%d%s Sunday of Advent", sunday_counter,
+                    ordinal_suffix(sunday_counter));
+        } else {
+            snprintf(current.description, sizeof(current.description),
+                    "%s of the %d%s week of Advent",
+                    day_string(current.date.tm_wday), sunday_counter,
+                    ordinal_suffix(sunday_counter));
+        }
+        
+        church_year_add(cy, current);
+    }
+}
+
+static void calculate_christmas(ChurchYear *cy, int year) {
+    ChurchDay epiphany_day = epiphany(year + 1);
+    ChurchDay baptism_day = baptism(epiphany_day);
+    
+    ChurchDay christmas = church_day_new(year, 12, 25, SOLEMNITY, CHRISTMAS,
+                                        "The Nativity of the Lord (Christmas)");
+    church_year_add(cy, christmas);
+    
+    ChurchDay current = christmas;
+    while (1) {
+        struct tm next_date = add_days(current.date, 1);
+        if (next_date.tm_mon == epiphany_day.date.tm_mon &&
+            next_date.tm_mday == epiphany_day.date.tm_mday) {
+            break;
+        }
+        
+        current.date = next_date;
+        current.season = CHRISTMAS;
+        current.class = (current.date.tm_wday == 0) ? FEAST : SEASONAL_WEEKDAY;
+        
+        if (current.date.tm_wday == 0) {
+            strcpy(current.description, "The Holy Family of Jesus, Mary, and Joseph");
+        } else {
+            switch (current.date.tm_mday) {
+                case 26: strcpy(current.description, "Saint Stephen, First Martyr"); break;
+                case 27: strcpy(current.description, "Saint John, Apostle and Evangelist"); break;
+                case 28: strcpy(current.description, "Holy Innocents"); break;
+                case 29: strcpy(current.description, "Fifth Day within the Octave of the Nativity of the Lord"); break;
+                case 30: strcpy(current.description, "Sixth Day within the Octave of the Nativity of the Lord"); break;
+                case 31: strcpy(current.description, "Seventh Day within the Octave of the Nativity of the Lord"); break;
+                default: strcpy(current.description, "Christmas Weekday"); break;
+            }
+        }
+        
+        church_year_add(cy, current);
+    }
+    
+    church_year_add(cy, epiphany_day);
+    
+    current = epiphany_day;
+    while (1) {
+        struct tm next_date = add_days(current.date, 1);
+        if (next_date.tm_mon == baptism_day.date.tm_mon &&
+            next_date.tm_mday == baptism_day.date.tm_mday) {
+            break;
+        }
+        
+        current.date = next_date;
+        current.season = CHRISTMAS;
+        current.class = SEASONAL_WEEKDAY;
+        snprintf(current.description, sizeof(current.description),
+                "%s between Epiphany and Baptism of the Lord",
+                day_string(current.date.tm_wday));
+        
+        church_year_add(cy, current);
+    }
+    
+    church_year_add(cy, baptism_day);
+}
+
+static void calculate_lent(ChurchYear *cy, ChurchDay ash_wed) {
+    ChurchDay easter = easter_for_year(ash_wed.date.tm_year + 1900);
+    struct tm stop_date = add_days(easter.date, -8);
+    
+    ChurchDay current = ash_wed;
+    int sunday_counter = 0;
+    
+    church_year_add(cy, current);
+    
+    while (compare_dates(current.date, stop_date) != 0) {
+        current.date = add_days(current.date, 1);
+        
+        if (current.date.tm_wday == 0) {
+            sunday_counter++;
+        }
+        
+        current.season = LENT;
+        current.class = (current.date.tm_wday == 0) ? SUNDAY : SEASONAL_WEEKDAY;
+        
+        if (sunday_counter == 0) {
+            snprintf(current.description, sizeof(current.description),
+                    "%s after Ash Wednesday", day_string(current.date.tm_wday));
+        } else if (current.date.tm_wday == 0) {
+            snprintf(current.description, sizeof(current.description),
+                    "%d%s Sunday of Lent", sunday_counter,
+                    ordinal_suffix(sunday_counter));
+        } else {
+            snprintf(current.description, sizeof(current.description),
+                    "%s of the %d%s week of Lent",
+                    day_string(current.date.tm_wday), sunday_counter,
+                    ordinal_suffix(sunday_counter));
+        }
+        
+        church_year_add(cy, current);
+    }
+}
+
+static void calculate_easter(ChurchYear *cy, ChurchDay sat_before) {
+    ChurchDay easter = easter_for_year(sat_before.date.tm_year + 1900);
+    struct tm ps_date = add_days(easter.date, -7);
+    
+    ChurchDay palm_sunday;
+    palm_sunday.date = ps_date;
+    palm_sunday.class = SUNDAY;
+    palm_sunday.season = LENT;
+    strcpy(palm_sunday.description, "Palm Sunday of the Passion of the Lord");
+    church_year_add(cy, palm_sunday);
+    
+    const char* holy_week_names[] = {
+        "",
+        "Monday of Holy Week",
+        "Tuesday of Holy Week",
+        "Wednesday of Holy Week",
+        "Holy Thursday",
+        "Friday of the Passion of the Lord",
+        "Holy Saturday"
+    };
+    
+    for (int days_after = 1; days_after <= 6; days_after++) {
+        ChurchDay day;
+        day.date = add_days(ps_date, days_after);
+        day.class = (days_after < 4) ? SEASONAL_WEEKDAY : SOLEMNITY;
+        day.season = (days_after < 4) ? LENT : TRIDUUM;
+        strcpy(day.description, holy_week_names[days_after]);
+        church_year_add(cy, day);
+    }
+    
+    church_year_add(cy, easter);
+    
+    const char* octave_names[] = {
+        "",
+        "Monday within the Octave of Easter",
+        "Tuesday within the Octave of Easter",
+        "Wednesday within the Octave of Easter",
+        "Thursday within the Octave of Easter",
+        "Friday within the Octave of Easter",
+        "Saturday within the Octave of Easter",
+        "Sunday of Divine Mercy"
+    };
+    
+    for (int octave_days = 1; octave_days <= 7; octave_days++) {
+        ChurchDay day;
+        day.date = add_days(easter.date, octave_days);
+        day.class = SOLEMNITY;
+        day.season = EASTER;
+        strcpy(day.description, octave_names[octave_days]);
+        church_year_add(cy, day);
+    }
+    
+    ChurchDay pentecost_day = pentecost(easter);
+    struct tm stop_date = add_days(pentecost_day.date, -1);
+    
+    ChurchDay current = cy->days[cy->count - 1];
+    int sunday_counter = 2;
+    
+    while (compare_dates(current.date, stop_date) != 0) {
+        current.date = add_days(current.date, 1);
+        
+        if (current.date.tm_wday == 0) {
+            sunday_counter++;
+        }
+        
+        current.season = EASTER;
+        current.class = (current.date.tm_wday == 0) ? SUNDAY : SEASONAL_WEEKDAY;
+        
+        if (current.date.tm_wday == 0) {
+            if (sunday_counter == 7) {
+                strcpy(current.description, "The Ascension of the Lord");
+            } else {
+                snprintf(current.description, sizeof(current.description),
+                        "%d%s Sunday of Easter", sunday_counter,
+                        ordinal_suffix(sunday_counter));
+            }
+        } else {
+            snprintf(current.description, sizeof(current.description),
+                    "%s of the %d%s week of Easter",
+                    day_string(current.date.tm_wday), sunday_counter,
+                    ordinal_suffix(sunday_counter));
+        }
+        
+        church_year_add(cy, current);
+    }
+    
+    church_year_add(cy, pentecost_day);
+}
+
+static void calculate_otime_prelent(ChurchYear *cy, ChurchDay baptism_day) {
+    ChurchDay easter = easter_for_year(baptism_day.date.tm_year + 1900);
+    ChurchDay ash_wed = ash_wednesday(&easter);
+    struct tm stop_date = add_days(ash_wed.date, -1);
+    
+    ChurchDay current;
+    current.date = add_days(baptism_day.date, 1);
+    current.class = FERIAL_WEEKDAY;
+    current.season = ORDINARY_TIME;
+    strcpy(current.description, "Monday of the 1st week in Ordinary Time");
+    
+    int sunday_counter = 1;
+    church_year_add(cy, current);
+    
+    while (compare_dates(current.date, stop_date) != 0) {
+        current.date = add_days(current.date, 1);
+        
+        if (current.date.tm_wday == 0) {
+            sunday_counter++;
+        }
+        
+        current.season = ORDINARY_TIME;
+        current.class = (current.date.tm_wday == 0) ? SUNDAY : FERIAL_WEEKDAY;
+        
+        if (current.date.tm_wday == 0) {
+            snprintf(current.description, sizeof(current.description),
+                    "%d%s Sunday of Ordinary Time", sunday_counter,
+                    ordinal_suffix(sunday_counter));
+        } else {
+            snprintf(current.description, sizeof(current.description),
+                    "%s of the %d%s week of Ordinary Time",
+                    day_string(current.date.tm_wday), sunday_counter,
+                    ordinal_suffix(sunday_counter));
+        }
+        
+        church_year_add(cy, current);
+    }
+}
+
+static void calculate_otime_posteaster(ChurchYear *cy, ChurchDay pentecost_day) {
+    ChurchDay first_advent = first_sunday_advent(pentecost_day.date.tm_year + 1900);
+    struct tm last_day = add_days(first_advent.date, -1);
+    
+    struct tm trinity_sunday = add_days(pentecost_day.date, 7);
+    struct tm corpus_christi = add_days(trinity_sunday, 7);
+    
+    // Build backwards
+    ChurchDay *temp_days = malloc(366 * sizeof(ChurchDay));
+    size_t temp_count = 0;
+    
+    ChurchDay current;
+    current.date = last_day;
+    current.class = FERIAL_WEEKDAY;
+    current.season = ORDINARY_TIME;
+    int sunday_counter = 34;
+    
+    snprintf(current.description, sizeof(current.description),
+            "%s of the %d%s Week in Ordinary Time",
+            day_string(current.date.tm_wday), sunday_counter,
+            ordinal_suffix(sunday_counter));
+    temp_days[temp_count++] = current;
+    
+    struct tm stop_date = add_days(pentecost_day.date, 1);
+    
+    while (compare_dates(current.date, stop_date) != 0) {
+        current.date = add_days(current.date, -1);
+        
+        if (current.date.tm_wday == 0) {
+            sunday_counter--;
+        }
+        
+        current.season = ORDINARY_TIME;
+        
+        if (current.date.tm_wday == 0) {
+            if (compare_dates(current.date, trinity_sunday) == 0) {
+                current.class = SOLEMNITY;
+                strcpy(current.description, "The Most Holy Trinity");
+            } else if (compare_dates(current.date, corpus_christi) == 0) {
+                current.class = SOLEMNITY;
+                strcpy(current.description, "The Most Holy Body and Blood of Christ");
+            } else if (sunday_counter == 33) {
+                current.class = SOLEMNITY;
+                strcpy(current.description, "Our Lord Jesus Christ, King of the Universe");
+            } else {
+                current.class = SUNDAY;
+                snprintf(current.description, sizeof(current.description),
+                        "%d%s Sunday of Ordinary Time", sunday_counter,
+                        ordinal_suffix(sunday_counter));
+            }
+        } else {
+            current.class = FERIAL_WEEKDAY;
+            snprintf(current.description, sizeof(current.description),
+                    "%s of the %d%s week of Ordinary Time",
+                    day_string(current.date.tm_wday), sunday_counter,
+                    ordinal_suffix(sunday_counter));
+        }
+        
+        temp_days[temp_count++] = current;
+    }
+    
+    // Reverse and add to main list
+    for (size_t i = temp_count; i > 0; i--) {
+        church_year_add(cy, temp_days[i - 1]);
+    }
+    
+    free(temp_days);
+}
+
+ChurchYear proper_of_seasons(struct tm today) {
+    ChurchYear cy = church_year_new();
+    
+    ChurchDay first_advent = first_sunday_advent(today.tm_year + 1900);
+    if (compare_dates(today, first_advent.date) < 0) {
+        first_advent = first_sunday_advent(today.tm_year + 1900 - 1);
+    }
+    
+    calculate_advent(&cy, &first_advent);
+    calculate_christmas(&cy, first_advent.date.tm_year + 1900);
+    
+    ChurchDay baptism_day = cy.days[cy.count - 1];
+    ChurchDay easter = easter_for_year(baptism_day.date.tm_year + 1900);
+    ChurchDay ash_wed = ash_wednesday(&easter);
+    
+    calculate_otime_prelent(&cy, baptism_day);
+    calculate_lent(&cy, ash_wed);
+    
+    ChurchDay sat_before = cy.days[cy.count - 1];
+    calculate_easter(&cy, sat_before);
+    
+    ChurchDay pentecost_day = cy.days[cy.count - 1];
+    calculate_otime_posteaster(&cy, pentecost_day);
+    
+    return cy;
+}

src/builder.h

@@ -0,0 +1,10 @@
+#ifndef BUILDER_H
+#define BUILDER_H
+
+#include "church_day.h"
+#include <time.h>
+
+//calculate proper of seasons for a given date
+ChurchYear proper_of_seasons(struct tm today);
+
+#endif //BUILDER_H

src/church_day.c

@@ -0,0 +1,81 @@
+#include "church_day.h"
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+ChurchDay church_day_new(int year, int month, int day, DayClass class, Season season, const char *description) {
+	ChurchDay cd;
+	memset(&cd.date, 0, sizeof(struct tm));
+
+	cd.date.tm_year = year - 1900;
+	cd.date.tm_mon = month - 1;
+	cd.date.tm_mday = day;
+
+	mktime(&cd.date);
+
+	cd.class = class;
+	cd.season = season;
+	strncpy(cd.description, description, sizeof(cd.description) - 1);
+	cd.description[sizeof(cd.description) - 1] = '\0';
+
+	return cd;
+}
+
+const char* church_day_month_name(const ChurchDay *day) {
+	static char buffer[32];
+	strftime(buffer, sizeof(buffer), "%B", &day->date);
+	return buffer;
+}
+
+const char* church_day_weekday_string(const ChurchDay *day) {
+	static char buffer[32];
+	strftime(buffer, sizeof(buffer), "%A", &day->date);
+	return buffer;
+}
+
+const char* day_class_to_string(DayClass class) {
+	switch (class) {
+		case SOLEMNITY: return "Solemnity";
+		case SUNDAY: return "Sunday";
+		case FEAST: return "Feast";
+		case MEMORIAL: return "Memorial";
+		case SEASONAL_WEEKDAY: return "Seasonal Weekday";
+		case FERIAL_WEEKDAY: return "Ferial";
+		default: return "Unknown";
+	}
+}
+
+const char* season_to_string(Season season) {
+	switch(season) {
+		case ADVENT: return "Advent";
+		case CHRISTMAS: return "Christmas";
+		case ORDINARY_TIME: return "Ordinary Time";
+		case LENT: return "Lent";
+		case TRIDUUM: return "Sacred Triduum";
+		case EASTER: return "Easter";
+		default: return "Unknown";
+	}
+}
+
+ChurchYear church_year_new(void) {
+	ChurchYear cy;
+	cy.capacity = 366;
+	cy.count = 0;
+	cy.days = malloc(cy.capacity * sizeof(ChurchDay));
+	return cy;
+}
+
+void church_year_add(ChurchYear *year, ChurchDay day) {
+	if (year->count >= year->capacity) {
+		year->capacity *= 2;
+		year->days = realloc(year->days, year->capacity * sizeof(ChurchDay));
+	}
+	year->days[year->count++] = day;
+}
+
+void church_year_free(ChurchYear *year) {
+	free(year->days);
+	year->days = NULL;
+	year->count = 0;
+	year->capacity = 0;
+}

src/church_day.h

@@ -0,0 +1,57 @@
+#ifndef CHURCH_DAY_H
+#define CHURCH_DAY_H
+
+#include <time.h>
+
+typedef enum {
+	SOLEMNITY,
+	SUNDAY,
+	FEAST,
+	MEMORIAL,
+	SEASONAL_WEEKDAY,
+	FERIAL_WEEKDAY
+} DayClass;
+
+typedef enum {
+	ADVENT,
+	CHRISTMAS,
+	ORDINARY_TIME,
+	LENT,
+	TRIDUUM,
+	EASTER
+} Season;
+
+typedef struct {
+	struct tm date;
+	DayClass class;
+	Season season;
+	char description[256];
+} ChurchDay;
+
+typedef struct {
+	ChurchDay *days;
+	size_t count;
+	size_t capacity;
+} ChurchYear;
+
+//Create a new ChurchDay
+ChurchDay church_day_new(int year, int month, int day, DayClass class, Season season, const char *description);
+
+//Get month name from ChurchDay
+const char* church_day_month_name(const ChurchDay *day);
+
+//Get day of week string from ChurchDay
+const char* church_day_weekday_string(const ChurchDay *day);
+
+//Get string representation of DayClass
+const char* day_class_to_string(DayClass class);
+
+//Get string representation of Season
+const char* season_to_string(Season season);
+
+//ChurchYear functions
+ChurchYear church_year_new(void);
+void church_year_add(ChurchYear *year, ChurchDay day);
+void church_year_free(ChurchYear *year);
+
+#endif // CHURCH_DAY_H

src/main.c

@@ -0,0 +1,26 @@
+#include <stdio.h>
+#include <time.h>
+#include "church_day.h"
+#include "builder.h"
+
+int main(void) {
+	time_t now = time(NULL);
+	struct tm *today = localtime(&now);
+
+	ChurchYear seasons = proper_of_seasons(*today);
+
+	for (size_t i = 0; i < seasons.count; i++) {
+		ChurchDay *day = &seasons.days[i];
+		printf("%s, %s %d, %d - %s - %s in %s\n",
+	 		church_day_weekday_string(day),
+	 		church_day_month_name(day),
+	 		day->date.tm_mday,
+	 		day->date.tm_year + 1900,
+	 		day->description,
+	 		day_class_to_string(day->class),
+	 		season_to_string(day->season));
+	}
+
+	church_year_free(&seasons);
+	return 0;
+}