1 files changed, 240 insertions, 0 deletions
diff --git a/src/openvic/types/Date.cpp b/src/openvic/types/Date.cpp
new file mode 100644
index 0000000..b6e1367
--- /dev/null
+++ b/src/openvic/types/Date.cpp
@@ -0,0 +1,240 @@
+#include "Date.hpp"
+
+#include <algorithm>
+#include <cassert>
+#include <cctype>
+#include <charconv>
+
+#include "openvic/utility/Logger.hpp"
+
+using namespace OpenVic;
+
+Timespan::Timespan(day_t value) : days { value } {}
+
+bool Timespan::operator<(Timespan other) const { return days < other.days; };
+bool Timespan::operator>(Timespan other) const { return days > other.days; };
+bool Timespan::operator<=(Timespan other) const { return days <= other.days; };
+bool Timespan::operator>=(Timespan other) const { return days >= other.days; };
+bool Timespan::operator==(Timespan other) const { return days == other.days; };
+bool Timespan::operator!=(Timespan other) const { return days != other.days; };
+
+Timespan Timespan::operator+(Timespan other) const { return days + other.days; }
+
+Timespan Timespan::operator-(Timespan other) const { return days - other.days; }
+
+Timespan Timespan::operator*(day_t factor) const { return days * factor; }
+
+Timespan Timespan::operator/(day_t factor) const { return days / factor; }
+
+Timespan& Timespan::operator+=(Timespan other) {
+	days += other.days;
+	return *this;
+}
+
+Timespan& Timespan::operator-=(Timespan other) {
+	days -= other.days;
+	return *this;
+}
+
+Timespan& Timespan::operator++() {
+	days++;
+	return *this;
+}
+
+Timespan Timespan::operator++(int) {
+	Timespan old = *this;
+	++(*this);
+	return old;
+}
+
+Timespan::operator day_t() const {
+	return days;
+}
+
+Timespan::operator double() const {
+	return days;
+}
+
+Timespan::operator std::string() const {
+	return std::to_string(days);
+}
+
+std::ostream& OpenVic::operator<<(std::ostream& out, Timespan const& timespan) {
+	return out << static_cast<std::string>(timespan);
+}
+
+Timespan Date::_dateToTimespan(year_t year, month_t month, day_t day) {
+	month = std::clamp<month_t>(month, 1, MONTHS_IN_YEAR);
+	day = std::clamp<day_t>(day, 1, DAYS_IN_MONTH[month - 1]);
+	return year * DAYS_IN_YEAR + DAYS_UP_TO_MONTH[month - 1] + day - 1;
+}
+
+Timespan::day_t const* Date::DAYS_UP_TO_MONTH = generate_days_up_to_month();
+
+Timespan::day_t const* Date::generate_days_up_to_month() {
+	static Timespan::day_t days_up_to_month[MONTHS_IN_YEAR];
+	Timespan::day_t days = 0;
+	for (int month = 0; month < MONTHS_IN_YEAR;
+		days_up_to_month[month] = days, days += DAYS_IN_MONTH[month++]);
+	assert(days == DAYS_IN_YEAR);
+	return days_up_to_month;
+}
+
+Date::month_t const* Date::MONTH_FROM_DAY_IN_YEAR = generate_month_from_day_in_year();
+
+Date::month_t const* Date::generate_month_from_day_in_year() {
+	static month_t month_from_day_in_year[DAYS_IN_YEAR];
+	Timespan::day_t days_left = 0;
+	for (int day = 0, month = 0; day < DAYS_IN_YEAR;
+		days_left = (days_left > 0 ? days_left : DAYS_IN_MONTH[month++]) - 1,
+		month_from_day_in_year[day++] = month);
+	assert(days_left == 0);
+	assert(month_from_day_in_year[DAYS_IN_YEAR - 1] == MONTHS_IN_YEAR);
+	return month_from_day_in_year;
+}
+
+Date::Date(Timespan total_days) : timespan { total_days } {
+	if (timespan < 0) {
+		Logger::error("Invalid timespan for date: ", timespan, " (cannot be negative)");
+		timespan = 0;
+	}
+}
+
+Date::Date(year_t year, month_t month, day_t day) : timespan { _dateToTimespan(year, month, day) } {}
+
+Date::year_t Date::getYear() const {
+	return static_cast<Timespan::day_t>(timespan) / DAYS_IN_YEAR;
+}
+
+Date::month_t Date::getMonth() const {
+	return MONTH_FROM_DAY_IN_YEAR[static_cast<Timespan::day_t>(timespan) % DAYS_IN_YEAR];
+}
+
+Date::day_t Date::getDay() const {
+	return (static_cast<Timespan::day_t>(timespan) % DAYS_IN_YEAR) - DAYS_UP_TO_MONTH[getMonth() - 1] + 1;
+}
+
+bool Date::operator<(Date other) const { return timespan < other.timespan; };
+bool Date::operator>(Date other) const { return timespan > other.timespan; };
+bool Date::operator<=(Date other) const { return timespan <= other.timespan; };
+bool Date::operator>=(Date other) const { return timespan >= other.timespan; };
+bool Date::operator==(Date other) const { return timespan == other.timespan; };
+bool Date::operator!=(Date other) const { return timespan != other.timespan; };
+
+Date Date::operator+(Timespan other) const { return timespan + other; }
+
+Timespan Date::operator-(Date other) const { return timespan - other.timespan; }
+
+Date& Date::operator+=(Timespan other) {
+	timespan += other;
+	return *this;
+}
+
+Date& Date::operator-=(Timespan other) {
+	timespan -= other;
+	return *this;
+}
+
+Date& Date::operator++() {
+	timespan++;
+	return *this;
+}
+
+Date Date::operator++(int) {
+	Date old = *this;
+	++(*this);
+	return old;
+}
+
+Date::operator std::string() const {
+	std::stringstream ss;
+	ss << *this;
+	return ss.str();
+}
+
+std::ostream& OpenVic::operator<<(std::ostream& out, Date const& date) {
+	return out << static_cast<int>(date.getYear()) << '.' << static_cast<int>(date.getMonth()) << '.' << static_cast<int>(date.getDay());
+}
+
+// Parsed from string of the form YYYY.MM.DD
+Date Date::from_string(const std::string_view date, bool* successful) {
+	if (successful != nullptr) *successful = true;
+	size_t first_pos = 0;
+	while (first_pos < date.length() && std::isdigit(date[first_pos])) {
+		first_pos++;
+	}
+
+	if (first_pos == 0) {
+		Logger::error("Failed to find year digits in date: ", date);
+		if (successful != nullptr) *successful = false;
+		return {};
+	}
+
+	int val = 0;
+	char const* start = date.data();
+	char const* end = start + first_pos;
+	std::from_chars_result result = std::from_chars(start, end, val);
+	if (result.ec != std::errc{} || result.ptr != end || val < 0 || val >= 1 << (8 * sizeof(year_t))) {
+		Logger::error("Failed to read year: ", date);
+		if (successful != nullptr) *successful = false;
+		return {};
+	}
+	year_t year = val;
+	month_t month = 1;
+	day_t day = 1;
+	if (first_pos < date.length()) {
+		if (date[first_pos] == '.') {
+			size_t second_pos = ++first_pos;
+			while (second_pos < date.length() && std::isdigit(date[second_pos])) {
+				second_pos++;
+			}
+			if (first_pos == second_pos) {
+				Logger::error("Failed to find month digits in date: ", date);
+				if (successful != nullptr) *successful = false;
+			} else {
+				start = date.data() + first_pos;
+				end = date.data() + second_pos;
+				result = std::from_chars(start, end, val);
+				if (result.ec != std::errc{} || result.ptr != end || val < 1 || val > MONTHS_IN_YEAR) {
+					Logger::error("Failed to read month: ", date);
+					if (successful != nullptr) *successful = false;
+				} else {
+					month = val;
+					if (second_pos < date.length()) {
+						if (date[second_pos] == '.') {
+							size_t third_pos = ++second_pos;
+							while (third_pos < date.length() && std::isdigit(date[third_pos])) {
+								third_pos++;
+							}
+							if (second_pos == third_pos) {
+								Logger::error("Failed to find day digits in date: ", date);
+								if (successful != nullptr) *successful = false;
+							} else {
+								start = date.data() + second_pos;
+								end = date.data() + third_pos;
+								result = std::from_chars(start, end, val);
+								if (result.ec != std::errc{} || result.ptr != end || val < 1 || val > DAYS_IN_MONTH[month - 1]) {
+									Logger::error("Failed to read day: ", date);
+									if (successful != nullptr) *successful = false;
+								} else {
+									day = val;
+									if (third_pos < date.length()) {
+										Logger::error("Unexpected string \"", date.substr(third_pos), "\" at the end of date ", date);
+										if (successful != nullptr) *successful = false;
+									}
+								}
+							}
+						} else {
+							Logger::error("Unexpected character \"", date[second_pos], "\" in month of date ", date);
+							if (successful != nullptr) *successful = false;
+						}
+					}
+				}
+			}
+		} else {
+			Logger::error("Unexpected character \"", date[first_pos], "\" in year of date ", date);
+			if (successful != nullptr) *successful = false;
+		}
+	}
+	return _dateToTimespan(year, month, day);
+};