1 files changed, 172 insertions, 0 deletions
diff --git a/intl/components/src/Calendar.cpp b/intl/components/src/Calendar.cpp
new file mode 100644
index 0000000000..d44dedaaae
--- /dev/null
+++ b/intl/components/src/Calendar.cpp
@@ -0,0 +1,172 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/intl/Calendar.h"
+
+#include "unicode/ucal.h"
+#include "unicode/uloc.h"
+#include "unicode/utypes.h"
+
+namespace mozilla::intl {
+
+/* static */
+Result<UniquePtr<Calendar>, ICUError> Calendar::TryCreate(
+    const char* aLocale, Maybe<Span<const char16_t>> aTimeZoneOverride) {
+  UErrorCode status = U_ZERO_ERROR;
+  const UChar* zoneID = nullptr;
+  int32_t zoneIDLen = 0;
+  if (aTimeZoneOverride) {
+    zoneIDLen = static_cast<int32_t>(aTimeZoneOverride->Length());
+    zoneID = aTimeZoneOverride->Elements();
+  }
+
+  UCalendar* calendar =
+      ucal_open(zoneID, zoneIDLen, aLocale, UCAL_DEFAULT, &status);
+
+  if (U_FAILURE(status)) {
+    return Err(ToICUError(status));
+  }
+
+  return MakeUnique<Calendar>(calendar);
+}
+
+Result<Span<const char>, ICUError> Calendar::GetBcp47Type() {
+  UErrorCode status = U_ZERO_ERROR;
+  const char* oldType = ucal_getType(mCalendar, &status);
+  if (U_FAILURE(status)) {
+    return Err(ToICUError(status));
+  }
+  const char* bcp47Type = uloc_toUnicodeLocaleType("calendar", oldType);
+
+  if (!bcp47Type) {
+    return Err(ICUError::InternalError);
+  }
+
+  return MakeStringSpan(bcp47Type);
+}
+
+static Weekday WeekdayFromDaysOfWeek(UCalendarDaysOfWeek weekday) {
+  switch (weekday) {
+    case UCAL_MONDAY:
+      return Weekday::Monday;
+    case UCAL_TUESDAY:
+      return Weekday::Tuesday;
+    case UCAL_WEDNESDAY:
+      return Weekday::Wednesday;
+    case UCAL_THURSDAY:
+      return Weekday::Thursday;
+    case UCAL_FRIDAY:
+      return Weekday::Friday;
+    case UCAL_SATURDAY:
+      return Weekday::Saturday;
+    case UCAL_SUNDAY:
+      return Weekday::Sunday;
+  }
+  MOZ_CRASH("unexpected weekday value");
+}
+
+Result<EnumSet<Weekday>, ICUError> Calendar::GetWeekend() {
+  static_assert(static_cast<int32_t>(UCAL_SUNDAY) == 1);
+  static_assert(static_cast<int32_t>(UCAL_SATURDAY) == 7);
+
+  UErrorCode status = U_ZERO_ERROR;
+
+  EnumSet<Weekday> weekend;
+  for (int32_t i = UCAL_SUNDAY; i <= UCAL_SATURDAY; i++) {
+    auto dayOfWeek = static_cast<UCalendarDaysOfWeek>(i);
+    auto type = ucal_getDayOfWeekType(mCalendar, dayOfWeek, &status);
+    if (U_FAILURE(status)) {
+      return Err(ToICUError(status));
+    }
+
+    switch (type) {
+      case UCAL_WEEKEND_ONSET:
+        // Treat days which start as a weekday as weekdays.
+        [[fallthrough]];
+      case UCAL_WEEKDAY:
+        break;
+
+      case UCAL_WEEKEND_CEASE:
+        // Treat days which start as a weekend day as weekend days.
+        [[fallthrough]];
+      case UCAL_WEEKEND:
+        weekend += WeekdayFromDaysOfWeek(dayOfWeek);
+        break;
+    }
+  }
+
+  return weekend;
+}
+
+Weekday Calendar::GetFirstDayOfWeek() {
+  int32_t firstDayOfWeek = ucal_getAttribute(mCalendar, UCAL_FIRST_DAY_OF_WEEK);
+  MOZ_ASSERT(UCAL_SUNDAY <= firstDayOfWeek && firstDayOfWeek <= UCAL_SATURDAY);
+
+  return WeekdayFromDaysOfWeek(
+      static_cast<UCalendarDaysOfWeek>(firstDayOfWeek));
+}
+
+int32_t Calendar::GetMinimalDaysInFirstWeek() {
+  int32_t minimalDays =
+      ucal_getAttribute(mCalendar, UCAL_MINIMAL_DAYS_IN_FIRST_WEEK);
+  MOZ_ASSERT(1 <= minimalDays && minimalDays <= 7);
+
+  return minimalDays;
+}
+
+Result<Ok, ICUError> Calendar::SetTimeInMs(double aUnixEpoch) {
+  UErrorCode status = U_ZERO_ERROR;
+  ucal_setMillis(mCalendar, aUnixEpoch, &status);
+  if (U_FAILURE(status)) {
+    return Err(ToICUError(status));
+  }
+  return Ok{};
+}
+
+/* static */
+Result<SpanEnumeration<char>, ICUError>
+Calendar::GetLegacyKeywordValuesForLocale(const char* aLocale) {
+  UErrorCode status = U_ZERO_ERROR;
+  UEnumeration* enumeration = ucal_getKeywordValuesForLocale(
+      "calendar", aLocale, /* commonlyUsed */ false, &status);
+
+  if (U_SUCCESS(status)) {
+    return SpanEnumeration<char>(enumeration);
+  }
+
+  return Err(ToICUError(status));
+}
+
+/* static */
+SpanResult<char> Calendar::LegacyIdentifierToBcp47(const char* aIdentifier,
+                                                   int32_t aLength) {
+  if (aIdentifier == nullptr) {
+    return Err(InternalError{});
+  }
+  // aLength is not needed here, as the ICU call uses the null terminated
+  // string.
+  return MakeStringSpan(uloc_toUnicodeLocaleType("ca", aIdentifier));
+}
+
+/* static */
+Result<Calendar::Bcp47IdentifierEnumeration, ICUError>
+Calendar::GetBcp47KeywordValuesForLocale(const char* aLocale,
+                                         CommonlyUsed aCommonlyUsed) {
+  UErrorCode status = U_ZERO_ERROR;
+  UEnumeration* enumeration = ucal_getKeywordValuesForLocale(
+      "calendar", aLocale, static_cast<bool>(aCommonlyUsed), &status);
+
+  if (U_SUCCESS(status)) {
+    return Bcp47IdentifierEnumeration(enumeration);
+  }
+
+  return Err(ToICUError(status));
+}
+
+Calendar::~Calendar() {
+  MOZ_ASSERT(mCalendar);
+  ucal_close(mCalendar);
+}
+
+}  // namespace mozilla::intl