1 files changed, 153 insertions, 0 deletions
diff --git a/intl/components/src/RelativeTimeFormat.cpp b/intl/components/src/RelativeTimeFormat.cpp
new file mode 100644
index 0000000000..da67f7587d
--- /dev/null
+++ b/intl/components/src/RelativeTimeFormat.cpp
@@ -0,0 +1,153 @@
+/* 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/RelativeTimeFormat.h"
+#include "mozilla/FloatingPoint.h"
+
+#include "unicode/unum.h"
+
+#include "NumberFormatFields.h"
+#include "ICU4CGlue.h"
+#include "ScopedICUObject.h"
+
+namespace mozilla::intl {
+
+/*static*/ Result<UniquePtr<RelativeTimeFormat>, ICUError>
+RelativeTimeFormat::TryCreate(const char* aLocale,
+                              const RelativeTimeFormatOptions& aOptions) {
+  UErrorCode status = U_ZERO_ERROR;
+
+  UFormattedRelativeDateTime* formattedRelativeDateTime =
+      ureldatefmt_openResult(&status);
+  if (U_FAILURE(status)) {
+    return Err(ToICUError(status));
+  }
+  ScopedICUObject<UFormattedRelativeDateTime, ureldatefmt_closeResult>
+      closeFormattedRelativeDate(formattedRelativeDateTime);
+
+  UNumberFormat* nf =
+      unum_open(UNUM_DECIMAL, nullptr, 0, IcuLocale(aLocale), nullptr, &status);
+  if (U_FAILURE(status)) {
+    return Err(ToICUError(status));
+  }
+  ScopedICUObject<UNumberFormat, unum_close> closeNumberFormatter(nf);
+
+  // Use the default values as if a new Intl.NumberFormat had been constructed.
+  unum_setAttribute(nf, UNUM_MIN_INTEGER_DIGITS, 1);
+  unum_setAttribute(nf, UNUM_MIN_FRACTION_DIGITS, 0);
+  unum_setAttribute(nf, UNUM_MAX_FRACTION_DIGITS, 3);
+  unum_setAttribute(nf, UNUM_GROUPING_USED, true);
+  unum_setAttribute(nf, UNUM_MINIMUM_GROUPING_DIGITS,
+                    UNUM_MINIMUM_GROUPING_DIGITS_AUTO);
+
+  UDateRelativeDateTimeFormatterStyle relDateTimeStyle;
+  switch (aOptions.style) {
+    case RelativeTimeFormatOptions::Style::Short:
+      relDateTimeStyle = UDAT_STYLE_SHORT;
+      break;
+    case RelativeTimeFormatOptions::Style::Narrow:
+      relDateTimeStyle = UDAT_STYLE_NARROW;
+      break;
+    case RelativeTimeFormatOptions::Style::Long:
+      relDateTimeStyle = UDAT_STYLE_LONG;
+      break;
+  }
+
+  URelativeDateTimeFormatter* formatter =
+      ureldatefmt_open(IcuLocale(aLocale), nf, relDateTimeStyle,
+                       UDISPCTX_CAPITALIZATION_FOR_STANDALONE, &status);
+
+  if (U_FAILURE(status)) {
+    return Err(ToICUError(status));
+  }
+
+  // Ownership was transferred to mFormatter.
+  closeNumberFormatter.forget();
+
+  UniquePtr<RelativeTimeFormat> rtf = MakeUnique<RelativeTimeFormat>(
+      aOptions.numeric, formatter, formattedRelativeDateTime);
+
+  // Ownership was transferred to rtf.
+  closeFormattedRelativeDate.forget();
+  return rtf;
+}
+
+RelativeTimeFormat::RelativeTimeFormat(
+    RelativeTimeFormatOptions::Numeric aNumeric,
+    URelativeDateTimeFormatter* aFormatter,
+    UFormattedRelativeDateTime* aFormattedRelativeDateTime)
+    : mNumeric(aNumeric),
+      mFormatter(aFormatter),
+      mFormattedRelativeDateTime(aFormattedRelativeDateTime) {}
+
+RelativeTimeFormat::~RelativeTimeFormat() {
+  if (mFormattedRelativeDateTime) {
+    ureldatefmt_closeResult(mFormattedRelativeDateTime);
+    mFormattedRelativeDateTime = nullptr;
+  }
+
+  if (mFormatter) {
+    ureldatefmt_close(mFormatter);
+    mFormatter = nullptr;
+  }
+}
+
+URelativeDateTimeUnit RelativeTimeFormat::ToURelativeDateTimeUnit(
+    FormatUnit unit) const {
+  switch (unit) {
+    case FormatUnit::Second:
+      return UDAT_REL_UNIT_SECOND;
+    case FormatUnit::Minute:
+      return UDAT_REL_UNIT_MINUTE;
+    case FormatUnit::Hour:
+      return UDAT_REL_UNIT_HOUR;
+    case FormatUnit::Day:
+      return UDAT_REL_UNIT_DAY;
+    case FormatUnit::Week:
+      return UDAT_REL_UNIT_WEEK;
+    case FormatUnit::Month:
+      return UDAT_REL_UNIT_MONTH;
+    case FormatUnit::Quarter:
+      return UDAT_REL_UNIT_QUARTER;
+    case FormatUnit::Year:
+      return UDAT_REL_UNIT_YEAR;
+  };
+  MOZ_ASSERT_UNREACHABLE();
+  return UDAT_REL_UNIT_SECOND;
+}
+
+Result<Span<const char16_t>, ICUError> RelativeTimeFormat::formatToParts(
+    double aNumber, FormatUnit aUnit, NumberPartVector& aParts) const {
+  UErrorCode status = U_ZERO_ERROR;
+
+  if (mNumeric == RelativeTimeFormatOptions::Numeric::Auto) {
+    ureldatefmt_formatToResult(mFormatter, aNumber,
+                               ToURelativeDateTimeUnit(aUnit),
+                               mFormattedRelativeDateTime, &status);
+  } else {
+    ureldatefmt_formatNumericToResult(mFormatter, aNumber,
+                                      ToURelativeDateTimeUnit(aUnit),
+                                      mFormattedRelativeDateTime, &status);
+  }
+  if (U_FAILURE(status)) {
+    return Err(ToICUError(status));
+  }
+
+  const UFormattedValue* formattedValue =
+      ureldatefmt_resultAsValue(mFormattedRelativeDateTime, &status);
+  if (U_FAILURE(status)) {
+    return Err(ToICUError(status));
+  }
+
+  bool isNegative = !std::isnan(aNumber) && IsNegative(aNumber);
+
+  // Necessary until all of intl is using Span (Bug 1709880)
+  return FormatResultToParts(formattedValue, Nothing(), isNegative,
+                             false /*formatForUnit*/, aParts)
+      .andThen([](std::u16string_view result)
+                   -> Result<Span<const char16_t>, ICUError> {
+        return Span<const char16_t>(result.data(), result.length());
+      });
+}
+
+}  // namespace mozilla::intl