Add time zone handling APIs

.gitignore

@@ -45,3 +45,5 @@ velocity.log*
 
 # VSCode
 .vscode
+.project
+.settings/

ballerina/time_apis.bal

@@ -69,7 +69,7 @@ public isolated function utcAddSeconds(Utc utc, Seconds seconds) returns Utc {
     [int, decimal] [secondsFromEpoch, lastSecondFraction] = utc;
     secondsFromEpoch = secondsFromEpoch + <int>seconds.floor();
     lastSecondFraction = lastSecondFraction + (seconds - seconds.floor());
-    if (lastSecondFraction >= 1.0d) {
+    if lastSecondFraction >= 1.0d {
         secondsFromEpoch = secondsFromEpoch + <int>lastSecondFraction.floor();
         lastSecondFraction = lastSecondFraction - lastSecondFraction.floor();
     }
@@ -132,7 +132,7 @@ public isolated function utcToCivil(Utc utc) returns Civil {
 # + civilTime - `Civil` time
 # + return - The corresponding `Utc` value or an error if `civilTime.utcOffset` is missing
 public isolated function utcFromCivil(Civil civilTime) returns Utc|Error {
-    if (civilTime?.utcOffset is ()) {
+    if civilTime?.utcOffset is () {
         return error FormatError("civilTime.utcOffset must not be null");
     }
     ZoneOffset utcOffset = <ZoneOffset>civilTime?.utcOffset;
@@ -164,7 +164,7 @@ public isolated function civilFromString(string dateTimeString) returns Civil|Er
 # + civil - `time:Civil` that needs to be converted
 # + return - The corresponding string value or an error if the specified `time:Civil` contains invalid parameters(e.g. `month` > 12)
 public isolated function civilToString(Civil civil) returns string|Error {
-    if (civil?.utcOffset is ()) {
+    if civil?.utcOffset is () {
         return error FormatError("civil.utcOffset must not be null");
     }
     ZoneOffset utcOffset = <ZoneOffset>civil?.utcOffset;

ballerina/time_types.bal

@@ -14,6 +14,8 @@
 // specific language governing permissions and limitations
 // under the License.
 
+import ballerina/jballerina.java;
+
 # Holds the seconds as a decimal value.  
 public type Seconds decimal;
 
@@ -172,3 +174,111 @@ public enum HeaderZoneHandling {
     PREFER_ZONE_OFFSET,
     ZONE_OFFSET_WITH_TIME_ABBREV_COMMENT
 }
+
+# Abstract object representation to handle time zones.  
+public type Zone readonly & object {
+
+    # If always at a fixed offset from Utc, then this function returns it; otherwise nil.
+    #
+    # + return - The fixed zone offset or nil
+    public isolated function fixedOffset() returns ZoneOffset?;
+
+    # Converts a given `Civil` value to an `Utc` timestamp based on the time zone value.
+    #
+    # + civil - `Civil` time
+    # + return - The corresponding `Utc` value or an error if `civil.timeAbbrev` is missing
+    public isolated function utcFromCivil(Civil civil) returns Utc|Error;
+
+    # Converts a given `Utc` timestamp to a `Civil` value based on the time zone value.
+    #
+    # + utc - `Utc` timestamp
+    # + return - The corresponding `Civil` value
+    public isolated function utcToCivil(Utc utc) returns Civil;
+};
+
+# Localized time zone implementation to handle time zones.  
+public readonly class TimeZone {
+    *Zone;
+
+    # Initialize a TimeZone class using a zone ID.
+    #
+    # + zoneId - Zone ID as a string or nil to initialize a TimeZone object with the system default time zone
+    # + return - An error or nil
+    public isolated function init(string? zoneId = ()) returns Error? {
+        if zoneId is string {
+            externTimeZoneInitWithId(self, zoneId);
+        } else {
+            check externTimeZoneInitWithSystemZone(self);
+        }
+    }
+
+    # If always at a fixed offset from Utc, then this function returns it; otherwise nil.
+    #
+    # + return - The fixed zone offset or nil
+    public isolated function fixedOffset() returns ZoneOffset? {
+        return externTimeZoneFixedOffset(self);
+    }
+
+    # Converts a given `Civil` value to an `Utc` timestamp based on the time zone value.
+    #
+    # + civil - `Civil` time
+    # + return - The corresponding `Utc` value or an error if `civil.timeAbbrev` is missing
+    public isolated function utcFromCivil(Civil civil) returns Utc|Error {
+        string? timeAbbrev = civil?.timeAbbrev;
+        if timeAbbrev is () {
+            return error FormatError("Abbreviation for the local time is required for the conversion");
+        }
+        decimal? civilTimeSecField = civil?.second;
+        decimal civilTimeSeconds = (civilTimeSecField is Seconds) ? civilTimeSecField : 0.0;
+
+        return externTimeZoneUtcFromCivil(self, civil.year, civil.month, civil.day, civil.hour, civil.minute, civilTimeSeconds, timeAbbrev, PREFER_TIME_ABBREV);
+    }
+
+    # Converts a given `Utc` timestamp to a `Civil` value based on the time zone value.
+    #
+    # + utc - `Utc` timestamp
+    # + return - The corresponding `Civil` value
+    public isolated function utcToCivil(Utc utc) returns Civil {
+        return externTimeZoneUtcToCivil(self, utc);
+    }
+}
+
+# Load the default time zone of the system.
+# + return - Zone value or error when the zone ID of the system is in invalid format. 
+public isolated function loadSystemZone() returns Zone|Error {
+    return check new TimeZone();
+}
+
+# Return the time zone object of a given zone ID.
+#
+# + id - Time zone ID (e.g. "Continent/City")
+# + return - Corresponding ime zone object or null 
+public isolated function getZone(string id) returns Zone? {
+    TimeZone|Error timeZone = new TimeZone(id);
+    if timeZone is TimeZone {
+        return timeZone;
+    }
+    return;
+}
+
+isolated function externTimeZoneInitWithSystemZone(TimeZone timeZone) returns Error? = @java:Method {
+    'class: "io.ballerina.stdlib.time.nativeimpl.TimeZoneExternUtils"
+} external;
+
+isolated function externTimeZoneInitWithId(TimeZone timeZone, string zoneId) = @java:Method {
+    'class: "io.ballerina.stdlib.time.nativeimpl.TimeZoneExternUtils"
+} external;
+
+isolated function externTimeZoneFixedOffset(TimeZone timeZone) returns ZoneOffset? = @java:Method {
+    'class: "io.ballerina.stdlib.time.nativeimpl.TimeZoneExternUtils"
+} external;
+
+isolated function externTimeZoneUtcToCivil(TimeZone timeZone, Utc utc) returns Civil = @java:Method {
+    'class: "io.ballerina.stdlib.time.nativeimpl.TimeZoneExternUtils"
+} external;
+
+isolated function externTimeZoneUtcFromCivil(TimeZone timeZone, int year, int month, int day,
+int hour, int minute, decimal second, string timeAbber, HeaderZoneHandling zoneHandling)
+returns Utc|Error = @java:Method {
+    'class: "io.ballerina.stdlib.time.nativeimpl.TimeZoneExternUtils"
+} external;

native/src/main/java/io/ballerina/stdlib/time/nativeimpl/Civil.java

@@ -15,20 +15,20 @@
  * specific language governing permissions and limitations
  * under the License.
  */
- package io.ballerina.stdlib.time.nativeimpl;
+package io.ballerina.stdlib.time.nativeimpl;
 
 import io.ballerina.runtime.api.creators.ValueCreator;
 import io.ballerina.runtime.api.utils.StringUtils;
 import io.ballerina.runtime.api.values.BMap;
 import io.ballerina.runtime.api.values.BString;
 import io.ballerina.stdlib.time.util.Constants;
 import io.ballerina.stdlib.time.util.ModuleUtils;
+import io.ballerina.stdlib.time.util.Utils;
 
 import java.math.BigDecimal;
 import java.math.MathContext;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
-import java.util.HashMap;
 import java.util.Map;
 import java.util.regex.Pattern;
 
@@ -41,13 +41,38 @@
  */
 public class Civil {
 
-    private ZonedDateTime zonedDateTime = ZonedDateTime.now();
-    private BMap<BString, Object> civilMap = ValueCreator.createRecordValue(ModuleUtils.getModule(),
+    private final ZonedDateTime zonedDateTime;
+    private boolean isSecondExists = false;
+    private boolean isLocalTimeZoneExists = false;
+    private final BMap<BString, Object> civilMap = ValueCreator.createRecordValue(ModuleUtils.getModule(),
             Constants.CIVIL_RECORD);
 
-    public BMap<BString, Object> buildFromZonedDateTime(ZonedDateTime zonedDateTime) {
+    public Civil(ZonedDateTime zonedDateTime) {
 
         this.zonedDateTime = zonedDateTime;
+    }
+
+    public Civil(String zonedDateTimeString, Constants.CivilInputStringTypes inputStringTypes) {
+
+        if (Constants.CivilInputStringTypes.EMAIL_STRING.toString().equals(inputStringTypes.toString())) {
+            DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern(Constants.EMAIL_DATE_TIME_FORMAT);
+            this.zonedDateTime = ZonedDateTime.parse(zonedDateTimeString, dateTimeFormatter);
+            this.isSecondExists = true;
+            this.isLocalTimeZoneExists = true;
+        } else {
+            this.zonedDateTime = ZonedDateTime.parse(zonedDateTimeString);
+            this.isSecondExists = isSecondExists(zonedDateTimeString);
+            this.isLocalTimeZoneExists = isLocalTimeZoneExists(zonedDateTimeString);
+        }
+    }
+
+    public ZonedDateTime getZonedDateTime() {
+
+        return zonedDateTime;
+    }
+
+    public BMap<BString, Object> build() {
+
         setCommonCivilFields();
         BigDecimal second = new BigDecimal(zonedDateTime.getSecond());
         second = second.add(new BigDecimal(zonedDateTime.getNano()).divide(ANALOG_GIGA, MathContext.DECIMAL128));
@@ -57,18 +82,16 @@ public BMap<BString, Object> buildFromZonedDateTime(ZonedDateTime zonedDateTime)
 
     }
 
-    public BMap<BString, Object> buildFromZonedDateTimeString(String zonedDateTimeString) {
+    public BMap<BString, Object> buildWithZone() {
 
-        ZonedDateTime zonedDateTime = ZonedDateTime.parse(zonedDateTimeString);
-        this.zonedDateTime = zonedDateTime;
         setCommonCivilFields();
         BigDecimal second = new BigDecimal(zonedDateTime.getSecond());
         second = second.add(new BigDecimal(zonedDateTime.getNano()).divide(ANALOG_GIGA, MathContext.DECIMAL128));
 
-        if (isSecondExists(zonedDateTimeString)) {
+        if (this.isSecondExists) {
             civilMap.put(Constants.TIME_OF_DAY_RECORD_SECOND_BSTRING, ValueCreator.createDecimalValue(second));
         }
-        if (isLocalTimeZoneExists(zonedDateTimeString)) {
+        if (this.isLocalTimeZoneExists) {
             civilMap.put(Constants.CIVIL_RECORD_UTC_OFFSET_BSTRING,
                     createZoneOffsetFromZonedDateTime(zonedDateTime));
         }
@@ -77,22 +100,6 @@ public BMap<BString, Object> buildFromZonedDateTimeString(String zonedDateTimeSt
 
     }
 
-    public BMap<BString, Object> buildFromEmailString(String zonedDateTimeString) {
-
-        DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern(Constants.EMAIL_DATE_TIME_FORMAT);
-        ZonedDateTime zonedDateTime = ZonedDateTime.parse(zonedDateTimeString, dateTimeFormatter);
-        this.zonedDateTime = zonedDateTime;
-        setCommonCivilFields();
-        BigDecimal second = new BigDecimal(zonedDateTime.getSecond());
-        second = second.add(new BigDecimal(zonedDateTime.getNano()).divide(ANALOG_GIGA, MathContext.DECIMAL128));
-        civilMap.put(Constants.TIME_OF_DAY_RECORD_SECOND_BSTRING, ValueCreator.createDecimalValue(second));
-        civilMap.put(Constants.CIVIL_RECORD_UTC_OFFSET_BSTRING,
-                createZoneOffsetFromZonedDateTime(zonedDateTime));
-
-        return civilMap;
-
-    }
-
     private void setCommonCivilFields() {
 
         civilMap.put(Constants.DATE_RECORD_YEAR_BSTRING, zonedDateTime.getYear());
@@ -119,60 +126,8 @@ private boolean isSecondExists(String time) {
 
     public BMap<BString, Object> createZoneOffsetFromZonedDateTime(ZonedDateTime zonedDateTime) {
 
-        BMap<BString, Object> civilMap = ValueCreator.createRecordValue(ModuleUtils.getModule(),
-                Constants.READABLE_ZONE_OFFSET_RECORD);
-        Map<String, Integer> zoneInfo = zoneOffsetMapFromString(zonedDateTime.getOffset().toString());
-        if (zoneInfo.get(Constants.ZONE_OFFSET_RECORD_HOUR) != null) {
-            civilMap.put(Constants.ZONE_OFFSET_RECORD_HOUR_BSTRING,
-                    zoneInfo.get(Constants.ZONE_OFFSET_RECORD_HOUR).longValue());
-        } else {
-            civilMap.put(Constants.ZONE_OFFSET_RECORD_HOUR_BSTRING, 0);
-        }
-
-        if (zoneInfo.get(Constants.ZONE_OFFSET_RECORD_MINUTE) != null) {
-            civilMap.put(Constants.ZONE_OFFSET_RECORD_MINUTE_BSTRING,
-                    zoneInfo.get(Constants.ZONE_OFFSET_RECORD_MINUTE).longValue());
-        } else {
-            civilMap.put(Constants.ZONE_OFFSET_RECORD_MINUTE_BSTRING, 0);
-        }
-
-        if (zoneInfo.get(Constants.ZONE_OFFSET_RECORD_SECOND) != null) {
-            civilMap.put(Constants.ZONE_OFFSET_RECORD_SECOND_BSTRING,
-                    zoneInfo.get(Constants.ZONE_OFFSET_RECORD_SECOND).longValue());
-        }
-        civilMap.freezeDirect();
-        return civilMap;
-    }
-
-    public Map<String, Integer> zoneOffsetMapFromString(String dateTime) {
-
-        Map<String, Integer> zone = new HashMap<>();
-        if (dateTime.strip().startsWith("+")) {
-            dateTime = dateTime.replaceFirst("\\+", "");
-            String[] zoneInfo = dateTime.split(":");
-            if (zoneInfo.length > 0 && zoneInfo[0] != null) {
-                zone.put(Constants.ZONE_OFFSET_RECORD_HOUR, Integer.parseInt(zoneInfo[0]));
-            }
-            if (zoneInfo.length > 1 && zoneInfo[1] != null) {
-                zone.put(Constants.ZONE_OFFSET_RECORD_MINUTE, Integer.parseInt(zoneInfo[1]));
-            }
-            if (zoneInfo.length > 2 && zoneInfo[2] != null) {
-                zone.put(Constants.ZONE_OFFSET_RECORD_SECOND, Integer.parseInt(zoneInfo[2]));
-            }
-        } else if (dateTime.strip().startsWith("-")) {
-            dateTime = dateTime.replaceFirst("\\-", "");
-            String[] zoneInfo = dateTime.split(":");
-            if (zoneInfo.length > 0 && zoneInfo[0] != null) {
-                zone.put(Constants.ZONE_OFFSET_RECORD_HOUR, Integer.parseInt(zoneInfo[0]) * -1);
-            }
-            if (zoneInfo.length > 1 && zoneInfo[1] != null) {
-                zone.put(Constants.ZONE_OFFSET_RECORD_MINUTE, Integer.parseInt(zoneInfo[1]) * -1);
-            }
-            if (zoneInfo.length > 2 && zoneInfo[2] != null) {
-                zone.put(Constants.ZONE_OFFSET_RECORD_SECOND, Integer.parseInt(zoneInfo[2]) * -1);
-            }
-        }
-        return zone;
+        Map<String, Integer> zoneInfo = Utils.zoneOffsetMapFromString(zonedDateTime.getOffset().toString());
+        return Utils.createZoneOffsetFromZoneInfoMap(zoneInfo);
     }
 
 }