source: PerfectFit/Dialog/src/main/java/tudelft/mentalhealth/perfectfit/updatefuncs/DateString.java

package tudelft.mentalhealth.perfectfit.updatefuncs;

import java.io.IOException;
import java.time.LocalDateTime;
import java.time.OffsetDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Arrays;
import java.util.List;
import java.util.Objects;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;

import tudelft.dialogmanager.parameters.Parameters;
import tudelft.dialogmanager.parameters.StringValue;
import tudelft.dialogmanager.updatefunctions.UpdateFunction;

/**
 * Function to convert given time (epoch = time since 1970 in seconds) to human
 * readable string.
 *
 */
public class DateString implements UpdateFunction {
        private final String timeepochdname;
        private final String timestringname;

        public static DateTimeFormatter dateformat = DateTimeFormatter
                        .ofPattern("dd-MM-yyyy");

        /**
         * 
         * @param timeepochdname the name of the param containing the epoch (seconds
         *                       since 1970)
         * @param timestringname the name of the param that will be filled with the
         *                       string representation.
         */
        @JsonCreator
        public DateString(@JsonProperty("timefieldname") String timeepochdname,
                        @JsonProperty("timeepochdname") String timestringname)
                        throws IOException {
                this.timeepochdname = timeepochdname;
                this.timestringname = timestringname;
        }

        @Override
        public Parameters call(Parameters parameters) {
                Double t = parameters.getDouble(timeepochdname);
                if (t == null)
                        throw new IllegalArgumentException("parameter " + timeepochdname
                                        + " has not been set to a double");
                LocalDateTime localdate = LocalDateTime.ofEpochSecond(Math.round(t), 0,
                                OffsetDateTime.now().getOffset());
                return parameters.with(timestringname,
                                new StringValue(localdate.format(dateformat)));
        }

        @Override
        public List<String> getAssignedParameters() {
                return Arrays.asList(timestringname);
        }

        @Override
        public int hashCode() {
                return Objects.hash(timeepochdname, timestringname);
        }

        @Override
        public boolean equals(Object obj) {
                if (this == obj)
                        return true;
                if (obj == null)
                        return false;
                if (getClass() != obj.getClass())
                        return false;
                DateString other = (DateString) obj;
                return Objects.equals(timeepochdname, other.timeepochdname)
                                && Objects.equals(timestringname, other.timestringname);
        }

}