// This Source Code is in the Public Domain per: http://unlicense.org
package InterModuleComm;

import org.litesoft.commonfoundation.base.*;
import org.litesoft.commonfoundation.typeutils.*;

public final class WelcomeMessage implements Message {
    protected static final String PREFIX =
            Constants.PROTOCOL_PREFIX + ModuleMsgLifecycleForm.Welcome + Constants.NV_SEP;

    private String mKnownAs;
    private String mId;

    protected WelcomeMessage( String pKnownAs, String pId ) {
        mKnownAs = pKnownAs;
        mId = pId;
    }

    @Override
    public String toString() {
        return getHeader();
    }

    public String ToSendText() {
        return getHeader() + "\n";
    }

    public String getHeader() {
        return PREFIX + getKnownAs() + Constants.SPECIAL_ID_SEP + getId();
    }

    public String getKnownAs() {
        return mKnownAs;
    }

    public String getId() {
        return mId;
    }

    public static class Builder {
        private String mKnownAs;
        private String mId;

        public static Builder FromHeader( String pHeader ) {
            if ( (pHeader != null) && pHeader.startsWith( PREFIX ) ) {
                String zRest = Strings.trimLeadingSpaces( pHeader.substring( PREFIX.length() ) );
                int zSepAt = zRest.indexOf( Constants.SPECIAL_ID_SEP );
                if ( zSepAt != -1 ) {
                    String zKnownAs = zRest.substring( 0, zSepAt ).trim();
                    String zId = zRest.substring( zSepAt + 1 ).trim();
                    return FromParams( zKnownAs, zId );
                }
            }
            return null;
        }

        private Builder( String pKnownAs, String pId ) {
            mKnownAs = pKnownAs;
            mId = pId;
        }

        private static Builder FromParams( String pKnownAs, String pId ) {
            pKnownAs = ConstrainTo.significantOrNull( pKnownAs );
            pId = ConstrainTo.significantOrNull( pId );
            if ( Strings.isAsciiIdentifier( pKnownAs ) && Strings.isNoSpaceAscii( pId ) ) {
                return new Builder( pKnownAs, pId );
            }
            return null;
        }

        public static Builder Acknowledge( HelloMessage pHelloMessage, String pKnownAs ) {
            pKnownAs = ConstrainTo.significantOrNull( pKnownAs );
            if ( (pHelloMessage != null) && Strings.isAsciiIdentifier( pKnownAs ) ) {
                return FromParams( pKnownAs, pHelloMessage.getId() );
            }
            return null;
        }

        public WelcomeMessage ToMsg() {
            return new WelcomeMessage( getKnownAs(), getId() );
        }

        public String getKnownAs() {
            return mKnownAs;
        }

        public String getId() {
            return mId;
        }
    }
}