/* Copyright 2014 Malcolm Herring
 *
 * This is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 3 of the License.
 *
 * For a copy of the GNU General Public License, see <http://www.gnu.org/licenses/>.
 */

package s57;

import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;

import s57.S57dat.*;
import s57.S57map.*;
import s57.S57obj.*;

public class S57dec {

	public static MapBounds decodeFile(FileInputStream in, ArrayList<Obj> types, S57map map) throws IOException {
		S57dat.rnum = 0;
		byte[] leader = new byte[24];
		boolean ddr = false;
		int length;
		int fields;
		int mapfl, mapfp, mapts, entry;
		String tag;
		int len;
		int pos;
		boolean inFeature = false;

		double comf = 1;
		double somf = 1;
		long name = 0;
		S57map.Nflag nflag = Nflag.ANON;
		S57map.Pflag pflag = S57map.Pflag.NOSP;
		long objl = 0;
		MapBounds bounds = map.new MapBounds();
		
		while (in.read(leader) == 24) {
			length = Integer.parseInt(new String(leader, 0, 5)) - 24;
			ddr = (leader[6] == 'L');
			fields = Integer.parseInt(new String(leader, 12, 5)) - 24;
			mapfl = leader[20] - '0';
			mapfp = leader[21] - '0';
			mapts = leader[23] - '0';
			entry = mapfl + mapfp + mapts;
			byte[] record = new byte[length];
			if (in.read(record) != length)
				break;
			for (int idx = 0; idx < fields-1; idx += entry) {
				tag = new String(record, idx, mapts);
				len = Integer.parseInt(new String(record, idx+mapts, mapfl));
				pos = Integer.parseInt(new String(record, idx+mapts+mapfl, mapfp));
				if (!ddr) {
					switch (S57dat.enumField(tag)) {
					case I8RI:
						int i8rn = ((Long) S57dat.getSubf(record, fields + pos, S57field.I8RI, S57subf.I8RN)).intValue();
						if (i8rn != ++S57dat.rnum) {
							System.err.println("Out of order record ID");
							in.close();
							System.exit(-1);
						}
						break;
					case DSSI:
						S57dat.getSubf(record, fields + pos, S57field.DSSI, S57subf.AALL);
						S57dat.getSubf(S57subf.NALL);
						break;
					case DSPM:
						comf = (double) (Long) S57dat.getSubf(record, fields + pos, S57field.DSPM, S57subf.COMF);
						somf = (double) (Long) S57dat.getSubf(S57subf.SOMF);
						break;
					case FRID:
						inFeature = true;
						switch (((Long)S57dat.getSubf(record, fields + pos, S57field.FRID, S57subf.PRIM)).intValue()) {
						case 1:
							pflag = S57map.Pflag.POINT;
							break;
						case 2:
							pflag = S57map.Pflag.LINE;
							break;
						case 3:
							pflag = S57map.Pflag.AREA;
							break;
						default:
							pflag = S57map.Pflag.NOSP;
						}
						objl = (Long)S57dat.getSubf(S57subf.OBJL);
						break;
					case FOID:
						name = (Long) S57dat.getSubf(record, fields + pos, S57field.FOID, S57subf.LNAM);
						map.newFeature(name, pflag, objl);
						break;
					case ATTF:
						S57dat.setField(record, fields + pos, S57field.ATTF, len);
						do {
							long attl = (Long) S57dat.getSubf(S57subf.ATTL);
							String atvl = ((String) S57dat.getSubf(S57subf.ATVL)).trim();
							if (!atvl.isEmpty()) {
								map.newAtt(attl, atvl);
							}
						} while (S57dat.more());
						break;
					case FFPT:
						S57dat.setField(record, fields + pos, S57field.FFPT, len);
						do {
							name = (Long) S57dat.getSubf(S57subf.LNAM);
							int rind = ((Long) S57dat.getSubf(S57subf.RIND)).intValue();
							S57dat.getSubf(S57subf.COMT);
							map.newObj(name, rind);
						} while (S57dat.more());
						break;
					case FSPT:
						S57dat.setField(record, fields + pos, S57field.FSPT, len);
						do {
							name = (Long) S57dat.getSubf(S57subf.NAME) << 16;
							map.newPrim(name, (Long) S57dat.getSubf(S57subf.ORNT), (Long) S57dat.getSubf(S57subf.USAG));
							S57dat.getSubf(S57subf.MASK);
						} while (S57dat.more());
						break;
					case VRID:
						inFeature = false;
						name = (long) (Long)S57dat.getSubf(record, fields + pos, S57field.VRID, S57subf.RCNM);
						switch ((int) name) {
						case 110:
							nflag = Nflag.ISOL;
							break;
						case 120:
							nflag = Nflag.CONN;
							break;
						default:
							nflag = Nflag.ANON;
							break;
						}
						name <<= 32;
						name += (Long) S57dat.getSubf(S57subf.RCID);
						name <<= 16;
						if (nflag == Nflag.ANON) {
							map.newEdge(name);
						}
						break;
					case VRPT:
						S57dat.setField(record, fields + pos, S57field.VRPT, len);
						do {
							long conn = (Long) S57dat.getSubf(S57subf.NAME) << 16;
							int topi = ((Long) S57dat.getSubf(S57subf.TOPI)).intValue();
							map.addConn(conn, topi);
							S57dat.getSubf(S57subf.MASK);
						} while (S57dat.more());
						break;
					case SG2D:
						S57dat.setField(record, fields + pos, S57field.SG2D, len);
						do {
							double lat = (double) ((Long) S57dat.getSubf(S57subf.YCOO)) / comf;
							double lon = (double) ((Long) S57dat.getSubf(S57subf.XCOO)) / comf;
							if (nflag == Nflag.ANON) {
								map.newNode(++name, lat, lon, nflag);
							} else {
								map.newNode(name, lat, lon, nflag);
							}
							if (lat < bounds.minlat)
								bounds.minlat = lat;
							if (lat > bounds.maxlat)
								bounds.maxlat = lat;
							if (lon < bounds.minlon)
								bounds.minlon = lon;
							if (lon > bounds.maxlon)
								bounds.maxlon = lon;
						} while (S57dat.more());
						break;
					case SG3D:
						S57dat.setField(record, fields + pos, S57field.SG3D, len);
						do {
							double lat = (double) ((Long) S57dat.getSubf(S57subf.YCOO)) / comf;
							double lon = (double) ((Long) S57dat.getSubf(S57subf.XCOO)) / comf;
							double depth = (double) ((Long) S57dat.getSubf(S57subf.VE3D)) / somf;
							map.newNode(name++, lat, lon, depth);
							if (lat < bounds.minlat)
								bounds.minlat = lat;
							if (lat > bounds.maxlat)
								bounds.maxlat = lat;
							if (lon < bounds.minlon)
								bounds.minlon = lon;
							if (lon > bounds.maxlon)
								bounds.maxlon = lon;
						} while (S57dat.more());
						break;
					default:
						break;
					}
				}
				if (inFeature) {
					map.endFeature();
					inFeature = false;
				}
			}
		}
		map.endFile();
		in.close();
		
		return bounds;
	}
	
}