/*
 * Copyright (c) 2000, 2004, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;

/**
 * Zone holds information corresponding to a "Zone" part of a time
 * zone definition file.
 *
 * @since 1.4
 */
class Zone {
    // zone name (e.g., "America/Los_Angeles")
    private String name;

    // zone records
    private List<ZoneRec> list;

    // target zone names for this compilation
    private static Set<String> targetZones;

    /**
     * Constructs a Zone with the specified zone name.
     * @param name the zone name
     */
    Zone(String name) {
        this.name = name;
        list = new ArrayList<ZoneRec>();
    }

    /**
     * Reads time zone names to be generated, called "target zone
     * name", from the specified text file and creats an internal hash
     * table to keep those names. It's assumed that one text line
     * contains a zone name or comments if it starts with
     * '#'. Comments can't follow a zone name in a single line.
     * @param fileName the text file name
     */
    static void readZoneNames(String fileName) {
        if (fileName == null) {
            return;
        }
        BufferedReader in = null;
        try {
            FileReader fr = new FileReader(fileName);
            in = new BufferedReader(fr);
        } catch (FileNotFoundException e) {
            Main.panic("can't open file: " + fileName);
        }
        targetZones = new HashSet<String>();
        String line;

        try {
            while ((line = in.readLine()) != null) {
                line = line.trim();
                if (line.length() == 0 || line.charAt(0) == '#') {
                    continue;
                }
                if (!targetZones.add(line)) {
                    Main.warning("duplicated target zone name: " + line);
                }
            }
            in.close();
        } catch (IOException e) {
            Main.panic("IO error: "+e.getMessage());
        }
    }

    /**
     * Determines whether the specified zone is one of the target zones.
     * If no target zones are specified, this method always returns
     * true for any zone name.
     * @param zoneName the zone name
     * @return true if the specified name is a target zone.
     */
    static boolean isTargetZone(String zoneName) {
        if (targetZones == null) {
            return true;
        }
        return targetZones.contains(zoneName);
    }

    /**
     * Forces to add "MET" to the target zone table. This is because
     * there is a conflict between Java zone name "WET" and Olson zone
     * name.
     */
    static void addMET() {
        if (targetZones != null) {
            targetZones.add("MET");
        }
    }

    /**
     * @return the zone name
     */
    String getName() {
        return name;
    }

    /**
     * Adds the specified zone record to the zone record list.
     */
    void add(ZoneRec rec) {
        list.add(rec);
    }

    /**
     * @param index the index at which the zone record in the list is returned.
     * @return the zone record specified by the index.
     */
    ZoneRec get(int index) {
        return list.get(index);
    }

    /**
     * @return the size of the zone record list
     */
    int size() {
        return list.size();
    }

    /**
     * Resolves the reference to a rule in each zone record.
     * @param zi the Zoneinfo object with which the rule reference is
     * resolved.
     */
    void resolve(Zoneinfo zi) {
        for (int i = 0; i < list.size(); i++) {
            ZoneRec rec = list.get(i);
            rec.resolve(zi);
        }
    }
}