/*
 *******************************************************************************
 * Copyright (C) 2009, International Business Machines Corporation and         *
 * others. All Rights Reserved.                                                *
 *******************************************************************************
 */

package com.ibm.icu.impl.locale;


public final class BaseLocale {

    private static final boolean JDKIMPL = false;

    private String _language = "";
    private String _script = "";
    private String _region = "";
    private String _variant = "";

    private transient volatile int _hash = 0;

    private static final LocaleObjectCache<Key, BaseLocale> BASELOCALE_CACHE
        = new LocaleObjectCache<Key, BaseLocale>();

    public static final BaseLocale ROOT = BaseLocale.getInstance("", "", "", "");

    private BaseLocale(String language, String script, String region, String variant) {
        if (language != null) {
            _language = AsciiUtil.toLowerString(language).intern();
        }
        if (script != null) {
            _script = AsciiUtil.toTitleString(script).intern();
        }
        if (region != null) {
            _region = AsciiUtil.toUpperString(region).intern();
        }
        if (variant != null) {
            if (JDKIMPL) {
                // preserve upper/lower cases
                _variant = variant.intern();
            } else {
                _variant = AsciiUtil.toUpperString(variant).intern();
            }
        }
    }

    public static BaseLocale getInstance(String language, String script, String region, String variant) {
        if (JDKIMPL) {
            // JDK uses deprecated ISO639.1 language codes for he, yi and id
            if (AsciiUtil.caseIgnoreMatch(language, "he")) {
                language = "iw";
            } else if (AsciiUtil.caseIgnoreMatch(language, "yi")) {
                language = "ji";
            } else if (AsciiUtil.caseIgnoreMatch(language, "id")) {
                language = "in";
            }
        }
        Key key = new Key(language, script, region, variant);
        BaseLocale baseLocale = BASELOCALE_CACHE.get(key);
        if (baseLocale == null) {
            baseLocale = new BaseLocale(language, script, region, variant);
            baseLocale = BASELOCALE_CACHE.put(baseLocale.createKey(), baseLocale);
        }
        return baseLocale;
    }

    public String getLanguage() {
        return _language;
    }

    public String getScript() {
        return _script;
    }

    public String getRegion() {
        return _region;
    }

    public String getVariant() {
        return _variant;
    }

    public String toString() {
        StringBuilder buf = new StringBuilder();
        if (_language.length() > 0) {
            buf.append("language=");
            buf.append(_language);
        }
        if (_script.length() > 0) {
            if (buf.length() > 0) {
                buf.append(", ");
            }
            buf.append("script=");
            buf.append(_script);
        }
        if (_region.length() > 0) {
            if (buf.length() > 0) {
                buf.append(", ");
            }
            buf.append("region=");
            buf.append(_region);
        }
        if (_variant.length() > 0) {
            if (buf.length() > 0) {
                buf.append(", ");
            }
            buf.append("variant=");
            buf.append(_variant);
        }
        return buf.toString();
    }

    public int hashCode() {
        int h = _hash;
        if (h == 0) {
            // Generating a hash value from language, script, region and variant
            for (int i = 0; i < _language.length(); i++) {
                h = 31*h + _language.charAt(i);
            }
            for (int i = 0; i < _script.length(); i++) {
                h = 31*h + _script.charAt(i);
            }
            for (int i = 0; i < _region.length(); i++) {
                h = 31*h + _region.charAt(i);
            }
            for (int i = 0; i < _variant.length(); i++) {
                h = 31*h + _variant.charAt(i);
            }
            _hash = h;
        }
        return h;
    }

    private Key createKey() {
        return new Key(_language, _script, _region, _variant);
    }

    private static class Key implements Comparable<Key> {
        private String _lang = "";
        private String _scrt = "";
        private String _regn = "";
        private String _vart = "";

        private volatile int _hash; // Default to 0

        public Key(String language, String script, String region, String variant) {
            if (language != null) {
                _lang = language;
            }
            if (script != null) {
                _scrt = script;
            }
            if (region != null) {
                _regn = region;
            }
            if (variant != null) {
                _vart = variant;
            }
        }

        public boolean equals(Object obj) {
            if (JDKIMPL) {
                return (this == obj) ||
                        (obj instanceof Key)
                        && AsciiUtil.caseIgnoreMatch(((Key)obj)._lang, this._lang)
                        && AsciiUtil.caseIgnoreMatch(((Key)obj)._scrt, this._scrt)
                        && AsciiUtil.caseIgnoreMatch(((Key)obj)._regn, this._regn)
                        && ((Key)obj)._vart.equals(_vart); // variant is case sensitive in JDK!
            }
            return (this == obj) ||
                    (obj instanceof Key)
                    && AsciiUtil.caseIgnoreMatch(((Key)obj)._lang, this._lang)
                    && AsciiUtil.caseIgnoreMatch(((Key)obj)._scrt, this._scrt)
                    && AsciiUtil.caseIgnoreMatch(((Key)obj)._regn, this._regn)
                    && AsciiUtil.caseIgnoreMatch(((Key)obj)._vart, this._vart);
        }

        public int compareTo(Key other) {
            int res = AsciiUtil.caseIgnoreCompare(this._lang, other._lang);
            if (res == 0) {
                res = AsciiUtil.caseIgnoreCompare(this._scrt, other._scrt);
                if (res == 0) {
                    res = AsciiUtil.caseIgnoreCompare(this._regn, other._regn);
                    if (res == 0) {
                        if (JDKIMPL) {
                            res = this._vart.compareTo(other._vart);
                        } else {
                            res = AsciiUtil.caseIgnoreCompare(this._vart, other._vart);
                        }
                    }
                }
            }
            return res;
        }

        public int hashCode() {
            int h = _hash;
            if (h == 0) {
                // Generating a hash value from language, script, region and variant
                for (int i = 0; i < _lang.length(); i++) {
                    h = 31*h + AsciiUtil.toLower(_lang.charAt(i));
                }
                for (int i = 0; i < _scrt.length(); i++) {
                    h = 31*h + AsciiUtil.toLower(_scrt.charAt(i));
                }
                for (int i = 0; i < _regn.length(); i++) {
                    h = 31*h + AsciiUtil.toLower(_regn.charAt(i));
                }
                for (int i = 0; i < _vart.length(); i++) {
                    if (JDKIMPL) {
                        h = 31*h + _vart.charAt(i);
                    } else {
                        h = 31*h + AsciiUtil.toLower(_vart.charAt(i));
                    }
                }
                _hash = h;
            }
            return h;
        }
    }
}